diff --git a/Makefile b/Makefile
index 22b6cd1..cdd04e2 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 LUA_VERSION = 5.1
 DEPS_DIR = deps
 TEST_DIR = tests
-ROCKSPEC = copy_with_context-2.1.0-1.rockspec
+ROCKSPEC = copy_with_context-3.0.0-1.rockspec
 BUSTED = $(DEPS_DIR)/bin/busted
 LUACHECK = $(DEPS_DIR)/bin/luacheck
 
diff --git a/README.md b/README.md
index 27fe99f..4c73f1f 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@
 ![GitHub Tag](https://img.shields.io/github/v/tag/zhisme/copy_with_context.nvim)
 ![GitHub License](https://img.shields.io/github/license/zhisme/copy_with_context.nvim)
 
-Copy lines with file path and line number metadata. Perfect for sharing code snippets with context.
+Copy lines with file path, line number, and repository URL metadata. Perfect for sharing code snippets with context.
 
 ## Why?
 
@@ -42,11 +42,12 @@ Here's my login function:
     validate_credentials(user)
   end
   # app/controllers/auth_controller.rb:45-47
+  # https://github.com/user/repo/blob/abc123/app/controllers/auth_controller.rb#L45-L47
 
 How do I add OAuth?
 ```
 
-**Result**: The second prompt gives AI file location, line numbers, and project structure insight. AI provides OAuth integration that fits your exact architecture instead of generic advice.
+**Result**: The second prompt gives AI file location, line numbers, project structure insight, and a direct link to the code. AI provides OAuth integration that fits your exact architecture instead of generic advice.
 
 ## Installation
 
@@ -70,11 +71,15 @@ use {
         -- Customize mappings
         mappings = {
           relative = '<leader>cy',
-          absolute = '<leader>cY'
+          absolute = '<leader>cY',
+          remote = '<leader>cr',
+        },
+        formats = {
+          default = '# {filepath}:{line}',  -- Used by relative and absolute mappings
+          remote = '# {remote_url}',  -- Custom format for remote mapping
         },
         -- whether to trim lines or not
         trim_lines = false,
-        context_format = '# %s:%s', -- Default format for context: "# Source file: filepath:line"
       })
     end
   }
@@ -89,11 +94,15 @@ use {
         -- Customize mappings
         mappings = {
           relative = '<leader>cy',
-          absolute = '<leader>cY'
+          absolute = '<leader>cY',
+          remote = '<leader>cr',
+        },
+        formats = {
+          default = '# {filepath}:{line}',  -- Used by relative and absolute mappings
+          remote = '# {remote_url}',
         },
         -- whether to trim lines or not
         trim_lines = false,
-        context_format = '# %s:%s', -- Default format for context: "# Source file: filepath:line"
       })
     end
   },
@@ -101,6 +110,8 @@ use {
 
 ## Usage
 
+### Default context
+
 1. Copy current line with relative path:
    - Press `<leader>cy` in normal mode.
    - Plugin copies line under cursor with relative path into your unnamed register.
@@ -151,6 +162,33 @@ Output example:
   # /Users/zh/dev/project_name/app/views/widgets/show.html.erb:4-6
 ```
 
+### Remote URL Support
+
+5. Copy current line with remote URL:
+   - Press `<leader>cr` in normal mode.
+   - Plugin copies line under cursor with repository URL into your unnamed register.
+   - Paste somewhere
+Output example:
+```
+    <% posts.each do |post| %>
+    # https://github.com/user/repo/blob/abc123def/app/views/widgets/show.html.erb#L4
+```
+
+6. Copy visual selection with remote URL:
+   - Select lines in visual mode.
+   - Press `<leader>cr`.
+   - Plugin copies the selected lines with repository URL into your unnamed register.
+   - Paste somewhere
+Output example:
+```
+    <% posts.each do |post| %>
+        <%= post.title %>
+    <% end %>
+    # https://github.com/user/repo/blob/abc123def/app/views/widgets/show.html.erb#L4-L6
+```
+
+
+
 ## Configuration
 
 There is no need to call setup if you are ok with the defaults.
@@ -161,16 +199,60 @@ require('copy_with_context').setup({
     -- Customize mappings
     mappings = {
       relative = '<leader>cy',
-      absolute = '<leader>cY'
+      absolute = '<leader>cY',
+    },
+    -- Define format strings for each mapping
+    formats = {
+      default = '# {filepath}:{line}',  -- Used by relative and absolute mappings
     },
     -- whether to trim lines or not
     trim_lines = false,
-    context_format = '# %s:%s',  -- Default format for context: "# Source file: filepath:line"
-  -- context_format = '# Source file: %s:%s',
-  -- Other format for context: "# Source file: /path/to/file:123"
 })
 ```
 
+### Format Variables
+
+You can use the following variables in format strings:
+
+- `{filepath}` - The file path (relative or absolute depending on mapping)
+- `{line}` - Line number or range (e.g., "42" or "10-20")
+- `{linenumber}` - Alias for `{line}`
+- `{remote_url}` - Repository URL (GitHub, GitLab, Bitbucket)
+
+### Custom Mappings and Formats
+
+You can define unlimited custom mappings with their own format strings:
+
+```lua
+require('copy_with_context').setup({
+  mappings = {
+    relative = '<leader>cy',
+    absolute = '<leader>cY',
+    remote = '<leader>cr',
+    full = '<leader>cx', -- Custom mapping with everything
+  },
+  formats = {
+    default = '# {filepath}:{line}',
+    remote = '# {remote_url}',
+    full = '# {filepath}:{line}\n# {remote_url}',
+  },
+})
+```
+
+**Important**: Every mapping name must have a matching format name. The special mappings `relative` and `absolute` use the `default` format.
+
+In case it fails to find the format for a mapping, it will fail during config load time with an error message. Check your config if that happens, whether everything specified in mappings is also present in formats.
+
+### Repository URL Support
+
+When you use `{remote_url}` in a format string, the plugin automatically generates permalink URLs for your code snippets. This feature works with:
+
+- **GitHub** (github.com and GitHub Enterprise)
+- **GitLab** (gitlab.com and self-hosted instances containing "gitlab" in the domain)
+- **Bitbucket** (bitbucket.org and *.bitbucket.org)
+
+The URLs always use the current commit SHA for stable permalinks. If you're not in a git repository or the repository provider is not recognized, the URL will simply be omitted (graceful degradation)
+
 ## Development
 Want to contribute to `copy_with_context.nvim`? Here's how to set up your local development environment:
 
@@ -230,13 +312,15 @@ use {
               -- Customize mappings
               mappings = {
               relative = '<leader>cy',
-              absolute = '<leader>cY'
+              absolute = '<leader>cY',
+              remote = '<leader>cr',
+              },
+              formats = {
+                default = '# {filepath}:{line}',
+                remote = '# {remote_url}',
               },
               -- whether to trim lines or not
               trim_lines = false,
-              context_format = '# %s:%s',  -- Default format for context: "# filepath:line"
-              -- context_format = '# Source file: %s:%s',
-              -- Other format for context: "# Source file: /path/to/file:123"
               })
   end
 }
@@ -251,18 +335,30 @@ With lazy.nvim:
   opts = {
       mappings = {
           relative = '<leader>cy',
-          absolute = '<leader>cY'
+          absolute = '<leader>cY',
+          remote = '<leader>cr',
+      },
+      formats = {
+        default = '# {filepath}:{line}',
+        remote = '# {remote_url}',
       },
       -- whether to trim lines or not
       trim_lines = false,
-      context_format = '# %s:%s',  -- Default format for context: "# filepath:line"
-      -- context_format = '# Source file: %s:%s',
-      -- Other format for context: "# Source file: /path/to/file:123"
   }
 }
 ```
 Then restart Neovim or run `:Lazy` sync to load the local version
 
+### Releasing
+
+For maintainers: see [RELEASING.md](./RELEASING.md) for the complete release process.
+
+The guide covers:
+- Version numbering (Semantic Versioning)
+- Generating release notes from git history
+- Creating and publishing releases
+- Publishing to LuaRocks
+
 ## Contributing
 Bug reports and pull requests are welcome on GitHub at https://github.com/zhisme/copy_with_context.nvim.
 Ensure to test your solution and provide a clear description of the problem you are solving.
diff --git a/RELEASING.md b/RELEASING.md
new file mode 100644
index 0000000..1c6f7f0
--- /dev/null
+++ b/RELEASING.md
@@ -0,0 +1,362 @@
+# Release Guide
+
+This guide covers the process for releasing a new version of `copy_with_context.nvim`.
+
+## Prerequisites
+
+- Write access to the repository
+- [LuaRocks](https://luarocks.org/) account (optional, for publishing to LuaRocks)
+- Familiarity with [Semantic Versioning](https://semver.org/)
+- All CI checks passing on main branch
+
+## Release Checklist
+
+### 1. Pre-Release Verification
+
+Before starting the release process, ensure:
+
+- [ ] All tests pass: `make test`
+- [ ] No linting errors: `make lint`
+- [ ] Code is formatted: `make fmt-check`
+- [ ] All CI/CD checks are passing on the main branch
+- [ ] Documentation is up to date (README.md)
+- [ ] All planned features/fixes for the release are merged
+
+### 2. Determine Version Number
+
+Follow [Semantic Versioning](https://semver.org/) (MAJOR.MINOR.PATCH):
+
+- **Major version (X.0.0)**: Breaking changes
+  - API changes
+  - Removed features
+  - Configuration structure changes
+
+- **Minor version (0.X.0)**: New features (backward compatible)
+  - New functionality
+  - New configuration options
+  - Performance improvements
+
+- **Patch version (0.0.X)**: Bug fixes (backward compatible)
+  - Bug fixes
+  - Documentation updates
+  - Internal refactoring
+
+**Examples:**
+- `2.1.0` → `3.0.0` (breaking change: API redesign)
+- `2.1.0` → `2.2.0` (new feature: added format variables)
+- `2.1.0` → `2.1.1` (bug fix: fixed URL parsing)
+
+### 3. Generate Release Notes
+
+Use git commit history to generate release notes instead of maintaining a CHANGELOG.md file.
+
+**Quick method:**
+```bash
+# Get commits since last release
+git log $(git describe --tags --abbrev=0)..HEAD --oneline
+```
+
+**Categorized method (recommended):**
+```bash
+# Use the provided script
+./scripts/generate-release-notes.sh > release-notes.md
+
+# Or specify a tag to compare against
+./scripts/generate-release-notes.sh v2.0.0 > release-notes.md
+```
+
+**GitHub auto-generate:**
+When creating a release on GitHub, click **"Generate release notes"** button. GitHub will automatically create notes from PRs and commits.
+
+The `scripts/generate-release-notes.sh` script categorizes commits by type:
+- ⚠️ Breaking Changes (commits with "BREAKING")
+- ✨ Features (commits starting with "feat")
+- 🐛 Bug Fixes (commits starting with "fix")
+- ♻️ Refactoring (commits starting with "refactor")
+- 📚 Documentation (commits starting with "docs")
+- ✅ Tests (commits starting with "test")
+- 🔧 Maintenance (commits starting with "chore")
+
+### 4. Update Rockspec
+
+Create a new rockspec file for the version:
+
+```bash
+# Determine new version (e.g., 3.0.0)
+NEW_VERSION="3.0.0"
+OLD_VERSION=$(ls copy_with_context-*.rockspec | head -1 | sed 's/copy_with_context-\(.*\)\.rockspec/\1/')
+
+# Copy the current rockspec
+cp copy_with_context-${OLD_VERSION}.rockspec copy_with_context-${NEW_VERSION}.rockspec
+```
+
+Edit `copy_with_context-${NEW_VERSION}.rockspec`:
+
+```lua
+package = "copy_with_context"
+version = "X.Y.Z-1"  -- Update this
+source = {
+  url = "git://github.com/zhisme/copy_with_context.nvim.git",
+  tag = "vX.Y.Z",  -- Update this
+}
+-- ... rest of the file
+```
+
+**Important:**
+- Update `version` field to match new version
+- Update `tag` field to match new version (with `v` prefix)
+- Verify all modules are listed in `build.modules` if you added new files
+- Dependencies should only include runtime dependencies (not luacheck, busted, etc.)
+
+### 5. Update Makefile
+
+Update the `ROCKSPEC` variable in `Makefile`:
+
+```makefile
+ROCKSPEC = copy_with_context-X.Y.Z-1.rockspec  # Update this
+```
+
+### 6. Commit Version Bump
+
+```bash
+# Stage the changes
+git add copy_with_context-*.rockspec Makefile
+
+# Commit with conventional commit message
+git commit -m "chore: bump version to X.Y.Z"
+
+# Push to main
+git push origin main
+```
+
+### 7. Create Git Tag
+
+```bash
+# Create an annotated tag
+git tag -a vX.Y.Z -m "Release vX.Y.Z
+
+Brief description of major changes in this release.
+
+Breaking changes (if any):
+- List breaking changes here
+
+New features:
+- List new features here
+
+Bug fixes:
+- List bug fixes here
+"
+
+# Verify the tag
+git tag -n9 vX.Y.Z
+
+# Push the tag to GitHub
+git push origin vX.Y.Z
+```
+
+**Tag naming convention:**
+- Format: `vMAJOR.MINOR.PATCH`
+- Examples: `v3.0.0`, `v2.1.5`, `v1.0.0-rc.1`
+
+### 8. Create GitHub Release
+
+1. Go to https://github.com/zhisme/copy_with_context.nvim/releases
+2. Click **"Draft a new release"**
+3. **Choose tag:** Select the tag you just pushed (e.g., `v3.0.0`)
+4. **Release title:** Format: `vX.Y.Z - Brief Description`
+   - Examples:
+     - `v3.0.0 - Flexible Mapping System`
+     - `v2.1.0 - Repository URL Support`
+     - `v2.0.1 - Bug Fixes`
+5. **Description:**
+   - Click **"Generate release notes"** button (recommended)
+   - Or paste from `release-notes.md` generated in step 3
+   - Or write manually using this template:
+
+```markdown
+# 🎉 vX.Y.Z - Release Title
+
+Brief summary of what this release is about.
+
+## ⚠️ Breaking Changes
+
+**If this is a major version (X.0.0), list breaking changes:**
+- Configuration change: explain what changed
+- API change: explain what changed
+
+**Migration guide:**
+- Step-by-step instructions for users to upgrade
+
+## ✨ New Features
+
+- Feature 1: description
+- Feature 2: description
+
+## 🐛 Bug Fixes
+
+- Fix 1: description
+- Fix 2: description
+
+## 📚 Documentation
+
+See commit history for full details:
+```bash
+git log vPREV..vX.Y.Z --oneline
+```
+
+Full documentation: [README.md](./README.md)
+```
+
+6. Check **"Set as the latest release"** (unless it's a pre-release)
+7. Click **"Publish release"**
+
+### 9. Publish to LuaRocks (Optional)
+
+If you want to publish to [LuaRocks](https://luarocks.org/):
+
+```bash
+# Install luarocks CLI if not already installed
+# See: https://github.com/luarocks/luarocks/wiki/Download
+
+# Login to LuaRocks (first time only)
+luarocks login
+
+# Upload the rockspec
+luarocks upload copy_with_context-X.Y.Z-1.rockspec
+```
+
+**Note:** You need a LuaRocks account and to be a maintainer of the package.
+
+### 10. Post-Release Tasks
+
+- [ ] Verify the release appears on GitHub Releases page
+- [ ] Verify the tag is visible: `git tag -l`
+- [ ] Test installation from the new tag:
+  ```bash
+  # In a test environment
+  cd /tmp
+  git clone https://github.com/zhisme/copy_with_context.nvim.git
+  cd copy_with_context.nvim
+  git checkout vX.Y.Z
+  make test
+  ```
+- [ ] (Optional) Announce the release:
+  - Reddit: r/neovim
+  - Twitter/X
+  - Discord communities
+- [ ] Close the milestone (if using GitHub milestones)
+
+## Quick Reference
+
+### Version Bumping Rules
+
+| Change Type | Example | Current | New Version |
+|-------------|---------|---------|-------------|
+| Breaking change | API redesign, config structure change | 2.1.0 | 3.0.0 |
+| New feature | Add format variables | 2.1.0 | 2.2.0 |
+| Bug fix | Fix URL parsing | 2.1.0 | 2.1.1 |
+| Multiple bug fixes | Several small fixes | 2.1.0 | 2.1.1 |
+| Feature + bug fix | Both in one release | 2.1.0 | 2.2.0 |
+
+### Rockspec Naming Convention
+
+Format: `<package>-<version>-<revision>.rockspec`
+
+- **Package:** `copy_with_context`
+- **Version:** Semantic version (e.g., `3.0.0`)
+- **Revision:** Usually `1` (increment if republishing same version with rockspec-only changes)
+
+Examples:
+- `copy_with_context-3.0.0-1.rockspec` (first release of 3.0.0)
+- `copy_with_context-3.0.0-2.rockspec` (rockspec fix for 3.0.0)
+
+### Tag Naming Convention
+
+Format: `v<version>`
+
+Examples:
+- `v3.0.0` (stable release)
+- `v3.0.0-rc.1` (release candidate)
+- `v3.0.0-beta.1` (beta release)
+- `v3.0.0-alpha.1` (alpha release)
+
+### Conventional Commit Prefixes
+
+Used for categorizing commits in release notes:
+
+- `feat:` - New feature
+- `fix:` - Bug fix
+- `docs:` - Documentation changes
+- `chore:` - Maintenance tasks
+- `refactor:` - Code refactoring
+- `test:` - Test updates
+- `perf:` - Performance improvements
+
+## Troubleshooting
+
+### Tag Already Exists
+
+```bash
+# Delete local tag
+git tag -d vX.Y.Z
+
+# Delete remote tag
+git push origin :refs/tags/vX.Y.Z
+
+# Recreate tag
+git tag -a vX.Y.Z -m "Release vX.Y.Z"
+git push origin vX.Y.Z
+```
+
+### Rockspec Validation Fails
+
+```bash
+# Validate rockspec locally
+luarocks lint copy_with_context-X.Y.Z-1.rockspec
+
+# Test local installation
+luarocks make copy_with_context-X.Y.Z-1.rockspec
+```
+
+### Wrong Rockspec in Makefile
+
+Make sure `Makefile` references the correct version:
+
+```makefile
+ROCKSPEC = copy_with_context-X.Y.Z-1.rockspec
+```
+
+### Release Notes Script Not Working
+
+```bash
+# Make sure script is executable
+chmod +x scripts/generate-release-notes.sh
+
+# Run with bash explicitly
+bash scripts/generate-release-notes.sh
+
+# Check if git tags exist
+git tag -l
+```
+
+### GitHub Release Not Showing Up
+
+- Ensure the tag was pushed: `git ls-remote --tags origin`
+- Check if CI is passing for the tag
+- Verify you have write access to the repository
+
+## Automation (Future)
+
+The release process can be automated with GitHub Actions. A workflow will be added in the future to:
+
+- Automatically create GitHub releases when tags are pushed
+- Run tests before releasing
+- Auto-generate release notes from commits
+- Optionally publish to LuaRocks
+
+## Additional Resources
+
+- [Semantic Versioning](https://semver.org/)
+- [GitHub Releases Documentation](https://docs.github.com/en/repositories/releasing-projects-on-github)
+- [LuaRocks Documentation](https://github.com/luarocks/luarocks/wiki)
+- [Conventional Commits](https://www.conventionalcommits.org/)
diff --git a/claude.md b/claude.md
index c7e9c2a..e6f8414 100644
--- a/claude.md
+++ b/claude.md
@@ -210,6 +210,7 @@ Contributions are welcome! Please:
 3. Run linters (`make lint`)
 4. Format code (`make fmt`)
 5. Provide clear descriptions in PRs
+6. Use conventional commit messages for consistency. Each commit message should contain the following (feat:, fix:, docs:, style:, refactor:, test:, chore:)
 
 ## License
 
diff --git a/copy_with_context-3.0.0-1.rockspec b/copy_with_context-3.0.0-1.rockspec
new file mode 100644
index 0000000..d0599d7
--- /dev/null
+++ b/copy_with_context-3.0.0-1.rockspec
@@ -0,0 +1,42 @@
+package = "copy_with_context"
+version = "3.0.0-1"
+source = {
+  url = "git://github.com/zhisme/copy_with_context.nvim.git",
+  tag = "v3.0.0",
+}
+description = {
+  summary = "A Neovim plugin for copying code with context",
+  detailed = [[
+    Copy lines with file path and line number metadata.
+    Supports flexible format strings with custom variables and
+    repository URL generation for GitHub, GitLab, and Bitbucket.
+
+    Features:
+    - Unlimited custom mappings with unique formats
+    - Template variables: {filepath}, {line}, {remote_url}
+    - Repository URL support with commit SHAs
+    - Works with nested groups (GitLab, GitHub, Bitbucket)
+  ]],
+  homepage = "https://github.com/zhisme/copy_with_context.nvim",
+  license = "MIT",
+}
+dependencies = {
+  "lua >= 5.1",
+}
+build = {
+  type = "builtin",
+  modules = {
+    ["copy_with_context"] = "lua/copy_with_context/init.lua",
+    ["copy_with_context.config"] = "lua/copy_with_context/config.lua",
+    ["copy_with_context.formatter"] = "lua/copy_with_context/formatter.lua",
+    ["copy_with_context.git"] = "lua/copy_with_context/git.lua",
+    ["copy_with_context.main"] = "lua/copy_with_context/main.lua",
+    ["copy_with_context.url_builder"] = "lua/copy_with_context/url_builder.lua",
+    ["copy_with_context.user_config_validation"] = "lua/copy_with_context/user_config_validation.lua",
+    ["copy_with_context.utils"] = "lua/copy_with_context/utils.lua",
+    ["copy_with_context.providers.init"] = "lua/copy_with_context/providers/init.lua",
+    ["copy_with_context.providers.github"] = "lua/copy_with_context/providers/github.lua",
+    ["copy_with_context.providers.gitlab"] = "lua/copy_with_context/providers/gitlab.lua",
+    ["copy_with_context.providers.bitbucket"] = "lua/copy_with_context/providers/bitbucket.lua",
+  },
+}
diff --git a/lua/copy_with_context/config.lua b/lua/copy_with_context/config.lua
index cfa9dba..6ba3f41 100644
--- a/lua/copy_with_context/config.lua
+++ b/lua/copy_with_context/config.lua
@@ -1,3 +1,5 @@
+local user_config_validation = require("copy_with_context.user_config_validation")
+
 local M = {}
 
 -- Default configuration
@@ -6,7 +8,9 @@ M.options = {
     relative = "<leader>cy",
     absolute = "<leader>cY",
   },
-  context_format = "# %s:%s", -- format for context: "# filepath:line", example: "# /path/to/file:123"
+  formats = {
+    default = "# {filepath}:{line}",
+  },
   trim_lines = false,
 }
 
@@ -15,6 +19,20 @@ function M.setup(opts)
   if opts then
     M.options = vim.tbl_deep_extend("force", M.options, opts)
   end
+
+  -- Validate configuration
+  local valid, err = user_config_validation.validate(M.options)
+  if not valid then
+    error(string.format("Invalid configuration: %s", err))
+  end
+
+  -- Validate each format string
+  for format_name, format_string in pairs(M.options.formats or {}) do
+    local format_valid, format_err = user_config_validation.validate_format_string(format_string)
+    if not format_valid then
+      error(string.format("Invalid format '%s': %s", format_name, format_err))
+    end
+  end
 end
 
 return M
diff --git a/lua/copy_with_context/formatter.lua b/lua/copy_with_context/formatter.lua
new file mode 100644
index 0000000..bc90bc5
--- /dev/null
+++ b/lua/copy_with_context/formatter.lua
@@ -0,0 +1,49 @@
+-- Formatter module for variable replacement in format strings
+
+local M = {}
+
+-- Build variables table from file and line information
+-- @param file_path string File path to use
+-- @param line_start number Starting line number
+-- @param line_end number|nil Ending line number (nil for single line)
+-- @param remote_url string|nil Remote repository URL (nil if not available)
+-- @return table Variables table
+function M.get_variables(file_path, line_start, line_end, remote_url)
+  local line_range
+  if line_end and line_end ~= line_start then
+    line_range = string.format("%d-%d", line_start, line_end)
+  else
+    line_range = tostring(line_start)
+  end
+
+  return {
+    filepath = file_path,
+    line = line_range,
+    linenumber = line_range, -- alias for 'line'
+    remote_url = remote_url or "",
+  }
+end
+
+-- Replace {variable} placeholders in format string with actual values
+-- @param format_string string Format string with {variable} placeholders
+-- @param vars table Variables table (from get_variables)
+-- @return string Formatted string with variables replaced
+function M.format(format_string, vars)
+  if not format_string then
+    return ""
+  end
+
+  -- Replace each {variable} with its value
+  local result = format_string:gsub("{([^}]+)}", function(var_name)
+    local value = vars[var_name]
+    if value == nil then
+      -- Return placeholder unchanged if variable not found
+      return "{" .. var_name .. "}"
+    end
+    return tostring(value)
+  end)
+
+  return result
+end
+
+return M
diff --git a/lua/copy_with_context/git.lua b/lua/copy_with_context/git.lua
new file mode 100644
index 0000000..11eceea
--- /dev/null
+++ b/lua/copy_with_context/git.lua
@@ -0,0 +1,167 @@
+-- Git utilities for repository information and URL generation
+
+local M = {}
+
+-- Check if current file is in a git repository
+function M.is_git_repo()
+  local result = vim.fn.system("git rev-parse --is-inside-work-tree 2>/dev/null")
+  return vim.v.shell_error == 0 and vim.fn.trim(result) == "true"
+end
+
+-- Get the remote URL (prefer 'origin', fallback to first available)
+function M.get_remote_url()
+  local result = vim.fn.system("git remote -v 2>/dev/null")
+  if vim.v.shell_error ~= 0 or result == "" then
+    return nil
+  end
+
+  -- Parse remote output
+  -- Format: "origin  https://github.com/user/repo.git (fetch)"
+  -- Prefer 'origin' remote
+  local origin_url = result:match("origin%s+([^%s]+)%s+%(fetch%)")
+  if origin_url then
+    return origin_url
+  end
+
+  -- Fallback to first available remote
+  local first_url = result:match("^[^%s]+%s+([^%s]+)%s+%(fetch%)")
+  return first_url
+end
+
+-- Parse remote URL to extract provider, owner, and repo
+-- Supports HTTPS, SSH, and git:// formats
+-- Handles nested groups (e.g., gitlab.com/group/subgroup/repo)
+function M.parse_remote_url(url)
+  if not url then
+    return nil
+  end
+
+  local provider, path
+
+  -- HTTPS: https://github.com/user/repo.git or https://gitlab.com/group/subgroup/repo.git
+  provider, path = url:match("https?://([^/]+)/(.+)%.git$")
+  if provider and path then
+    local owner, repo = path:match("(.+)/([^/]+)$")
+    if owner and repo then
+      return { provider = provider, owner = owner, repo = repo }
+    end
+  end
+
+  -- HTTPS without .git: https://github.com/user/repo
+  provider, path = url:match("https?://([^/]+)/(.+)$")
+  if provider and path then
+    local owner, repo = path:match("(.+)/([^/]+)$")
+    if owner and repo then
+      return { provider = provider, owner = owner, repo = repo }
+    end
+  end
+
+  -- SSH: git@github.com:user/repo.git or git@gitlab.com:group/subgroup/repo.git
+  provider, path = url:match("git@([^:]+):(.+)%.git$")
+  if provider and path then
+    local owner, repo = path:match("(.+)/([^/]+)$")
+    if owner and repo then
+      return { provider = provider, owner = owner, repo = repo }
+    end
+  end
+
+  -- SSH without .git: git@github.com:user/repo
+  provider, path = url:match("git@([^:]+):(.+)$")
+  if provider and path then
+    local owner, repo = path:match("(.+)/([^/]+)$")
+    if owner and repo then
+      return { provider = provider, owner = owner, repo = repo }
+    end
+  end
+
+  -- git protocol: git://github.com/user/repo.git
+  provider, path = url:match("git://([^/]+)/(.+)%.git$")
+  if provider and path then
+    local owner, repo = path:match("(.+)/([^/]+)$")
+    if owner and repo then
+      return { provider = provider, owner = owner, repo = repo }
+    end
+  end
+
+  -- git protocol without .git: git://github.com/user/repo
+  provider, path = url:match("git://([^/]+)/(.+)$")
+  if provider and path then
+    local owner, repo = path:match("(.+)/([^/]+)$")
+    if owner and repo then
+      return { provider = provider, owner = owner, repo = repo }
+    end
+  end
+
+  return nil
+end
+
+-- Get current commit SHA (full 40 characters)
+function M.get_current_commit()
+  local result = vim.fn.system("git rev-parse HEAD 2>/dev/null")
+  if vim.v.shell_error ~= 0 then
+    return nil
+  end
+  return vim.fn.trim(result)
+end
+
+-- Convert absolute path to repo-relative path
+function M.get_file_git_path(file_path)
+  -- Get the absolute path if not already absolute
+  local abs_path = file_path
+  if not file_path:match("^/") and not file_path:match("^%a:") then
+    abs_path = vim.fn.fnamemodify(file_path, ":p")
+  end
+
+  local result = vim.fn.system(
+    string.format("git ls-files --full-name %s 2>/dev/null", vim.fn.shellescape(abs_path))
+  )
+  if vim.v.shell_error ~= 0 or result == "" then
+    return nil
+  end
+
+  local git_path = vim.fn.trim(result)
+
+  -- Convert Windows backslashes to forward slashes
+  git_path = git_path:gsub("\\", "/")
+
+  return git_path
+end
+
+-- Aggregate function to get all git info for a file
+-- Returns: {provider="github.com", owner="user", repo="repo", commit="abc123", file_path="path/to/file"}
+-- Returns nil if not in git repo or any step fails
+function M.get_git_info(file_path)
+  if not M.is_git_repo() then
+    return nil
+  end
+
+  local remote_url = M.get_remote_url()
+  if not remote_url then
+    return nil
+  end
+
+  local parsed = M.parse_remote_url(remote_url)
+  if not parsed then
+    return nil
+  end
+
+  local commit = M.get_current_commit()
+  if not commit then
+    return nil
+  end
+
+  local git_path = M.get_file_git_path(file_path)
+  if not git_path then
+    return nil
+  end
+
+  return {
+    provider = parsed.provider,
+    owner = parsed.owner,
+    repo = parsed.repo,
+    commit = commit,
+    file_path = git_path,
+  }
+end
+
+return M
diff --git a/lua/copy_with_context/main.lua b/lua/copy_with_context/main.lua
index 5db5178..ab33ad5 100644
--- a/lua/copy_with_context/main.lua
+++ b/lua/copy_with_context/main.lua
@@ -1,15 +1,47 @@
 local M = {}
 
-function M.copy_with_context(absolute_path, is_visual)
+-- Generic copy function that works with any mapping
+function M.copy_with_context(mapping_name, is_visual)
+  local config = require("copy_with_context.config")
   local utils = require("copy_with_context.utils")
+  local formatter = require("copy_with_context.formatter")
+  local url_builder = require("copy_with_context.url_builder")
+
+  -- Get lines and line numbers
   local lines, start_lnum, end_lnum = utils.get_lines(is_visual)
   local content = table.concat(utils.process_lines(lines), "\n")
 
-  local output = utils.format_output(
-    content,
-    utils.get_file_path(absolute_path),
-    utils.format_line_range(start_lnum, end_lnum)
-  )
+  -- Determine file path based on mapping type
+  local file_path
+  if mapping_name == "relative" then
+    file_path = utils.get_file_path(false)
+  elseif mapping_name == "absolute" then
+    file_path = utils.get_file_path(true)
+  else
+    -- For custom mappings, default to relative path
+    file_path = utils.get_file_path(false)
+  end
+
+  -- Get remote URL if needed (check if format uses {remote_url})
+  local format_name = mapping_name
+  if mapping_name == "relative" or mapping_name == "absolute" then
+    format_name = "default"
+  end
+
+  local format_string = config.options.formats[format_name]
+  local remote_url = nil
+
+  -- Only fetch remote URL if format string uses it
+  if format_string and format_string:match("{remote_url}") then
+    remote_url = url_builder.build_url(file_path, start_lnum, end_lnum)
+  end
+
+  -- Build variables and format output
+  local vars = formatter.get_variables(file_path, start_lnum, end_lnum, remote_url)
+  local context = formatter.format(format_string, vars)
+
+  -- Combine content and context
+  local output = content .. "\n" .. context
 
   utils.copy_to_clipboard(output)
 
@@ -23,25 +55,24 @@ end
 function M.setup()
   local config = require("copy_with_context.config")
 
-  -- Apply mappings
-  vim.keymap.set("n", config.options.mappings.relative, function()
-    M.copy_with_context(false, false)
-  end, { silent = false })
-  vim.keymap.set("n", config.options.mappings.absolute, function()
-    M.copy_with_context(true, false)
-  end, { silent = false })
-  vim.keymap.set(
-    "x",
-    config.options.mappings.relative,
-    ':<C-u>lua require("copy_with_context.main").copy_with_context(false, true)<CR>',
-    { silent = true }
-  )
-  vim.keymap.set(
-    "x",
-    config.options.mappings.absolute,
-    ':<C-u>lua require("copy_with_context.main").copy_with_context(true, true)<CR>',
-    { silent = true }
-  )
+  -- Set up keymaps for all defined mappings
+  for mapping_name, keymap in pairs(config.options.mappings) do
+    -- Normal mode mapping
+    vim.keymap.set("n", keymap, function()
+      M.copy_with_context(mapping_name, false)
+    end, { silent = false })
+
+    -- Visual mode mapping
+    vim.keymap.set(
+      "x",
+      keymap,
+      string.format(
+        ':<C-u>lua require("copy_with_context.main").copy_with_context("%s", true)<CR>',
+        mapping_name
+      ),
+      { silent = true }
+    )
+  end
 end
 
 return M
diff --git a/lua/copy_with_context/providers/bitbucket.lua b/lua/copy_with_context/providers/bitbucket.lua
new file mode 100644
index 0000000..cd4ade2
--- /dev/null
+++ b/lua/copy_with_context/providers/bitbucket.lua
@@ -0,0 +1,32 @@
+-- Bitbucket provider for URL generation
+
+local M = {}
+
+M.name = "bitbucket"
+
+-- Check if this provider handles the given domain
+function M.matches(domain)
+  return domain == "bitbucket.org" or domain:match("%.bitbucket%.org$") ~= nil
+end
+
+-- Build URL for Bitbucket
+-- Format: https://bitbucket.org/{owner}/{repo}/src/{commit_sha}/{file_path}#lines-{start}[:{end}]
+function M.build_url(git_info, line_start, line_end)
+  local base_url = string.format(
+    "https://%s/%s/%s/src/%s/%s",
+    git_info.provider,
+    git_info.owner,
+    git_info.repo,
+    git_info.commit,
+    git_info.file_path
+  )
+
+  -- Add line fragment
+  if line_start == line_end then
+    return base_url .. "#lines-" .. line_start
+  else
+    return base_url .. "#lines-" .. line_start .. ":" .. line_end
+  end
+end
+
+return M
diff --git a/lua/copy_with_context/providers/github.lua b/lua/copy_with_context/providers/github.lua
new file mode 100644
index 0000000..f47f353
--- /dev/null
+++ b/lua/copy_with_context/providers/github.lua
@@ -0,0 +1,32 @@
+-- GitHub provider for URL generation
+
+local M = {}
+
+M.name = "github"
+
+-- Check if this provider handles the given domain
+function M.matches(domain)
+  return domain == "github.com" or domain:match("github") ~= nil
+end
+
+-- Build URL for GitHub
+-- Format: https://github.com/{owner}/{repo}/blob/{commit_sha}/{file_path}#L{start}[-L{end}]
+function M.build_url(git_info, line_start, line_end)
+  local base_url = string.format(
+    "https://%s/%s/%s/blob/%s/%s",
+    git_info.provider,
+    git_info.owner,
+    git_info.repo,
+    git_info.commit,
+    git_info.file_path
+  )
+
+  -- Add line fragment
+  if line_start == line_end then
+    return base_url .. "#L" .. line_start
+  else
+    return base_url .. "#L" .. line_start .. "-L" .. line_end
+  end
+end
+
+return M
diff --git a/lua/copy_with_context/providers/gitlab.lua b/lua/copy_with_context/providers/gitlab.lua
new file mode 100644
index 0000000..9809322
--- /dev/null
+++ b/lua/copy_with_context/providers/gitlab.lua
@@ -0,0 +1,33 @@
+-- GitLab provider for URL generation
+
+local M = {}
+
+M.name = "gitlab"
+
+-- Check if this provider handles the given domain
+-- GitLab.com or assume self-hosted GitLab as fallback
+function M.matches(domain)
+  return domain == "gitlab.com" or domain:match("gitlab") ~= nil
+end
+
+-- Build URL for GitLab
+-- Format: https://gitlab.com/{owner}/{repo}/-/blob/{commit_sha}/{file_path}#L{start}[-{end}]
+function M.build_url(git_info, line_start, line_end)
+  local base_url = string.format(
+    "https://%s/%s/%s/-/blob/%s/%s",
+    git_info.provider,
+    git_info.owner,
+    git_info.repo,
+    git_info.commit,
+    git_info.file_path
+  )
+
+  -- Add line fragment
+  if line_start == line_end then
+    return base_url .. "#L" .. line_start
+  else
+    return base_url .. "#L" .. line_start .. "-" .. line_end
+  end
+end
+
+return M
diff --git a/lua/copy_with_context/providers/init.lua b/lua/copy_with_context/providers/init.lua
new file mode 100644
index 0000000..1c69233
--- /dev/null
+++ b/lua/copy_with_context/providers/init.lua
@@ -0,0 +1,39 @@
+-- Provider detection and factory
+
+local M = {}
+
+-- Lazy-loaded provider modules
+local providers = {
+  "copy_with_context.providers.github",
+  "copy_with_context.providers.gitlab",
+  "copy_with_context.providers.bitbucket",
+}
+
+-- Detect which provider handles the given domain
+function M.detect_provider(domain)
+  if not domain then
+    return nil
+  end
+
+  -- Try each provider in order
+  for _, provider_path in ipairs(providers) do
+    local ok, provider = pcall(require, provider_path)
+    if ok and provider.matches and provider.matches(domain) then
+      return provider
+    end
+  end
+
+  -- Return nil for unknown providers (graceful degradation)
+  return nil
+end
+
+-- Factory method to get provider from git info
+function M.get_provider(git_info)
+  if not git_info or not git_info.provider then
+    return nil
+  end
+
+  return M.detect_provider(git_info.provider)
+end
+
+return M
diff --git a/lua/copy_with_context/url_builder.lua b/lua/copy_with_context/url_builder.lua
new file mode 100644
index 0000000..32690e0
--- /dev/null
+++ b/lua/copy_with_context/url_builder.lua
@@ -0,0 +1,30 @@
+-- URL builder module for generating repository URLs
+
+local M = {}
+
+-- Build a repository URL for the given file and line range
+-- @param file_path string File path (relative or absolute)
+-- @param line_start number Starting line number
+-- @param line_end number|nil Ending line number (nil for single line)
+-- @return string|nil Repository URL or nil if not available
+function M.build_url(file_path, line_start, line_end)
+  -- Get git info
+  local git = require("copy_with_context.git")
+  local git_info = git.get_git_info(file_path)
+  if not git_info then
+    return nil
+  end
+
+  -- Get provider
+  local providers = require("copy_with_context.providers")
+  local provider = providers.get_provider(git_info)
+  if not provider then
+    return nil
+  end
+
+  -- Build URL
+  local url = provider.build_url(git_info, line_start, line_end)
+  return url
+end
+
+return M
diff --git a/lua/copy_with_context/user_config_validation.lua b/lua/copy_with_context/user_config_validation.lua
new file mode 100644
index 0000000..b1e14ea
--- /dev/null
+++ b/lua/copy_with_context/user_config_validation.lua
@@ -0,0 +1,89 @@
+-- User configuration validation module
+
+local M = {}
+
+-- Validate that mappings and formats match
+-- @param config table User configuration
+-- @return boolean, string|nil Success status and error message
+function M.validate(config)
+  if not config then
+    return true, nil
+  end
+
+  local mappings = config.mappings or {}
+  local formats = config.formats or {}
+
+  -- Special cases that map to "default" format
+  local default_mappings = {
+    relative = true,
+    absolute = true,
+  }
+
+  -- Check: every mapping must have a format
+  for mapping_name, _ in pairs(mappings) do
+    -- relative/absolute use "default" format
+    if default_mappings[mapping_name] then
+      if not formats.default then
+        return false,
+          string.format("Mapping '%s' requires 'formats.default' to be defined", mapping_name)
+      end
+    else
+      -- All other mappings need matching format
+      if not formats[mapping_name] then
+        return false,
+          string.format(
+            "Mapping '%s' has no matching format. Add 'formats.%s'",
+            mapping_name,
+            mapping_name
+          )
+      end
+    end
+  end
+
+  -- Check: every format (except default) should have a mapping
+  for format_name, _ in pairs(formats) do
+    if format_name ~= "default" then
+      if not mappings[format_name] then
+        return false,
+          string.format(
+            "Format '%s' has no matching mapping. Add 'mappings.%s' or remove the format",
+            format_name,
+            format_name
+          )
+      end
+    end
+  end
+
+  return true, nil
+end
+
+-- Validate format string has valid variables
+-- @param format_string string Format string to validate
+-- @return boolean, string|nil Success status and error message
+function M.validate_format_string(format_string)
+  if not format_string then
+    return false, "Format string cannot be nil"
+  end
+
+  local valid_vars = {
+    filepath = true,
+    line = true,
+    linenumber = true,
+    remote_url = true,
+  }
+
+  -- Extract all variables from format string
+  for var in format_string:gmatch("{([^}]+)}") do
+    if not valid_vars[var] then
+      return false,
+        string.format(
+          "Unknown variable '{%s}' in format string. Valid variables: filepath, line, linenumber, remote_url",
+          var
+        )
+    end
+  end
+
+  return true, nil
+end
+
+return M
diff --git a/lua/copy_with_context/utils.lua b/lua/copy_with_context/utils.lua
index df5150a..13fc969 100644
--- a/lua/copy_with_context/utils.lua
+++ b/lua/copy_with_context/utils.lua
@@ -22,11 +22,6 @@ function M.get_file_path(absolute)
   return absolute and vim.fn.expand("%:p") or vim.fn.expand("%")
 end
 
-function M.format_line_range(start_line, end_line)
-  return start_line == end_line and tostring(start_line)
-    or string.format("%d-%d", start_line, end_line)
-end
-
 function M.process_lines(lines)
   local config = require("copy_with_context.config")
   local processed = {}
@@ -47,11 +42,4 @@ function M.copy_to_clipboard(output)
   vim.fn.setreg("+", output)
 end
 
-function M.format_output(content, file_path, line_range)
-  local config = require("copy_with_context.config")
-  local comment_line = string.format(config.options.context_format, file_path, line_range)
-
-  return string.format("%s\n%s", content, comment_line)
-end
-
 return M
diff --git a/scripts/generate-release-notes.sh b/scripts/generate-release-notes.sh
new file mode 100755
index 0000000..3d3405c
--- /dev/null
+++ b/scripts/generate-release-notes.sh
@@ -0,0 +1,130 @@
+#!/bin/bash
+# Generate release notes from git commit history
+# Usage: ./scripts/generate-release-notes.sh [TAG]
+# If TAG is not provided, generates notes since last tag
+
+set -e
+
+# Get the tag to compare against
+if [ -n "$1" ]; then
+  LAST_TAG="$1"
+else
+  LAST_TAG=$(git describe --tags --abbrev=0 2>/dev/null || echo "")
+fi
+
+if [ -z "$LAST_TAG" ]; then
+  echo "## All Commits"
+  echo ""
+  git log --pretty=format:"- %s (%h)" --reverse
+  exit 0
+fi
+
+echo "## Changes since ${LAST_TAG}"
+echo ""
+
+# Function to print commits matching a pattern
+print_commits() {
+  local pattern="$1"
+  local commits=$(git log ${LAST_TAG}..HEAD --grep="$pattern" --pretty=format:"- %s (%h)" --reverse 2>/dev/null)
+  if [ -n "$commits" ]; then
+    echo "$commits"
+  fi
+}
+
+# Breaking changes (highest priority)
+echo "### ⚠️  Breaking Changes"
+breaking=$(print_commits "BREAKING")
+if [ -z "$breaking" ]; then
+  echo "_None_"
+else
+  echo "$breaking"
+fi
+echo ""
+
+# Features
+echo "### ✨ Features"
+features=$(print_commits "^feat")
+if [ -z "$features" ]; then
+  echo "_None_"
+else
+  echo "$features"
+fi
+echo ""
+
+# Bug fixes
+echo "### 🐛 Bug Fixes"
+fixes=$(print_commits "^fix")
+if [ -z "$fixes" ]; then
+  echo "_None_"
+else
+  echo "$fixes"
+fi
+echo ""
+
+# Refactoring
+echo "### ♻️  Refactoring"
+refactor=$(print_commits "^refactor")
+if [ -z "$refactor" ]; then
+  echo "_None_"
+else
+  echo "$refactor"
+fi
+echo ""
+
+# Documentation
+echo "### 📚 Documentation"
+docs=$(print_commits "^docs")
+if [ -z "$docs" ]; then
+  echo "_None_"
+else
+  echo "$docs"
+fi
+echo ""
+
+# Tests
+echo "### ✅ Tests"
+tests=$(print_commits "^test")
+if [ -z "$tests" ]; then
+  echo "_None_"
+else
+  echo "$tests"
+fi
+echo ""
+
+# Chores
+echo "### 🔧 Maintenance"
+chores=$(print_commits "^chore")
+if [ -z "$chores" ]; then
+  echo "_None_"
+else
+  echo "$chores"
+fi
+echo ""
+
+# All other commits not matching patterns above
+echo "### 📝 Other Changes"
+other=$(git log ${LAST_TAG}..HEAD \
+  --invert-grep \
+  --grep="BREAKING" \
+  --grep="^feat" \
+  --grep="^fix" \
+  --grep="^refactor" \
+  --grep="^docs" \
+  --grep="^test" \
+  --grep="^chore" \
+  --pretty=format:"- %s (%h)" \
+  --reverse 2>/dev/null)
+if [ -z "$other" ]; then
+  echo "_None_"
+else
+  echo "$other"
+fi
+echo ""
+
+# Summary statistics
+echo "---"
+echo ""
+total=$(git rev-list ${LAST_TAG}..HEAD --count)
+contributors=$(git log ${LAST_TAG}..HEAD --format='%an' | sort -u | wc -l)
+echo "**Total commits:** $total"
+echo "**Contributors:** $contributors"
diff --git a/tests/copy_with_context/config_spec.lua b/tests/copy_with_context/config_spec.lua
index dab4391..840108c 100644
--- a/tests/copy_with_context/config_spec.lua
+++ b/tests/copy_with_context/config_spec.lua
@@ -17,21 +17,45 @@ _G.vim = {
 
 -- Ensure fresh module loading
 package.loaded["copy_with_context.config"] = nil
+package.loaded["copy_with_context.user_config_validation"] = nil
 
 local config = require("copy_with_context.config")
 
 describe("Config Module", function()
+  before_each(function()
+    -- Reset config.options to defaults before each test
+    config.options = {
+      mappings = {
+        relative = "<leader>cy",
+        absolute = "<leader>cY",
+      },
+      formats = {
+        default = "# {filepath}:{line}",
+      },
+      trim_lines = false,
+    }
+  end)
+
   it("has default options", function()
     assert.same({
       mappings = {
         relative = "<leader>cy",
         absolute = "<leader>cY",
       },
-      context_format = "# %s:%s",
+      formats = {
+        default = "# {filepath}:{line}",
+      },
       trim_lines = false,
     }, config.options)
   end)
 
+  it("can be called without arguments", function()
+    config.setup()
+    -- Should not error and keep default options
+    assert.is_not_nil(config.options.mappings)
+    assert.is_not_nil(config.options.formats)
+  end)
+
   it("merges user options with defaults", function()
     config.setup({
       mappings = { relative = "<leader>new" },
@@ -43,8 +67,91 @@ describe("Config Module", function()
         relative = "<leader>new",
         absolute = "<leader>cY",
       },
-      context_format = "# %s:%s",
+      formats = {
+        default = "# {filepath}:{line}",
+      },
       trim_lines = true,
     }, config.options)
   end)
+
+  it("validates configuration on setup", function()
+    local success = pcall(config.setup, {
+      mappings = {
+        custom = "<leader>cc",
+      },
+      formats = {
+        default = "# {filepath}:{line}",
+        -- missing 'custom' format
+      },
+    })
+
+    assert.is_false(success)
+  end)
+
+  it("validates format strings on setup", function()
+    local success = pcall(config.setup, {
+      mappings = {
+        relative = "<leader>cy",
+      },
+      formats = {
+        default = "# {invalid_variable}",
+      },
+    })
+
+    assert.is_false(success)
+  end)
+
+  it("validates custom format strings with invalid variables", function()
+    -- This test covers the error on line 33 of config.lua
+    local success = pcall(config.setup, {
+      mappings = {
+        relative = "<leader>cy",
+        custom = "<leader>cc",
+      },
+      formats = {
+        default = "# {filepath}:{line}",
+        custom = "# {invalid_custom_var}", -- Invalid variable in custom format
+      },
+    })
+
+    assert.is_false(success)
+  end)
+
+  it("handles missing formats gracefully", function()
+    -- Manually reset config to have no formats
+    config.options = {
+      mappings = {
+        relative = "<leader>cy",
+      },
+      trim_lines = false,
+    }
+
+    -- Setup without providing formats - should fail because no default format
+    local success = pcall(config.setup, {
+      mappings = {
+        relative = "<leader>cy",
+      },
+    })
+
+    -- Should fail validation because no default format
+    assert.is_false(success)
+  end)
+
+  it("validates multiple format strings", function()
+    local success = pcall(config.setup, {
+      mappings = {
+        relative = "<leader>cy",
+        custom1 = "<leader>c1",
+        custom2 = "<leader>c2",
+      },
+      formats = {
+        default = "# {filepath}:{line}",
+        custom1 = "# {remote_url}",
+        custom2 = "# {filepath}",
+      },
+    })
+
+    -- All formats are valid, should succeed
+    assert.is_true(success)
+  end)
 end)
diff --git a/tests/copy_with_context/formatter_spec.lua b/tests/copy_with_context/formatter_spec.lua
new file mode 100644
index 0000000..3902bc7
--- /dev/null
+++ b/tests/copy_with_context/formatter_spec.lua
@@ -0,0 +1,134 @@
+local formatter = require("copy_with_context.formatter")
+
+describe("Formatter", function()
+  describe("get_variables", function()
+    it("creates variables table with single line", function()
+      local vars = formatter.get_variables("/path/to/file.lua", 42, nil, nil)
+
+      assert.same({
+        filepath = "/path/to/file.lua",
+        line = "42",
+        linenumber = "42",
+        remote_url = "",
+      }, vars)
+    end)
+
+    it("creates variables table with line range", function()
+      local vars = formatter.get_variables("/path/to/file.lua", 10, 20, nil)
+
+      assert.same({
+        filepath = "/path/to/file.lua",
+        line = "10-20",
+        linenumber = "10-20",
+        remote_url = "",
+      }, vars)
+    end)
+
+    it("creates variables table with remote URL", function()
+      local vars = formatter.get_variables(
+        "/path/to/file.lua",
+        5,
+        5,
+        "https://github.com/user/repo/blob/abc123/file.lua#L5"
+      )
+
+      assert.same({
+        filepath = "/path/to/file.lua",
+        line = "5",
+        linenumber = "5",
+        remote_url = "https://github.com/user/repo/blob/abc123/file.lua#L5",
+      }, vars)
+    end)
+
+    it("handles line_end same as line_start", function()
+      local vars = formatter.get_variables("/path/to/file.lua", 7, 7, nil)
+
+      assert.same({
+        filepath = "/path/to/file.lua",
+        line = "7",
+        linenumber = "7",
+        remote_url = "",
+      }, vars)
+    end)
+  end)
+
+  describe("format", function()
+    it("replaces variables in format string", function()
+      local vars = {
+        filepath = "src/main.lua",
+        line = "42",
+        linenumber = "42",
+        remote_url = "https://github.com/user/repo/blob/abc/main.lua#L42",
+      }
+
+      local result = formatter.format("# {filepath}:{line}", vars)
+      assert.equals("# src/main.lua:42", result)
+    end)
+
+    it("replaces multiple instances of same variable", function()
+      local vars = {
+        filepath = "test.lua",
+        line = "1",
+        linenumber = "1",
+        remote_url = "",
+      }
+
+      local result = formatter.format("{filepath} - {filepath}", vars)
+      assert.equals("test.lua - test.lua", result)
+    end)
+
+    it("replaces all available variables", function()
+      local vars = {
+        filepath = "file.lua",
+        line = "10-20",
+        linenumber = "10-20",
+        remote_url = "https://example.com",
+      }
+
+      local result = formatter.format("# {filepath}:{line} - {remote_url}", vars)
+      assert.equals("# file.lua:10-20 - https://example.com", result)
+    end)
+
+    it("handles empty remote_url", function()
+      local vars = {
+        filepath = "file.lua",
+        line = "5",
+        linenumber = "5",
+        remote_url = "",
+      }
+
+      local result = formatter.format("# {filepath}:{line} {remote_url}", vars)
+      assert.equals("# file.lua:5 ", result)
+    end)
+
+    it("returns empty string for nil format string", function()
+      local vars = { filepath = "test.lua", line = "1", linenumber = "1", remote_url = "" }
+      local result = formatter.format(nil, vars)
+      assert.equals("", result)
+    end)
+
+    it("leaves unknown variables unchanged", function()
+      local vars = {
+        filepath = "test.lua",
+        line = "1",
+        linenumber = "1",
+        remote_url = "",
+      }
+
+      local result = formatter.format("# {filepath} {unknown}", vars)
+      assert.equals("# test.lua {unknown}", result)
+    end)
+
+    it("uses linenumber as alias for line", function()
+      local vars = {
+        filepath = "test.lua",
+        line = "42",
+        linenumber = "42",
+        remote_url = "",
+      }
+
+      local result = formatter.format("# {filepath}:{linenumber}", vars)
+      assert.equals("# test.lua:42", result)
+    end)
+  end)
+end)
diff --git a/tests/copy_with_context/git_spec.lua b/tests/copy_with_context/git_spec.lua
new file mode 100644
index 0000000..dea6f69
--- /dev/null
+++ b/tests/copy_with_context/git_spec.lua
@@ -0,0 +1,424 @@
+-- Git utilities tests
+-- luacheck: globals vim
+
+-- Set up vim mock before requiring the module
+_G.vim = {
+  fn = {},
+  v = {
+    shell_error = 0,
+  },
+}
+
+-- Clear cached modules
+package.loaded["copy_with_context.git"] = nil
+
+local git = require("copy_with_context.git")
+
+describe("Git utilities", function()
+  local original_system, original_trim, original_shellescape, original_fnamemodify
+
+  before_each(function()
+    -- Save originals
+    original_system = vim.fn.system
+    original_trim = vim.fn.trim
+    original_shellescape = vim.fn.shellescape
+    original_fnamemodify = vim.fn.fnamemodify
+
+    -- Set defaults
+    vim.v.shell_error = 0
+    vim.fn.system = function(_cmd)
+      return ""
+    end
+    vim.fn.trim = function(s)
+      if not s then
+        return ""
+      end
+      return s:match("^%s*(.-)%s*$") or s
+    end
+    vim.fn.shellescape = function(s)
+      return "'" .. s:gsub("'", "'\\''") .. "'"
+    end
+    vim.fn.fnamemodify = function(path, _mod)
+      return path
+    end
+  end)
+
+  after_each(function()
+    -- Restore originals
+    vim.fn.system = original_system
+    vim.fn.trim = original_trim
+    vim.fn.shellescape = original_shellescape
+    vim.fn.fnamemodify = original_fnamemodify
+  end)
+
+  describe("is_git_repo", function()
+    it("returns true when in a git repository", function()
+      vim.fn.system = function(_cmd)
+        return "true\n"
+      end
+      vim.v.shell_error = 0
+
+      local result = git.is_git_repo()
+      assert.is_true(result)
+    end)
+
+    it("returns false when not in a git repository", function()
+      vim.fn.system = function(_cmd)
+        return "fatal: not a git repository\n"
+      end
+      vim.v.shell_error = 128
+
+      local result = git.is_git_repo()
+      assert.is_false(result)
+    end)
+  end)
+
+  describe("get_remote_url", function()
+    it("returns origin remote URL", function()
+      vim.fn.system = function(_cmd)
+        return "origin\thttps://github.com/user/repo.git (fetch)\norigin\thttps://github.com/user/repo.git (push)\n"
+      end
+      vim.v.shell_error = 0
+
+      local result = git.get_remote_url()
+      assert.equals("https://github.com/user/repo.git", result)
+    end)
+
+    it("returns first remote if origin not available", function()
+      vim.fn.system = function(_cmd)
+        return "upstream\thttps://github.com/other/repo.git (fetch)\n"
+          .. "upstream\thttps://github.com/other/repo.git (push)\n"
+      end
+      vim.v.shell_error = 0
+
+      local result = git.get_remote_url()
+      assert.equals("https://github.com/other/repo.git", result)
+    end)
+
+    it("returns nil when no remotes available", function()
+      vim.fn.system = function(_cmd)
+        return ""
+      end
+      vim.v.shell_error = 0
+
+      local result = git.get_remote_url()
+      assert.is_nil(result)
+    end)
+
+    it("returns nil on git error", function()
+      vim.fn.system = function(_cmd)
+        return "fatal: not a git repository\n"
+      end
+      vim.v.shell_error = 128
+
+      local result = git.get_remote_url()
+      assert.is_nil(result)
+    end)
+  end)
+
+  describe("parse_remote_url", function()
+    it("parses HTTPS URL with .git", function()
+      local result = git.parse_remote_url("https://github.com/user/repo.git")
+      assert.same({ provider = "github.com", owner = "user", repo = "repo" }, result)
+    end)
+
+    it("parses HTTP URL with .git", function()
+      local result = git.parse_remote_url("http://github.com/user/repo.git")
+      assert.same({ provider = "github.com", owner = "user", repo = "repo" }, result)
+    end)
+
+    it("parses HTTPS URL without .git", function()
+      local result = git.parse_remote_url("https://github.com/user/repo")
+      assert.same({ provider = "github.com", owner = "user", repo = "repo" }, result)
+    end)
+
+    it("parses HTTP URL without .git", function()
+      local result = git.parse_remote_url("http://github.com/user/repo")
+      assert.same({ provider = "github.com", owner = "user", repo = "repo" }, result)
+    end)
+
+    it("parses SSH URL with .git", function()
+      local result = git.parse_remote_url("git@github.com:user/repo.git")
+      assert.same({ provider = "github.com", owner = "user", repo = "repo" }, result)
+    end)
+
+    it("parses SSH URL without .git", function()
+      local result = git.parse_remote_url("git@github.com:user/repo")
+      assert.same({ provider = "github.com", owner = "user", repo = "repo" }, result)
+    end)
+
+    it("parses git protocol URL with .git", function()
+      local result = git.parse_remote_url("git://github.com/user/repo.git")
+      assert.same({ provider = "github.com", owner = "user", repo = "repo" }, result)
+    end)
+
+    it("parses git protocol URL without .git", function()
+      local result = git.parse_remote_url("git://github.com/user/repo")
+      assert.same({ provider = "github.com", owner = "user", repo = "repo" }, result)
+    end)
+
+    it("parses GitLab URL with nested groups (HTTPS with .git)", function()
+      local result = git.parse_remote_url("https://gitlab.example.com/frontend/web/dashboard.git")
+      assert.same({
+        provider = "gitlab.example.com",
+        owner = "frontend/web",
+        repo = "dashboard",
+      }, result)
+    end)
+
+    it("parses GitLab URL with nested groups (SSH with .git)", function()
+      local result = git.parse_remote_url("git@gitlab.example.com:backend/api/service.git")
+      assert.same({
+        provider = "gitlab.example.com",
+        owner = "backend/api",
+        repo = "service",
+      }, result)
+    end)
+
+    it("parses GitLab URL with nested groups (HTTPS without .git)", function()
+      local result = git.parse_remote_url("https://gitlab.company.com/team/subteam/project")
+      assert.same({
+        provider = "gitlab.company.com",
+        owner = "team/subteam",
+        repo = "project",
+      }, result)
+    end)
+
+    it("parses GitLab URL with nested groups (SSH without .git)", function()
+      local result = git.parse_remote_url("git@gitlab.company.com:team/subteam/project")
+      assert.same({
+        provider = "gitlab.company.com",
+        owner = "team/subteam",
+        repo = "project",
+      }, result)
+    end)
+
+    it("parses GitHub Enterprise URL with nested paths", function()
+      local result = git.parse_remote_url("https://github.enterprise.com/org/team/repo.git")
+      assert.same({
+        provider = "github.enterprise.com",
+        owner = "org/team",
+        repo = "repo",
+      }, result)
+    end)
+
+    it("parses deeply nested group paths", function()
+      local result = git.parse_remote_url("git@gitlab.com:group/subgroup/subsubgroup/project.git")
+      assert.same({
+        provider = "gitlab.com",
+        owner = "group/subgroup/subsubgroup",
+        repo = "project",
+      }, result)
+    end)
+
+    it("returns nil for invalid URL", function()
+      local result = git.parse_remote_url("invalid-url")
+      assert.is_nil(result)
+    end)
+
+    it("returns nil for nil input", function()
+      local result = git.parse_remote_url(nil)
+      assert.is_nil(result)
+    end)
+  end)
+
+  describe("get_current_commit", function()
+    it("returns commit SHA", function()
+      vim.fn.system = function(_cmd)
+        return "abc123def456\n"
+      end
+      vim.v.shell_error = 0
+
+      local result = git.get_current_commit()
+      assert.equals("abc123def456", result)
+    end)
+
+    it("returns nil on git error", function()
+      vim.fn.system = function(_cmd)
+        return "fatal: not a git repository\n"
+      end
+      vim.v.shell_error = 128
+
+      local result = git.get_current_commit()
+      assert.is_nil(result)
+    end)
+  end)
+
+  describe("get_file_git_path", function()
+    it("returns repo-relative path", function()
+      vim.fn.system = function(_cmd)
+        return "lua/copy_with_context/git.lua\n"
+      end
+      vim.v.shell_error = 0
+
+      local result = git.get_file_git_path("/home/user/project/lua/copy_with_context/git.lua")
+      assert.equals("lua/copy_with_context/git.lua", result)
+    end)
+
+    it("converts relative path to absolute before querying git", function()
+      vim.fn.system = function(_cmd)
+        return "lua/test.lua\n"
+      end
+      vim.fn.fnamemodify = function(path, _mod)
+        return "/home/user/project/" .. path
+      end
+      vim.v.shell_error = 0
+
+      local result = git.get_file_git_path("lua/test.lua")
+      assert.equals("lua/test.lua", result)
+    end)
+
+    it("converts Windows backslashes to forward slashes", function()
+      vim.fn.system = function(_cmd)
+        return "lua\\copy_with_context\\git.lua\n"
+      end
+      vim.v.shell_error = 0
+
+      local result = git.get_file_git_path("C:\\project\\lua\\copy_with_context\\git.lua")
+      assert.equals("lua/copy_with_context/git.lua", result)
+    end)
+
+    it("returns nil for untracked file", function()
+      vim.fn.system = function(_cmd)
+        return ""
+      end
+      vim.v.shell_error = 128
+
+      local result = git.get_file_git_path("/home/user/project/untracked.lua")
+      assert.is_nil(result)
+    end)
+  end)
+
+  describe("get_git_info", function()
+    local orig_is_git_repo, orig_get_remote_url, orig_get_current_commit, orig_get_file_git_path
+
+    before_each(function()
+      -- Save originals
+      orig_is_git_repo = git.is_git_repo
+      orig_get_remote_url = git.get_remote_url
+      orig_get_current_commit = git.get_current_commit
+      orig_get_file_git_path = git.get_file_git_path
+    end)
+
+    after_each(function()
+      -- Restore originals
+      git.is_git_repo = orig_is_git_repo
+      git.get_remote_url = orig_get_remote_url
+      git.get_current_commit = orig_get_current_commit
+      git.get_file_git_path = orig_get_file_git_path
+    end)
+
+    it("returns complete git info", function()
+      -- Mock functions
+      git.is_git_repo = function()
+        return true
+      end
+      git.get_remote_url = function()
+        return "https://github.com/user/repo.git"
+      end
+      git.get_current_commit = function()
+        return "abc123def456"
+      end
+      git.get_file_git_path = function(_path)
+        return "lua/file.lua"
+      end
+
+      local result = git.get_git_info("/home/user/project/lua/file.lua")
+
+      assert.same({
+        provider = "github.com",
+        owner = "user",
+        repo = "repo",
+        commit = "abc123def456",
+        file_path = "lua/file.lua",
+      }, result)
+    end)
+
+    it("returns nil when not in git repo", function()
+      git.is_git_repo = function()
+        return false
+      end
+
+      local result = git.get_git_info("/home/user/project/file.lua")
+      assert.is_nil(result)
+    end)
+
+    it("returns nil when remote URL not available", function()
+      git.is_git_repo = function()
+        return true
+      end
+      git.get_remote_url = function()
+        return nil
+      end
+
+      local result = git.get_git_info("/home/user/project/file.lua")
+      assert.is_nil(result)
+    end)
+
+    it("returns nil when remote URL cannot be parsed", function()
+      git.is_git_repo = function()
+        return true
+      end
+      git.get_remote_url = function()
+        return "invalid-url-format"
+      end
+
+      local result = git.get_git_info("/home/user/project/file.lua")
+      assert.is_nil(result)
+    end)
+
+    it("returns nil when commit is not available", function()
+      git.is_git_repo = function()
+        return true
+      end
+      git.get_remote_url = function()
+        return "https://github.com/user/repo.git"
+      end
+      git.get_current_commit = function()
+        return nil
+      end
+
+      local result = git.get_git_info("/home/user/project/file.lua")
+      assert.is_nil(result)
+    end)
+
+    it("returns nil when file git path is not available", function()
+      git.is_git_repo = function()
+        return true
+      end
+      git.get_remote_url = function()
+        return "https://github.com/user/repo.git"
+      end
+      git.get_current_commit = function()
+        return "abc123"
+      end
+      git.get_file_git_path = function(_path)
+        return nil
+      end
+
+      local result = git.get_git_info("/home/user/project/file.lua")
+      assert.is_nil(result)
+    end)
+  end)
+
+  describe("get_file_git_path with relative paths", function()
+    it("converts relative path to absolute before calling git", function()
+      local fnamemodify_called = false
+      local mod_value = nil
+      vim.fn.fnamemodify = function(path, mod)
+        fnamemodify_called = true
+        mod_value = mod
+        return "/home/user/project/" .. path
+      end
+      vim.fn.system = function(_cmd)
+        return "lua/file.lua\n"
+      end
+      vim.v.shell_error = 0
+
+      local result = git.get_file_git_path("lua/file.lua")
+      assert.is_true(fnamemodify_called)
+      assert.equals(":p", mod_value)
+      assert.equals("lua/file.lua", result)
+    end)
+  end)
+end)
diff --git a/tests/copy_with_context/main_spec.lua b/tests/copy_with_context/main_spec.lua
index a24349d..8037deb 100644
--- a/tests/copy_with_context/main_spec.lua
+++ b/tests/copy_with_context/main_spec.lua
@@ -13,10 +13,14 @@ local stub = require("luassert.stub")
 package.loaded["copy_with_context.main"] = nil
 package.loaded["copy_with_context.utils"] = nil
 package.loaded["copy_with_context.config"] = nil
+package.loaded["copy_with_context.formatter"] = nil
+package.loaded["copy_with_context.url_builder"] = nil
 
 local main = require("copy_with_context.main")
 local utils = require("copy_with_context.utils")
 local config = require("copy_with_context.config")
+local formatter = require("copy_with_context.formatter")
+local url_builder = require("copy_with_context.url_builder")
 
 describe("Main Module", function()
   before_each(function()
@@ -24,9 +28,15 @@ describe("Main Module", function()
     stub(utils, "get_lines").returns({ "line 1", "line 2" }, 1, 2)
     stub(utils, "process_lines").returns({ "line 1", "line 2" })
     stub(utils, "get_file_path").returns("/fake/path.lua")
-    stub(utils, "format_line_range").returns("1-2")
-    stub(utils, "format_output").returns("Processed output")
     stub(utils, "copy_to_clipboard")
+    stub(formatter, "get_variables").returns({
+      filepath = "/fake/path.lua",
+      line = "1-2",
+      linenumber = "1-2",
+      remote_url = "",
+    })
+    stub(formatter, "format").returns("# /fake/path.lua:1-2")
+    stub(url_builder, "build_url").returns(nil)
     stub(vim.api, "nvim_echo")
     stub(vim.keymap, "set")
   end)
@@ -36,43 +46,110 @@ describe("Main Module", function()
     utils.get_lines:revert()
     utils.process_lines:revert()
     utils.get_file_path:revert()
-    utils.format_line_range:revert()
-    utils.format_output:revert()
     utils.copy_to_clipboard:revert()
+    formatter.get_variables:revert()
+    formatter.format:revert()
+    url_builder.build_url:revert()
     vim.api.nvim_echo:revert()
     vim.keymap.set:revert()
   end)
 
-  it("copies content with context (relative path, non-visual mode)", function()
-    main.copy_with_context(false, false)
+  it("copies content with context (relative mapping, non-visual mode)", function()
+    main.copy_with_context("relative", false)
 
     assert.stub(utils.get_lines).was_called_with(false)
     assert.stub(utils.process_lines).was_called_with({ "line 1", "line 2" })
     assert.stub(utils.get_file_path).was_called_with(false)
-    assert.stub(utils.format_line_range).was_called_with(1, 2)
-    assert.stub(utils.format_output).was_called_with("line 1\nline 2", "/fake/path.lua", "1-2")
+    assert.stub(formatter.get_variables).was_called()
+    assert.stub(formatter.format).was_called()
+    assert.stub(utils.copy_to_clipboard).was_called()
     assert.stub(vim.api.nvim_echo).was_called()
   end)
 
-  it("copies content with context (absolute path, visual mode)", function()
-    main.copy_with_context(true, true)
+  it("copies content with context (absolute mapping, visual mode)", function()
+    main.copy_with_context("absolute", true)
 
     assert.stub(utils.get_lines).was_called_with(true)
     assert.stub(utils.get_file_path).was_called_with(true)
-    assert.stub(utils.format_output).was_called()
+    assert.stub(formatter.get_variables).was_called()
+    assert.stub(formatter.format).was_called()
     assert.stub(utils.copy_to_clipboard).was_called()
     assert.stub(vim.api.nvim_echo).was_called()
   end)
 
-  it("sets up key mappings", function()
+  it("copies content with custom mapping", function()
+    -- Add custom mapping to config
+    config.options.mappings.custom = "<leader>cc"
+    config.options.formats.custom = "# {filepath}"
+
+    main.copy_with_context("custom", false)
+
+    assert.stub(utils.get_lines).was_called_with(false)
+    assert.stub(utils.process_lines).was_called_with({ "line 1", "line 2" })
+    assert.stub(utils.get_file_path).was_called_with(false)
+    assert.stub(formatter.get_variables).was_called()
+    assert.stub(formatter.format).was_called_with("# {filepath}", match._)
+    assert.stub(utils.copy_to_clipboard).was_called()
+
+    -- Cleanup
+    config.options.mappings.custom = nil
+    config.options.formats.custom = nil
+  end)
+
+  it("fetches remote URL only when format uses it", function()
+    -- Add remote mapping that uses {remote_url}
+    config.options.mappings.remote = "<leader>cr"
+    config.options.formats.remote = "# {remote_url}"
+
+    url_builder.build_url:revert()
+    stub(url_builder, "build_url").returns(
+      "https://github.com/user/repo/blob/abc123/path.lua#L1-L2"
+    )
+
+    main.copy_with_context("remote", false)
+
+    -- Should call build_url because format uses {remote_url}
+    assert.stub(url_builder.build_url).was_called()
+
+    -- Cleanup
+    config.options.mappings.remote = nil
+    config.options.formats.remote = nil
+  end)
+
+  it("does not fetch remote URL when format doesn't use it", function()
+    main.copy_with_context("relative", false)
+
+    -- Should not call build_url because default format doesn't use {remote_url}
+    assert.stub(url_builder.build_url).was_not_called()
+  end)
+
+  it("handles missing format gracefully", function()
+    -- Add mapping without corresponding format to simulate edge case
+    config.options.mappings.missing = "<leader>cm"
+    -- Don't add format for it (this would normally be caught by validation)
+
+    -- This should not error, just use nil format_string
+    main.copy_with_context("missing", false)
+
+    -- Should not call build_url because format_string is nil
+    assert.stub(url_builder.build_url).was_not_called()
+
+    -- Cleanup
+    config.options.mappings.missing = nil
+  end)
+
+  it("sets up key mappings for all defined mappings", function()
     main.setup()
 
+    -- Should set up normal mode mappings
     assert
       .stub(vim.keymap.set)
       .was_called_with("n", config.options.mappings.relative, match._, { silent = false })
     assert
       .stub(vim.keymap.set)
       .was_called_with("n", config.options.mappings.absolute, match._, { silent = false })
+
+    -- Should set up visual mode mappings
     assert
       .stub(vim.keymap.set)
       .was_called_with("x", config.options.mappings.relative, match._, { silent = true })
@@ -80,4 +157,20 @@ describe("Main Module", function()
       .stub(vim.keymap.set)
       .was_called_with("x", config.options.mappings.absolute, match._, { silent = true })
   end)
+
+  it("sets up key mappings for custom mappings", function()
+    -- Add custom mapping
+    config.options.mappings.custom = "<leader>cc"
+    config.options.formats.custom = "# {filepath}"
+
+    main.setup()
+
+    -- Should set up mappings for custom mapping too
+    assert.stub(vim.keymap.set).was_called_with("n", "<leader>cc", match._, { silent = false })
+    assert.stub(vim.keymap.set).was_called_with("x", "<leader>cc", match._, { silent = true })
+
+    -- Cleanup
+    config.options.mappings.custom = nil
+    config.options.formats.custom = nil
+  end)
 end)
diff --git a/tests/copy_with_context/providers/bitbucket_spec.lua b/tests/copy_with_context/providers/bitbucket_spec.lua
new file mode 100644
index 0000000..8ea3405
--- /dev/null
+++ b/tests/copy_with_context/providers/bitbucket_spec.lua
@@ -0,0 +1,78 @@
+-- Bitbucket provider tests
+
+-- Clear cached modules
+package.loaded["copy_with_context.providers.bitbucket"] = nil
+
+local bitbucket = require("copy_with_context.providers.bitbucket")
+
+describe("Bitbucket provider", function()
+  describe("matches", function()
+    it("matches bitbucket.org", function()
+      assert.is_true(bitbucket.matches("bitbucket.org"))
+    end)
+
+    it("matches Bitbucket Server domains", function()
+      assert.is_true(bitbucket.matches("code.bitbucket.org"))
+      assert.is_true(bitbucket.matches("enterprise.bitbucket.org"))
+    end)
+
+    it("does not match non-Bitbucket domains", function()
+      assert.is_false(bitbucket.matches("github.com"))
+      assert.is_false(bitbucket.matches("gitlab.com"))
+      assert.is_false(bitbucket.matches("example.com"))
+    end)
+  end)
+
+  describe("build_url", function()
+    local git_info = {
+      provider = "bitbucket.org",
+      owner = "user",
+      repo = "repo",
+      commit = "abc123def456",
+      file_path = "lua/file.lua",
+    }
+
+    it("builds URL for single line", function()
+      local url = bitbucket.build_url(git_info, 42, 42)
+      assert.equals("https://bitbucket.org/user/repo/src/abc123def456/lua/file.lua#lines-42", url)
+    end)
+
+    it("builds URL for multiple lines", function()
+      local url = bitbucket.build_url(git_info, 10, 20)
+      assert.equals(
+        "https://bitbucket.org/user/repo/src/abc123def456/lua/file.lua#lines-10:20",
+        url
+      )
+    end)
+
+    it("builds URL for Bitbucket Enterprise", function()
+      local enterprise_info = {
+        provider = "bitbucket.example.com",
+        owner = "team",
+        repo = "project",
+        commit = "xyz789",
+        file_path = "src/main.rb",
+      }
+      local url = bitbucket.build_url(enterprise_info, 5, 5)
+      assert.equals(
+        "https://bitbucket.example.com/team/project/src/xyz789/src/main.rb#lines-5",
+        url
+      )
+    end)
+
+    it("builds URL for Bitbucket with nested project keys", function()
+      local nested_info = {
+        provider = "bitbucket.org",
+        owner = "company/engineering",
+        repo = "api",
+        commit = "abc123",
+        file_path = "handlers/auth.go",
+      }
+      local url = bitbucket.build_url(nested_info, 100, 120)
+      assert.equals(
+        "https://bitbucket.org/company/engineering/api/src/abc123/handlers/auth.go#lines-100:120",
+        url
+      )
+    end)
+  end)
+end)
diff --git a/tests/copy_with_context/providers/github_spec.lua b/tests/copy_with_context/providers/github_spec.lua
new file mode 100644
index 0000000..c4c37a4
--- /dev/null
+++ b/tests/copy_with_context/providers/github_spec.lua
@@ -0,0 +1,72 @@
+-- GitHub provider tests
+
+-- Clear cached modules
+package.loaded["copy_with_context.providers.github"] = nil
+
+local github = require("copy_with_context.providers.github")
+
+describe("GitHub provider", function()
+  describe("matches", function()
+    it("matches github.com", function()
+      assert.is_true(github.matches("github.com"))
+    end)
+
+    it("matches GitHub Enterprise domains", function()
+      assert.is_true(github.matches("github.example.com"))
+      assert.is_true(github.matches("code.github.com"))
+    end)
+
+    it("does not match non-GitHub domains", function()
+      assert.is_false(github.matches("gitlab.com"))
+      assert.is_false(github.matches("bitbucket.org"))
+      assert.is_false(github.matches("example.com"))
+    end)
+  end)
+
+  describe("build_url", function()
+    local git_info = {
+      provider = "github.com",
+      owner = "user",
+      repo = "repo",
+      commit = "abc123def456",
+      file_path = "lua/file.lua",
+    }
+
+    it("builds URL for single line", function()
+      local url = github.build_url(git_info, 42, 42)
+      assert.equals("https://github.com/user/repo/blob/abc123def456/lua/file.lua#L42", url)
+    end)
+
+    it("builds URL for multiple lines", function()
+      local url = github.build_url(git_info, 10, 20)
+      assert.equals("https://github.com/user/repo/blob/abc123def456/lua/file.lua#L10-L20", url)
+    end)
+
+    it("builds URL for GitHub Enterprise", function()
+      local enterprise_info = {
+        provider = "github.example.com",
+        owner = "user",
+        repo = "repo",
+        commit = "abc123",
+        file_path = "src/main.js",
+      }
+      local url = github.build_url(enterprise_info, 5, 5)
+      assert.equals("https://github.example.com/user/repo/blob/abc123/src/main.js#L5", url)
+    end)
+
+    it("builds URL for GitHub with nested paths (org structure)", function()
+      local nested_info = {
+        provider = "github.com",
+        owner = "myorg/team",
+        repo = "project",
+        commit = "def456abc",
+        file_path = "packages/core/index.ts",
+      }
+      local url = github.build_url(nested_info, 15, 25)
+      assert.equals(
+        "https://github.com/myorg/team/project/blob/def456abc/packages/core/index.ts#L15-L25",
+        url
+      )
+    end)
+  end)
+end)
diff --git a/tests/copy_with_context/providers/gitlab_spec.lua b/tests/copy_with_context/providers/gitlab_spec.lua
new file mode 100644
index 0000000..71d5b76
--- /dev/null
+++ b/tests/copy_with_context/providers/gitlab_spec.lua
@@ -0,0 +1,81 @@
+-- GitLab provider tests
+
+-- Clear cached modules
+package.loaded["copy_with_context.providers.gitlab"] = nil
+
+local gitlab = require("copy_with_context.providers.gitlab")
+
+describe("GitLab provider", function()
+  describe("matches", function()
+    it("matches gitlab.com", function()
+      assert.is_true(gitlab.matches("gitlab.com"))
+    end)
+
+    it("matches self-hosted GitLab domains", function()
+      assert.is_true(gitlab.matches("gitlab.example.com"))
+      assert.is_true(gitlab.matches("mygitlab.company.com"))
+    end)
+  end)
+
+  describe("build_url", function()
+    local git_info = {
+      provider = "gitlab.com",
+      owner = "user",
+      repo = "repo",
+      commit = "abc123def456",
+      file_path = "lua/file.lua",
+    }
+
+    it("builds URL for single line", function()
+      local url = gitlab.build_url(git_info, 42, 42)
+      assert.equals("https://gitlab.com/user/repo/-/blob/abc123def456/lua/file.lua#L42", url)
+    end)
+
+    it("builds URL for multiple lines", function()
+      local url = gitlab.build_url(git_info, 10, 20)
+      assert.equals("https://gitlab.com/user/repo/-/blob/abc123def456/lua/file.lua#L10-20", url)
+    end)
+
+    it("builds URL for self-hosted GitLab", function()
+      local selfhosted_info = {
+        provider = "gitlab.example.com",
+        owner = "team",
+        repo = "project",
+        commit = "xyz789",
+        file_path = "src/main.py",
+      }
+      local url = gitlab.build_url(selfhosted_info, 5, 5)
+      assert.equals("https://gitlab.example.com/team/project/-/blob/xyz789/src/main.py#L5", url)
+    end)
+
+    it("builds URL for nested groups (GitLab)", function()
+      local nested_info = {
+        provider = "gitlab.example.com",
+        owner = "frontend/web",
+        repo = "dashboard",
+        commit = "abc123def456",
+        file_path = "src/components/App.tsx",
+      }
+      local url = gitlab.build_url(nested_info, 42, 42)
+      assert.equals(
+        "https://gitlab.example.com/frontend/web/dashboard/-/blob/abc123def456/src/components/App.tsx#L42",
+        url
+      )
+    end)
+
+    it("builds URL for deeply nested groups", function()
+      local deeply_nested_info = {
+        provider = "gitlab.company.com",
+        owner = "org/team/subteam",
+        repo = "service",
+        commit = "xyz789abc",
+        file_path = "lib/utils.js",
+      }
+      local url = gitlab.build_url(deeply_nested_info, 10, 20)
+      assert.equals(
+        "https://gitlab.company.com/org/team/subteam/service/-/blob/xyz789abc/lib/utils.js#L10-20",
+        url
+      )
+    end)
+  end)
+end)
diff --git a/tests/copy_with_context/providers/init_spec.lua b/tests/copy_with_context/providers/init_spec.lua
new file mode 100644
index 0000000..278d839
--- /dev/null
+++ b/tests/copy_with_context/providers/init_spec.lua
@@ -0,0 +1,80 @@
+-- Provider detection and factory tests
+
+-- Clear cached modules
+package.loaded["copy_with_context.providers.init"] = nil
+package.loaded["copy_with_context.providers.github"] = nil
+package.loaded["copy_with_context.providers.gitlab"] = nil
+package.loaded["copy_with_context.providers.bitbucket"] = nil
+
+local providers = require("copy_with_context.providers")
+
+describe("Provider detection and factory", function()
+  describe("detect_provider", function()
+    it("detects GitHub provider", function()
+      local provider = providers.detect_provider("github.com")
+      assert.is_not_nil(provider)
+      assert.equals("github", provider.name)
+    end)
+
+    it("detects GitHub Enterprise provider", function()
+      local provider = providers.detect_provider("github.example.com")
+      assert.is_not_nil(provider)
+      assert.equals("github", provider.name)
+    end)
+
+    it("detects GitLab provider", function()
+      local provider = providers.detect_provider("gitlab.com")
+      assert.is_not_nil(provider)
+      assert.equals("gitlab", provider.name)
+    end)
+
+    it("detects Bitbucket provider", function()
+      local provider = providers.detect_provider("bitbucket.org")
+      assert.is_not_nil(provider)
+      assert.equals("bitbucket", provider.name)
+    end)
+
+    it("returns nil for unknown domains", function()
+      local provider = providers.detect_provider("unknown.example.com")
+      assert.is_nil(provider)
+    end)
+
+    it("returns nil for nil domain", function()
+      local provider = providers.detect_provider(nil)
+      assert.is_nil(provider)
+    end)
+  end)
+
+  describe("get_provider", function()
+    it("returns provider from git info", function()
+      local git_info = {
+        provider = "github.com",
+        owner = "user",
+        repo = "repo",
+        commit = "abc123",
+        file_path = "lua/file.lua",
+      }
+
+      local provider = providers.get_provider(git_info)
+      assert.is_not_nil(provider)
+      assert.equals("github", provider.name)
+    end)
+
+    it("returns nil for nil git info", function()
+      local provider = providers.get_provider(nil)
+      assert.is_nil(provider)
+    end)
+
+    it("returns nil for git info without provider", function()
+      local git_info = {
+        owner = "user",
+        repo = "repo",
+        commit = "abc123",
+        file_path = "lua/file.lua",
+      }
+
+      local provider = providers.get_provider(git_info)
+      assert.is_nil(provider)
+    end)
+  end)
+end)
diff --git a/tests/copy_with_context/url_builder_spec.lua b/tests/copy_with_context/url_builder_spec.lua
new file mode 100644
index 0000000..0ad4bcb
--- /dev/null
+++ b/tests/copy_with_context/url_builder_spec.lua
@@ -0,0 +1,184 @@
+local url_builder = require("copy_with_context.url_builder")
+
+describe("URL Builder", function()
+  before_each(function()
+    -- Clear module cache
+    package.loaded["copy_with_context.git"] = nil
+    package.loaded["copy_with_context.providers"] = nil
+  end)
+
+  describe("build_url", function()
+    it("returns URL when git info and provider are available", function()
+      local git_mock = {
+        get_git_info = function(_file_path)
+          return {
+            provider = "github.com",
+            owner = "user",
+            repo = "repo",
+            commit = "abc123",
+            file_path = "lua/test.lua",
+          }
+        end,
+      }
+      package.loaded["copy_with_context.git"] = git_mock
+
+      local provider_mock = {
+        build_url = function(_git_info, _start, _end)
+          return "https://github.com/user/repo/blob/abc123/lua/test.lua#L10-L20"
+        end,
+      }
+      local providers_mock = {
+        get_provider = function(_git_info)
+          return provider_mock
+        end,
+      }
+      package.loaded["copy_with_context.providers"] = providers_mock
+
+      local url = url_builder.build_url("lua/test.lua", 10, 20)
+      assert.equals("https://github.com/user/repo/blob/abc123/lua/test.lua#L10-L20", url)
+    end)
+
+    it("returns nil when git info is not available", function()
+      local git_mock = {
+        get_git_info = function(_file_path)
+          return nil
+        end,
+      }
+      package.loaded["copy_with_context.git"] = git_mock
+
+      local url = url_builder.build_url("lua/test.lua", 10, 20)
+      assert.is_nil(url)
+    end)
+
+    it("returns nil when provider is not available", function()
+      local git_mock = {
+        get_git_info = function(_file_path)
+          return {
+            provider = "unknown.com",
+            owner = "user",
+            repo = "repo",
+            commit = "abc123",
+            file_path = "lua/test.lua",
+          }
+        end,
+      }
+      package.loaded["copy_with_context.git"] = git_mock
+
+      local providers_mock = {
+        get_provider = function(_git_info)
+          return nil -- Unknown provider
+        end,
+      }
+      package.loaded["copy_with_context.providers"] = providers_mock
+
+      local url = url_builder.build_url("lua/test.lua", 10, 20)
+      assert.is_nil(url)
+    end)
+
+    it("returns nil when provider build_url returns nil", function()
+      local git_mock = {
+        get_git_info = function(_file_path)
+          return {
+            provider = "github.com",
+            owner = "user",
+            repo = "repo",
+            commit = "abc123",
+            file_path = "lua/test.lua",
+          }
+        end,
+      }
+      package.loaded["copy_with_context.git"] = git_mock
+
+      local provider_mock = {
+        build_url = function(_git_info, _start, _end)
+          return nil -- Provider failed to build URL
+        end,
+      }
+      local providers_mock = {
+        get_provider = function(_git_info)
+          return provider_mock
+        end,
+      }
+      package.loaded["copy_with_context.providers"] = providers_mock
+
+      local url = url_builder.build_url("lua/test.lua", 10, 20)
+      assert.is_nil(url)
+    end)
+
+    it("handles single line numbers", function()
+      local git_mock = {
+        get_git_info = function(_file_path)
+          return {
+            provider = "github.com",
+            owner = "user",
+            repo = "repo",
+            commit = "abc123",
+            file_path = "lua/test.lua",
+          }
+        end,
+      }
+      package.loaded["copy_with_context.git"] = git_mock
+
+      local captured_start, captured_end
+      local provider_mock = {
+        build_url = function(_git_info, start, end_line)
+          captured_start = start
+          captured_end = end_line
+          return "https://github.com/user/repo/blob/abc123/lua/test.lua#L42"
+        end,
+      }
+      local providers_mock = {
+        get_provider = function(_git_info)
+          return provider_mock
+        end,
+      }
+      package.loaded["copy_with_context.providers"] = providers_mock
+
+      local url = url_builder.build_url("lua/test.lua", 42, 42)
+      assert.equals(42, captured_start)
+      assert.equals(42, captured_end)
+      assert.equals("https://github.com/user/repo/blob/abc123/lua/test.lua#L42", url)
+    end)
+
+    it("passes correct parameters to provider", function()
+      local git_mock = {
+        get_git_info = function(_file_path)
+          return {
+            provider = "gitlab.com",
+            owner = "user",
+            repo = "repo",
+            commit = "def456",
+            file_path = "src/main.lua",
+          }
+        end,
+      }
+      package.loaded["copy_with_context.git"] = git_mock
+
+      local captured_git_info, captured_start, captured_end
+      local provider_mock = {
+        build_url = function(git_info, start, end_line)
+          captured_git_info = git_info
+          captured_start = start
+          captured_end = end_line
+          return "https://gitlab.com/user/repo/-/blob/def456/src/main.lua#L5-10"
+        end,
+      }
+      local providers_mock = {
+        get_provider = function(_git_info)
+          return provider_mock
+        end,
+      }
+      package.loaded["copy_with_context.providers"] = providers_mock
+
+      url_builder.build_url("src/main.lua", 5, 10)
+
+      assert.equals("gitlab.com", captured_git_info.provider)
+      assert.equals("user", captured_git_info.owner)
+      assert.equals("repo", captured_git_info.repo)
+      assert.equals("def456", captured_git_info.commit)
+      assert.equals("src/main.lua", captured_git_info.file_path)
+      assert.equals(5, captured_start)
+      assert.equals(10, captured_end)
+    end)
+  end)
+end)
diff --git a/tests/copy_with_context/user_config_validation_spec.lua b/tests/copy_with_context/user_config_validation_spec.lua
new file mode 100644
index 0000000..bede0c8
--- /dev/null
+++ b/tests/copy_with_context/user_config_validation_spec.lua
@@ -0,0 +1,198 @@
+local validation = require("copy_with_context.user_config_validation")
+
+describe("User Config Validation", function()
+  describe("validate", function()
+    it("accepts nil config", function()
+      local valid, err = validation.validate(nil)
+      assert.is_true(valid)
+      assert.is_nil(err)
+    end)
+
+    it("accepts empty config", function()
+      local valid, err = validation.validate({})
+      assert.is_true(valid)
+      assert.is_nil(err)
+    end)
+
+    it("accepts valid config with default mapping", function()
+      local config = {
+        mappings = {
+          relative = "<leader>cy",
+          absolute = "<leader>cY",
+        },
+        formats = {
+          default = "# {filepath}:{line}",
+        },
+      }
+
+      local valid, err = validation.validate(config)
+      assert.is_true(valid)
+      assert.is_nil(err)
+    end)
+
+    it("accepts valid config with custom mappings", function()
+      local config = {
+        mappings = {
+          relative = "<leader>cy",
+          custom = "<leader>cc",
+        },
+        formats = {
+          default = "# {filepath}:{line}",
+          custom = "# {remote_url}",
+        },
+      }
+
+      local valid, err = validation.validate(config)
+      assert.is_true(valid)
+      assert.is_nil(err)
+    end)
+
+    it("rejects mapping without matching format", function()
+      local config = {
+        mappings = {
+          custom = "<leader>cc",
+        },
+        formats = {
+          default = "# {filepath}:{line}",
+          -- missing 'custom' format
+        },
+      }
+
+      local valid, err = validation.validate(config)
+      assert.is_false(valid)
+      assert.is_not_nil(err)
+      assert.matches("custom", err)
+    end)
+
+    it("rejects format without matching mapping", function()
+      local config = {
+        mappings = {
+          relative = "<leader>cy",
+        },
+        formats = {
+          default = "# {filepath}:{line}",
+          orphan = "# {filepath}",
+        },
+      }
+
+      local valid, err = validation.validate(config)
+      assert.is_false(valid)
+      assert.is_not_nil(err)
+      assert.matches("orphan", err)
+    end)
+
+    it("requires default format for relative mapping", function()
+      local config = {
+        mappings = {
+          relative = "<leader>cy",
+        },
+        formats = {
+          -- missing default format
+        },
+      }
+
+      local valid, err = validation.validate(config)
+      assert.is_false(valid)
+      assert.is_not_nil(err)
+      assert.matches("relative", err)
+      assert.matches("default", err)
+    end)
+
+    it("requires default format for absolute mapping", function()
+      local config = {
+        mappings = {
+          absolute = "<leader>cY",
+        },
+        formats = {
+          -- missing default format
+        },
+      }
+
+      local valid, err = validation.validate(config)
+      assert.is_false(valid)
+      assert.is_not_nil(err)
+      assert.matches("absolute", err)
+      assert.matches("default", err)
+    end)
+
+    it("allows default format without explicit mapping", function()
+      local config = {
+        mappings = {
+          relative = "<leader>cy",
+        },
+        formats = {
+          default = "# {filepath}:{line}",
+        },
+      }
+
+      local valid, err = validation.validate(config)
+      assert.is_true(valid)
+      assert.is_nil(err)
+    end)
+  end)
+
+  describe("validate_format_string", function()
+    it("accepts valid format with filepath", function()
+      local valid, err = validation.validate_format_string("# {filepath}")
+      assert.is_true(valid)
+      assert.is_nil(err)
+    end)
+
+    it("accepts valid format with line", function()
+      local valid, err = validation.validate_format_string("# {line}")
+      assert.is_true(valid)
+      assert.is_nil(err)
+    end)
+
+    it("accepts valid format with linenumber", function()
+      local valid, err = validation.validate_format_string("# {linenumber}")
+      assert.is_true(valid)
+      assert.is_nil(err)
+    end)
+
+    it("accepts valid format with remote_url", function()
+      local valid, err = validation.validate_format_string("# {remote_url}")
+      assert.is_true(valid)
+      assert.is_nil(err)
+    end)
+
+    it("accepts valid format with multiple variables", function()
+      local valid, err = validation.validate_format_string("# {filepath}:{line} - {remote_url}")
+      assert.is_true(valid)
+      assert.is_nil(err)
+    end)
+
+    it("accepts format with no variables", function()
+      local valid, err = validation.validate_format_string("# No variables here")
+      assert.is_true(valid)
+      assert.is_nil(err)
+    end)
+
+    it("rejects nil format string", function()
+      local valid, err = validation.validate_format_string(nil)
+      assert.is_false(valid)
+      assert.is_not_nil(err)
+    end)
+
+    it("rejects unknown variable", function()
+      local valid, err = validation.validate_format_string("# {invalid_var}")
+      assert.is_false(valid)
+      assert.is_not_nil(err)
+      assert.matches("invalid_var", err)
+    end)
+
+    it("rejects format with multiple unknown variables", function()
+      local valid, err = validation.validate_format_string("# {filepath} {unknown1} {unknown2}")
+      assert.is_false(valid)
+      assert.is_not_nil(err)
+      -- Should error on first unknown variable
+      assert.matches("unknown", err)
+    end)
+
+    it("accepts repeated valid variables", function()
+      local valid, err = validation.validate_format_string("# {filepath} - {filepath}")
+      assert.is_true(valid)
+      assert.is_nil(err)
+    end)
+  end)
+end)
diff --git a/tests/copy_with_context/utils_spec.lua b/tests/copy_with_context/utils_spec.lua
index 06b089b..384cbfe 100644
--- a/tests/copy_with_context/utils_spec.lua
+++ b/tests/copy_with_context/utils_spec.lua
@@ -91,18 +91,6 @@ describe("Utility Functions", function()
     end)
   end)
 
-  describe("format_line_range", function()
-    it("returns a single line number when start and end are the same", function()
-      local result = utils.format_line_range(5, 5)
-      assert.equals("5", result)
-    end)
-
-    it("returns a range when start and end are different", function()
-      local result = utils.format_line_range(2, 6)
-      assert.equals("2-6", result)
-    end)
-  end)
-
   describe("process_lines", function()
     local config_mock = {
       options = { trim_lines = false },
@@ -136,21 +124,4 @@ describe("Utility Functions", function()
       assert.equals("copied text", setreg_calls["+"])
     end)
   end)
-
-  describe("format_output", function()
-    local config_mock = {
-      options = {
-        context_format = "-- %s (lines: %s)",
-      },
-    }
-
-    before_each(function()
-      package.loaded["copy_with_context.config"] = config_mock
-    end)
-
-    it("formats output correctly", function()
-      local result = utils.format_output("content here", "file.lua", "5-10")
-      assert.equals("content here\n-- file.lua (lines: 5-10)", result)
-    end)
-  end)
 end)