Merge branch 'main' into inspector/error-popup

Author: cliffhall

.github/ISSUE_TEMPLATE/bug_report.md

@@ -34,3 +34,7 @@ If applicable, add screenshots to help explain your problem.
 
 **Additional context**
 Add any other context about the problem here.
+
+**Version Consideration**
+
+Inspector V2 is under development to address architectural and UX improvements. During this time, V1 contributions should focus on **bug fixes and MCP spec compliance**. See [CONTRIBUTING.md](../../CONTRIBUTING.md) for more details.

.github/pull_request_template.md

@@ -0,0 +1,57 @@
+## Summary
+
+<!-- Provide a brief description of what this PR does -->
+
+> **Note:** Inspector V2 is under development to address architectural and UX improvements. During this time, V1 contributions should focus on **bug fixes and MCP spec compliance**. See [CONTRIBUTING.md](../CONTRIBUTING.md) for more details.
+
+## Type of Change
+
+<!-- Mark the relevant option with an "x" -->
+
+- [ ] Bug fix (non-breaking change that fixes an issue)
+- [ ] New feature (non-breaking change that adds functionality)
+- [ ] Documentation update
+- [ ] Refactoring (no functional changes)
+- [ ] Test updates
+- [ ] Build/CI improvements
+
+## Changes Made
+
+<!-- Describe the changes in detail. Include screenshots/recordings if applicable -->
+
+## Related Issues
+
+<!-- Link to related issues using #issue_number or "Fixes #issue_number" -->
+
+## Testing
+
+<!-- Describe how you tested these changes, where applicable -->
+
+- [ ] Tested in UI mode
+- [ ] Tested in CLI mode
+- [ ] Tested with STDIO transport
+- [ ] Tested with SSE transport
+- [ ] Tested with Streamable HTTP transport
+- [ ] Added/updated automated tests
+- [ ] Manual testing performed
+
+### Test Results and/or Instructions
+
+<!-- Provide steps for reviewers to test your changes -->
+
+Screenshots are encouraged to share your testing results for this change.
+
+## Checklist
+
+- [ ] Code follows the style guidelines (ran `npm run prettier-fix`)
+- [ ] Self-review completed
+- [ ] Code is commented where necessary
+- [ ] Documentation updated (README, comments, etc.)
+
+## Breaking Changes
+
+<!-- If this is a breaking change, describe the impact and migration path -->
+
+## Additional Context
+
+<!-- Add any other context, screenshots, or information about the PR here -->

.github/workflows/claude.yml

@@ -27,14 +27,48 @@ jobs:
       id-token: write
       actions: read
     steps:
+      - name: Get PR details
+        if: |
+          (github.event_name == 'issue_comment' && github.event.issue.pull_request) ||
+          github.event_name == 'pull_request_review_comment' ||
+          github.event_name == 'pull_request_review'
+        id: pr
+        uses: actions/github-script@v7
+        with:
+          script: |
+            let prNumber;
+            if (context.eventName === 'issue_comment') {
+              prNumber = context.issue.number;
+            } else {
+              prNumber = context.payload.pull_request.number;
+            }
+
+            const pr = await github.rest.pulls.get({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: prNumber
+            });
+
+            core.setOutput('sha', pr.data.head.sha);
+            core.setOutput('repo', pr.data.head.repo.full_name);
+
+      - name: Checkout PR branch
+        if: steps.pr.outcome == 'success'
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ steps.pr.outputs.sha }}
+          repository: ${{ steps.pr.outputs.repo }}
+          fetch-depth: 0
+
       - name: Checkout repository
+        if: steps.pr.outcome != 'success'
         uses: actions/checkout@v4
         with:
-          fetch-depth: 1
+          fetch-depth: 0
 
       - name: Run Claude Code
         id: claude
-        uses: anthropics/claude-code-action@beta
+        uses: anthropics/claude-code-action@v1
         with:
           anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
 
@@ -45,9 +79,6 @@ jobs:
           # Trigger when assigned to an issue
           assignee_trigger: "claude"
 
-          # Allow Claude to run bash
-          # This should be safe given the repo is already public
-          allowed_tools: "Bash"
-
-          custom_instructions: |
-            If posting a comment to GitHub, give a concise summary of the comment at the top and put all the details in a <details> block.
+          claude_args: |
+            --allowedTools Bash
+            --system-prompt "If posting a comment to GitHub, give a concise summary of the comment at the top and put all the details in a <details> block."

.github/workflows/e2e_tests.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   test:
-    # Installing Playright dependencies can take quite awhile, and also depends on GitHub CI load.
+    # Installing Playwright dependencies can take quite awhile, and also depends on GitHub CI load.
     timeout-minutes: 15
     runs-on: ubuntu-latest
 

.gitignore

@@ -10,6 +10,7 @@ client/tsconfig.node.tsbuildinfo
 cli/build
 test-output
 tool-test-output
+metadata-test-output
 # symlinked by `npm run link:sdk`:
 sdk
 client/playwright-report/

AGENTS.md

@@ -1,5 +1,7 @@
 # MCP Inspector Development Guide
 
+> **Note:** Inspector V2 is under development to address architectural and UX improvements. During this time, V1 contributions should focus on **bug fixes and MCP spec compliance**. See [CONTRIBUTING.md](CONTRIBUTING.md) for more details.
+
 ## Build Commands
 
 - Build all: `npm run build`

CONTRIBUTING.md

@@ -9,6 +9,16 @@ Thanks for your interest in contributing! This guide explains how to get involve
 3. Run `npm run dev` to start both client and server in development mode
 4. Use the web UI at http://localhost:6274 to interact with the inspector
 
+## Inspector V2 Development
+
+We're actively developing **Inspector V2** to address architectural and UX improvements. We invite you to follow progress and participate in the Inspector V2 Working Group in [Discord](https://modelcontextprotocol.io/community/communication), [weekly meetings](https://meet.modelcontextprotocol.io/tag/inspector-v2-wg), and [GitHub Discussions](https://github.com/modelcontextprotocol/modelcontextprotocol/discussions/categories/meeting-notes-other) (where notes are posted after meetings).
+
+**Current version (V1) contribution scope:**
+
+- Bug fixes and MCP spec compliance are actively maintained
+- Documentation updates are always appreciated
+- Major changes will be directed to V2 development
+
 ## Development Process & Pull Requests
 
 1. Create a new branch for your changes
@@ -30,7 +40,7 @@ If you find a security vulnerability, please refer to our [Security Policy](SECU
 
 ## Questions?
 
-Feel free to [open an issue](https://github.com/modelcontextprotocol/mcp-inspector/issues) for questions or create a discussion for general topics.
+Feel free to [open an issue](https://github.com/modelcontextprotocol/inspector/issues) for questions or join the MCP Contributor [Discord server](https://modelcontextprotocol.io/community/communication). Also, please see notes above on Inspector V2 Development.
 
 ## License
 

README.md

@@ -34,7 +34,12 @@ The server will start up and the UI will be accessible at `http://localhost:6274
 You can also start it in a Docker container with the following command:
 
 ```bash
-docker run --rm --network host -p 6274:6274 -p 6277:6277 ghcr.io/modelcontextprotocol/inspector:latest
+docker run --rm \
+  -p 127.0.0.1:6274:6274 \
+  -p 127.0.0.1:6277:6277 \
+  -e HOST=0.0.0.0 \
+  -e MCP_AUTO_OPEN_ENABLED=false \
+  ghcr.io/modelcontextprotocol/inspector:latest
 ```
 
 ### From an MCP server repository
@@ -236,13 +241,15 @@ ALLOWED_ORIGINS=http://localhost:6274,http://localhost:8000 npm start
 
 The MCP Inspector supports the following configuration settings. To change them, click on the `Configuration` button in the MCP Inspector UI:
 
-| Setting                                 | Description                                                                                                                                       | Default |
-| --------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------- | ------- |
-| `MCP_SERVER_REQUEST_TIMEOUT`            | Timeout for requests to the MCP server (ms)                                                                                                       | 10000   |
-| `MCP_REQUEST_TIMEOUT_RESET_ON_PROGRESS` | Reset timeout on progress notifications                                                                                                           | true    |
-| `MCP_REQUEST_MAX_TOTAL_TIMEOUT`         | Maximum total timeout for requests sent to the MCP server (ms) (Use with progress notifications)                                                  | 60000   |
-| `MCP_PROXY_FULL_ADDRESS`                | Set this if you are running the MCP Inspector Proxy on a non-default address. Example: http://10.1.1.22:5577                                      | ""      |
-| `MCP_AUTO_OPEN_ENABLED`                 | Enable automatic browser opening when inspector starts (works with authentication enabled). Only as environment var, not configurable in browser. | true    |
+| Setting                                 | Description                                                                                                                                         | Default |
+| --------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------- | ------- |
+| `MCP_SERVER_REQUEST_TIMEOUT`            | Client-side timeout (ms) - Inspector will cancel the request if no response is received within this time. Note: servers may have their own timeouts | 300000  |
+| `MCP_REQUEST_TIMEOUT_RESET_ON_PROGRESS` | Reset timeout on progress notifications                                                                                                             | true    |
+| `MCP_REQUEST_MAX_TOTAL_TIMEOUT`         | Maximum total timeout for requests sent to the MCP server (ms) (Use with progress notifications)                                                    | 60000   |
+| `MCP_PROXY_FULL_ADDRESS`                | Set this if you are running the MCP Inspector Proxy on a non-default address. Example: http://10.1.1.22:5577                                        | ""      |
+| `MCP_AUTO_OPEN_ENABLED`                 | Enable automatic browser opening when inspector starts (works with authentication enabled). Only as environment var, not configurable in browser.   | true    |
+
+**Note on Timeouts:** The timeout settings above control when the Inspector (as an MCP client) will cancel requests. These are independent of any server-side timeouts. For example, if a server tool has a 10-minute timeout but the Inspector's timeout is set to 30 seconds, the Inspector will cancel the request after 30 seconds. Conversely, if the Inspector's timeout is 10 minutes but the server times out after 30 seconds, you'll receive the server's timeout error. For tools that require user interaction (like elicitation) or long-running operations, ensure the Inspector's timeout is set appropriately.
 
 These settings can be adjusted in real-time through the UI and will persist across sessions.
 
@@ -361,7 +368,7 @@ http://localhost:6274/?transport=stdio&serverCommand=npx&serverArgs=arg1%20arg2
 You can also set initial config settings via query params, for example:
 
 ```
-http://localhost:6274/?MCP_SERVER_REQUEST_TIMEOUT=10000&MCP_REQUEST_TIMEOUT_RESET_ON_PROGRESS=false&MCP_PROXY_FULL_ADDRESS=http://10.1.1.22:5577
+http://localhost:6274/?MCP_SERVER_REQUEST_TIMEOUT=60000&MCP_REQUEST_TIMEOUT_RESET_ON_PROGRESS=false&MCP_PROXY_FULL_ADDRESS=http://10.1.1.22:5577
 ```
 
 Note that if both the query param and the corresponding localStorage item are set, the query param will take precedence.
@@ -456,6 +463,17 @@ npx @modelcontextprotocol/inspector --cli https://my-mcp-server.example.com --me
 | **Automation**           | N/A                                                                       | Ideal for CI/CD pipelines, batch processing, and integration with coding assistants                                                                  |
 | **Learning MCP**         | Rich visual interface helps new users understand server capabilities      | Simplified commands for focused learning of specific endpoints                                                                                       |
 
+## Tool Input Validation Guidelines
+
+When implementing or modifying tool input parameter handling in the Inspector:
+
+- **Omit optional fields with empty values** - When processing form inputs, omit empty strings or null values for optional parameters, UNLESS the field has an explicit default value in the schema that matches the current value
+- **Preserve explicit default values** - If a field schema contains an explicit default (e.g., `default: null`), and the current value matches that default, include it in the request. This is a meaningful value the tool expects
+- **Always include required fields** - Preserve required field values even when empty, allowing the MCP server to validate and return appropriate error messages
+- **Defer deep validation to the server** - Implement basic field presence checking in the Inspector client, but rely on the MCP server for parameter validation according to its schema
+
+These guidelines maintain clean parameter passing and proper separation of concerns between the Inspector client and MCP servers.
+
 ## License
 
 This project is licensed under the MIT License—see the [LICENSE](LICENSE) file for details.

cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@modelcontextprotocol/inspector-cli",
-  "version": "0.17.1",
+  "version": "0.18.0",
   "description": "CLI for the Model Context Protocol inspector",
   "license": "MIT",
   "author": "Anthropic, PBC (https://anthropic.com)",
@@ -24,7 +24,7 @@
   },
   "devDependencies": {},
   "dependencies": {
-    "@modelcontextprotocol/sdk": "^1.18.0",
+    "@modelcontextprotocol/sdk": "^1.25.2",
     "commander": "^13.1.0",
     "spawn-rx": "^5.1.2"
   }