Add RALPH-loop recipes to Copilot SDK cookbook

cookbook/copilot-sdk/README.md

@@ -6,6 +6,7 @@ This cookbook collects small, focused recipes showing how to accomplish common t
 
 ### .NET (C#)
 
+- [Ralph Loop](dotnet/ralph-loop.md): Build autonomous AI coding loops with fresh context per iteration, planning/building modes, and backpressure.
 - [Error Handling](dotnet/error-handling.md): Handle errors gracefully including connection failures, timeouts, and cleanup.
 - [Multiple Sessions](dotnet/multiple-sessions.md): Manage multiple independent conversations simultaneously.
 - [Managing Local Files](dotnet/managing-local-files.md): Organize files by metadata using AI-powered grouping strategies.
@@ -14,6 +15,7 @@ This cookbook collects small, focused recipes showing how to accomplish common t
 
 ### Node.js / TypeScript
 
+- [Ralph Loop](nodejs/ralph-loop.md): Build autonomous AI coding loops with fresh context per iteration, planning/building modes, and backpressure.
 - [Error Handling](nodejs/error-handling.md): Handle errors gracefully including connection failures, timeouts, and cleanup.
 - [Multiple Sessions](nodejs/multiple-sessions.md): Manage multiple independent conversations simultaneously.
 - [Managing Local Files](nodejs/managing-local-files.md): Organize files by metadata using AI-powered grouping strategies.
@@ -22,6 +24,7 @@ This cookbook collects small, focused recipes showing how to accomplish common t
 
 ### Python
 
+- [Ralph Loop](python/ralph-loop.md): Build autonomous AI coding loops with fresh context per iteration, planning/building modes, and backpressure.
 - [Error Handling](python/error-handling.md): Handle errors gracefully including connection failures, timeouts, and cleanup.
 - [Multiple Sessions](python/multiple-sessions.md): Manage multiple independent conversations simultaneously.
 - [Managing Local Files](python/managing-local-files.md): Organize files by metadata using AI-powered grouping strategies.
@@ -30,6 +33,7 @@ This cookbook collects small, focused recipes showing how to accomplish common t
 
 ### Go
 
+- [Ralph Loop](go/ralph-loop.md): Build autonomous AI coding loops with fresh context per iteration, planning/building modes, and backpressure.
 - [Error Handling](go/error-handling.md): Handle errors gracefully including connection failures, timeouts, and cleanup.
 - [Multiple Sessions](go/multiple-sessions.md): Manage multiple independent conversations simultaneously.
 - [Managing Local Files](go/managing-local-files.md): Organize files by metadata using AI-powered grouping strategies.
@@ -83,4 +87,4 @@ go run <filename>.go
 
 ## Status
 
-Cookbook structure is complete with 4 recipes across all 4 supported languages. Each recipe includes both markdown documentation and runnable examples.
+Cookbook structure is complete with 6 recipes across all 4 supported languages. Each recipe includes both markdown documentation and runnable examples.

cookbook/copilot-sdk/dotnet/ralph-loop.md

@@ -0,0 +1,260 @@
+# Ralph Loop: Autonomous AI Task Loops
+
+Build autonomous coding loops where an AI agent picks tasks, implements them, validates against backpressure (tests, builds), commits, and repeats — each iteration in a fresh context window.
+
+> **Runnable example:** [recipe/ralph-loop.cs](recipe/ralph-loop.cs)
+>
+> ```bash
+> cd dotnet
+> dotnet run recipe/ralph-loop.cs
+> ```
+
+## What is a Ralph Loop?
+
+A [Ralph loop](https://ghuntley.com/ralph/) is an autonomous development workflow where an AI agent iterates through tasks in isolated context windows. The key insight: **state lives on disk, not in the model's context**. Each iteration starts fresh, reads the current state from files, does one task, writes results back to disk, and exits.
+
+```
+┌─────────────────────────────────────────────────┐
+│                   loop.sh                       │
+│  while true:                                    │
+│    ┌─────────────────────────────────────────┐  │
+│    │  Fresh session (isolated context)       │  │
+│    │                                         │  │
+│    │  1. Read PROMPT.md + AGENTS.md          │  │
+│    │  2. Study specs/* and code              │  │
+│    │  3. Pick next task from plan            │  │
+│    │  4. Implement + run tests               │  │
+│    │  5. Update plan, commit, exit           │  │
+│    └─────────────────────────────────────────┘  │
+│    ↻ next iteration (fresh context)             │
+└─────────────────────────────────────────────────┘
+```
+
+**Core principles:**
+
+- **Fresh context per iteration**: Each loop creates a new session — no context accumulation, always in the "smart zone"
+- **Disk as shared state**: `IMPLEMENTATION_PLAN.md` persists between iterations and acts as the coordination mechanism
+- **Backpressure steers quality**: Tests, builds, and lints reject bad work — the agent must fix issues before committing
+- **Two modes**: PLANNING (gap analysis → generate plan) and BUILDING (implement from plan)
+
+## Simple Version
+
+The minimal Ralph loop — the SDK equivalent of `while :; do cat PROMPT.md | copilot ; done`:
+
+```csharp
+using GitHub.Copilot.SDK;
+
+var client = new CopilotClient();
+await client.StartAsync();
+
+try
+{
+    var prompt = await File.ReadAllTextAsync("PROMPT.md");
+    var maxIterations = 50;
+
+    for (var i = 1; i <= maxIterations; i++)
+    {
+        Console.WriteLine($"\n=== Iteration {i}/{maxIterations} ===");
+
+        // Fresh session each iteration — context isolation is the point
+        var session = await client.CreateSessionAsync(
+            new SessionConfig { Model = "gpt-5.1-codex-mini" });
+        try
+        {
+            var done = new TaskCompletionSource<string>();
+            session.On(evt =>
+            {
+                if (evt is AssistantMessageEvent msg)
+                    done.TrySetResult(msg.Data.Content);
+            });
+
+            await session.SendAsync(new MessageOptions { Prompt = prompt });
+            await done.Task;
+        }
+        finally
+        {
+            await session.DisposeAsync();
+        }
+
+        Console.WriteLine($"Iteration {i} complete.");
+    }
+}
+finally
+{
+    await client.StopAsync();
+}
+```
+
+This is all you need to get started. The prompt file tells the agent what to do; the agent reads project files, does work, commits, and exits. The loop restarts with a clean slate.
+
+## Ideal Version
+
+The full Ralph pattern with planning and building modes, matching the [Ralph Playbook](https://github.com/ClaytonFarr/ralph-playbook) architecture:
+
+```csharp
+using GitHub.Copilot.SDK;
+
+// Parse args: dotnet run [plan] [max_iterations]
+var mode = args.Contains("plan") ? "plan" : "build";
+var maxArg = args.FirstOrDefault(a => int.TryParse(a, out _));
+var maxIterations = maxArg != null ? int.Parse(maxArg) : 50;
+var promptFile = mode == "plan" ? "PROMPT_plan.md" : "PROMPT_build.md";
+
+var client = new CopilotClient();
+await client.StartAsync();
+
+Console.WriteLine(new string('━', 40));
+Console.WriteLine($"Mode:   {mode}");
+Console.WriteLine($"Prompt: {promptFile}");
+Console.WriteLine($"Max:    {maxIterations} iterations");
+Console.WriteLine(new string('━', 40));
+
+try
+{
+    var prompt = await File.ReadAllTextAsync(promptFile);
+
+    for (var i = 1; i <= maxIterations; i++)
+    {
+        Console.WriteLine($"\n=== Iteration {i}/{maxIterations} ===");
+
+        // Fresh session — each task gets full context budget
+        var session = await client.CreateSessionAsync(
+            new SessionConfig
+            {
+                Model = "gpt-5.1-codex-mini",
+                // Pin the agent to the project directory
+                WorkingDirectory = Environment.CurrentDirectory,
+                // Auto-approve tool calls for unattended operation
+                OnPermissionRequest = (_, _) => Task.FromResult(
+                    new PermissionRequestResult { Kind = "approved" }),
+            });
+        try
+        {
+            var done = new TaskCompletionSource<string>();
+            session.On(evt =>
+            {
+                // Log tool usage for visibility
+                if (evt is ToolExecutionStartEvent toolStart)
+                    Console.WriteLine($"  ⚙ {toolStart.Data.ToolName}");
+                else if (evt is AssistantMessageEvent msg)
+                    done.TrySetResult(msg.Data.Content);
+            });
+
+            await session.SendAsync(new MessageOptions { Prompt = prompt });
+            await done.Task;
+        }
+        finally
+        {
+            await session.DisposeAsync();
+        }
+
+        Console.WriteLine($"\nIteration {i} complete.");
+    }
+
+    Console.WriteLine($"\nReached max iterations: {maxIterations}");
+}
+finally
+{
+    await client.StopAsync();
+}
+```
+
+### Required Project Files
+
+The ideal version expects this file structure in your project:
+
+```
+project-root/
+├── PROMPT_plan.md              # Planning mode instructions
+├── PROMPT_build.md             # Building mode instructions
+├── AGENTS.md                   # Operational guide (build/test commands)
+├── IMPLEMENTATION_PLAN.md      # Task list (generated by planning mode)
+├── specs/                      # Requirement specs (one per topic)
+│   ├── auth.md
+│   └── data-pipeline.md
+└── src/                        # Your source code
+```
+
+### Example `PROMPT_plan.md`
+
+```markdown
+0a. Study `specs/*` to learn the application specifications.
+0b. Study IMPLEMENTATION_PLAN.md (if present) to understand the plan so far.
+0c. Study `src/` to understand existing code and shared utilities.
+
+1. Compare specs against code (gap analysis). Create or update
+   IMPLEMENTATION_PLAN.md as a prioritized bullet-point list of tasks
+   yet to be implemented. Do NOT implement anything.
+
+IMPORTANT: Do NOT assume functionality is missing — search the
+codebase first to confirm. Prefer updating existing utilities over
+creating ad-hoc copies.
+```
+
+### Example `PROMPT_build.md`
+
+```markdown
+0a. Study `specs/*` to learn the application specifications.
+0b. Study IMPLEMENTATION_PLAN.md.
+0c. Study `src/` for reference.
+
+1. Choose the most important item from IMPLEMENTATION_PLAN.md. Before
+   making changes, search the codebase (don't assume not implemented).
+2. After implementing, run the tests. If functionality is missing, add it.
+3. When you discover issues, update IMPLEMENTATION_PLAN.md immediately.
+4. When tests pass, update IMPLEMENTATION_PLAN.md, then `git add -A`
+   then `git commit` with a descriptive message.
+
+5. When authoring documentation, capture the why.
+6. Implement completely. No placeholders or stubs.
+7. Keep IMPLEMENTATION_PLAN.md current — future iterations depend on it.
+```
+
+### Example `AGENTS.md`
+
+Keep this brief (~60 lines). It's loaded every iteration, so bloat wastes context.
+
+```markdown
+## Build & Run
+
+dotnet build
+
+## Validation
+
+- Tests: `dotnet test`
+- Build: `dotnet build --no-restore`
+```
+
+## Best Practices
+
+1. **Fresh context per iteration**: Never accumulate context across iterations — that's the whole point
+2. **Disk is your database**: `IMPLEMENTATION_PLAN.md` is shared state between isolated sessions
+3. **Backpressure is essential**: Tests, builds, lints in `AGENTS.md` — the agent must pass them before committing
+4. **Start with PLANNING mode**: Generate the plan first, then switch to BUILDING
+5. **Observe and tune**: Watch early iterations, add guardrails to prompts when the agent fails in specific ways
+6. **The plan is disposable**: If the agent goes off track, delete `IMPLEMENTATION_PLAN.md` and re-plan
+7. **Keep `AGENTS.md` brief**: It's loaded every iteration — operational info only, no progress notes
+8. **Use a sandbox**: The agent runs autonomously with full tool access — isolate it
+9. **Set `WorkingDirectory`**: Pin the session to your project root so tool operations resolve paths correctly
+10. **Auto-approve permissions**: Use `OnPermissionRequest` to allow tool calls without interrupting the loop
+
+## When to Use a Ralph Loop
+
+**Good for:**
+
+- Implementing features from specs with test-driven validation
+- Large refactors broken into many small tasks
+- Unattended, long-running development with clear requirements
+- Any work where backpressure (tests/builds) can verify correctness
+
+**Not good for:**
+
+- Tasks requiring human judgment mid-loop
+- One-shot operations that don't benefit from iteration
+- Vague requirements without testable acceptance criteria
+- Exploratory prototyping where direction isn't clear
+
+## See Also
+
+- [Error Handling](error-handling.md) — timeout patterns and graceful shutdown for long-running sessions
+- [Persisting Sessions](persisting-sessions.md) — save and resume sessions across restarts

cookbook/copilot-sdk/dotnet/recipe/ralph-loop.cs

@@ -0,0 +1,83 @@
+#:package GitHub.Copilot.SDK@*
+
+using GitHub.Copilot.SDK;
+
+// Ralph loop: autonomous AI task loop with fresh context per iteration.
+//
+// Two modes:
+//   - "plan": reads PROMPT_plan.md, generates/updates IMPLEMENTATION_PLAN.md
+//   - "build": reads PROMPT_build.md, implements tasks, runs tests, commits
+//
+// Each iteration creates a fresh session so the agent always operates in
+// the "smart zone" of its context window. State is shared between
+// iterations via files on disk (IMPLEMENTATION_PLAN.md, AGENTS.md, specs/*).
+//
+// Usage:
+//   dotnet run                      # build mode, 50 iterations
+//   dotnet run plan                 # planning mode
+//   dotnet run 20                   # build mode, 20 iterations
+//   dotnet run plan 5               # planning mode, 5 iterations
+
+var mode = args.Contains("plan") ? "plan" : "build";
+var maxArg = args.FirstOrDefault(a => int.TryParse(a, out _));
+var maxIterations = maxArg != null ? int.Parse(maxArg) : 50;
+var promptFile = mode == "plan" ? "PROMPT_plan.md" : "PROMPT_build.md";
+
+var client = new CopilotClient();
+await client.StartAsync();
+
+Console.WriteLine(new string('━', 40));
+Console.WriteLine($"Mode:   {mode}");
+Console.WriteLine($"Prompt: {promptFile}");
+Console.WriteLine($"Max:    {maxIterations} iterations");
+Console.WriteLine(new string('━', 40));
+
+try
+{
+    var prompt = await File.ReadAllTextAsync(promptFile);
+
+    for (var i = 1; i <= maxIterations; i++)
+    {
+        Console.WriteLine($"\n=== Iteration {i}/{maxIterations} ===");
+
+        // Fresh session — each task gets full context budget
+        var session = await client.CreateSessionAsync(
+            new SessionConfig
+            {
+                Model = "gpt-5.1-codex-mini",
+                // Pin the agent to the project directory
+                WorkingDirectory = Environment.CurrentDirectory,
+                // Auto-approve tool calls for unattended operation
+                OnPermissionRequest = (_, _) => Task.FromResult(
+                    new PermissionRequestResult { Kind = "approved" }),
+            });
+
+        try
+        {
+            var done = new TaskCompletionSource<string>();
+            session.On(evt =>
+            {
+                // Log tool usage for visibility
+                if (evt is ToolExecutionStartEvent toolStart)
+                    Console.WriteLine($"  ⚙ {toolStart.Data.ToolName}");
+                else if (evt is AssistantMessageEvent msg)
+                    done.TrySetResult(msg.Data.Content);
+            });
+
+            await session.SendAsync(new MessageOptions { Prompt = prompt });
+            await done.Task;
+        }
+        finally
+        {
+            await session.DisposeAsync();
+        }
+
+        Console.WriteLine($"\nIteration {i} complete.");
+    }
+
+    Console.WriteLine($"\nReached max iterations: {maxIterations}");
+}
+finally
+{
+    await client.StopAsync();
+}