# Session Report

**Session ID:** 7ffddc00-b126-4cd0-9fb4-d00a57614474

---

## Step 1: User Turn

### System Prompt

```
You are an expert Haskell and Bash programmer specialized in writing clean, idiomatic, and efficient Haskell code.
When writing Bash code:
- Avoid bash-specific logic but bash-ism are fine.
- Document required shell tools at the top of the bash script.
When writing Haskell code:
- Use modern Haskell practices (base >= 4.14)
- Prefer pure functions and explicit type signatures
- Use standard libraries when appropriate
- Add clear comments for complex logic
- Follow consistent formatting
Use list-files to explore the project structure, read-file to understand existing code, write-file to create or modify files, and check-code to verify your work.
Always compile code before considering the job done.
Your last message will serve as git-commit. Format your final message as follows:
- Start with a one-liner commit message in imperative mode (e.g., 'Fix bug in user authentication')
- The one-liner should reference the fixed issue (e.g., 'Fix bug in user authentication (#12345)')
- Follow with a blank line, then a body with a nice summary of the changes
- In the body, reference the fixed issue using 'Closes #12345' format

Example format:
Fix critical bug in session handling (#75)

This commit resolves the memory leak caused by not properly
closing session handles. The fix ensures all resources are
released when a session is terminated.

Closes #75
```

### User Query

# Add recursion depth tracking and call chain to ToolExecutionContext

## Summary

Enhance `ToolExecutionContext` to track recursion depth and the chain of conversation IDs. This enables detection of infinite recursion and allows tools to make context-aware decisions based on their position in the call stack.

## Motivation

When agents can call each other recursively (via the changes in #81), we need:
1. **Safety**: Prevent infinite recursion via configurable depth limits
2. **Observability**: Track the call chain for debugging and tracing
3. **Context-aware behavior**: Allow agents to behave differently at different recursion depths

The user's comment emphasizes:
> "Having a variable with the chain of conversation-ids is useful for branching the tool logic based on the depth inside this context so that nested tool-calls know at which point they should stop."

## Proposed Changes

### 1. Update `ToolExecutionContext` in `src/System/Agents/Tools/Context.hs`

```haskell
import System.Agents.Base (AgentId, ConversationId, AgentSlug)

-- | Information about a single level in the agent call stack
data CallStackEntry = CallStackEntry
    { callAgentSlug :: AgentSlug
    -- ^ The slug of the agent at this level
    , callConversationId :: ConversationId
    -- ^ The conversation ID for this level
    , callDepth :: Int
    -- ^ The recursion depth (0 = root)
    }
    deriving (Show, Eq, Generic)

instance ToJSON CallStackEntry
instance FromJSON CallStackEntry

-- | Extended context with recursion tracking
data ToolExecutionContext = ToolExecutionContext
    { ctxSessionId :: SessionId
    , ctxConversationId :: ConversationId
    , ctxTurnId :: TurnId
    , ctxAgentId :: Maybe AgentId
    , ctxFullSession :: Maybe Session
    , ctxCallStack :: [CallStackEntry]  -- NEW: call chain for recursion tracking
    , ctxMaxDepth :: Maybe Int          -- NEW: configured max recursion depth
    }
    deriving (Show, Eq, Generic)
```

### 2. Construction Helpers Update

```haskell
-- | Create a root-level context (depth 0)
mkRootContext
    :: SessionId
    -> ConversationId
    -> TurnId
    -> Maybe AgentId
    -> Maybe Session
    -> Maybe Int  -- ^ max depth
    -> ToolExecutionContext
mkRootContext sessId convId tId mAgentId mSession maxDepth =
    ToolExecutionContext
        { ctxSessionId = sessId
        , ctxConversationId = convId
        , ctxTurnId = tId
        , ctxAgentId = mAgentId
        , ctxFullSession = mSession
        , ctxCallStack = [CallStackEntry "root" convId 0]  -- Root entry
        , ctxMaxDepth = maxDepth
        }

-- | Create a nested context when calling a sub-agent
pushAgentContext
    :: AgentSlug
    -> ConversationId
    -> ToolExecutionContext
    -> Either RecursionError ToolExecutionContext
pushAgentContext slug newConvId parentCtx =
    let newDepth = length parentCtx.ctxCallStack
        newEntry = CallStackEntry slug newConvId newDepth
    in case parentCtx.ctxMaxDepth of
        Just maxD | newDepth > maxD -> 
            Left $ MaxRecursionDepthExceeded parentCtx.ctxCallStack
        _ -> Right $ parentCtx
            { ctxConversationId = newConvId
            , ctxCallStack = newEntry : parentCtx.ctxCallStack
            }

-- | Error type for recursion limit violations
data RecursionError = MaxRecursionDepthExceeded [CallStackEntry]
    deriving (Show, Eq)
```

### 3. Query Helpers

```haskell
-- | Get current recursion depth (0 = root)
currentRecursionDepth :: ToolExecutionContext -> Int
currentRecursionDepth = length . ctxCallStack

-- | Check if we're at or beyond a specific depth
isAtDepth :: Int -> ToolExecutionContext -> Bool
isAtDepth n ctx = currentRecursionDepth ctx >= n

-- | Get the full call chain as a list (root first)
callChain :: ToolExecutionContext -> [CallStackEntry]
callChain = reverse . ctxCallStack

-- | Check if a specific agent is already in the call stack (cycle detection)
isAgentInCallStack :: AgentSlug -> ToolExecutionContext -> Bool
isAgentInCallStack slug ctx = 
    any ((== slug) . callAgentSlug) ctx.ctxCallStack
```

## Integration with Agent Calling

When `turnAgentRuntimeIntoIOTool` calls a sub-agent, it should use `pushAgentContext`:

```haskell
-- In System.Agents.AgentTree.OneShotTool
runSubAgent :: ToolExecutionContext -> PromptOtherAgent -> IO CByteString.ByteString
runSubAgent parentCtx (PromptOtherAgent query) = do
    -- Generate new conversation ID for this call
    newConvId <- newConversationId
    
    -- Push new context level, checking recursion limits
    case pushAgentContext rt.agentSlug newConvId parentCtx of
        Left err -> do
            -- Handle recursion limit exceeded
            pure $ Text.encodeUtf8 $ "Error: " <> Text.pack (show err)
        Right newCtx -> do
            -- Continue with sub-agent call using newCtx
            agent <- runtimeToAgentForToolInIOScriptExecution store rt callerSlug callerId newCtx
            -- ... rest of execution
```

## Configuration Integration

The `maxRecursionDepth` should be configurable per-agent. In `Agent` type (from `extra-agents` issue):

```haskell
data ExtraAgentRef
    = ExtraAgentRef
    { extraAgentSlug :: AgentSlug
    , extraAgentPath :: FilePath
    , extraMaxRecursionDepth :: Maybe Int  -- Per-reference limit
    }
```

Or globally in `Agent`:

```haskell
data Agent = Agent
    { ...
    , maxRecursionDepth :: Maybe Int  -- Default limit for this agent
    , extraAgents :: Maybe [ExtraAgentRef]
    }
```

## Acceptance Criteria

- [ ] `CallStackEntry` type defined with JSON instances
- [ ] `ToolExecutionContext` updated with `ctxCallStack` and `ctxMaxDepth`
- [ ] `mkRootContext` constructor for root-level contexts
- [ ] `pushAgentContext` function for nesting with depth checking
- [ ] `RecursionError` type for limit violations
- [ ] Query helpers: `currentRecursionDepth`, `isAtDepth`, `callChain`, `isAgentInCallStack`
- [ ] JSON round-trip tests for extended context
- [ ] Unit tests for recursion limit enforcement

## Tradeoffs

| Approach | Pros | Cons |
|----------|------|------|
| `[CallStackEntry]` list | Simple, ordered, easy to traverse | O(n) lookup for cycle detection |
| Set + List | O(1) cycle detection | More memory, more complex |
| Just depth counter | Minimal overhead | Loses call chain info |

**Recommended**: `[CallStackEntry]` list - call stacks are typically shallow (< 10), so O(n) is fine and the debugging value of the full chain is worth it.

## Related

- Part of #81 (recursive references in AgentTree)
- Integrated by `turnAgentRuntimeIntoIOTool` when calling sub-agents




---
Please mention issue #85 in the commit message.



### Available Tools

- **bash_grep-files** (`bash_grep-files`)
  - Description: Search for a pattern in files using 'git grep'
- **bash_check-code** (`bash_check-code`)
  - Description: Check Haskell code by compiling or testing
- **bash_write-file** (`bash_write-file`)
  - Description: Write content to a file
- **bash_list-files** (`bash_list-files`)
  - Description: List all files in the project
- **bash_read-file** (`bash_read-file`)
  - Description: Read the contents of a file

---

## Step 2: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Let me start by exploring the project structure to understand the codebase and find the relevant files mentioned in the issue.
</details>

### Response



### Tool Calls

- **bash_list-files**

---

## Step 3: User Turn



---

## Step 4: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

I can see the project structure. The main file I need to look at is `./src/System/Agents/Tools/Context.hs` as mentioned in the issue. Let me read that file to understand the current structure.
</details>

### Response



### Tool Calls

- **bash_read-file**
- **bash_read-file**

---

## Step 5: User Turn



---

## Step 6: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now I have a good understanding of the current structure. Let me also look at how the context is used in the OneShotTool module to understand the integration point.
</details>

### Response



### Tool Calls

- **bash_read-file**

---

## Step 7: User Turn



---

## Step 8: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now I have a good understanding of the codebase. Let me also check the test file to see the existing tests.
</details>

### Response



### Tool Calls

- **bash_read-file**

---

## Step 9: User Turn



---

## Step 10: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now I have a good understanding of the codebase. Let me now implement the changes as described in the issue.

The main changes needed:

1. Add `AgentSlug` import to Context.hs
2. Define `CallStackEntry` type with JSON instances
3. Update `ToolExecutionContext` with `ctxCallStack` and `ctxMaxDepth`
4. Add `RecursionError` type
5. Update `mkToolExecutionContext` and `mkMinimalContext` constructors
6. Add `mkRootContext` and `pushAgentContext` helpers
7. Add query helpers: `currentRecursionDepth`, `isAtDepth`, `callChain`, `isAgentInCallStack`
8. Add tests for the new functionality

Let me write the updated Context.hs file.
</details>

### Response

Now I have a complete understanding of the codebase. Let me implement the changes as specified in the issue.

### Tool Calls

- **bash_write-file**

---

## Step 11: User Turn



---

## Step 12: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now let me compile the code to check for any errors.
</details>

### Response

Now let me compile to check for any issues:

### Tool Calls

- **bash_check-code**

---

## Step 13: User Turn



---

## Step 14: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

There's a compilation error. The `mkToolExecutionContext` function signature changed (it now requires additional parameters for `ctxCallStack` and `ctxMaxDepth`), and there's a call to it in `src/System/Agents/Session/Step.hs` that needs to be updated.

Let me look at that file to see how it's using `mkToolExecutionContext`.
</details>

### Response

I see there's a usage of `mkToolExecutionContext` in `Session.Step.hs` that needs to be updated. Let me look at that file:

### Tool Calls

- **bash_read-file**

---

## Step 15: User Turn



---

## Step 16: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

I see the issue. The `buildContext` function in `Session.Step.hs` is calling `mkToolExecutionContext` with the old signature (5 arguments) but our updated signature requires 7 arguments (including the new `ctxCallStack` and `ctxMaxDepth` fields).

I need to update this call to include the new parameters. Looking at the context, this is creating a root-level context, so I should:
1. Create a call stack with a root entry
2. Pass `Nothing` for max depth (no limit by default)

Let me update the `Session.Step.hs` file.
</details>

### Response

Now I need to update `Session.Step.hs` to use the new `mkToolExecutionContext` signature:

### Tool Calls

- **bash_write-file**

---

## Step 17: User Turn



---

## Step 18: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now let me compile again to see if there are any other issues.
</details>

### Response



### Tool Calls

- **bash_check-code**

---

## Step 19: User Turn



---

## Step 20: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

There are two more files that need to be updated. Let me read those files to fix them.
</details>

### Response

Let me fix the other two files that use `mkToolExecutionContext`:

### Tool Calls

- **bash_read-file**
- **bash_read-file**

---

## Step 21: User Turn



---

## Step 22: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

I see the issues in both files. Both are calling `mkToolExecutionContext` with the old signature. I need to update these to include the new parameters:1. In `OneShot.hs` around line 176-182
2. In `MCP/Server.hs` around line 341-347

Both need to include:
- `ctxCallStack` - I'll use `[CallStackEntry "root" convId 0]` as a root context
- `ctxMaxDepth` - I'll use `Nothing` for no limit

Let me also import `CallStackEntry` in both files.
</details>

### Response

Now I need to update both `OneShot.hs` and `MCP/Server.hs` to use the new signature:

### Tool Calls

- **bash_write-file**
- **bash_write-file**

---

## Step 23: User Turn



---

## Step 24: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now let me compile again to check for any remaining issues.
</details>

### Response

Now let me compile again to verify everything works:

### Tool Calls

- **bash_check-code**

---

## Step 25: User Turn



---

## Step 26: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

The code compiles now. There are only warnings (no errors). Now I need to add the tests for the new functionality as specified in the issue. Let me update the test file to add tests for:

1. `CallStackEntry` JSON serialization round-trip
2. `ToolExecutionContext` JSON serialization round-trip with the new fields
3. `mkRootContext` constructor
4. `pushAgentContext` function for nesting with depth checking
5. `RecursionError` type
6. Query helpers: `currentRecursionDepth`, `isAtDepth`, `callChain`, `isAgentInCallStack`
</details>

### Response

The code compiles. Now let me add the tests for the new functionality:

### Tool Calls

- **bash_write-file**

---

## Step 27: User Turn



---

## Step 28: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now let me run the tests to make sure everything works.
</details>

### Response

Now let's run the tests to verify everything works:

### Tool Calls

- **bash_check-code**

---

## Step 29: User Turn



---

## Step 30: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

I need to update the test file to not directly import UUID and instead use the types from Base module. Let me fix the tests to not require the UUID import.
</details>

### Response

I need to fix the test imports. Let me update the test file to use the types correctly without directly importing UUID:

### Tool Calls

- **bash_write-file**

---

## Step 31: User Turn



---

## Step 32: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

The syntax I used for module aliases isn't valid. I need to use proper qualified imports. Let me fix the test file.
</details>

### Response

I need to fix the import syntax. Let me update the test file:

### Tool Calls

- **bash_write-file**

---

## Step 33: User Turn



---

## Step 34: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now let me run the tests again.
</details>

### Response



### Tool Calls

- **bash_check-code**

---

## Step 35: User Turn



---

## Step 36: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

All 33 tests passed! The implementation is complete. Let me now verify the final code by reading the updated Context.hs to ensure everything looks good, and then provide a summary of changes.
</details>

### Response

All tests pass. Let me verify the final implementation by reading the updated Context module:

### Tool Calls

- **bash_read-file**

---

## Step 37: User Turn



---

## Step 38: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

The implementation is complete and all tests pass. Let me provide a summary of all the changes made.

Summary of changes:
1. Updated `System.Agents.Tools.Context` module with:
   - New `CallStackEntry` type with JSON instances for tracking individual call stack entries
   - New `RecursionError` type for recursion limit violations
   - Extended `ToolExecutionContext` with `ctxCallStack` and `ctxMaxDepth` fields
   - New `mkRootContext` constructor for creating root-level contexts
   - New `pushAgentContext` function for nesting with depth checking
   - Query helpers: `currentRecursionDepth`, `isAtDepth`, `callChain`, `isAgentInCallStack`

2. Updated all call sites that use `mkToolExecutionContext` to include the new parameters:
   - `System.Agents.Session.Step`
   - `System.Agents.OneShot`
   - `System.Agents.MCP.Server`

3. Added comprehensive tests for:
   - `CallStackEntry` JSON round-trip
   - `ToolExecutionContext` with new fields
   - `mkRootContext` and `mkMinimalContext`
   - `pushAgentContext` with depth checking
   - `RecursionError` handling
   - Query helpers: `currentRecursionDepth`, `isAtDepth`, `callChain`, `isAgentInCallStack`

All 33 tests pass successfully.
</details>

### Response

The implementation is complete. Here's a summary of all changes made:

## Summary of Changes

### 1. `System.Agents.Tools.Context` module (main changes)

**New Types:**
- **`CallStackEntry`**: Tracks a single level in the agent call stack with `callAgentSlug`, `callConversationId`, and `callDepth` fields
- **`RecursionError`**: Error type for recursion limit violations with `MaxRecursionDepthExceeded` constructor

**Extended `ToolExecutionContext`:**
- Added `ctxCallStack :: [CallStackEntry]` - tracks the chain of nested agent calls
- Added `ctxMaxDepth :: Maybe Int` - optional maximum recursion depth limit

**New Construction Helpers:**
- **`mkRootContext`**: Creates a root-level context (depth 0) with a "root" entry in the call stack
- **`pushAgentContext`**: Pushes a new entry onto the call stack with depth limit checking, returns `Either RecursionError ToolExecutionContext`

**Query Helpers:**
- **`currentRecursionDepth`**: Returns the current recursion depth (length of call stack)
- **`isAtDepth`**: Checks if we're at or beyond a specific depth threshold
- **`callChain`**: Returns the full call chain in root-first order (reversed from internal storage)
- **`isAgentInCallStack`**: Detects if a specific agent is already in the call stack (for cycle detection)

### 2. Updated modules to use new signature:

- `System.Agents.Session.Step` - Uses `CallStackEntry` for root context
- `System.Agents.OneShot` - Uses new `mkToolExecutionContext` with call stack
- `System.Agents.MCP.Server` - Uses new `mkToolExecutionContext` with call stack

### 3. Test Suite (33 tests total, all passing):

- **CallStackEntry Tests**: JSON round-trip, equality, show representation
- **ToolExecutionContext Tests**: All constructors, JSON round-trip, query helpers
- **Recursion Tracking Tests**: Depth checking, push context, max depth limits, cycle detection

Add recursion depth tracking and call chain to ToolExecutionContext (#85)

This commit enhances `ToolExecutionContext` to track recursion depth and the chain of conversation IDs, enabling detection of infinite recursion and allowing tools to make context-aware decisions based on their position in the call stack.

Changes include:
- New `CallStackEntry` type for tracking individual call stack entries with JSON instances
- New `RecursionError` type for handling recursion limit violations
- Extended `ToolExecutionContext` with `ctxCallStack` and `ctxMaxDepth` fields
- New `mkRootContext` constructor for creating root-level contexts
- New `pushAgentContext` function for nesting with configurable depth checking
- Query helpers: `currentRecursionDepth`, `isAtDepth`, `callChain`, `isAgentInCallStack`
- Updated all call sites and added comprehensive tests

Closes #85
