* fix(subagents): cleanup background tasks after completion to prevent memory leak
Added cleanup_background_task() function to remove completed subagent results
from the global _background_tasks dict. Found a small issue: completed tasks
were never removed, causing memory to grow indefinitely with each subagent
execution.
Alternative approaches considered:
- Future + SubagentHandle pattern: Not chosen due to requiring refactoring
Chose the simple cleanup approach for minimal code changes while effectively
resolving the memory leak.
Changes:
- Add cleanup_background_task() in executor.py
- Call cleanup in all task_tool return paths (completed, failed, timed out)
* fix(subagents): prevent race condition in background task cleanup
Address Copilot review feedback on memory leak fix:
- Add terminal state check in cleanup_background_task() to only remove
tasks that are COMPLETED/FAILED/TIMED_OUT or have completed_at set
- Remove cleanup call from polling safety-timeout branch in task_tool
since the task may still be running
- Add comprehensive tests for cleanup behavior including:
- Verification that cleanup is called on terminal states
- Verification that cleanup is NOT called on polling timeout
- Tests for terminal state check logic in executor
This prevents KeyError when the background executor tries to update
a task that was prematurely removed from _background_tasks.
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Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
* fix(subagent): support async MCP tools in subagent executor
SubagentExecutor.execute() was synchronous and could not handle async-only tools like MCP tools. This caused failures when trying to use MCP tools within subagents.
Changes:
- Add _aexecute() async method using agent.astream() for async execution
- Refactor execute() to use asyncio.run() wrapping _aexecute()
- This allows subagents to use async tools (MCP) within ThreadPoolExecutor
* test(subagent): add unit tests for executor async/sync paths
Add comprehensive tests covering:
- Async _aexecute() with success/error cases
- Sync execute() wrapper using asyncio.run()
- Async tool (MCP) support verification
- Thread pool execution safety
* fix(subagent): subagent-test-circular-depend
- Use session-scoped fixture with delayed import to handle circular dependencies
without affecting other test modules
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Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
* feat(subagents): make subagent timeout configurable via config.yaml
- Add SubagentsAppConfig supporting global and per-agent timeout_seconds
- Load subagents config section in AppConfig.from_file()
- Registry now applies config.yaml overrides without mutating builtin defaults
- Polling safety-net in task_tool is now dynamic (execution timeout + 60s buffer)
- Document subagents section in config.example.yaml
- Add make test command and enforce TDD policy in CLAUDE.md
- Add 38 unit tests covering config validation, timeout resolution, registry
override behavior, and polling timeout formula
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* feat(subagents): add logging for subagent timeout config and execution
- Log loaded timeout config (global default + per-agent overrides) on startup
- Log debug message in registry when config.yaml overrides a builtin timeout
- Include timeout in executor's async execution start log
- Log effective timeout and polling limit when a task is dispatched
- Fix UnboundLocalError: move max_poll_count assignment before logger.info
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* ci(backend): add lint step and run all unit tests via Makefile
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* fix lint
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Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Support configuring max_concurrent_subagents (2-4, default 3) through
config.configurable, with automatic clamping and dynamic prompt generation.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Backend: add citation format to lead_agent and general_purpose prompts
- Add CitationLink component (Badge + HoverCard) for citation cards
- MarkdownContent: detect citation: prefix in link text, render CitationLink
- Message/artifact/subtask: use MarkdownContent or Streamdown with CitationLink
- message-list-item: pass img via components prop (remove isHuman/img)
- message-group, subtask-card: drop unused imports; fix import order (lint)
Co-authored-by: Cursor <cursoragent@cursor.com>
- Keep upstream subagent HARD LIMIT (max 3 task calls, batching) in subagent_reminder
- Keep our removal of Citations: do not add back 'Citations when synthesizing'
Co-authored-by: Cursor <cursoragent@cursor.com>
Add two new middlewares to improve robustness of the agent pipeline:
- DanglingToolCallMiddleware injects placeholder ToolMessages for
interrupted tool calls, preventing LLM errors from malformed history
- SubagentLimitMiddleware truncates excess parallel task tool calls at
the model response level, replacing the runtime check in task_tool
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add "present_files" to disallowed_tools for bash and general-purpose
subagents to prevent them from presenting files directly. Also add the
new market-analysis skill for generating consulting-grade reports.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Prevent resource exhaustion by capping the number of parallel subagents.
Adds runtime enforcement in task_tool and updates prompts/examples accordingly.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Enable task tool to capture and stream AI messages as they are generated by subagents. This replaces simple polling status updates with detailed message-level progress updates.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
- Reorder task tool parameters to prioritize description first for better usability
- Add tool_call_id injection for better task traceability
- Use tool_call_id as task_id in executor for consistent tracking
- Simplify event messages by removing redundant task_type field
- Update task examples in prompt to reflect new parameter order
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
