ACP Support

[0xSero]

Add ACP Support with Zed Integration, Protocol Fixes, and Tool Streaming

Overview

• Adds first-class Agent Client Protocol (ACP) support to Mini‑Agent, enabling integration with ACP-compatible clients like Zed.
• Fixes protocol compliance issues (stopReason values, tool-call update shape).
• Improves reliability and security (no secrets in repo, safer logging, offline-safe token counting).
• Updates documentation with a concrete Zed setup guide.

Why

• Zed rejected invalid stopReason values ("error", "max_steps") and tool-call updates that didn’t match ACP’s SDK signature.
• A misuse of the skills loader injected a list into the tools collection, causing "'list' object has no attribute 'name'".
• Ensure consistent usage from Zed by pointing to the exact local venv install.

What’s Included

• ACP server entry and agent
  • mini_agent/acp/server.py: stdio ACP server entry (mini-agent-acp), config/bootstrap.
  • mini_agent/acp/agent.py: ACP Agent implementation with multi‑session, streaming, tool execution.
  • mini_agent/acp/session.py: Session manager.
  • mini_agent/acp/converter.py: Message/content conversion.
  • mini_agent/acp/schema_fix.py: Monkeypatch to accept string protocolVersion from some clients (e.g., “1.0.0”).
• Protocol compliance fixes
  • Stop reasons now return only ACP-allowed values: end_turn, max_tokens, max_turn_requests, refusal, cancelled.
  • Tool streaming uses start_tool_call(...) and update_tool_call(...) with status, raw_input, raw_output, and content blocks.
  • InitializeResponse uses string protocolVersion; InitializeRequest accepts string versions via monkeypatch.
• LLM/tool integration improvements
  • Pass tool schemas (tool.to_schema()) to the LLM instead of Tool objects.
• Robustness and safety
  • mini_agent/logger.py: Fallback log path in CWD when HOME is not writable.
  • mini_agent/tools/file_tools.py: Offline-safe token counting fallback if tiktoken isn’t available.
  • Config secrets avoided: repository ignores config.yaml.
• Documentation
  • README.md: Detailed Zed integration steps (using absolute venv path), version verification wrapper, and configuration search order.
  • mini_agent/acp/README.md: Expanded “With Zed” section, config locations, and explicit statement of ACP stopReason compliance.

How To Test

• Unit/Integration (without network):
  • pytest -q (44 passed, 3 skipped in local run).
• Manual ACP server:
  • mini-agent-acp and connect an ACP client over stdio.
  • Or python -m acp.examples.client mini-agent-acp.
• Zed integration (recommended):
  • Agent Panel → New External Agent → ACP
  • Command: /absolute/path/to/venv/bin/mini-agent-acp
  • Optional wrapper to confirm version:
    • Command: /bin/bash
    • Args: -lc, echo 'mini-agent:' $(python -c 'import importlib.metadata as m; print(m.version("mini-agent"))') 'at' $(python -c 'import mini_agent; print(mini_agent.__file__)') >&2; exec /absolute/path/to/venv/bin/mini-agent-acp
  • Start a thread, invoke file tools or bash. You should see tool status transitions (in_progress → completed|failed) with raw_input and raw_output.

Compatibility

• No breaking changes to the core CLI (mini-agent).
• Adds new entrypoint mini-agent-acp.
• ACP mode skips dynamic MCP tool loading for now (logged notice).

Known Limitations

• loadSession and setSessionMode not implemented.
• Permission prompts for tools are not yet included.
• ACP-mode MCP integration is stubbed (planned).

Notes For Reviewers

• Main focus is correctness of ACP handshake and streaming semantics.
• Documentation emphasizes Zed usage and avoiding version drift.
• Changes are isolated to ACP modules and small targeted fixes in shared utilities.

Changelog

• feat: ACP server + agent; Zed-ready integration.
• fix: ACP stopReason mapping; valid tool-call streaming API usage.
• fix: Skills loader misusage causing “list has no attribute 'name'”.
• fix: Logger fallback when HOME is not writable.
• fix: Token counting fallback when tiktoken encoder unavailable.
• docs: Add Zed setup steps, config guidance, and ACP compliance notes.
• chore: Remove local config file with API key; ensure secrets not tracked.

How To Roll Back

• Remove mini-agent-acp entrypoint and mini_agent/acp/*.
• Revert changes in mini_agent/acp/agent.py, mini_agent/acp/server.py, mini_agent/config.py, mini_agent/tools/file_tools.py, mini_agent/logger.py, and the README updates.

[adao-max]

Thanks for you PR, our engineer will review it soon

[AkairoDev]

Thank you @0xSero for this comprehensive PR!
However, we've decided not to merge this into Mini-Agent. This project is designed as a minimal, educational example for MCP best practices, and adding ~1,300 lines for ACP support would significantly increase complexity beyond our intended scope.
We encourage you to fork Mini-Agent and maintain an ACP-enhanced version independently where it can evolve without the constraints of keeping Mini-Agent minimal.
Thanks for your contribution!