not-ace-tool-rs

An MCP server that gives AI coding agents grounded codebase context, prompt enhancement, web search, and mid-task advice from a Finnian/ACE backend.

Your editor launches this binary as a subprocess. It speaks JSON-RPC 2.0 over stdio and proxies tool calls to your Finnian/ACE server, so the agent answers from a real index of your codebase instead of guessing.

Quick Start

npx not-ace-tool-rs --base-url <API_URL> --token <AUTH_TOKEN>

npx downloads the right platform package, starts the server, and serves MCP tools over stdio. Supports Linux (x64/ARM64), macOS (x64/ARM64), and Windows (x64/ARM64).

Tools

Tool	What it does
codebase_retrieval	Sync the project index and retrieve ranked code context for a natural-language question
enhance_prompt	Rewrite a prompt using retrieved codebase context
web_search	Search the web through the server
advisor	Ask for a course correction mid-task: assessment, recommendation, and the failure mode to watch for

advisor requires a server exposing POST /agents/advisor. Against an older backend it returns a clear "not supported" result instead of failing the session, so one binary works across server versions.

MCP Client Setup

Claude Code

claude mcp add-json not-ace-tool --scope user '{
  "type": "stdio",
  "command": "npx",
  "args": ["not-ace-tool-rs", "--base-url", "https://your-api.example.com", "--token", "your-token"]
}'

Then allow the tools in ~/.claude/settings.json:

{
  "permissions": {
    "allow": [
      "mcp__not-ace-tool__codebase_retrieval",
      "mcp__not-ace-tool__enhance_prompt",
      "mcp__not-ace-tool__web_search",
      "mcp__not-ace-tool__advisor"
    ]
  }
}

Claude Desktop

~/Library/Application Support/Claude/claude_desktop_config.json on macOS:

{
  "mcpServers": {
    "not-ace-tool": {
      "command": "npx",
      "args": ["not-ace-tool-rs", "--base-url", "https://your-api.example.com", "--token", "your-token"]
    }
  }
}

Codex CLI

~/.codex/config.toml:

[mcp_servers.not-ace-tool]
command = "npx"
args = ["not-ace-tool-rs", "--base-url", "https://your-api.example.com", "--token", "your-token"]
startup_timeout_ms = 60000

Configuration

Flag	Environment variable	Required
--base-url	FINNIAN_BASE_URL	Yes
--token	FINNIAN_API_TOKEN	Yes

Flags take precedence over environment variables. The base URL must be HTTP(S); trailing slashes are stripped. Startup fails with a message on stderr if either is missing.

Tool Reference

codebase_retrieval

Parameter	Type	Required	Description
project_root_path	string	Yes	Absolute project root path, using forward slashes
query	string	Yes	What you want to know, in natural language

Local index cache

Before each retrieval, the client incrementally indexes project_root_path. It stores the index cache at <project_root>/.not-ace-tool/index.json and uploads only files whose contents have changed. The client supplies the resulting blob scope to the Finnian/ACE server automatically; callers provide only the project root and query.

enhance_prompt

Parameter	Type	Required	Description
prompt	string	Yes	The prompt to rewrite
conversation_history	any	No	Prior turns, for continuity
blobs	object	No	Blob scope to ground the rewrite

web_search

Parameter	Type	Required	Description
query	string	Yes	Search query
count	integer	No	Results to return (the server caps this)

advisor

Parameter	Type	Required	Description
situation	string	Yes	The decision you face
proposed_approach	string	No	What you are about to do; also sharpens retrieval
transcript	string	No	Recent turns; tail-truncated when long
blobs	object	No	Blob scope. Omit it and the advice is ungrounded — the response says so via grounded_in_code

Notes

• stdout carries only JSON-RPC frames; all diagnostics go to stderr, so the protocol stays clean.
• Requests time out after 30 seconds.
• Upstream error bodies are truncated and stripped of the auth token before being surfaced, since MCP errors surface in your editor.

Building from Source

cargo build --release
./target/release/not-ace-tool-rs --base-url <API_URL> --token <AUTH_TOKEN>

License

GPL-3.0-only OR LicenseRef-Commercial. See LICENSE and LICENSE-COMMERCIAL.