021-mcp

MCP server for interacting with LLM traces. Search, analyze, and debug your AI agent executions through any MCP-compatible client.

Installation

pip install 021-mcp

Or with uvx:

uvx 021-mcp

Configuration

Environment Variables

Variable	Required	Description
TRACES_API_KEY	Yes	Your API key for authentication
TRACES_BASE_URL	No	Base URL of the traces API (default: https://api.021labs.ai)

Claude Desktop

Add to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json):

{
  "mcpServers": {
    "traces": {
      "command": "uvx",
      "args": ["021-mcp"],
      "env": {
        "TRACES_API_KEY": "your-api-key-here"
      }
    }
  }
}

Manus

Add to your Manus MCP configuration:

{
  "servers": {
    "traces": {
      "command": "uvx",
      "args": ["021-mcp"],
      "env": {
        "TRACES_API_KEY": "your-api-key-here"
      }
    }
  }
}

Cursor / Other MCP Clients

Most MCP clients support a similar configuration format. The key elements are:

• command: uvx (or python -m mcp_traces.server if installed via pip)
• args: ["021-mcp"]
• env: Must include TRACES_API_KEY

Available Tools

list_traces

List traces with optional filters.

Parameters:

• status - Filter by status: SUCCESS, ERROR, or RUNNING
• search - Full-text search query
• start_time - Filter traces after this ISO timestamp
• end_time - Filter traces before this ISO timestamp
• session_id - Filter by session ID
• user_id - Filter by user ID
• project_id - Filter by project ID
• limit - Maximum results (1-100, default 20)

Example usage:

"Show me the last 10 traces that failed" "Find traces from yesterday that mention 'database'"

get_trace

Get detailed information about a specific trace.

Parameters:

• trace_id - The trace ID to fetch
• include_io - Include full input/output data (default: false)

Example usage:

"Get details for trace abc123" "Show me trace xyz789 with all the LLM inputs and outputs"

get_span

Get full details for a specific span including input/output.

Parameters:

• span_id - The span ID to fetch

Example usage:

"What was the input to span def456?" "Show me the LLM response in span ghi789"

get_analytics

Get analytics summary for traces.

Parameters:

• start_time - Start of time range
• end_time - End of time range
• granularity - hour, day, or week (default: day)
• project_id - Filter by project ID

Example usage:

"Show me trace analytics for the last week" "What's the error rate for project X?"

search_errors

Find recent traces that ended in errors.

Parameters:

• limit - Maximum results (default: 10)
• start_time - Filter errors after this timestamp
• project_id - Filter by project ID

Example usage:

"Find recent errors" "What failed in the last hour?"

Development

# Clone and install
git clone https://github.com/021labs/rl.git
cd rl/packages/mcp

# Install dependencies
uv sync

# Run locally
uv run 021-mcp

# Run tests
uv run pytest

License

MIT