Agents

MCP

Streamable HTTP at /mcp. Compact payloads, since_minutes, and a playbook in server instructions.

With the API running, agents talk Streamable HTTP at http://127.0.0.1:4318/mcp.

The server is agent-first: compact payloads, since_minutes, and a playbook in server instructions. Tools still call the same execute services as HTTP. Do not attach a raw SQLite MCP.

Cursor

.cursor/mcp.json:

{
  "mcpServers": {
    "localtrace": {
      "url": "http://127.0.0.1:4318/mcp"
    }
  }
}

Claude Code

.mcp.json in the project you are debugging:

{
  "mcpServers": {
    "localtrace": {
      "type": "http",
      "url": "http://127.0.0.1:4318/mcp"
    }
  }
}

Inspector

npx @modelcontextprotocol/inspector http://127.0.0.1:4318/mcp

Tools

Tool	What the agent gets
`list_facets`	Valid trace filter values
`list_traces`	Recent traces (paginated). Prefer `since_minutes`
`get_trace`	Overview (default) or `detail=full`
`get_span`	One span with attributes
`get_trace_sql`	DB queries in a trace, sorted by duration
`get_trace_spans`	Typed payloads: `sql` / `redis` / `mongo` / `prisma` / `http` / `express` / `s3` / `openrouter` / `trpc` / `error`
`search_spans`	Cross-trace search (name/attributes, type, service)
`get_trace_logs`	Logs correlated to a `trace_id`
`list_log_facets`	Services and severity buckets for log filters
`list_logs`	Recent logs (attributes omitted unless `raw`)
`list_services`	Services that have ingested traces
`list_metric_facets`	Metric names and services
`query_metrics`	Recent metric points

Prompts: investigate_trace, debug_errors, find_slow.

See the investigation playbook for how agents should call these tools.