ToolTrace

zero-config call tracing for your MCP tool servers

npx -y github:Isco0819/tool-trace

Ever run into this?

Like Langfuse which has real traction ($2M+ ARR, Product Hunt launch) for LLM observability, but no equivalent exists at the MCP tool-call level. When your Claude agent fires 40+ tool calls per session you get zero visibility into which tools are slow, which fail silently, or which get called redundantly — debugging agent harnesses is pure guesswork.

The fix

A drop-in npx MCP proxy that transparently wraps any stdio MCP server with zero config changes, logs structured JSONL traces locally, and renders a live timing table in terminal so you can see exactly what your agent is doing.

What it does

npx -y github:Isco0819/tool-trace