LangChain

LangChain callback handler that writes local AgentInspect JSONL traces.

Capture LangGraph / LangChain runs as local AgentInspect traces, evaluate them with TraceFacts and TraceContract, and produce Evidence v2 — without a collector or default upload.

Install

npm install agent-inspect @agent-inspect/langchain
npx agent-inspect init --framework langgraph --yes

Or wire the LangChain callback path manually via @agent-inspect/langchain.

No-key gate + Evidence recipe

Repository recipe (no API keys): examples/recipes/langgraph-gate-evidence.

Typical loop:

capture → check / TraceContract → gate → bundle --profile share → bundle verify

Semantics to expect

• Raw JSONL events remain on disk.
• Built-in checks and TraceContract use the logical lifecycle projection (logicalEvents / TraceFacts).
• Canonical tool identity resolves bridged tool names (including nested metadata.toolName where applicable).

Details: TRACE-FACTS.md · LANGGRAPH-FIDELITY.md · ADAPTERS.md.

Related NestJS path

For NestJS + LangGraph-style local evidence, see NESTJS.md and the public-safe case study under case-studies/ when present.