Migrate from LangSmith
Point your existing LangSmith client at langprobe. One env var, no code change.
langprobe's ingest is LangSmith-compatible: it accepts the native RunCreate /
RunUpdate shapes a LangSmith client already sends. Migrating is import-and-go —
you don't touch your instrumentation code, you re-point it.
Re-point your client
Set the two environment variables your LangSmith SDK already reads to your langprobe host and key:
export LANGSMITH_ENDPOINT=http://localhost:7080
export LANGSMITH_API_KEY="lt_<public_id>.<secret>"That's the whole change. Your existing traceable functions and callbacks keep
running; the langprobe shim translates each RunCreate / RunUpdate into the
same ingest queue that native runs land in, so they show up alongside everything
else in /runs.
Swap http://localhost:7080 for your own ingest host (or the hosted
https://app.langprobe.com). Mint the lt_… key in API keys — see the
Quickstart.
What carries over
- Runs and spans — the run tree, inputs/outputs, latency, and token/cost attributes map onto langprobe's run and span model.
- Nothing to re-instrument — no new decorators, no new SDK. If it worked against LangSmith, it works here.
Once traces are landing, the parts LangSmith doesn't do are what you came for:
- Replay — edit a prompt, model, or tool config, re-run, and diff span by span with a determinism verdict.
- Agent surface / MCP — token-budgeted, LLM-legible run views so an agent can debug an agent.
- Eval-rigor — judge your judges before you trust a score.