API Reference
The langprobe REST API — authentication, the interactive playground, and 101 endpoints generated from the OpenAPI schema.
The langprobe API reference is generated directly from the committed OpenAPI
schema (openapi/openapi.json) — 101 operations across 30 resource groups. Every
operation page shows the request/response shape, an interactive request panel,
and a copy-ready curl.
Set your host and key
Set these once and every curl and request panel on this site fills itself in:
Stored only in your browser (localStorage).
They're stored only in your browser (localStorage). The default host is
https://app.langprobe.com; self-hosters set it to their own ingest/api host
(e.g. http://localhost:7080).
Authentication
Every request authenticates with an API key — the lt_<public_id>.<secret> value
you mint under API keys → New key (see the
Quickstart). The schema declares two
equivalent security schemes:
Authorization: Bearer lt_<public_id>.<secret>X-Api-Key: lt_<public_id>.<secret>
Send whichever your client prefers. A quick smoke test:
curl https://app.langprobe.com/v1/runs \ -H "Authorization: Bearer lt_YOUR_PUBLIC_ID.YOUR_SECRET"
Trying requests in-browser
Requests from the interactive panel are made directly from your browser to
the configured host — there is no server-side proxy, which is what keeps this
site fully static. If your host doesn't allow cross-origin requests from the docs
origin, use the curl command shown on each page instead.
Resources
Runs
Query and manage agent/LLM runs
Traces
Send OpenTelemetry traces (/v1/traces)
Replays
Replay recorded runs and diff them
Eval Runs
Trigger and inspect eval runs
Prompts
Version prompts and pin aliases
Datasets
Curate runs into datasets
See Errors, pagination & rate limits for status codes and conventions.