Telemetry.dev is an observability platform for AI and LLM apps, capturing every model call, tool step, and retrieval as OpenTelemetry traces with attached tokens, cost, latency, and errors.
Built on OpenTelemetry, it supports any framework and language without lock-in; first trace can be set up in five minutes.
Free plan offers 10,000 spans per month with no credit card required, 7-day retention, one project, and two seats.
Real-time monitoring surfaces failures as they happen, with error type, status, and full trace attached.
Key metrics include volume, cost, p95 latency, and errors, split by model, provider, and environment.
Input and output capture is per-environment, with built-in secret redaction and custom redaction patterns.
Traces can be searched by name, filtered by status, environment, framework, or session, and opened in full detail.
Supports SDKs for TypeScript and Python, plus integrations with Vercel AI SDK, LangChain, and any OTLP/HTTP exporter.
Cost is calculated server-side using real token usage against current pricing for 4,700+ models, with optional per-span override.