Show HN: Observability for Coding Agents and LLM Applications

Telemetry.dev launches an observability platform for AI and LLM applications, capturing every model call, tool step, and retrieval as OpenTelemetry traces with tokens, cost, latency, and errors attached. The platform supports any framework and language with no lock-in, offering a free plan of 10,000 spans per month and a five-minute setup time.

Stop guessing what your AI is doing Every model call, tool step, and retrieval in one trace — tokens, cost, latency, and errors attached. Built on OpenTelemetry: any framework, any language, no lock-in. First trace in five minutes. Free plan: 10k spans a month. No credit card. When something breaks, you'll know why One slow request or a month of spend: the traces and metrics to answer it, fast. Volume, cost, p95, errors The four numbers you actually check, split by model, provider, and environment. Failures surface as they happen Failed calls and timeouts stream in as they happen, with error type, status, and the full trace attached. Success rate 98%chat.completion · gpt-5.5 · 1,204 tok · $0.004 retrieval · pinecone · 8 docs · 120ms tool · get invoice · running User message LLM call · 820ms Response streamed Inputs and outputs, on your terms Flip capture on per environment to store exact inputs and outputs. Secrets are redacted at ingest, and you can add your own patterns. One bad trace in a million? Found. Search by name, filter by status, environment, framework, or session, and open the full trace in seconds. Send traces from anywhere Drop in our SDK, or point any OpenTelemetry exporter at our endpoint. Any framework, any language, no lock-in. Any framework. Any language. One endpoint. However you added AI to your app, send the traces here. We normalize them into one model of spans, tokens, and cost. - Connected Vercel AI SDK TypeScript · generateText, streamText - Connected LangChain Python · agents, RAG, tools - Connect OpenTelemetry Any language · OTLP/HTTP Tokens 30d 4.2M Cost 30d $1.2K p95 latency 1.8s By model By provider By environment Frequently Asked Questions What is telemetry.dev? telemetry.dev is an observability platform for AI and LLM apps. It captures every model call, tool step, and retrieval as OpenTelemetry traces, then attaches tokens, cost, latency, and errors — so you can debug failures and track spend across models, providers, and environments. How do I start sending traces? Drop in our SDK, or point any OpenTelemetry exporter at our endpoint. Add your project API key and your first trace shows up in about five minutes. Which frameworks and languages are supported? TypeScript and Python have first-party SDKs, and the Vercel AI SDK has a drop-in integration. Anything else that emits standard OTLP over HTTP — LangChain, OpenLLMetry-instrumented apps, or your own OpenTelemetry setup — works through the same endpoint. More drop-in integrations are on the way. How is cost calculated? Cost is computed server-side from each call's real token usage — input, output, cached, and reasoning — against current per-model pricing for 4,700+ models. There are no client-side estimates to keep in sync, and you can override cost per span when you need to. Is the free plan actually free? Yes, with no credit card. You get 10k spans a month, 7-day retention, one project, and two seats, free for as long as you want. Upgrade only when your volume outgrows it. Can I keep prompts and completions out of storage? Yes. Input and output capture is a per-environment switch, so you can store full prompts in development and none in production. Secrets like API keys are redacted at ingest, and you can add custom redaction patterns per project. Your first trace is five minutes away Install one package, add an API key, send a request. That's the whole setup. Free plan includes 10k spans a month. No credit card required.