spanlens/Spanlens

spanlens

TypeScript9updated 4mo ago

Open source LLM observability and monitoring. Drop-in proxy for OpenAI, Anthropic, and Gemini with request logging, cost tracking, and agent tracing. Self-host with one Docker command. MIT.

Claude

ai-agentsanthropicclickhousecost-trackinggeminillmllm-monitoringllm-observabilityllmopsmonitoringnextjsobservability

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README

Spanlens

Open-source LLM observability and monitoring. Record every OpenAI / Anthropic / Gemini / Azure OpenAI / Ollama call with one line of code. Plugs into Vercel AI SDK, LangChain, and LlamaIndex too. Query the same data directly from Cursor, Claude Desktop, or Continue via the bundled MCP server. Get cost, latency, tokens, traces, anomalies, PII scan, and model-swap suggestions out of the box. Self-hostable. MIT.

Hosted: spanlens.io · npm: @spanlens/sdk · PyPI: spanlens · CLI: @spanlens/cli · MCP: @spanlens/mcp-server · Status: status.spanlens.io · Changelog: spanlens.io/changelog

Why Spanlens?

Helicone was acquired and its roadmap is uncertain.
Langfuse is powerful but complex to set up and expensive to scale.
Spanlens ships the 20% of features that cover 80% of real production needs. You get request log, cost tracking, agent tracing, anomaly detection, PII scanning, and prompt versioning with a clean UI, a two-minute setup, and pricing that doesn't punish growth.

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