LangWatch vs PetalTrace

LangWatch is an AI agent engineering platform for teams preparing agents for production. Simulations cover multi-turn conversations, tool use, recovery, and business outcomes before launch. Evaluations can run on datasets, production traffic, or in CI/CD workflows that gate merges. Traces show agent steps alongside cost, tokens, duration, errors, evaluations, and annotations. Integrations include Python and TypeScript SDKs, OpenTelemetry, REST ingestion, model providers, and frameworks such as LangGraph, LangChain, CrewAI, and DSPy. Voice-agent testing supports OpenAI Realtime, Gemini, ElevenLabs, Google Live API, Pipecat, WebSocket bots, and Twilio. Deployment options are managed cloud, self-hosted, and hybrid; self-hosting uses Docker Compose and the customer’s ClickHouse. LangWatch is open source under Apache 2.0. The Developer plan costs nothing and includes 50k events per month, 14-day data access, and two users. Growth costs €29 a month per core seat and includes 200k events. The trust center lists encryption, access controls, privacy features, and enterprise DPAs.

PetalTrace is an open-source observability platform for developers examining AI agent workflows. It captures prompts and completions, tool calls, token use, costs, and execution timelines, with a React web interface plus CLI, HTTP API, and MCP server access. Full prompt capture can include system prompts, message history, tool definitions, and model responses. Users can search prompt and completion text, compare runs for structural, content, and cost differences, and replay runs with changed models or temperatures or in mocked mode. The platform accepts standard OpenTelemetry traces, including from applications that do not use PetalFlow. PetalFlow integration adds graph topology, node inputs and outputs, and replay-capable snapshots. Trace data is documented as stored in SQLite, and the software can be built from source or run from a release binary as a local daemon. Authentication is described as future functionality and disabled by default. The public repository identifies an MIT license; no commercial pricing or usage limits are stated.