u/ComposerFirm8218

When your agent pipeline fails at step 3, you shouldn't have to re-run steps 1 and 2 to test a fix.

SwarmTrace records every agent action as a span tree and lets you fork execution from any past step — edit a prompt or tool output, replay only the downstream agents, and compare the two runs side by side.

- Open source, self-hostable

- PyPI SDK: pip install swarmtrace

- OTLP export (Jaeger/Datadog compatible)

- WebSocket live streaming as agents run

Demo: https://swarm-trace.vercel.app

GitHub: https://github.com/codewithleo1/SwarmTrace

Debugging LangGraph pipelines is painful. When a 4-agent system fails,

you don't know which agent caused it, logs are flat, and you have to

re-run everything from scratch to test a fix.

I built SwarmTrace to solve this:

- Records every agent action as an OpenTelemetry span tree

- Visualises the execution graph interactively (React Flow)

- Time-travel replay — click any past step, edit the prompt or tool

output, and replay only the downstream agents

- LLM-as-judge scores each agent's output automatically

- WebSocket live streaming as agents run

- OTLP export (Jaeger/Datadog compatible)

- PyPI SDK: pip install swarmtrace

Live demo: https://swarm-trace.vercel.app

GitHub: https://github.com/codewithleo1/SwarmTrace

Stack: FastAPI + LangGraph + Neon Postgres + React + Groq

Would love feedback from anyone building multi-agent systems.

Debugging LangGraph pipelines is painful. When a 4-agent system fails,

you don't know which agent caused it, logs are flat, and you have to

re-run everything from scratch to test a fix.

I built SwarmTrace to solve this:

- Records every agent action as an OpenTelemetry span tree

- Visualises the execution graph interactively (React Flow)

- Time-travel replay — click any past step, edit the prompt or tool

output, and replay only the downstream agents

- LLM-as-judge scores each agent's output automatically

- WebSocket live streaming as agents run

- OTLP export (Jaeger/Datadog compatible)

- PyPI SDK: pip install swarmtrace

Live demo: https://swarm-trace.vercel.app

GitHub: https://github.com/codewithleo1/SwarmTrace

Stack: FastAPI + LangGraph + Neon Postgres + React + Groq

Would love feedback from anyone building multi-agent systems.

Debugging LangGraph pipelines is painful. When a 4-agent system fails,

you don't know which agent caused it, logs are flat, and you have to

re-run everything from scratch to test a fix.

I built SwarmTrace to solve this:

- Records every agent action as an OpenTelemetry span tree

- Visualises the execution graph interactively (React Flow)

- Time-travel replay — click any past step, edit the prompt or tool

output, and replay only the downstream agents

- LLM-as-judge scores each agent's output automatically

- WebSocket live streaming as agents run

- OTLP export (Jaeger/Datadog compatible)

- PyPI SDK: pip install swarmtrace

Live demo: https://swarm-trace.vercel.app

GitHub: https://github.com/codewithleo1/SwarmTrace

Stack: FastAPI + LangGraph + Neon Postgres + React + Groq

Would love feedback from anyone building multi-agent systems.

Debugging LangGraph pipelines is painful. When a 4-agent system fails,

you don't know which agent caused it, logs are flat, and you have to

re-run everything from scratch to test a fix.

I built SwarmTrace to solve this:

- Records every agent action as an OpenTelemetry span tree

- Visualises the execution graph interactively (React Flow)

- Time-travel replay — click any past step, edit the prompt or tool

output, and replay only the downstream agents

- LLM-as-judge scores each agent's output automatically

- WebSocket live streaming as agents run

- OTLP export (Jaeger/Datadog compatible)

- PyPI SDK: pip install swarmtrace

Live demo: https://swarm-trace.vercel.app

GitHub: https://github.com/codewithleo1/SwarmTrace

Stack: FastAPI + LangGraph + Neon Postgres + React + Groq

Would love feedback from anyone building multi-agent systems.