JamJet
Open Source

Open Source

JamJet's open-source durable workflow runtime — Rust core, Python and Java SDKs, native MCP and A2A support.

JamJet Open Source

The open-source side of JamJet is a durable workflow runtime built specifically for AI agents. The core is Rust (for performance). The authoring surface is Python and Java (for ergonomics). Every execution is event-sourced, checkpointed, and replayable.

If you want to govern an existing AI app — block tools, set cost ceilings, get a dashboard — see JamJet Cloud instead. Cloud and the open-source runtime work together but are separate products.

Get started

Quickstart

Python or Java in 60 seconds.

Concepts

Agent, Workflow, Span, Checkpoint.

Python Runtime

Decorators, asyncio, Pydantic.

Java Runtime

Annotations, Spring, Maven Central.

Protocols

MCP

Native Model Context Protocol support.

A2A

Agent-to-Agent protocol bridging.

Research & Eval

Eval Harness

Replay, fork, statistical compare.

Coordinator

Dynamic agent routing.

Research Guide

For paper authors and academic users.

Integrations

Use JamJet Cloud with the AI frameworks you already have — Vercel AI SDK, LangChain4j, Spring Boot.

Quickstart

Run a durable JamJet workflow in 60 seconds. Python or Java.

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JamJet Open SourceGet startedProtocolsResearch & Eval