Harn

Research summary

Harn is an agent framework expressed as a dedicated pipeline-oriented language and runtime. Programs define prompts, tools, policies, data flow, parallel work, retries, and agent loops explicitly instead of assembling these concerns from separate SDKs. The runtime supplies session and transcript management, context assembly, provider normalization, persistence, evaluation, and deterministic replay.

Typed tool declarations and compile-time capability checks govern filesystem, process, and network access, while durable steps allow long-running pipelines to checkpoint and resume after interruption. Harn can expose or consume integrations through MCP, ACP, and A2A, run as a server, or be embedded from Rust. Its intended workflows include coding agents, review and triage pipelines, MCP servers, evaluations, scheduled jobs, and webhook-triggered automation.

Harn is not primarily an end-user coding chat product, although templates can scaffold coding-oriented agents. The project is pre-1.0, so its language, standard library, and CLI may change between releases. Its workspace offers MIT or Apache-2.0 as alternative licenses.

Repository summary

Stars

23

Open issues

82

Last push

2026-09-13

Commits, 90 days

3,296

Repository activity

Active · 81/100

Version

0.10.137

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Classification

Pricing & services

Paid services unknown

Whether the provider offers paid products or services has not been established.

Licence scope