AI AgentsOpen_source
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Prime Agent

A self-improving RLM harness for long-running coding and research work

Overview

About Prime Agent

Prime Agent is an open-source coding and research agent from Prime Intellect, built for work that runs longer than a chat window. Its design rests on two ideas that set it apart from the usual agent loop. The Recursive Language Model treats context as variables - a prompt is a value you can hold and pass around - and treats tools and subagents as function calls inside a persistent Python REPL. The Continual Harness stores supplemental prompts, memories, skill descriptions and reusable subagent specifications as durable state the agent can refine over time, local to the session by default.

The practical consequence is that everything is programmatic. The REPL is the model's built-in tool, so file operations, shell commands, tool use, subagent spawning and context management all happen as code rather than as a fixed menu of tool calls. rlm(...) spawns real child agents for parallel or background work and hands their results back as values. /refine reviews the current trajectory and applies small, evidence-backed updates to the harness state, never touching the immutable base system prompt, with recorded snapshots so a bad refinement can be rolled back. One warning belongs at the top because the project puts it there itself: Prime Agent executes model-generated Python and project commands with your user permissions, and its worker and kernel processes improve lifecycle isolation and recovery but are explicitly not a security sandbox. Run it against a disposable clone, a clean worktree or a restricted environment, not a checkout you cannot restore. There is a paper behind the design (arXiv 2608.23552), and the agent and TUI are built on top of pi by earendil-works, which the project credits.

Pricing

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Free tier
  • Free (MIT, bring your own provider)$0/mo

Checked 2026-09-30

Details

GitHub Stars 21,423
Forks 2,353
Data from: GitHub • Website•Updated: Sep 30, 2026
code-generationsoftware-engineeringopen-sourceautonomous-agent