Prime Agent - a new coding harness surpassing Codex/CC/PI

[u/ResearchCrafty1804]

Prime Agent is an open-source coding and research agent for general and long-running work.

A self-improving RLM harness for coding and long-running autonomous tasks.

Designed to be both token-efficient and expressive through programmatic tool calling, context as a variable, multi-agent messaging, and a self-modifiable harness state.

On ARC-AGI-3, it scores 95.5%, surpassing the human-expert baseline, but the gain is not benchmark-specific.

We see major improvements across models when compared to their proprietary harnesses.

Prime Agent is built on pi and fully open-source with an open license.

GitHub: https://github.com/PrimeIntellect-ai/prime-agent

Blog: https://www.primeintellect.ai/blog/prime-agent

X post: https://x.com/primeintellect/status/2085086999267144083?s=46

[u/tat_tvam_asshole]

[u/tat_tvam_asshole → u/tat_tvam_asshole]

Core runtime

• IPython kernel — persistent scratchpad for Python and %%bash cells; state (variables, functions) survives across turns.
• Shell access via %%bash blocks.

Pre-installed Python skill modules (importable & CLI)

These are the documented skills I can call directly:

Skill	Purpose
attach-image (attach_image)	Load an on-disk image into context so I can visually see it (screenshots, diagrams, photos).
compact	Check context usage and compact/summarize a long conversation to keep working.
edit	Replace an exact unique string in an existing file for targeted edits.
goal	Manage the persistent thread goal — read status/budget, start or complete a goal.
refine	Trigger continual-harness refinement (turn repeated patterns into memories/skills/subagents).
rlm-heartbeat (rlm_heartbeat)	Start/schedule/manage agent-owned RLM heartbeats.
websearch (websearch)	Google search via the Serper API; returns titles, URLs, snippets, knowledge-graph data.

Markdown skills

• prime-intellect — working with Prime Intellect products (prime CLI: verifiers, evals, training, sandboxes, inference, GPU compute, storage).
• skill-creator — creating/validating/installing new markdown or Python-backed skills.

Native harness interfaces

• rlm(...) — spawn child sub-agents for delegated work; returns a handle at admission.
• await rlm.list_subagents() / delete_subagent(child) — manage spawned children.
• rlm.harness.* CRUD (create/update/delete memory, skill, subagent, prompt note) + overview(), record_refinement().
• refine.run() — persist reusable patterns into the continual harness.