# Reef

> Updated 2026-09-12 · type: tool · category: mcp-agents · status: active · rev 1

Reef gives agents a serve-observe-grow-commit loop: production feedback becomes versioned updates to weights or to the agent's prompts, rules and skills.

- Open source: yes (Apache-2.0)
- Self-hostable: yes
- Pricing model: free
- Best for: Teams running agents in production who currently improve them by hand-editing prompts, and want that loop observed, versioned and repeatable.
- Last verified: 2026-09-12

- **Canonical:** https://gtmstacker.com/registry/tool/reef/
- **Source:** [github · human-agent-society/reef](https://github.com/human-agent-society/reef)
- **Tags:** mcp-agents, agent-infrastructure, continual-learning, feedback-loops, self-hostable
- **Repository:** https://github.com/human-agent-society/reef

## Is Reef open source?

Yes, Reef is open source under the Apache-2.0 license.

## How much does Reef cost?

Reef is free to use.

## Can I self-host Reef?

Yes, Reef can be self-hosted (the source is available under the Apache-2.0 license).


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Open-source infrastructure (Apache-2.0, 1.1k★ within ~10 days of release) for continually self-improving agents: a serve → observe → grow → commit loop that matches production feedback to updates and ships them as versioned changes — either training model weights (via Slime/SGLang) or evolving the agent's harness of prompts, rules and skills.

## Provenance

- Apache-2.0 independently WebFetch-verified 2026-09-12 (1.1k★, 258 commits, active Discord/Discussions). Surfaced via the 2026-09-12 viral-posts brief (maintainer's milestone post).
- Curated from the GTM Stacker signal registry (2026-09-12 pass: daily pull + viral-posts brief); license independently WebFetch-verified 2026-09-12.

## Why it matters for a GTM stack

Every team running outreach or enrichment agents is already doing continual improvement — informally, by editing prompts after bad runs. Versioning that loop (observe the failure, generate the update, commit it like code) is the difference between an agent that drifts and one that compounds.