# Precedent - the Harness for Evolving Memory

- **Event:** [The Harness Engineering & Model Wrangling Hackathon](https://cerebralvalley.ai/e/mongodb-nyc-hackathon)
- **When:** Sat, Sep 26 at 9:00 AM – 10:00 PM (EDT)
- **Where:** New York, NY
- **Team:** [Jason Peng](https://cerebralvalley.ai/u/jasonpeng2019), [Benjamin Huh](https://cerebralvalley.ai/u/buh0713), [Brianna Wang](https://cerebralvalley.ai/u/brianna-wang), [Connor Zhang](https://cerebralvalley.ai/u/XGHou)
- **GitHub:** https://github.com/brianna-wng/MA-Harness
- **Demo video:** https://drive.google.com/file/d/1TreRQ7mgPwAbzU1J5kkDSdKPG2aV3pt5/view?usp=sharing
- **Gallery:** https://cerebralvalley.ai/e/mongodb-nyc-hackathon/hackathon/gallery
- **Page:** https://cerebralvalley.ai/e/mongodb-nyc-hackathon/hackathon/gallery/60

We built a complete orchestration and memory system for teams of coding agents. At the foundation is our custom Orchestrator Harness. Every campaign begins with a fresh epoch, and ROOT divides the work into
  > parallel lanes. Each lane gets its own Git branch, isolated worktree, task card, and provider session, preventing workers from interfering with one another. The super-cache stages the standard tools, hooks, skills,
  > and provider configuration that every worker needs. A persistent monitor watches processes, results, leases, and lane health. Workers can send progress reports or request help through queue notifications, and ROOT
  > can respond without restarting their sessions.
  >
  > The harness also controls the complete result lifecycle. A worker must produce evidence tied to its exact lane and run. A separate reviewer decides whether the result passed, failed, or was blocked, and ROOT
  > separately accepts or rejects it. The harness can resume stopped lanes, correct invalid results, retire completed work, and clean up resources using exact identities.
  >
  > On top of this, we built a memory feedback loop built on top of the open source EverOS (not ours) and MongoDB-langchain Atlas (not ours). After work is reviewed, we record a trajectory describing the task, what was attempted, the result, and the review decision. EverOS turns reviewed experience into
  > historical cases and reusable skills. Our custom trust system verifies where those skills came from. An approved skill can become a trusted procedure with an immutable version, permissions, applicability rules,
  > current-version status, and revocation support.
  >
  > Trusted procedures can be published to MongoDB Atlas and found using real Vector Search. When a new task starts, the system searches EverOS for relevant local experience and Atlas for shared procedures. It
  > validates every result before use, builds a safe task-specific plan and worker context, and then launches a real coding worker. The reviewed outcome feeds back into memory for future tasks.
  >
  > The result is a coding-agent harness that can safely learn from reviewed work, reuse proven lessons, coordinate parallel agents, and improve across tasks while still working normally when every optional memory
  > feature is disabled.

On SWE-Marathon v1.1 ZSTD, our harness scored 47.3% above the official high average and 7.3% above the official xhigh average while xhigh used 91% fewer uncached tokens—11.14× lower—although our runs took longer, due to the agent no longer doing early termination.

## More from The Harness Engineering & Model Wrangling Hackathon

- [OneShot(Aegis)](https://cerebralvalley.ai/e/mongodb-nyc-hackathon/hackathon/gallery/57)
- [CyclopsDiary](https://cerebralvalley.ai/e/mongodb-nyc-hackathon/hackathon/gallery/58)
- [Incident Memory](https://cerebralvalley.ai/e/mongodb-nyc-hackathon/hackathon/gallery/59)
- [Harness Journey](https://cerebralvalley.ai/e/mongodb-nyc-hackathon/hackathon/gallery/61)
- [Team SG](https://cerebralvalley.ai/e/mongodb-nyc-hackathon/hackathon/gallery/62)
- [Sightline](https://cerebralvalley.ai/e/mongodb-nyc-hackathon/hackathon/gallery/63)

---

Markdown version of https://cerebralvalley.ai/e/mongodb-nyc-hackathon/hackathon/gallery/60. Site index for agents: https://cerebralvalley.ai/llms.txt · full text: https://cerebralvalley.ai/llms-full.txt