Coding Harness

YaOS developer-experience capability for reliable AI-assisted engineering.

YaOS CAPABILITYPlatform → Developer Experience → Coding Harness

Definition. Coding Harness is the YaOS developer-experience layer that gives AI coding agents the context, engineering standards, workflows, tools, verification and guardrails needed to work reliably across Yarnit codebases.

PLAN BUILD RUN OPERATE Planner Copilot → Coding Harness → YaOS Runtime → AgentOps / Evals What to build How agents build it How agents execute How we observe & govern

Two planes, one operating system

Development plane

Coding Harness governs Claude, Codex, Antigravity, Cursor and Copilot while they inspect, modify, validate and review code.

Runtime plane

Agent Harness / YaOS Runtime governs production agents, models, context, tools, memory, policies and observability.

Design principles

One source of truth: engineering policy is vendor-neutral; tool adapters stay thin.
Progressive disclosure: only the minimum useful context is loaded for a task.
Prompt for judgment, code for enforcement: linting, typing, architecture and CI are deterministic.
Repository knowledge survives chat sessions: architecture, decisions and ExecPlans live with code.
Evidence before completion: an agent cannot claim a test or check passed unless it actually ran.

Repository locations

yaos/
├── docs/platform/developer-experience/coding-harness/   # human-facing HTML
└── tooling/coding-harness/                              # executable harness
    ├── config/
    ├── context/
    ├── standards/
    ├── skills/
    ├── workflows/
    ├── enforcement/
    ├── templates/
    ├── evals/
    └── distribution/

YaOS Coding Harness · Human documentation layer. Machine-consumed files live under /tooling/coding-harness/.