[new-rules] Reworking the agent harness based on Anthropic + Google papers — feedback wanted

[mhenke]

Two papers changed how I think about agent harnesses.

Anthropic (The new rules of context engineering for Claude 5 generation models, Aug 2026) cut 80% of Claude Code's system prompt with no eval loss. They swapped rules for judgment, examples for interfaces, upfront context for progressive disclosure. Google (The New SDLC with Vibe Coding, May 2026) frames "vibe coding" vs. "agentic engineering" as a harness problem, not a model problem.

This branch applies those ideas to OMOS.

What changed

• Orchestrator routing (src/agents/orchestrator.ts): simplified from rigid rules to a routing threshold with judgment guidance.
• Progressive disclosure: 10 skills restructured as slim SKILL.md files pointing to references/full-guide.md. Agents load deep content only when needed.
• Eval system (src/evals/): assertion-based framework that verifies progressive disclosure actually works end-to-end.
• Edge-case guidance in the orchestrator prompt: clarification-seeking, architectural judgment, the "looks right" trap.

What I'm deferring

• Auto-memory. No cross-session memory yet.
• Conductor mode. No /conductor toggle or bounded-autonomy loop.
• Tool interface design. Tools already use enums where it matters.
• Token economics events. No consumer for JSONL cost events yet.

What I'm asking

1. Does judgment-over-rules feel right, or are there cases where explicit rules still win?
2. Are auto-memory and conductor mode the right next priorities?
3. Anything deferred that should move up?

Branch: omos/new-rules

Key files: src/agents/orchestrator.ts, src/evals/, src/observability.ts, src/skills/*/SKILL.md + references/full-guide.md

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For developers: Eval CLI: bun run eval. Add cases in src/evals/orchestrator-routing/eval.json. Cloned deps at .slim/clonedeps/repos/ are read-only. this is manual. you paste in the prompt, then copy the results.

[mhenke]

https://github.com/alvinunreal/oh-my-opencode-slim/tree/omos/new-rules

To try it locally:

git fetch upstream omos/new-rules
git checkout omos/new-rules
bun run build

Then point OpenCode at the branch. In OpenCode, run:

/omos-set-locations /home/mhenke/Projects/oh-my-opencode-slim/.slim/worktrees/new-rules

Restart OpenCode after that — it loads plugins on startup, so the restart is what actually swaps in the new code.

If you don't have the upstream remote yet: git remote add upstream https://github.com/alvinunreal/oh-my-opencode-slim.git