Add harness

Add a harness to agentsync

Adding a harness is judgment work (mapping the harness's config concepts) wrapped around a deterministic scaffold. Do the steps in order; don't skip the doc-reading.

1. Check it isn't already handled

Look in core/adapters/__init__.py (ADAPTERS) and config/profile.json. If the harness is there, stop — there's nothing to add.

2. Scaffold the adapter (deterministic)

python3 skills/add-harness/scaffold-adapter.py <name>

This writes core/adapters/<name>.py (stubbed) and registers it. It does NOT know the harness — you fill that in next.

3. Read the harness's docs (the judgment — do not guess)

Find and confirm, from the harness's own documentation:

• Instructions — does it read a user-scope instructions/rules file? Where? (If only inline in settings, mirror VS Code's approach.)
• MCP — its MCP config format and file location (or that it has none).
• Skills/permissions — any skill-availability control (or none).
• Enforcement (hooks) — the tricky part: can it run a command before a tool call? What JSON does the hook get on stdin (the command field name)? How does it signal "block"? If it has no hook surface but has a plugin system, mirror OpenCode's plugin. If it can't enforce at all, leave enforcement out of capabilities().

4. Fill the adapter

Implement capabilities() (honestly — only what the harness actually supports) and targets() using the existing target types (Link, Json, Merge, HookSpec). Reuse the shared core/enforcement/guard-commit.sh and session-nudge.sh — point the harness's hook at them per its contract; don't re-implement the gate. Keep extra_owned/extra_hooks from self._passthrough(ctx) so settings passthrough works.

5. Detection + test + verify

• Add a detection line for it in init.sh.
• Add assertions to tests/test_apply.py (its files render correctly in the sandbox).
• Run make verify. It must pass before you're done.

Reference

core/adapters/claude.py (full-featured) and vscode.py (instructions-only, reuses another harness's hooks) are the two ends of the spectrum to copy from.