Harness reference

Where each harness expects context files. The source of truth init, document, and scope read from.

Claude Code

Purpose	Location
Project rules	`CLAUDE.md` (symlink to `AGENTS.md` by default)
Skills	`.claude/skills/<name>/SKILL.md`
Slash commands	`.claude/commands/<name>.md`
Sub-agents	`.claude/agents/<name>.md`
Hooks	`.claude/hooks.json`
Auto-loaded rules	`.claude/rules/<NN>-<name>.md` (optional)

Cursor

Purpose	Location
Pointer to AGENTS.md	`.cursor/rules/main.mdc` with `alwaysApply: true`
Scoped rules	`.cursor/rules/<area>.mdc` with `globs`

---
description: Always-on pointer to /AGENTS.md
globs: []
alwaysApply: true
---

Codex / generic

AGENTS.md at the repo root. The emerging cross-tool standard.

GitHub Copilot

Purpose	Location
Pointer to AGENTS.md	`.github/copilot-instructions.md`
Path-specific	`.github/instructions/<name>.instructions.md` with `applyTo`
Domain profiles	`.github/agents/<name>.agent.md`

Windsurf

Purpose	Location	Limit
Pointer to AGENTS.md	`.windsurf/rules/main.md`
Workspace rules (legacy)	`.windsurfrules`	6,000 chars
Rule directory	`.windsurf/rules/<name>.md`	12,000 chars total
Cross-session memories	`.windsurfmemories`	Agent-managed

Character budgets are hard limits; exceeding them silently truncates.

Cowork

Skills as <skill-name>/SKILL.md in the workspace folder, packageable as .plugin.

Which to target

Default reasoning:

Claude Code or Cowork → AGENTS.md with CLAUDE.md symlink.
Cursor → .cursor/rules/main.mdc pointer.
Codex → AGENTS.md already covers it.
Copilot → .github/copilot-instructions.md pointer.
Windsurf → .windsurf/rules/main.md pointer.
None mentioned → ask. Do not assume.

`docs/agents/`: harness-agnostic overflow

When AGENTS.md grows past ~80 lines, per-area conventions split into docs/agents/<area>.md. No harness auto-loads this, but any agent can be told to read it. Reference from AGENTS.md's "See also".

`.claude/rules/`: optional Claude-Code-only auto-load

Claude Code reads every file in this directory in filename-sort order. No other harness does. Use only if you specifically want auto-loading; for harness-agnostic overflow, use docs/agents/.

Numeric prefix sets load order:

00-09 orientation
10-29 global style
30-49 verification and build
50-69 per-area (frontend, db, infra)
70-89 security, MCP, credentials
90-99 exceptions and overrides

Leave gaps so future rules slot in without renumbering.