agent-config-test

A test harness for empirically validating which .claude configuration features are supported by different AI coding IDEs (Claude Code, Cursor, Windsurf, GitHub Copilot, etc.).

Each configuration mechanism embeds a unique magic word. Running the test prompts confirms which layers are actually loaded and active in a given IDE.

How it works

Each magic word maps to one configuration concept:

Word	Source file	Config concept
TRELLIS	CLAUDE.md (root)	Persistent instructions (root)
WISTERIA	.claude/CLAUDE.md	Persistent instructions (alt)
OBSIDIAN	.claude/rules/conventions.md	Rules directory
STONEFLY	.claude/settings.json hooks	Hooks (UserPromptSubmit)
CORMORANT	.claude/skills/config-test/SKILL.md	Skills
GARNET	.claude/agents/config-test-agent.md	Subagents
PELICAN	.claude/mcp-servers/config-test-server.js	MCP servers (via .mcp.json)
FERRET	.claude/commands/legacy-test.md	Legacy slash commands
LARKSPUR	docs/CLAUDE.md	Nested CLAUDE.md (non-special)

If a word appears in the AI's response, the corresponding config layer was loaded.

Setup

The MCP server test requires installing dependencies first:

cd .claude/mcp-servers && npm install

Cursor

Cursor requires the "Include third-party Plugins, Skills, and other configs" setting to be enabled for .claude/ configuration files to be loaded. Without this setting, most magic words will not be detected.

Running the test

Single-shot test (8 of 9 magic words)

Paste the prompt from TEST-PROMPT.md into the IDE chat. It tests TRELLIS, WISTERIA, OBSIDIAN, STONEFLY, CORMORANT, GARNET, PELICAN, and LARKSPUR in one shot.

Manual test: FERRET

Type /legacy-test using the IDE's slash command menu. FERRET appearing in the response confirms .claude/commands/ slash commands are supported.

Results

Config feature	Claude Code	Cursor	Windsurf	GitHub Copilot
TRELLIS — CLAUDE.md (root)	✅	✅	✅	✅
WISTERIA — .claude/CLAUDE.md	✅	✅¹	✅	✅
OBSIDIAN — .claude/rules/	✅	❌	✅	✅
STONEFLY — .claude/settings.json hooks	✅	❌	✅	❌
CORMORANT — .claude/skills/	✅	✅	✅	✅
GARNET — .claude/agents/	✅	✅	❌	✅
PELICAN — .mcp.json	✅	❌	❌	❌
FERRET — .claude/commands/	✅	✅	❌	✅³
LARKSPUR — docs/CLAUDE.md	✅²	✅¹	❌	❌

¹ Cursor on-demand loading: WISTERIA and LARKSPUR are not auto-loaded at session start. Instead, Cursor surfaces them via its "relevant cursor rules" system when files in the corresponding directory are accessed. The words appear, but the loading mechanism is on-demand rather than pre-loaded.

² Claude Code on-demand loading: LARKSPUR (directory-scoped docs/CLAUDE.md) is loaded on-demand when files in that directory are accessed, not at session start. WISTERIA (.claude/CLAUDE.md) is auto-loaded at session start.

³ GitHub Copilot slash commands: FERRET is detected when /legacy-test is invoked, but this works via the AI agent searching for .claude/commands/legacy-test.md rather than the IDE natively registering slash commands from .claude/commands/. The command is not surfaced in autocomplete.

Repository structure

.
├── README.md                          # This file
├── CLAUDE.md                          # Root persistent instructions (TRELLIS)
├── TEST-PROMPT.md                     # Test prompts and results table
├── .mcp.json                          # MCP server registration
├── docs/
│   ├── CLAUDE.md                      # Directory-scoped config (LARKSPUR)
│   └── test-file.md                   # Test file to trigger docs/CLAUDE.md loading
└── .claude/
    ├── CLAUDE.md                      # Alt persistent instructions (WISTERIA)
    ├── settings.json                  # Hooks config (STONEFLY)
    ├── rules/
    │   └── conventions.md             # Auto-loaded rules (OBSIDIAN)
    ├── skills/
    │   └── config-test/
    │       └── SKILL.md               # Skills (CORMORANT)
    ├── agents/
    │   └── config-test-agent.md       # Subagent definition (GARNET)
    ├── commands/
    │   └── legacy-test.md             # Legacy slash command (FERRET)
    └── mcp-servers/
        ├── config-test-server.js      # MCP tool server (PELICAN)
        ├── package.json               # MCP server dependencies
        └── package-lock.json          # MCP server lockfile