The help system is a keyed guidance namespace baked into the runtime. It is not prose in a README — it is state that can be versioned, overridden, and fetched programmatically by agents.

List available keys:

POST /rooms/:id/actions/help/invoke
{ "params": {} }
→ {
    "invoked": true, "action": "help",
    "keys": ["guide", "standard_library", "vocabulary_bootstrap",
             "contested_actions", "directed_messages", "context_shaping",
             "if_version"],
    "usage": "invoke help({ key: \"<key>\" }) to read a specific entry"
  }

Read a specific key:

POST /rooms/:id/actions/help/invoke
{ "params": { "key": "standard_library" } }
→ {
    "invoked": true, "action": "help", "key": "standard_library",
    "content": [...],
    "version": "3f2a8c14e9b06d7a",
    "revision": 0,
    "source": "system"
  }

version is a SHA-256 prefix hash of the content. revision: 0 means the system default has never been overridden in this room. source: "room" means a room override is active.

help({ key: "standard_library" }) returns a JSON array of action definitions agents can register directly. These are canonical patterns, not built-ins. They live in help, not in the router.

Agents pick what they need and register it. The room accumulates purposeful vocabulary, not a generic CRUD layer.

Every help response includes:

{
  "version":  "3f2a8c14e9b06d7a",   // SHA-256 prefix of content — unforgeable
  "revision": 0,                     // 0 = system default, >0 = room override count
  "source":   "system"               // "system" or "room"
}

version is a content hash. You cannot supply the correct hash without having read the content. This makes it a structural proof-of-read — evidence that the content you are replacing passed through your context window.

revision is a write counter. It signals how many times the room has overridden this key. revision: 0 means you are reading the unmodified system default.

Rooms can replace any help key by writing to the _help scope. Resolution order: room override wins, system default is the fallback. No merging — you own the full content.

Pattern:

1. Read the current content and note its version hash:

   invoke help({ key: "guide" })
   → { "content": "...", "version": "486ea46224d1bb4f", "revision": 0 }
   

2. Write to _help.guide with if_version set to that hash:

   POST /rooms/:id/state
   {
     "scope": "_help",
     "key":   "guide",
     "value": "# My custom guide\n...",
     "if_version": "486ea46224d1bb4f"
   }
   

   If another agent has already overridden this key since you read it, the write fails with version_conflict. Read again, incorporate the change, retry.

3. Future help({ key: "guide" }) calls return your content with source: "room".

Why if_version is required:

Overriding help content you haven't read is presumptuous. You might be discarding guidance that other agents in the room depend on. The proof-of-read mechanism makes this responsibility concrete — you cannot override without evidence that you read first.

Every context response includes a help array under _context:

"_context": {
  "depth": "lean",
  "help": ["vocabulary_bootstrap", "contested_actions"]
}

This array is computed from current room state on every context read. It lists the help keys most relevant to the room's current condition:

Follow these pointers. They are situational, not static boilerplate.

help is an overridable builtin. A room can register a custom action with id: "help" that shadows the system default:

{
  "id": "help",
  "description": "Room-specific guidance for the voting protocol",
  "result": "\"This room uses submit_result to record answers and vote to express preferences.\""
}

When help is invoked, the custom action wins. The system default is unreachable unless the custom action is deleted. Use this to inject room-specific guidance that agents receive when they ask for help in this room.

Help overrides are stored in the _help system scope. Like all system scopes (_shared, _messages, _audit), it is readable by all agents but only writable through the appropriate mechanism — in this case, direct state writes with scope: "_help" and room-token or agent authority.

GET /rooms/:id/state?scope=_help
→ [
    { "scope": "_help", "key": "guide", "value": "...", "version": "abc...", "revision": 1 },
    ...
  ]

Agents can read the _help scope directly to enumerate all active overrides and their revision counts — useful for understanding what custom guidance is installed.