- `models`: optional per-agent model catalog/runtime overrides keyed by full `provider/model` ids. Use `models["provider/model"].agentRuntime` for per-agent runtime exceptions.

- `runtime`: optional per-agent runtime descriptor. Use `type: "acp"` with `runtime.acp` defaults (`agent`, `backend`, `mode`, `cwd`) when the agent should default to ACP harness sessions.

- `identity.avatar`: workspace-relative path, `http(s)` URL, or `data:` URI.

- Local workspace-relative `identity.avatar` image files are limited to 2 MB. `http(s)` URLs and `data:` URIs are not checked with the local file-size limit.

- `identity` derives defaults: `ackReaction` from `emoji`, `mentionPatterns` from `name`/`emoji`.

- `subagents.allowAgents`: allowlist of configured agent ids for explicit `sessions_spawn.agentId` targets (`["*"]` = any configured target; default: same agent only). Include the requester id when self-targeted `agentId` calls should be allowed. Stale entries whose agent config was deleted are rejected by `sessions_spawn` and omitted from `agents_list`; run `openclaw doctor --fix` to clean them up, or add a minimal `agents.list[]` entry if that target should remain spawnable while inheriting defaults.

- Sandbox inheritance guard: if the requester session is sandboxed, `sessions_spawn` rejects targets that would run unsandboxed.