acp-provider

# ACP providers Known agents can be discovered automatically when their CLI is installed on the host: `opencode`, `omp`, `grok`, and `hermes` appear as `acp-opencode`, `acp-omp`, `acp-grok`, and `acp-hermes-agent`. Inspect the target host's catalog with `bb provider list` and `bb provider models <provider-id>` using its environment or machine selector. Agents in the official ACP registry can be added without writing JSON. `bb acp registry [--refresh] [--json]` lists them with a status: `available`, `added`, `update available`, `built in` (bb already ships it), or `manual install` (the agent ships only as a downloadable binary). `bb acp add <agent-id>` adds the agent as provider `acp-<agent-id>`, or moves an added agent to the registry's current version while keeping the fields edited by hand. `bb acp remove <agent-id>` removes it. The plugin's settings page shows the same list. An added agent is an entry in the `Custom agents` setting that runs `npx -y <package>` or `uvx <package>` on the thread's host, so the host needs Node.js or uv. The list is cached for six hours; when the registry cannot be reached the saved copy is shown with the reason. To hide a detected ACP agent, use `bb provider disable acp-opencode`, or Disable on Settings → Providers. Restore it with `bb provider enable acp-opencode`. This leaves other ACP agents and the host CLI intact. Disabled agents skip background capability probing. `bb provider list --all` includes disabled agents. Cursor project skills come from `.cursor/skills`, which can link to `.agents/skills`. BB lists these linked skills as read-only under `cursor-project`. ACP agents may reject unlisted model IDs. OpenCode requires models in its own configuration; BB discovers them there. OpenCode agents are session modes, not models selectable through BB's model field. Grok Build advertises models and `thought_level` options over ACP, so the picker follows the connected agent (including `xhigh` on grok-4.6). BB launches OpenCode sessions with `OPENCODE_CLIENT=acp` and `OPENCODE_ENABLE_QUESTION_TOOL=false`, overriding inherited and custom launch values. Native questions have no ACP interaction handler in BB; agents use the ask-user-question plugin’s `AskUserQuestion` tool instead. This also applies to custom agents with `dialect: "opencode"` and does not change OpenCode config files. OpenCode and Grok ACP support the core `bb thread compact` command; Cursor ACP does not expose compatible compaction. Check the actual agent's capabilities before attempting provider-specific recovery. OpenCode Go subscription usage is available in Provider usage when the selected machine has OpenCode installed and a Go subscription. Sign in to Go in OpenCode on that machine, then refresh its OpenCode tab. Verify with `bb settings usage --machine <id-or-name> --json`; the SDK equivalent is `bb.sdk.system.usageLimits({ hostId, providerId: "acp-opencode" })`. BB reports Go's five-hour, weekly, and monthly usage and reset times, not local session token totals or other OpenCode providers' subscriptions. The collector checks `OPENCODE_API_KEY`, then the active official Console account and organization in `$XDG_DATA_HOME/opencode/opencode.db`, then active v2 `credential` table API keys or official Console OAuth credentials (`opencode-go` before `opencode`), then `OPENCODE_AUTH_CONTENT` or `$XDG_DATA_HOME/opencode/auth.json`. The default data directory is `~/.local/share/opencode`. Database storage is read only; expired Console sessions must be refreshed by OpenCode. V2 OAuth requires the device login method and account/organization metadata for the official Console server. API-key login prefers the `opencode-go` credential and accepts the shared `opencode` credential when Go is subscribed. Custom launch `env` values take precedence over the host environment. A custom OpenCode wrapper must declare `dialect: "opencode"` and `providerUsage: true` to expose its usage. Missing credentials, rejected keys, and collection errors remain unavailable states rather than zero usage. Never print API keys when diagnosing setup.