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. 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 report their own models and may reject unlisted model IDs. For `acp-opencode` the list mirrors the OpenCode catalog, so add a model to the OpenCode config rather than bb's `customModels`: ```sh bb provider models acp-opencode --environment "$BB_ENVIRONMENT_ID" bb thread spawn --provider acp-opencode --model <provider/model> ``` OpenCode agents are session modes, not models selectable through BB's model field. OpenCode reports its primary agents as the `mode` session option, including custom agents from the OpenCode config directory and from the project's `.opencode/` directory, so project agents appear when the list is read for that project or environment: ```sh bb provider models acp-opencode --project "$BB_PROJECT_ID" bb thread spawn --provider acp-opencode --option mode=<agent> ``` bb lists only the agents OpenCode itself loads, and OpenCode does not read agent files from other folders such as `.agents/agents/`. To use such a folder, set `OPENCODE_CONFIG_DIR` as a machine variable or in a custom agent's `env`; a relative value is resolved in each workspace, so `.agents` lists every project's own `.agents/agents/*.md`: ```sh printf '.agents' | bb machine env set OPENCODE_CONFIG_DIR ``` Every file in that folder must be a valid OpenCode agent file; OpenCode refuses to start on one it cannot parse, such as `tools` written as a comma-separated list. 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. ## Custom ACP agents Register another ACP agent in the ACP providers plugin's `customAgents` setting, a JSON array: `bb plugin config provider-acp set customAgents '[...]'`. The plugin re-registers its providers as soon as the setting changes; no restart is needed. - Required: `id` (lowercase letters, digits, and dashes; permanent), `displayName`, and `command`. The provider id is `acp-<id>`. `cursor` is reserved; an entry with id `opencode`, `omp`, `grok`, or `hermes-agent` replaces the shipped agent. - Launch: `args`, `env`, and `cwd`. - `modelCli` for CLI model listing and selection, `reasoningCli` for launch-time reasoning flags, `nativeReasoning` for ACP `session/set_config_option` reasoning, and `permissionCli` for permission-mode launch flags. - `dialect` (`cursor`, `opencode`, `omp`, or `grok`) selects the vendor side channels bb reads. - `nativeSkillRoots` adds native skills to the composer: a `user` list resolved from the target host's home directory and a `project` list resolved from the workspace, each a relative path without dot segments. - `supportsManualCompaction` (default `false`) shows `/compact` only for agents that accept an explicit compaction request.