opencode-ccgo-provider/README.md

# opencode-commandcode-provider

A native [AI SDK](https://ai-sdk.dev/) provider that connects [opencode](https://opencode.ai)
to the **CommandCode** `/alpha/generate` API.

It is the TypeScript successor to the `server.py` proxy in this directory. Where the proxy
exposed an OpenAI-compatible `/v1/chat/completions` endpoint that opencode reached with
`@ai-sdk/openai-compatible`, this package implements the `LanguageModelV3` interface directly,
so opencode talks to CommandCode with no Python process and no local proxy in the middle.

```
opencode  ──►  @ai-sdk/provider (LanguageModelV3)
                     │
                     ▼
           opencode-commandcode-provider
             transform → POST /alpha/generate
             NDJSON events → V3 stream parts
                     │
                     ▼
              api.commandcode.ai
```

`server.py` is kept in the repository as the reference implementation. All wire-shape decisions
(error reshaping, tool-call pairing, `tool_choice` emulation, retry policy, credential redaction)
originate there and are mirrored here.

## Requirements

- **Node.js >= 18** (uses global `fetch`, `ReadableStream`, `TextDecoder`, `structuredClone`).
- **opencode >= 1.17** that ships `@ai-sdk/provider@3.0.8` (verified against opencode 1.18.30).
- A CommandCode account and API key with access to the `/alpha/generate` endpoint.

## Install and wire into opencode

The provider is consumed directly from its build output via a `file://` spec. This bypasses
npm install and is the intended development workflow.

```powershell
# 1. build the provider
npm install
npm run build
```

```jsonc
// 2. ~/.config/opencode/opencode.json  (or a project opencode.json)
{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "commandcode": {
      "name": "Command Code",
      "npm": "file:///C:/DevTools/pienv/ccprovider/dist/index.js",
      "options": {
        "apiKey": "{env:COMMANDCODE_API_KEY}"
      },
      "models": {
        "deepseek/deepseek-v4-flash-vision-exp": {
          "name": "DeepSeek V4 Flash (Vision)",
          "limit": { "context": 1048576, "output": 256000 },
          "attachment": true,
          "modalities": { "input": ["text", "image"], "output": ["text"] }
        }
      }
    }
  }
}
```

Then set the key and restart opencode:

```powershell
$env:COMMANDCODE_API_KEY = "user_..."
opencode models commandcode
```

> opencode loads configuration **once at startup**. After changing `opencode.json`, a plugin, or
> a rebuilt provider, quit and relaunch opencode for the change to take effect.

The `models` map is required — opencode silently drops a custom provider whose model list is
empty. List every model you want selectable; the provider itself only needs `languageModel(id)`,
which it implements for any id passed to it.

## Configuration options

`provider.commandcode.options` is forwarded to `createCommandCode(options)`.

| Option | Type | Default | Description |
| --- | --- | --- | --- |
| `apiKey` | `string` | — | CommandCode API key. A bare token or `Bearer <token>` both work. |
| `headers` | `Record<string,string>` | `{}` | Extra request headers, merged over the built-in ones. An `Authorization` header is accepted as an alternative auth source. |
| `baseURL` | `string` | `https://api.commandcode.ai` | Upstream origin. Trailing slashes are stripped. |
| `ccVersion` | `string` | `1.15.1` | Value of the `x-command-code-version` header. |
| `maxRetries` | `number` | `2` | Retry attempts for retryable failures (429/5xx/network). |
| `retryMaxDelaySeconds` | `number` | `60` | Longest wait honoured from `Retry-After`; longer values are not retried. |
| `name` | `string` | `commandcode` | Provider id reported to the AI SDK. opencode sets this automatically. |

**Auth precedence:** `options.apiKey` wins; otherwise the value of an `Authorization` header in
`options.headers` (with a leading `Bearer ` stripped). If neither is present, requests are sent
unauthenticated and CommandCode will reject them.

## Features

| Capability | Status |
| --- | --- |
| Streaming (`doStream`) | Yes — CommandCode is always streamed upstream, then re-emitted as V3 stream parts |
| Non-streaming (`doGenerate`) | Yes — buffers the stream internally |
| Text deltas | Yes |
| Reasoning deltas | Yes — emitted as `reasoning-start` / `reasoning-delta` / `reasoning-end` |
| Tool calls | Yes — `tool-input-start` / `tool-input-delta` / `tool-input-end` / `tool-call` |
| Tool results | Yes — paired results are replayed; unpaired ids are dropped |
| Multiple images (vision) | Yes — `data:` URIs, raw base64, `Uint8Array`, and remote URLs |
| Token usage | Yes — input/output totals, cache read, reasoning tokens |
| Finish reasons | Yes — unified (`stop`, `length`, `tool-calls`, `content-filter`, `error`, `other`) plus raw |
| Sampling parameters | Yes — `temperature`, `topP`, `topK`, `stopSequences`, `seed`, presence/frequency penalties |
| `reasoning_effort` | Yes — via `providerOptions.commandcode` |
| Retry with backoff | Yes — 429/5xx and network errors, honouring `Retry-After` |
| Credential redaction | Yes — error bodies are scrubbed before surfacing |

### `tool_choice` handling

CommandCode accepts exactly one upstream value, `{"type":"auto"}`. The provider maps the AI SDK
values accordingly:

- `auto` — forwarded as `{"type":"auto"}`.
- `none` — emulated by sending **no tools at all**.
- `{ type: "tool", toolName }` — emulated by sending only that tool.
- `required` — not expressible upstream; tools are sent and the model decides.

### Reasoning effort

Set the per-request reasoning effort through provider options:

```jsonc
// opencode model options / variant
"options": { "providerOptions": { "commandcode": { "reasoningEffort": "high" } } }
```

Both `reasoning_effort` and `reasoningEffort` keys are recognised and forwarded as
`params.reasoning_effort`.

## How it works

```
src/index.ts      Public exports: createCommandCode + default.
src/model.ts      CommandCodeLanguageModel (LanguageModelV3): HTTP, retries, stream/generate.
src/transform.ts  LanguageModelV3CallOptions -> /alpha/generate envelope (JSON string).
src/events.ts     NDJSON/SSE line iterator over the upstream response body.
src/usage.ts      finish event -> V3 usage; finish-reason unification.
src/redact.ts     Credential scrubbing for error surfaces.
src/constants.ts  Defaults, header names, passthrough params, static config block.
scripts/smoke.mjs Live end-to-end check against api.commandcode.ai.
```

### Request lifecycle

1. opencode calls `provider.languageModel(id)`, then `model.doStream(options)`.
2. `transform()` converts the AI SDK prompt into the CommandCode envelope:
   - `system` text is joined into `params.system`.
   - user/assistant/tool messages become `params.messages` content parts.
   - assistant `tool-call` parts and `tool` results are only included when their ids are paired;
     unmatched ids (common after history truncation) are dropped because upstream rejects them.
   - image file parts become `{ type: "image", image, mimeType }`.
   - function tools become `{ type: "function", name, description, input_schema }`.
   - `stream` is **forced to `true`** — the endpoint answers `stream:false` with
     "Proxy use detected. This endpoint only serves CLI."
3. `model.ts` POSTs the envelope with the CommandCode headers and retries 429/5xx.
4. `events.ts` parses the NDJSON body (tolerating `data:` prefixes and `[DONE]`).
5. `model.ts` maps each upstream event to a `LanguageModelV3StreamPart` and always terminates
   with a `finish` part.
6. `doGenerate` drains the same stream and assembles a `LanguageModelV3GenerateResult`.

## Development

```powershell
npm install        # installs typescript, @types/node, @ai-sdk/provider
npm run typecheck  # tsc --noEmit
npm run build      # tsc -> dist/
npm run smoke      # live request against CommandCode
```

`scripts/smoke.mjs` reads the key from `COMMANDCODE_API_KEY`, falling back to
`provider.commandcode.options.apiKey` in `~/.config/opencode/opencode.json`. It exercises both
`doGenerate` and `doStream` and prints content, finish reason, and usage.

To smoke-test a specific model:

```powershell
node scripts/smoke.mjs deepseek/deepseek-v4.1-flash
```

### Verifying inside opencode

```powershell
opencode models commandcode
opencode run "Reply with exactly: pong" -m commandcode/deepseek/deepseek-v4-flash-vision-exp
opencode run "Use the glob tool to list *.mjs and report the filenames." -m commandcode/deepseek/deepseek-v4-flash-vision-exp
```

## Troubleshooting

| Symptom | Likely cause / fix |
| --- | --- |
| `Provider not found: commandcode` | Provider was dropped because `models` is empty, or the `npm` path is wrong. Confirm `dist/index.js` exists (`npm run build`) and that the `file://` path is absolute. |
| Models appear but every call fails auth | `options.apiKey` missing/expired, or `{env:COMMANDCODE_API_KEY}` not set in the environment opencode was launched with. |
| `stream ended ... no finish` / truncated output | Upstream closed the connection early. The provider emits a synthetic `finish`, but the response is incomplete; retry the turn. |
| Images are ignored by the model | The selected model is not vision-capable. Mark it with `"attachment": true` and `modalities.input: ["text","image"]` in `models`, and pick a vision model id. |
| Upstream 400 about tool calls | A `tool-call` or `tool-result` without a matching pair slipped through. Pairing is enforced in `src/transform.ts`; report a repro if it still occurs. |
| `tool_choice` seemingly ignored | Expected for `required`; upstream cannot force a call. `none` and named-tool are emulated via the tool list. |
| Config change had no effect | opencode reads config once at startup. Restart it. |

## Security

- Prefer `{env:COMMANDCODE_API_KEY}` (or opencode's `/connect` credential store) over an inline
  key in `opencode.json`.
- Upstream error bodies can echo credentials. `src/redact.ts` scrubs `Bearer` tokens, `user_`/`cc_`
  keys, `sk-…`-style keys, JWTs, and `key=value` secrets from any error surfaced to the client.
  Do not add logging of raw request/response bodies without passing them through `redact()`.
- Never commit real keys. `dist/`, `node_modules/`, `dump/`, and `*.log` are gitignored.