@seonggukchoi/opencode-claude-code-provider

Claude Code CLI based provider for OpenCode.

What it does

• Exposes a custom LanguageModelV2 provider named claude-code
• Runs claude -p --verbose --input-format text --tools "" --output-format stream-json as a pure LLM client
• Injects OpenCode tool schemas into the Claude system prompt and converts <tool_call> text blocks into AI SDK tool-call parts
• Keeps all tool execution inside OpenCode, including OpenCode-only tools such as todowrite and task
• Persists the Claude session id in providerMetadata["claude-code"].sessionId
• Sends prompt text over stdin so long transcript bootstrap does not hit argv size limits

Tool behavior

• Claude native tools are disabled for every request
• Claude must emit exactly one <tool_call>{"name":"...","arguments":{...}}</tool_call> block when a tool is needed
• OpenCode executes the tool and feeds the result back through its normal tool loop

Known limits

• Non-streaming generation is intentionally not supported
• effort is retained for config compatibility but is not sent to the CLI yet
• maxTurns is hardcoded to 1 because Claude does not execute tools directly in this mode
• loadClaudeMd is hardcoded to false — CLAUDE.md loading is not supported
• permissionMode is hardcoded to bypassPermissions (--dangerously-skip-permissions)
• OpenCode custom providers still need a models block in config for model discovery
• OpenCode 1.3.0 currently breaks direct file: package loading by appending @latest

Configuration examples

{
  "plugin": ["@seonggukchoi/opencode-claude-code-plugin"],
  "provider": {
    "claude-code": {
      "npm": "@seonggukchoi/opencode-claude-code-provider",
      "models": {
        "sonnet": { "id": "claude-sonnet-4-6" },
        "opus": { "id": "claude-opus-4-6" },
        "haiku": { "id": "claude-haiku-4-5" }
      }
    }
  },
  "model": "claude-code/sonnet"
}

• Full config example: packages/opencode-claude-code-provider/docs/config.example.json
• Minimal config example: packages/opencode-claude-code-provider/docs/config.minimal.example.json

OpenCode custom providers still require a models block for model discovery, so the minimal example keeps only the model ids.

For local unpublished testing, replace the package names in those examples with your local install strategy such as a tarball or registry override.

Local testing

• Build:
  • pnpm --filter @seonggukchoi/opencode-claude-code-provider build
  • pnpm --filter @seonggukchoi/opencode-claude-code-plugin build
• Smoke test:
  • pnpm --filter @seonggukchoi/opencode-claude-code-provider test:smoke
• Smoke script:
  • packages/opencode-claude-code-provider/test/smoke.mjs
• Current limitation:
  • OpenCode 1.3.0 breaks direct file: package loading by appending @latest

Failure handling

• Missing CLI executable: expect a process spawn failure such as ENOENT
• Unsupported auth status command on older CLI builds: use claude auth status || claude doctor
• Invalid CLI JSONL output: the provider fails the stream with a parsing error
• Invalid <tool_call> payloads are surfaced back as plain text instead of being executed

Release checklist

• pnpm --filter @seonggukchoi/opencode-claude-code-provider test
• pnpm --filter @seonggukchoi/opencode-claude-code-provider build
• pnpm --filter @seonggukchoi/opencode-claude-code-provider test:smoke
• Verify packages/opencode-claude-code-provider/docs/config.example.json
• Verify packages/opencode-claude-code-provider/docs/config.minimal.example.json

Internal docs

• Full config example: packages/opencode-claude-code-provider/docs/config.example.json
• Minimal config example: packages/opencode-claude-code-provider/docs/config.minimal.example.json
• Smoke test: packages/opencode-claude-code-provider/test/smoke.mjs