feat(kimi-code): add ACP server support

[robinfai]

Related Issue

Closes #133

Problem

See linked issue.

Kimi Code did not expose an ACP server entry point, so ACP-capable clients could not start, authenticate, create sessions, stream prompt turns, or use Kimi Code session capabilities through the Agent Client Protocol.

What changed

Adds a kimi acp stdio server backed by @agentclientprotocol/sdk.

Implemented ACP support for:

• initialize
• authentication method discovery and authenticate
• session/new
• session/prompt
• session/cancel
• session/close
• session/list
• session/resume
• unstable session/fork
• unstable session/set_model

The ACP bridge maps prompt content, assistant/thinking/tool updates, tool permission requests, configured models, and session-scoped MCP servers into the existing Kimi Code SDK/session flow. ACP-provided MCP servers are passed through create/resume/fork session paths, with stdio and HTTP transports supported.

Unsupported ACP inputs such as audio prompt blocks, additionalDirectories, session/list cursors, SSE MCP servers, and ACP-transport MCP servers return invalid_params instead of silently degrading.

Also included:

• CLI/docs updates for kimi acp
• ACP adapter/unit tests
• SDK/core tests for session-scoped MCP config
• a changeset for @moonshot-ai/kimi-code and @moonshot-ai/kimi-code-sdk

ACP Compatibility Validation

Validated supported behavior:

• initialize returns Kimi Code agent metadata, auth methods, prompt image/context capabilities, HTTP MCP support, and session close/list/resume/fork capabilities.
• authenticate checks existing Kimi Code config, configured model/provider state, OAuth readiness, model-env configuration, and terminal auth availability when the ACP client supports it.
• session/new, session/prompt, session/cancel, and session/close are covered.
• session/list, session/resume, unstable session/fork, and unstable session/set_model are covered.
• stdout remains reserved for JSON-RPC protocol messages in stdio mode.
• ACP prompt blocks for text, image, resource links, embedded text resources, and embedded image resources are mapped to Kimi Code SDK input.
• ACP stdio and HTTP MCP servers are mapped into session-scoped Kimi Code MCP config.
• Kimi Code assistant text, thinking, tool calls, tool results, warnings, and MCP status events are streamed as ACP session updates.
• Kimi Code tool approval requests are mapped to ACP permission requests.

Intentional MVP boundaries:

• audio prompt blocks return invalid_params
• additionalDirectories returns invalid_params
• session/list cursor pagination returns invalid_params
• SSE MCP servers return invalid_params
• ACP-transport MCP servers return invalid_params

Validation performed:

• ACP registry auth check helper passed.
• pnpm run lint passed with 0 errors; existing repository warnings remain.
• pnpm run typecheck passed.
• pnpm test passed.
• tsdown build for apps/kimi-code passed.
• Merge check against latest MoonshotAI/kimi-code/main passed with no conflicts.
• Temporary merged validation against latest main passed pnpm run lint, pnpm run typecheck, and pnpm test.
• changeset status --since upstream/main reports minor bumps for @moonshot-ai/kimi-code and @moonshot-ai/kimi-code-sdk.

Checklist

• I have read the CONTRIBUTING document.
• I have linked a related issue, or explained the problem above.
• I have added tests that prove my feature works.
• Ran gen-changesets skill, or this PR needs no changeset.
• Ran gen-docs skill, or this PR needs no doc update.

[changeset-bot]

🦋 Changeset detected

Latest commit: 797d9ea

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
@moonshot-ai/kimi-code	Minor
@moonshot-ai/kimi-code-sdk	Minor

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