opencode-kimi-full

An opencode plugin that makes the Kimi Code path in opencode work like the official kimi-cli, using Kimi-specific extensions instead of just a generic OpenAI-compatible provider.

Compared with stock opencode Kimi setups, this plugin:

• uses the official Kimi device-flow OAuth against https://auth.kimi.com
• talks to https://api.kimi.com/coding/v1 through @ai-sdk/openai-compatible
• sends the same User-Agent / X-Msh-* fingerprint headers as kimi-cli
• reuses ~/.kimi/device_id for X-Msh-Device-Id
• adds prompt_cache_key, thinking, and reasoning_effort for kimi-for-coding requests
• discovers the authoritative wire model slug, display name, context length, and media-input capabilities from /coding/v1/models
• keeps tokens in opencode's auth store while mirroring kimi-cli's refresh / retry behavior
• provides a /kimi:usage TUI command to check subscription usage

Contributor and agent documentation lives in AGENTS.md.

---

Quick Start

1. Install the plugin globally: opencode plugin opencode-kimi-full --global
2. If you are testing a local checkout instead of the published package, install the checkout path instead: opencode plugin /absolute/path/to/opencode-kimi-full --global
3. Run opencode auth login -p kimi-for-coding-oauth and approve the device flow in your browser.
4. Paste the provider block from Configure into your opencode config.
5. Select kimi-for-coding-oauth/kimi-for-coding in opencode.

Requirements

• opencode >= 1.4.6
• A Kimi account with an active Kimi For Coding subscription (the same plan that works with kimi-cli)

Install

Recommended:

opencode plugin opencode-kimi-full --global

That installs the published package and adds the plugin to your global opencode config, so opencode auth login -p kimi-for-coding-oauth works from any directory.

From a local checkout:

opencode plugin /absolute/path/to/opencode-kimi-full --global

That is the command you want when you are editing this repo and want opencode to load your working tree. Changing files in a checkout does nothing unless opencode is pointed at that checkout path.

If you prefer managing plugin registration manually, add the plugin to the plugin list in ~/.config/opencode/opencode.json or a project-local .opencode/opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": ["opencode-kimi-full"]
}

For a local checkout, point the plugin entry at the repo root instead of the npm package name:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": ["/absolute/path/to/opencode-kimi-full"]
}

If you use a project-local .opencode/opencode.json, the plugin only exists when you run opencode inside that project tree. If you want opencode auth login to work from anywhere, use the --global install above.

Configure

After the plugin is installed and login works, paste this provider entry into ~/.config/opencode/opencode.json or .opencode/opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "kimi-for-coding-oauth": {
      "name": "Kimi For Coding (OAuth)",
      "npm": "@ai-sdk/openai-compatible",
      "options": {
        "baseURL": "https://api.kimi.com/coding/v1"
      },
      "models": {
        "kimi-for-coding": {
          "name": "Kimi For Coding",
          "attachment": true,
          "reasoning": true,
          "modalities": {
            "input": ["text", "image"],
            "output": ["text"]
          },
          "options": {},
          "variants": {
            "off":    { "reasoning_effort": "off" },
            "auto":   { "reasoning_effort": "auto" },
            "low":    { "reasoning_effort": "low" },
            "medium": { "reasoning_effort": "medium" },
            "high":   { "reasoning_effort": "high" }
          }
        }
      }
    }
  }
}

Important: The attachment and modalities fields are required for image input to work. Without them, opencode strips image parts before they reach Kimi. If you previously pasted an older config block without these fields, update it.

This block is for using the model after login. It does not register the auth provider by itself. What makes opencode auth login -p kimi-for-coding-oauth work is the plugin being loaded via opencode plugin ... or the plugin array above.

Use these two ids exactly as written:

• provider id kimi-for-coding-oauth -- the plugin's auth and chat.params hooks match on it.
• model id kimi-for-coding -- a stable opencode-side alias. At login and on every token refresh the plugin queries /coding/v1/models and rewrites the wire model field if the server reports a different slug for your account.

Note. The provider id is intentionally not kimi-for-coding. That id is already published by models.dev and points at a static-API-key flow using a different SDK and auth shape. Using a distinct id keeps the two paths from colliding under a single opencode auth login entry.

Log in

opencode auth login -p kimi-for-coding-oauth

Then complete the device-flow approval in your browser.

During login the plugin:

• shows a verification URL and user code
• stores the OAuth token in opencode's auth store
• discovers the exact model slug, display name, context length, and media-input capabilities your account should send to Kimi
• prints a config hint that uses the discovered display name and capabilities

Access tokens refresh automatically while you use the model.

Troubleshooting: Unknown provider "kimi-for-coding-oauth"

That error means opencode did not load this plugin at all. The Kimi OAuth flow has not started yet.

The usual causes are:

• You skipped opencode plugin opencode-kimi-full --global or opencode plugin /absolute/path/to/opencode-kimi-full --global.
• You edited a local checkout, but opencode is not pointed at that checkout path.
• You put the plugin in a project-local .opencode/opencode.json, but ran opencode auth login from another directory.
• You added the provider block, but not the plugin entry or plugin install.

Fastest fix:

1. Install the plugin globally with opencode plugin opencode-kimi-full --global, or opencode plugin /absolute/path/to/opencode-kimi-full --global for a checkout.
2. Confirm your opencode config now contains the plugin entry.
3. Run opencode auth login -p kimi-for-coding-oauth again.

Troubleshooting: Images not working / "this model does not support image input"

opencode gates image input on model metadata. If your config block is missing attachment: true and modalities, opencode strips image parts before they reach Kimi.

Fix: update your config block to match the one in Configure above -- specifically add "attachment": true and "modalities": { "input": ["text", "image"], "output": ["text"] } to the model entry.

The plugin also backfills these capabilities at runtime from /coding/v1/models discovery, but the static config must be correct for the initial request.

Login and refresh details

• The plugin queries /coding/v1/models during login so it can discover the current wire model id, context length, and media capabilities for your account.
• The plugin uses that discovery response to backfill image and video input support into opencode's runtime model metadata, so pasted or dropped images reach Kimi instead of being downgraded into local error text.
• The printed config hint intentionally omits limit, because opencode requires both limit.context and limit.output, while Kimi's models endpoint only exposes context_length.
• Model discovery runs again on every token refresh, and a fresh loader instance can re-query /coding/v1/models on first use if it needs the current wire model id.
• On a 401, the loader refreshes the access token once and retries the request once.
• Refreshes are coordinated through opencode's live auth store so concurrent workspaces do not keep using an older refresh-token chain from a stale OPENCODE_AUTH_CONTENT snapshot.

Use

Select kimi-for-coding-oauth/kimi-for-coding in opencode.

The default variant-cycle keybind is Ctrl+T. The variants map as follows:

• off -- sends thinking: { "type": "disabled" }
• auto -- omits both thinking and reasoning_effort
• low / medium / high -- send thinking: { "type": "enabled" } plus the matching reasoning_effort

These variants only affect Kimi's reasoning request fields. They do not switch models or auth paths. In practice:

• off asks the backend to disable thinking
• auto leaves the decision to the server
• low / medium / high ask for enabled thinking with the corresponding reasoning effort

Effort levels xhigh and max are clamped to high, matching kimi-cli's behavior (Kimi's backend does not support higher tiers).

Every kimi-for-coding request also gets prompt_cache_key set to opencode's session id. That mirrors kimi-cli's cache hint so follow-up turns in the same session can reuse Kimi's prompt cache.

Usage command

The plugin registers a /kimi:usage TUI slash command that shows your Kimi Code subscription usage (weekly and rolling-window limits) in a compact dialog. Run it from the opencode command palette.

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Why this plugin exists

Stock opencode can already talk to generic Moonshot and OpenAI-compatible endpoints. This plugin exists for the Kimi Code path specifically: it brings the official Kimi OAuth flow and Kimi-specific request behavior into opencode without sharing kimi-cli's credential files.

What it adds over the generic route.

• OAuth device flow against https://auth.kimi.com.
• @ai-sdk/openai-compatible pointed at https://api.kimi.com/coding/v1.
• prompt_cache_key set to opencode's session id, for session-scoped cache reuse.
• Paired thinking + reasoning_effort fields, with effort clamping to match kimi-cli.
• The seven X-Msh-* headers and a kimi-cli-shaped User-Agent.
• ~/.kimi/device_id shared with a locally-installed kimi-cli.
• Runtime model discovery from /coding/v1/models, including the server-reported wire slug, display_name, context_length, and media-input capabilities.
• Tokens stored in opencode's auth store under a dedicated provider id, so the plugin and kimi-cli keep independent refresh-token chains and do not invalidate each other.
• Live auth-store rereads plus a provider-scoped refresh lock, so concurrent opencode workspaces converge on the latest refresh-token chain instead of tripping invalid_grant.
• Streaming, reasoning_content deltas, and tool-call schemas are handled upstream by @ai-sdk/openai-compatible -- not reimplemented here.

Request fields in detail

Field	Wire shape	Purpose
prompt_cache_key	top-level body, snake_case, set to opencode's sessionID	Opt-in, session-scoped cache key, mirroring kimi-cli.
thinking + reasoning_effort	thinking: { type: "enabled" | "disabled" } with sibling reasoning_effort: "low" | "medium" | "high"	Sent together, matching kimi-cli. xhigh/max clamped to high.
Seven X-Msh-* headers + UA	User-Agent, X-Msh-Platform, X-Msh-Version, X-Msh-Device-Name, X-Msh-Device-Model, X-Msh-Device-Id, X-Msh-Os-Version	Matches kimi-cli's _common_headers() at the pinned KIMI_CLI_VERSION.
/coding/v1/models discovery	id, display_name, context_length, supports_image_in, supports_video_in	Supplies the authoritative wire model slug plus runtime model metadata.
~/.kimi/device_id	UUID persisted on disk, embedded in X-Msh-Device-Id	Sends the same X-Msh-Device-Id as a locally-installed kimi-cli.

Effort-to-field mapping used by the plugin:

user effort	reasoning_effort	thinking
auto	(omitted)	(omitted) -- server picks dynamically
off	(omitted)	{ type: "disabled" }
low / medium / high	same string	{ type: "enabled" }
xhigh / max	"high" (clamped)	{ type: "enabled" }

Files the plugin touches

Path	Purpose
~/.kimi/device_id	Stable UUID used in X-Msh-Device-Id. Shared with kimi-cli.
opencode auth store (auth.json in opencode's XDG data dir; on Linux typically ~/.local/share/opencode/auth.json)	Token storage, managed by opencode through client.auth.*; the plugin also live-reads this entry to avoid stale workspace auth snapshots during refresh.

No other state is persisted. Credentials are never written to ~/.kimi/credentials/; that path belongs to kimi-cli, and sharing it would cause refresh-token races between the two clients.

Architecture at a glance

                      opencode core
 ──────────────────────────────────────────────────
  auth.login ──> plugin.auth.authorize()     device-code flow, poll
                   └──> oauth.ts

  chat ────────> plugin.loader()             custom fetch that:
                   ├──> ensureFresh()          proactive refresh
                   └──> kimiHeaders()          7 X-Msh-* headers
                                               /models slug discovery
                                               401 -> force-refresh + retry

  chat.params ─> plugin "chat.params"        thinking / reasoning_effort /
                                              prompt_cache_key

  /kimi:usage ─> tui.tsx                     subscription usage dialog
                   └──> usage.ts

A full description of the invariants that keep this working is in AGENTS.md, under "Architecture" and "Contracts to keep intact".

License

MIT.