opencode-claude

Claude Code in OpenCode. Local CLI auth. Agent SDK.

opencode-claude is the OpenCode plugin for running Claude models — Fable, Opus, Sonnet, and Haiku — from a Claude Pro/Max subscription, with effort variants, tools, attachments, and auto-compact.

Use Claude from OpenCode and OpenChamber without an Anthropic API key. The plugin runs the official Anthropic Agent SDK plus the local claude CLI and proxies an OpenAI-compatible /v1/chat/completions surface into OpenCode. Claude Code owns authentication; the plugin never reads, copies, refreshes, or sends your credentials itself.

Official Claude runtime

Built on Anthropic's official Agent SDK and Claude Code authentication flow. Designed for local, user-operated Claude Code usage.

No OAuth tokens are extracted, copied, stored, injected, or sent by this plugin. All authentication and model access are performed internally by the official Claude Code runtime. The plugin does not call Anthropic inference endpoints directly and does not impersonate Anthropic API clients.

Sibling plugins: @openchamber/opencode-cursor and @openchamber/opencode-commandcode.

What you can do

Use your local Claude Code login

The OpenCode/OpenChamber sign-in action launches claude auth login --claudeai and relays it: the CLI's own sign-in page opens from the host, and the code Claude shows is pasted back into the host, not a separate terminal. The official CLI performs the OAuth exchange and stores its own credentials. The plugin stores no credentials or connection markers in OpenCode; every inference request, including title and summary generation, runs through the Agent SDK.

Pick models and thinking effort

Aliases fable / opus / sonnet / haiku plus pinned ids. Native OpenCode variants low → max map to Claude --effort and adaptive thinking.

Keep agent loops moving

OpenCode tools bridge as in-process MCP. Calls park and resume instead of deadlocking or inventing output. Streaming, MCP, and sticky Claude session IDs keep follow-ups on the same Agent SDK turn.

Attachments, compact, and history

Images and PDFs from OpenCode reach Claude (data URLs and remote URLs). Long sessions auto-compact like Claude Code. When a Claude session cannot be resumed, the prior conversation is serialized into the prompt so Claude does not start blind.

Rate-limit counter

Subscription limit state is tracked with its reset time. GET /v1/rate-limit answers when limits return; doomed turns fail fast with 429 and Retry-After.

Quick start

claude-code is not a built-in OpenCode provider. Install the plugin first, or opencode auth login --provider claude-code fails with Unknown provider "claude-code".

1. Install the plugin

npm install -g @openchamber/opencode-claude

Or with OpenCode:

# global (recommended)
opencode plugin @openchamber/opencode-claude -g

# or project-local (writes .opencode/opencode.json)
opencode plugin @openchamber/opencode-claude

2. Register it in OpenCode

Add (or merge) this into ~/.config/opencode/opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": ["@openchamber/opencode-claude"],
  "provider": {
    "claude-code": { "name": "Claude Code" }
  }
}

3. Authenticate

claude auth login
opencode auth login --provider claude-code
# pick "Sign in with Claude Code CLI"

4. Run a Claude model

opencode run "Summarise this repository in five bullets." --model claude-code/sonnet

In the TUI, pick provider claude-code, choose a model, and set the effort variant (low / medium / high / xhigh / max) when you want deeper thinking.

From source (optional)

git clone https://github.com/openchamber/opencode-claude.git
cd opencode-claude
bun install && bun run build
opencode plugin file://$PWD

Authenticate

Step	What happens
Sign in with Claude Code CLI	Shown when the CLI is installed: launches the official CLI login and opens the sign-in page the CLI asked for
Install Claude Code CLI and sign in	Shown only when the CLI is missing: runs the official installer (`npm i -g @anthropic-ai/claude-code`, official install script as fallback), then continues with the sign-in relay
Paste the code from the Claude page	Goes straight to the CLI's stdin; the CLI does the token exchange and owns the result
`claude auth login --claudeai`	Terminal alternative, always called out in the instructions — also the offered fallback when the CLI is missing (with the install command alongside)
Successful verification	Completes without writing to OpenCode's auth store
Access expires	Claude Code refreshes its own credentials

Signing in is either the link and its code or the terminal command — the sign-in page the CLI asks for is the only URL the plugin ever hands to the host.

The plugin does not implement OAuth, inspect Claude credential files, inject tokens, or call Anthropic inference endpoints directly.

Architecture

OpenCode
  └─ /v1/chat/completions
       └─ Bun.serve proxy (ephemeral port; configured by the plugin)
            └─ Claude Agent SDK query()
                 └─ claude CLI (subscription OAuth)

Layer	Responsibility
Plugin hooks	Provider config, model catalog, effort headers
Proxy	OpenAI ↔ Agent SDK protocol, tool parking, compact, rate-limit gate
CLI	Subscription credentials and the Claude Code harness

Model catalog: aliases fable / opus / sonnet / haiku plus pinned ids. Effort selection is encoded in x-opencode-claude-effort so the proxy passes the exact effort (and adaptive thinking) into the Agent SDK.

Rate-limit counter

The proxy records Agent SDK rate_limit_event telemetry and hard session-limit errors (including the parsed reset time) to ~/.local/share/opencode-claude/rate-limit.json.

GET /v1/rate-limit → { limited, status, rateLimitType, utilization, resetsAt, resetsAtISO, resetInSeconds, message, updatedAt } — poll this for a "limits reset in …" countdown. utilization is only present when the latest SDK event reported it — it is never carried over from an earlier limit window.
GET /health includes a compact rateLimit summary.
While a confirmed hard limit is active, new turns return HTTP 429 with Retry-After + x-claude-rate-limit-reset headers and an error.type = "rate_limit_error" body. The block lifts automatically at reset time; the next turn resumes the same Claude session.
OPENCODE_CLAUDE_RATE_LIMIT_FAST_FAIL=0 disables the 429 gate (turns are attempted and error normally).

Requirements

OpenCode
Claude Code CLI — on PATH or installed via the provider's install action (npm is used, or the official install script); the plugin also checks ~/.local/bin and the npm global bin for a CLI the server PATH cannot see
Claude plan supported by Claude Code
Bun (plugin runtime) · Node.js ≥ 18

Development

bun install
bun run build
bun run test

Debug logging: OPENCODE_CLAUDE_DEBUG=1.

Optional knobs:

OPENCODE_CLAUDE_PROXY_PORT — optional pinned proxy port (default: ephemeral / OS-assigned; live URL is published to OpenCode via plugin config)
OPENCODE_CLAUDE_CWD — working directory passed to the Agent SDK
OPENCODE_CLAUDE_RATE_LIMIT_FAST_FAIL — 0 disables the 429 rate-limit gate
OPENCODE_CLAUDE_RATE_LIMIT_STORE — override the rate-limit store path (tests)
OPENCODE_CLAUDE_HISTORY_MAX_CHARS — budget for transferred conversation history when a Claude session cannot be resumed (default 400000; newest messages are kept, 0 disables transfer)

Troubleshooting

Symptom	Fix
Unknown provider `claude-code`	Install `@openchamber/opencode-claude` and restart OpenCode
Claude Code missing from provider list	Confirm `plugin` includes `@openchamber/opencode-claude` and restart OpenCode
Authentication error	Run `claude auth login`, verify `claude auth status --json`, then restart OpenCode
429 / rate-limit	Poll `GET /v1/rate-limit` or wait until `resetsAt`; the next turn resumes the same session
Tools hang or invent output	Update to the latest plugin — park/resume MCP bridging is required
Attachments ignored	Use a current build; image/PDF parts are converted to Claude blocks

Release

Publish via GitHub Actions → Actions → Release → Run workflow:

Input	Purpose
`version`	Explicit semver (`0.6.0`). Empty → use bump
`bump`	`minor` (default) / `patch` / `major`
`dry_run`	Skip npm publish; create a draft GitHub release

Requires repo secrets: NPM_TOKEN, optional DISCORD_WEBHOOK_URL.

Local pin refresh after a release:

./scripts/update-plugin.sh --dry-run
./scripts/update-plugin.sh

Contributing

Issues and pull requests belong in this repository: openchamber/opencode-claude.

bun install
bun run build
bun run test

Acknowledgments

This plugin started as community work around Claude Code in OpenCode. Special thanks to:

OpenCode for the plugin API
OpenChamber for the workspace that runs this plugin in production
Anthropic for the Claude Agent SDK and Claude Code CLI
Contributors who shaped OAuth, the proxy, tools, and compact

License

MIT

Name		Name	Last commit message	Last commit date
Latest commit History 17 Commits
.github/workflows		.github/workflows
.opencode		.opencode
docs		docs
scripts		scripts
src		src
test		test
.gitignore		.gitignore
CHANGELOG.md		CHANGELOG.md
LICENSE		LICENSE
README.md		README.md
bun.lock		bun.lock
opencode-claude.js		opencode-claude.js
package.json		package.json
tsconfig.json		tsconfig.json

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opencode-claude

Claude Code in OpenCode. Local CLI auth. Agent SDK.

Official Claude runtime

What you can do

Use your local Claude Code login

Pick models and thinking effort

Keep agent loops moving

Attachments, compact, and history

Rate-limit counter

Quick start

1. Install the plugin

2. Register it in OpenCode

3. Authenticate

4. Run a Claude model

From source (optional)

Authenticate

Architecture

Rate-limit counter

Requirements

Development

Troubleshooting

Release

Contributing

Acknowledgments

License

About

Releases

Packages

Contributors

Languages

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Repository files navigation

opencode-claude

Claude Code in OpenCode. Local CLI auth. Agent SDK.

Official Claude runtime

What you can do

Use your local Claude Code login

Pick models and thinking effort

Keep agent loops moving

Attachments, compact, and history

Rate-limit counter

Quick start

1. Install the plugin

2. Register it in OpenCode

3. Authenticate

4. Run a Claude model

From source (optional)

Authenticate

Architecture

Rate-limit counter

Requirements

Development

Troubleshooting

Release

Contributing

Acknowledgments

License

About

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