Imagen

Generate and edit images with OpenAI GPT Image 2 from any OpenCode V2 agent. The plugin reuses OpenCode's existing ChatGPT/Codex OAuth connection, so it does not require a separate OpenAI API key.

Requirements

• OpenCode V2 0.0.0-next-17444 or a compatible release
• An active OpenAI ChatGPT/Codex OAuth connection in OpenCode
• A ChatGPT plan with Codex and image-generation access

OpenCode's V2 plugin API is currently beta. This package pins the matching OpenCode SDK and Effect versions and will publish compatibility updates as the API changes.

Install

Add the package to the plugins array in your global OpenCode V2 config at ~/.config/opencode/opencode.jsonc:

{
  "$schema": "https://opencode.ai/config.json",
  "plugins": ["opencode-imagen@0.1.0"],
}

Connect OpenAI through OpenCode if it is not already connected:

/connect

Select OpenAI and authenticate with ChatGPT/Codex OAuth. Restart OpenCode after installing or changing the package version.

Use

Ask any agent to use the imagen tool. For example:

Create a wide editorial illustration of a lunar greenhouse at dawn. Save it
to assets/lunar-greenhouse.webp.

The tool accepts:

Input	Values	Default
prompt	Non-empty image description	Required
size	auto, 1024x1024, 1536x1024, 1024x1536	auto
quality	auto, low, medium, high	auto
background	auto, opaque, transparent	auto
outputFormat	png, webp, jpeg	png
thinking	off, minimal, low, medium, high	low
referencePaths	Local image paths used as visual references	[]
outputPath	Exact file path, or a directory when extensionless	Generated path

Without outputPath, images are written under .opencode/generated-images/<image-id>.<format> in the current OpenCode working directory. The tool returns both structured metadata and OpenCode file content, allowing compatible agents and interfaces to inspect the result. Existing files are never overwritten; choose a new outputPath when a target already exists.

How It Works

1. The plugin asks OpenCode for the active openai connection.
2. OpenCode resolves that connection without exposing or reading credential storage directly.
3. The plugin sends a typed Responses request to ChatGPT's Codex backend using the native image_generation tool with gpt-image-2.
4. Effect Schema decodes the OAuth token claims and Codex SSE events.
5. Effect platform services write the returned image to disk.

The access token is wrapped as Redacted and is never logged or returned in tool output.

Development

For local development, load the repository directly:

{
  "plugins": ["/absolute/path/to/opencode-imagen/dist/index.js"],
}

OpenCode imports local files directly, so install dependencies and build the plugin first:

bun install
bun run build
bun run check
npm pack --dry-run

The completion gate runs strict TypeScript with the Effect language service, Oxlint with Effect-specific rules, Vitest, dprint, and the publish build.

Limitations

• This plugin intentionally supports only OpenCode V2 and ChatGPT/Codex OAuth.
• The Codex image endpoint is not a stable public API and can change without notice.
• Image availability and usage limits depend on the connected ChatGPT account.
• Browser galleries, batch generation, and slash commands are outside the initial scope.

License

MIT