pi-9router-imagegen

Pi extension for image generation via 9router’s Codex Responses image_generation tool (gpt-image-2). Uses your existing 9router auth and ChatGPT plan.

Adds an agent-callable imagegen tool and an /img command.

Install

pi install npm:pi-9router-imagegen

Then /reload.

Requires:

1. pi with the 9router provider configured (pi-9router-ext, /9router-config)
2. A 9router instance whose Codex route supports image_generation

Optional smoke test:

curl -s http://localhost:20128/v1/responses \
  -H "Authorization: Bearer <your-9router-key>" \
  -H "Content-Type: application/json" \
  -d '{"model":"cx/gpt-5.5","input":"draw a red dot","tools":[{"type":"image_generation","model":"gpt-image-2"}]}'

If the response includes an image_generation_call output, you're good.

From source

git clone https://github.com/JunDev76/pi-9router-imagegen.git
cd pi-9router-imagegen
pi install .
/reload

Usage

Agent tool

The model can call imagegen on its own when an image would help. Give it a task, not just an image prompt:

Build a landing page for a coffee brand. Use imagegen freely for the hero image, product shots, and any other assets you need.

Mock up a mobile app onboarding flow and generate the illustration assets as you go.

It skips SVG, icons, diagrams, and code-that-draws — those stay as code.

/img command

One image, now:

/img gen a product photo of a ceramic mug on a white background
/img gen --size 1536x1024 --quality high a cinematic expedition poster for a lava cavern
/img gen --format webp --out ./assets/hero.png coffee shop storefront at golden hour
/img gen --ref ./input.png make it a watercolor painting
/img gen --ref ./sketch.png,./mood.png --size 1024x1024 render in this style

Flag	Values	Default
--size	auto · 1024x1024 · 1536x1024 · 1024x1536	auto
--quality	auto · low · medium · high	auto
--background	auto · opaque · transparent	auto
--format	png · webp · jpeg	png
--out	path	~/.pi/agent/generated-images/<ts>-<id>.<ext>
--ref	path (comma-separated, repeatable)	none — text-to-image

Pass --ref one or more image paths to condition the generation on them (edit / transform / style-match):

Output

Images land in ~/.pi/agent/generated-images/ by default. The tool returns the saved path plus an inline image attachment, so vision-capable models can inspect the result without opening the file.

Configuration

Dispatch model and image model are constants at the top of imagegen.ts:

const PROVIDER = "9router";
const RESPONSE_MODEL = "cx/gpt-5.5"; // text LLM that dispatches image_generation
const IMAGE_MODEL = "gpt-image-2";

Change RESPONSE_MODEL to whatever Codex text model id your 9router instance exposes.

How it works

gpt-image-2 is not a top-level chat model — it's a tool on the Codex Responses API. This extension posts to 9router’s /v1/responses with a text model and an image_generation tool:

{
  "model": "cx/gpt-5.5",
  "tools": [{
    "type": "image_generation",
    "model": "gpt-image-2",
    "size": "1024x1024",
    "quality": "medium"
  }]
}

9router routes that to Codex; the base64 image comes back in an image_generation_call output. Auth and base URL come from the existing 9router provider — no extra login.

Troubleshooting

Symptom	Fix
Missing 9router auth	Configure with /9router-config / pi-9router-ext
HTTP 400 / no image_generation_call	Confirm your Codex route supports image_generation; re-run the smoke test above
Image saved but model can't "see" it	Switch to a vision-capable model for that turn

License

MIT