🪞 GPT Image 2 — Image Generation via Your ChatGPT Subscription

agentspace.so · GitHub

Generate images with GPT Image 2 (ChatGPT Images 2.0) inside your agent, using your existing ChatGPT Plus or Pro subscription — no separate OpenAI access, no Fal or Replicate tokens, no per-image billing.

Text-to-image, image-to-image editing, style transfer, and multi-reference composition. Runs entirely through the local codex CLI you're already logged into.

Heads up — this skill requires a ChatGPT Plus or Pro subscription plus the Codex CLI installed locally. If you have neither, you can use GPT Image 2 in the browser via RunComfy instead — hosted, no ChatGPT subscription or local install needed (RunComfy account required):

• Text-to-image: https://www.runcomfy.com/models/openai/gpt-image-2/text-to-image
• Image edit (i2i): https://www.runcomfy.com/models/openai/gpt-image-2/edit

The rest of this document covers the local Codex CLI flow for agents whose user has a ChatGPT subscription.

Example output: a plain flat-color icon repainted via --ref in ukiyo-e style — composition preserved, rendering swapped, period-appropriate red seal added by the model unprompted.

When to trigger

Trigger when the user explicitly asks for GPT Image 2 via their ChatGPT subscription, for example:

• "use GPT Image 2" / "use gpt-image-2" / "use ChatGPT Images 2.0"
• "use Image 2" / "image 2 this"
• attached a reference image and asked to remix / edit / restyle it

Do not auto-trigger for a plain "generate an image" request if the user didn't specify this route. If they did specify it, do not silently fall back to HTML mockups, screenshots, or a different image model.

How to invoke

A single bash script handles everything: runs codex exec with the right flags, then decodes the generated image from the persisted session rollout.

Text-to-image:

bash scripts/gen.sh \
  --prompt "<user's raw prompt>" \
  --out <absolute/path/to/output.png>

Image-to-image (reference flag is repeatable for multi-reference composition):

bash scripts/gen.sh \
  --prompt "<user's raw prompt, e.g. 'repaint in watercolor'>" \
  --ref /absolute/path/to/reference.png \
  --out <absolute/path/to/output.png>

Optional: --timeout-sec 300 (default 300).

Default behavior

• Pass the user's prompt through raw. Do not translate, polish, or add style modifiers unless the user asked for it.
• Choose the output path. Default to ./image-<YYYYMMDD-HHMMSS>.png in the current working directory if the user didn't specify.
• Deliver the image. After the script succeeds, display / attach the output file. Do not stop at "done, see path X".
• Text-heavy layouts are fine. Image 2 handles infographics and timeline prompts well. Do not preemptively warn just because a prompt has a lot of text.

Hard constraints

• Do not switch routes without permission. If the user said "use GPT Image 2", do not substitute DALL·E, Midjourney, an HTML mockup, or a manual screenshot workflow.
• Do not rewrite the prompt unless asked.
• Do not imply this skill works without a local codex login and a valid ChatGPT subscription with image-generation entitlement.

Prerequisites

1. codex CLI installed — brew install codex or see openai/codex.
2. Logged in with a ChatGPT plan that includes Image 2 — codex login.
3. python3 on PATH (ships with macOS; apt install python3 on Linux).

This skill does not grant image-generation capability on its own. It exposes the capability the user already has through their ChatGPT subscription.

Exit codes

| code | meaning | |------|---------| | 0 | success — output path printed on stdout | | 2 | bad args | | 3 | codex or python3 CLI missing | | 4 | --ref file does not exist | | 5 | codex exec failed (auth? network? model?) | | 6 | no new session file detected | | 7 | imagegen did not produce an image payload (feature not enabled, quota, or capability refused) |

On failure, name the layer in one sentence instead of dumping the full stderr at the user.

How it works

The codex CLI reuses the logged-in ChatGPT session and exposes an imagegen tool (gated behind the image_generation feature flag). The script:

1. snapshots ~/.codex/sessions/ before the run
2. runs codex exec --enable image_generation --sandbox read-only ... (with -i <file> for each reference image)
3. diffs the sessions directory, then invokes scripts/extract_image.py to scan every new rollout JSONL for a base64 image payload (PNG / JPEG / WebP magic-header match)
4. decodes the largest matching blob and writes it to --out

Two non-obvious flags other wrappers get wrong on codex-cli 0.111.0+:

• --enable image_generation is required; the feature is still under-development and off by default.
• --ephemeral must not be used — ephemeral sessions aren't persisted, so the image payload has nowhere to live.

Data handling

The script is narrowly scoped on purpose:

• It reads only session rollout files created by its own codex exec invocation. The sessions directory is snapshotted before the call and diffed after, so any prior ~/.codex/sessions/* files (which may contain unrelated Codex conversations) are never touched, read, or transmitted.
• It writes only two kinds of file: the output PNG at the caller's --out path, and short-lived mktemp logs that are auto-deleted on exit via a trap.
• No environment variables are read. No credentials are requested. No other paths under ~/.codex/ are accessed.
• No network calls leave this skill. The only outbound traffic is the one made by the codex CLI itself (to OpenAI, using the user's existing ChatGPT login) — this skill does not add endpoints, telemetry, or callbacks.

What this skill is not

Not a direct OpenAI API client. Not a capability grant — it depends on the user's working Codex CLI login. Not a multi-tenant service (one call per invocation; concurrent calls are serialized by the filesystem-snapshot diff).