Generate an image from a text prompt using OpenAI's gpt-image-2 model. The image is written to disk and also returned inline so you can see it. gpt-image-2 handles photoreal, illustrations, infographics, multilingual text (incl. CJK), and complex structured visuals. It does NOT support transparent backgrounds. Sizes accept presets or any custom "WxH" where edges are multiples of 16, max edge 3840px, aspect ratio within 1:3–3:1, total pixels 655K–8.29M.

Edit or compose images with gpt-image-2. Give 1–8 input images plus a text prompt; optionally include a PNG mask whose transparent regions mark what to change (mask applies to the first image). Great for: swap backgrounds, retouch products, combine multiple reference images into one composition, maintain a character across scenes. gpt-image-2 always processes inputs at high fidelity (no input_fidelity knob needed). The edited image is saved to disk and returned inline.

Begin a stateful multi-turn edit session. Returns a session_id you then pass to continue_edit_session to iteratively refine the image (each turn uses the previous turn's output as the input). Use end_edit_session when done.

Apply another edit turn to an existing session. The previous turn's output image is used as the input. Use short, focused prompts like "make the sky more orange" or "add a small boat on the horizon"; include "keep everything else the same" to limit drift. Returns the new image and the updated session.

Free an iterative-edit session. Safe to skip — sessions are in-memory only and are discarded on server restart — but calling this frees memory sooner and keeps list_edit_sessions tidy.

List active iterative-edit sessions (in-memory only, discarded on server restart). Useful to recover a session_id after a client reconnect.