Image Editing

Image Editing

Metadata

• Category: compute
• SDK: @0gfoundation/0g-compute-ts-sdk ^0.9.0, ethers 6.13.1
• Activation Triggers: "edit image", "image editing", "modify image", "inpaint", "change this image", "image-to-image"

Purpose

Apply prompt-driven edits to an existing image using 0G Compute Network providers (serviceType: image-editing). The endpoint is OpenAI-compatible: POST ${endpoint}/images/edits.

Use Text to Image instead when creating an image from nothing.

Models

Discover at runtime — never hardcode. At last verification the image-editing service type was present on testnet (qwen/qwen-image-edit-2511, TEE-attested) and not on mainnet — the opposite of most service types. Check both networks before assuming availability.

Supported request parameters: prompt, image, n, size, response_format. Defaults were n: 1, size: "1024x1024". Billing is per output image (pricing.image), with prompt and completion priced at zero — so cost scales with n, not prompt length.

That provider also advertised a rate limit of 30 requests/minute; read rate_limits from its /v1/models response rather than assuming.

Prerequisites

• Node.js >= 20
• @0gfoundation/0g-compute-ts-sdk and ethers installed
• Funded and acknowledged provider with an image-editing service
• A source image to edit
• .env with PRIVATE_KEY, RPC_URL, PROVIDER_ADDRESS

Quick Workflow

1. Initialize broker
2. Find an image-editing provider via listService() (paged, ≤ 50 per call)
3. Ensure the sub-account exists and is acknowledged
4. Get service metadata (endpoint, model)
5. Build the request with the source image and the edit prompt
6. Generate auth headers with the prompt as the signed content
7. POST ${endpoint}/images/edits
8. Extract ChatID from the ZG-Res-Key header
9. Call processResponse(providerAddress, chatID) — supported for this service type

Core Rules

ALWAYS

• Call processResponse() after every edit — image-editing is one of the four service types the SDK's extractor supports (chatbot, text-to-image, image-editing, speech-to-text)
• Get ChatID from the ZG-Res-Key header
• Include the prompt when generating auth headers (signing requirement)
• Keep n small — you are billed per output image
• Respect the provider's advertised rate_limits
• Page listService() in chunks of ≤ 50

NEVER

• Assume this service type exists on mainnet — at last check it was testnet-only
• Send a huge image without checking the provider's limits
• Raise n to explore variations without accounting for per-image cost
• Hardcode private keys
• Use ethers v5 syntax

Code Examples

Edit an Image

import { ethers } from 'ethers';
import { createZGComputeNetworkBroker } from '@0gfoundation/0g-compute-ts-sdk';
import * as fs from 'fs';
import 'dotenv/config';

async function editImage(sourcePath: string, prompt: string, outputPath: string): Promise<string> {
  const provider = new ethers.JsonRpcProvider(process.env.RPC_URL);
  const wallet = new ethers.Wallet(process.env.PRIVATE_KEY!, provider);
  const broker = await createZGComputeNetworkBroker(wallet);
  const providerAddress = process.env.PROVIDER_ADDRESS!;

  const { endpoint, model } = await broker.inference.getServiceMetadata(providerAddress);

  // Inline the source image as a data URI
  const sourceB64 = fs.readFileSync(sourcePath).toString('base64');
  const body = JSON.stringify({
    model,
    prompt,
    image: `data:image/png;base64,${sourceB64}`,
    n: 1,
    size: '1024x1024',
    response_format: 'b64_json',
  });

  // Sign over the prompt
  const headers = await broker.inference.getRequestHeaders(providerAddress, prompt);

  const response = await fetch(`${endpoint}/images/edits`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json', ...headers },
    body,
  });
  if (!response.ok) {
    throw new Error(`Image edit failed: HTTP ${response.status} ${await response.text()}`);
  }

  const data = await response.json();

  // ChatID comes from the response header for image services
  const chatID = response.headers.get('ZG-Res-Key') || response.headers.get('zg-res-key');

  // Supported for image-editing — unlike embedding/video-generation
  await broker.inference.processResponse(providerAddress, chatID ?? undefined, '');

  const edited = data.data[0];
  if (edited.b64_json) {
    fs.writeFileSync(outputPath, Buffer.from(edited.b64_json, 'base64'));
  } else if (edited.url) {
    const img = await fetch(edited.url);
    fs.writeFileSync(outputPath, Buffer.from(await img.arrayBuffer()));
  } else {
    throw new Error('Response contained neither b64_json nor url');
  }

  console.log(`edited image written to ${outputPath}`);
  return outputPath;
}

// Usage
await editImage('./input.png', 'make the sky look like a sunset', './output.png');

Find an Image-Editing Provider on Either Network

import { createReadOnlyInferenceBroker } from '@0gfoundation/0g-compute-ts-sdk';

async function findImageEditor(rpcUrl: string) {
  const broker = await createReadOnlyInferenceBroker(rpcUrl);

  const services = [];
  for (let offset = 0; ; offset += 50) {
    const page = await broker.listService(offset, 50, true);
    services.push(...page);
    if (page.length < 50) break;
  }

  const editors = services.filter((s) => s.serviceType === 'image-editing');
  for (const s of editors) {
    console.log(
      `${s.provider} model=${s.model} perImage=${s.outputPrice} neuron tee=${s.teeSignerAcknowledged}`,
    );
  }
  return editors[0];
}

// image-editing was testnet-only at last check — try both
const findImageEditor('https://evmrpc-testnet.0g.ai');
const findImageEditor('https://evmrpc.0g.ai');

Check Limits and Pricing First

async function inspectEditor(providerAddress: string) {
  const broker = await createReadOnlyInferenceBroker(process.env.RPC_URL!);
  const { models } = await broker.getProviderModels(providerAddress);

  for (const m of models) {
    console.log({
      id: m.id,
      supported: m.supported_parameters, // ['prompt','image','n','size','response_format']
      defaults: m.default_parameters, // { n: 1, size: '1024x1024' }
      perImage: m.pricing?.image,
      perImageUsd: m.pricing_usd?.image,
      inputs: m.architecture?.input_modalities, // ['text','image']
    });
  }
}

Anti-Patterns

// BAD: skipping processResponse() — it IS supported here, unlike embedding/video
const data = await response.json();
return data.data[0];

// BAD: signing without the prompt
const headers = await broker.inference.getRequestHeaders(providerAddress);

// BAD: cranking n to browse variations — billed per output image
body: JSON.stringify({ model, prompt, image, n: 10 });

// BAD: assuming mainnet has this service type
const editor = services.find((s) => s.serviceType === 'image-editing')!; // may be undefined

Common Errors & Fixes

Related Skills

• Text to Image — generate a new image from a prompt
• Provider Discovery — find and verify providers
• Account Management — funding and balances
• Compute + Storage — store originals and edits

References

• 0G Compute SDK
• OpenAI Image Edit API shape