Image Upload for GitHub

Upload an image to img402.dev's free tier and embed the returned URL in GitHub markdown.

Quick reference

# Upload (multipart)
curl -s -X POST https://img402.dev/api/free -F image=@/tmp/screenshot.png

# Response
# {"url":"https://i.img402.dev/aBcDeFgHiJ.png","id":"aBcDeFgHiJ","contentType":"image/png","sizeBytes":182400,"expiresAt":"2026-02-17T..."}

Workflow

1. Get image: Use an existing file, or capture a screenshot: bash screencapture -x /tmp/screenshot.png # macOS — full screen screencapture -xw /tmp/screenshot.png # macOS — frontmost window
2. Verify size: Must be under 1MB. If larger, resize: bash sips -Z 1600 /tmp/screenshot.png # macOS — scale longest edge to 1600px
3. Upload: bash curl -s -X POST https://img402.dev/api/free -F image=@/tmp/screenshot.png
4. Embed the returned url in GitHub markdown: markdown !Screenshot description

GitHub integration

Use gh CLI to embed images in PRs and issues:

# Add to PR description
gh pr edit --body "$(gh pr view --json body -q .body)

!Screenshot"

# Add as PR comment
gh pr comment --body "!Screenshot"

# Add to issue
gh issue comment 123 --body "!Screenshot"

Constraints

• Max size: 1MB
• Retention: 7 days — suitable for PR reviews, not permanent docs
• Formats: PNG, JPEG, GIF, WebP
• Rate limit: 1,000 free uploads/day (global)
• No auth required

Tips

• Prefer PNG for UI screenshots (sharp text). Use JPEG for photos.
• If a screenshot is too large, reduce dimensions with sips -Z 1600 before uploading.
• When adding to a PR body or comment, use gh pr comment or gh pr edit with the image markdown.

Paid tier

For permanent images (1 year, 5MB max), use the paid endpoint at $0.01 USDC via x402. See https://img402.dev/blog/paying-x402-apis for details.