ghimg

Upload images to GitHub's user-attachments CDN from the command line and get a markdown reference back. Replicates GitHub's web UI upload flow, so the resulting URLs are scoped to the repository they're uploaded to (private-repo images stay private).

Setup

npx ghimg init

The wizard asks for your github.com user_session cookie value — copy it from devtools (Application -> Cookies -> https://github.com -> user_session). It's saved to .env as GH_SESSION_TOKEN and validated against GitHub.

Usage

# repo inferred from the current git remote
npx ghimg upload screenshot.png

# target a repo explicitly, multiple files at once
npx ghimg upload --repo owner/repo a.png b.png

# verify the saved token
npx ghimg check

Each upload prints ![name](https://github.com/user-attachments/assets/...).

Commands

| Command | Description | | -------- | ---------------------------------------------------------------- | | init | Setup wizard for your GitHub session token | | upload | Upload one or more images and print markdown references | | check | Verify the saved token and print the authenticated username |

All commands accept --config <path> to point at a specific .env file (defaults to .env in the current directory). upload also takes --repo owner/repo.

Requirements

• Node 22+ — uses global fetch, FormData, and Blob.
• gh CLI, authenticated — used to resolve the numeric repository ID (works for private repos).

Security

This tool uses your user_session cookie, which is your full authenticated GitHub web session — more powerful than a scoped token. It is only ever sent to github.com and to the presigned S3 URL GitHub returns. The token is stored in .env (gitignored); don't commit it.

License

MIT