Vellum Github App Setup

Overview

This skill creates a GitHub App under a GitHub organization, giving the assistant its own bot identity for git operations. After setup, commits, PRs, and comments will attribute to <app-name>[bot] instead of the user's personal account.

Total manual effort: 7 interactions — Continue to GitHub → Create App → 3 secure credential prompts → Install on repo → (optional) upload avatar. Everything else is automated.

Note: This skill currently supports GitHub organizations only, not personal accounts.

What Gets Created

• A GitHub App owned by the org (not the user's personal account)
• Installation on selected repositories with configurable permissions (default: contents:write, pull_requests:write, checks:read, metadata:read)
• Credentials stored in the assistant's encrypted vault (7 fields)
• Token helper script at bin/gh-app-token.mjs (in the workspace root) for refreshing auth tokens

Prerequisites

• User must be an admin of the GitHub organization
• User must be logged into GitHub in their browser
• The assistant credentials CLI must be available
• Python 3 on the host machine (for the manifest flow server)
• bun in the container (for the token helper script)

Setup Flow

Step 1: Create the GitHub App

Run the manifest flow script on the user's host machine (it needs to open a browser and catch a localhost callback):

python3 scripts/create-github-app.py \
  --org=ORG_NAME \
  --name=APP_NAME \
  --url="https://example.com" \
  --output=/tmp/github-app-credentials.json

This starts a local server on localhost:29170, opens the browser, and guides the user through two clicks:

1. "Continue to GitHub" — submits the pre-filled manifest form