MCPecrets

A lightweight MCP secrets manager that uses Cloudflare Workers for compute and GitHub for persistence.

What it does

MCPecrets stores secrets as GitHub Actions Secrets and retrieves them via a triggered GitHub Action with ephemeral key encryption. It exposes five MCP tools over OAuth 2.1 with dynamic client registration, so it works with any MCP-compatible client -- Claude, ChatGPT, or anything else that speaks the protocol.

No database. No additional storage. Just Cloudflare Workers and GitHub.

Screenshots

Creating a vault with init_vault (shown in Claude on claude.ai):

Storing a secret with set_secret (shown in Claude on claude.ai):

Retrieving a secret with get_secret -- works across MCP clients (shown here in ChatGPT on chatgpt.com):

How it works

1. Authentication: OAuth 2.1 with dynamic client registration, delegating to GitHub for identity. The Worker acts as both the MCP server and the OAuth provider.
2. Storing secrets: Values are encrypted using the repository's public key (libsodium sealed box) and stored via the GitHub Actions Secrets API. A retrieval workflow is committed/updated in the vault repo whenever secrets change.
3. Retrieving secrets: The Worker generates an ephemeral X25519 keypair and triggers a GitHub Actions workflow. The workflow encrypts the secret with the ephemeral public key and POSTs the ciphertext back to the Worker. The Worker decrypts with the ephemeral private key and returns the plaintext to the MCP client.

Secrets are encrypted at rest by GitHub and encrypted in transit with ephemeral keys. The Worker never persists secret values.

MCP Tools

Tool	Description
init_vault	Create a new private GitHub repo as a secrets vault
set_secret	Store a secret (encrypted with the repo's public key)
get_secret	Retrieve a secret value via GitHub Actions callback
list_secrets	List secret names in a vault (values are never exposed)
delete_secret	Remove a secret from a vault

Setup

1. Create a GitHub OAuth App at github.com/settings/developers. Set the callback URL to https://<your-worker>.workers.dev/callback.

2. Deploy to Cloudflare Workers:

   npm install
   npx wrangler deploy

3. Set secrets on the deployed Worker:

   npx wrangler secret put GITHUB_CLIENT_ID
   npx wrangler secret put GITHUB_CLIENT_SECRET

4. Connect your MCP client to https://<your-worker>.workers.dev/mcp. The deployed instance is at:

   https://mcpecrets.minivelos.workers.dev/mcp
   

Tech Stack

• Cloudflare Workers + Durable Objects + KV
• GitHub OAuth + Actions Secrets API
• MCP (Streamable HTTP transport) via @modelcontextprotocol/sdk
• tweetnacl + blakejs for X25519 / sealed box crypto
• Octokit for GitHub API