askell-mcp

MCP server for the Askell payment and subscription API.

Connect it to Cursor, Claude Desktop, or any MCP client to discover Askell endpoints, inspect customers/contracts/billing, and call the API — with confirmation before mutating requests.

Requirements

• An Askell account and secret API key (from the Askell dashboard)
• One of:
  • Bun ≥ 1.3.14 (for bunx), or
  • a prebuilt binary from Releases (no Bun needed)

Quick start

1. Get API keys

In the Askell dashboard, copy your private (secret) API key. Optionally also the public key (only needed for temporary payment-method / checkout status endpoints).

2. Add to your MCP client

With Bun (bunx):

{
  "mcpServers": {
    "askell": {
      "command": "bunx",
      "args": ["-y", "askell-mcp"],
      "env": {
        "ASKELL_PRIVATE_API_KEY": "your_secret_api_key"
      }
    }
  }
}

With a binary (download askell-mcp-<os>-<arch> from Releases, then chmod +x):

{
  "mcpServers": {
    "askell": {
      "command": "/absolute/path/to/askell-mcp-linux-x64",
      "env": {
        "ASKELL_PRIVATE_API_KEY": "your_secret_api_key"
      }
    }
  }
}

Example file: mcp.json.example.

Restart the client after saving.

Configuration

Variable	Required	Default	Description
ASKELL_PRIVATE_API_KEY	yes*	—	Secret API key (or ASKELL_SECRET_API_KEY)
ASKELL_PUBLIC_API_KEY	no	—	Public key for a few checkout/payment endpoints
ASKELL_API_URL	no	https://askell.is/api	API base URL (or ASKELL_API_BASE_URL)
ASKELL_RESPONSE_MAX_BYTES	no	64000	Max response size returned to the model
ASKELL_REQUIRE_MUTATION_APPROVAL	no	true	Confirm before POST/PUT/PATCH/DELETE

Askell has no separate sandbox host — production and test traffic use the same URL. Use the Áskell Test Gateway acquirer in your dashboard for safe payment testing. See Askell getting started.

What you can do

Typical agent workflow:

1. Discover — askell_list_operations / askell_describe_operation (from bundled OpenAPI v1 + v2)
2. Support tasks — customer/contract/billing helpers below
3. Anything else — askell_call for a raw endpoint (mutations ask for approval when enabled)

Tools

Tool	Description
askell_list_operations	Search bundled OpenAPI operations
askell_describe_operation	Params and body schema for one operation
askell_call	Call any v1/v2 endpoint
askell_paginate_all	Follow paginated list endpoints
askell_customer_overview	v1 customer + subscriptions
askell_contract_overview	v2 subscription contract + billing runs
askell_billing_run_triage	v2 billing run (+ optional contract)
askell_list_webhooks	List configured webhooks

Resources

URI	Content
askell://spec/v1	OpenAPI v1
askell://spec/v2	OpenAPI v2
askell://docs/webhook-events	Webhook event reference

API notes (short)

• v1 — legacy paths like /customers/, /subscriptions/ (no /v2 prefix)
• v2 — current model: catalogs, quotes, checkouts, contracts, billing runs under /v2/
• Paths use trailing slashes
• Prefer v2 for new integrations; v1 remains for existing ones
• Docs: docs.askell.is · OpenAPI: v1 · v2

License

MIT

Contributing

See CONTRIBUTING.md for local development, tests, and releases.