RevRule by Payload

RevRule by Payload — MCP Server

An MCP server (stdio transport, Node.js standard library only, zero dependencies) that exposes RevRule, Payload's revenue-entitlement engine, to AI agents.

RevRule turns revenue sharing into declarative entitlement rules on the Payload rail: define who gets paid what, and every payout carries evidence linked back to the original entitlement ledger entry and its on-chain settlement. This server is a read + dry-run surface: there are deliberately no write/submit tools in v1. Every call goes to the live Payload rail (https://payload-rail.fly.dev) authenticated with your own rail API key (a free self-serve key from the console is enough to evaluate).

Tools

Tool	Upstream route	What it does
revrule_get_graph	GET /v1/graphs/{graph_id}	Fetch one of your RevRule revenue entitlement graphs by id: its participants, rules, and ledger wiring. Read-only.
revrule_list_payout_evidence	GET /v1/graphs/{graph_id}/payout-evidence	List payout evidence recorded for a graph: verified payouts linked back to the original entitlement ledger entries (transaction hash, log index, block data, authorizing signature). Read-only.
revrule_simulate_event	POST /v1/graphs/{graph_id}/simulate	Dry-run a revenue event against a graph's rules and see what the rules would produce, with zero side effects: nothing is recorded, no payout is prepared or submitted. The tool wraps the supplied event as {event: ...} for the production rail; simulation has no side effects.

Install

Verified MCPB release

Install the revrule v1.1.0 MCPB bundle in an MCPB-compatible client, or run from source below. The published bundle declares the supported MCP tools. This direct release is the verified installation path while third-party directory listings are revalidated.

From source

git clone https://github.com/Payloadhq/revrule-mcp
cd revrule-mcp
node mcp/index.js

Or run it straight from GitHub with npx:

npx -y github:Payloadhq/revrule-mcp

MCP client configuration (stdio):

{
  "mcpServers": {
    "revrule": {
      "command": "node",
      "args": ["/path/to/revrule-mcp/mcp/index.js"],
      "env": {
        "PAYLOAD_RAIL_API_KEY": "your-rail-api-key"
      }
    }
  }
}

Configuration

Variable	Required	Default	Purpose
PAYLOAD_RAIL_API_KEY	Required for tool calls	—	Your own Payload rail API key. A free self-serve key from the console works for evaluation; the paid license covers production use. Sent to the rail only as a Bearer Authorization header.
PAYLOAD_RAIL_URL	Optional	https://payload-rail.fly.dev	Payload rail base URL.

Fail-closed: with no API key configured, the server still starts and lists its tools, and every tool call returns a clear API key not configured error. The key never leaves your machine except as the Authorization header to the rail.

Free evaluation and the paid license

Free. You can evaluate RevRule end to end without paying:

• The RevRule sandbox runs the actual engine in your browser: define a graph, fire events, and inspect the entitlement ledger.
• The RevRule console issues a free self-serve Payload rail API key. With that key, this server's reads (revrule_get_graph, revrule_list_payout_evidence) and the zero-side-effect dry run (revrule_simulate_event) work against your own graphs. A paid entitlement is not required to evaluate.

Paid. The RevRule license is $99 one-time. It is the production product: run your real revenue graphs on the rail with the entitlement ledger and payout evidence as your system of record, instead of evaluating in the sandbox.

RevRule computes who is owed what and records the evidence. It does not execute payments and it never holds funds; your own systems and payment partners move the money.

License

MIT — see LICENSE.

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RevRule is a product of Payload, separate from Veyline (Payload's authorization layer) and from callx402 by Payload, the MCP client layer for x402-priced actions.