Zerker vs MCPay
MCPay is the closest thing to us that exists.
It is a live, Apache-2.0, self-hostable x402 payment layer for MCP servers. On payments alone it does more than Gateway does today. The difference is runtime and custody, and for many teams MCPay is the right answer.
Self-host it. Charge for it. Keep payment keys yours. Zerker combines self-hosting, payment gating, and no custody in one open-source Gateway.
Start here
One question decides it.
Do you need money to move today, or do you need to fully control everything in the payment path?
Pick MCPay if
- You want on-chain settlement now. It verifies, settles, and retries the original request after payment
- You're a TypeScript shop and a Node runtime is what you already operate
- You're happy pointing settlement at a hosted facilitator and not running one
- Your upstreams are MCP servers, and only MCP servers
- You want the shortest path from an MCP server to a paid one
Pick Zerker if
- You need to self-host the whole path, facilitator included, with nothing pointed at a third party
- You'd rather deploy one static Go binary than a Node application
- You're fronting plain HTTP upstreams as well as MCP servers
- You need mandatory OIDC and per-tenant credential isolation, not API keys
- Verify-only meets your current need while Zerker settlement remains in progress
Where they're ahead
They collect. We verify.
This is the real gap. MCPay negotiates x402, confirms the payment on-chain, and retries the original request once it has settled. Gateway ships the gate: it checks that a signed authorization is valid, sufficient, and unexpired, then forwards. No funds move.
On payments alone, we are a step behind. Verification needs no key and no outbound call, so it lives in the open-source core. Collection requires someone to hold a gas key. If you need money in an account today, MCPay does that and our gate does not.
Without a settlement step to consume the on-chain nonce, gate-only replay protection is best-effort. Enabling settlement closes it. See the x402 gate.
Side by side
Everything else.
| MCPay | Zerker | |
|---|---|---|
| License | Apache-2.0 | Apache-2.0 |
| Runtime | TypeScript / Node | One static Go binary |
| Deployment posture | Open source. Docs and examples point at mcpay.tech | Self-host first. Nothing phones home |
| x402 | Verify + settle + retry | Verify gate shipped; settlement through a facilitator is in progress |
| Custody | Settlement is delegated to a facilitator service | The gateway holds no signing key, ever. The facilitator is separable and self-hostable |
| Auth | API keys | Mandatory OIDC bearer; the process refuses to start without an issuer and audience |
| Credentials | Not a separate resource | Envelope-encrypted under a per-tenant key, write-only, never echoed |
| Upstreams | MCP servers | MCP over Streamable HTTP, plus generic HTTP upstreams |
| Traction | ~91 stars, actively developed | Newer and smaller. One binary you can audit in an afternoon |
The actual difference
Who has to be trusted for a payment to work.
Both projects gate a call on a signed authorization. MCPay's settlement runs through a facilitator service. Gateway's self-hostable facilitator is still in progress, and Gateway itself never holds a signing key.
For most teams that distinction does not matter, and MCPay's shorter path wins. For an operator who is regulated, air-gapped, or under a data-residency rule, it is the only thing that matters.
Sources
Compared against publicly available information on 3 August 2026, verified directly rather than quoted from our own earlier research. MCPay: github.com/microchipgnu/MCPay and docs.mcpay.tech. If something here has gone out of date, tell us — open an issue and we'll correct it rather than leave it standing.