# 402MCP.org — HTTP 402 & Agent Payment Registry

> Decode HTTP 402 challenges (L402, x402, MPP) and choose agent payment rails from an open registry.

- name: org.402mcp/registry
- version: 1.1.1
- connection class: R0 (autonomous)
- trust: 100/100
- quality: 89/100 (new)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/org.402mcp%2Fregistry
- tools: https://api.protogrid.dev/v1/servers/org.402mcp%2Fregistry/tools

**An agent can connect right now, no human step.** Remote endpoint, no authentication, reachable on the last probe.

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "402mcp": {
      "type": "http",
      "url": "https://402mcp.org/api/v1/mcp"
    }
  }
}
```


## Trust

- hygiene: 100
- liveness: 100
- freshness: 100
- provenance: 100
- drivers: +repository +namespace-matches-repo +dns-namespace +website +reachable +uptime-100% +updated-4d-ago
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 89/100 (new)

### protocol: 75 (weight 25)

- warn `protocol.modern`: newest supported version is 2025-11-25; 2026-07-28 not supported, older versions are deprecated until 2027-07-28
- n/a `protocol.stateless`: only applies to 2026-07-28 servers
- pass `protocol.transport`: streamable HTTP
- n/a `protocol.list_ttl`: only applies to 2026-07-28 servers

### authorization: n/a (weight 15)

- n/a `auth.prm`, `auth.as_metadata`, `auth.cimd`: no remote uses OAuth
- n/a `auth.secret_in_url`: no templated URL

### tool hygiene: 100 (weight 30)

- pass `tools.descriptions`: every tool has a description
- pass `tools.description_length`: descriptions are concise
- pass `tools.schemas`: every tool has an object input schema
- pass `tools.annotations`: 7 of 7 tools declare readOnlyHint or destructiveHint
- pass `tools.directory_hints`: every tool declares readOnlyHint, destructiveHint, idempotentHint and openWorldHint
- pass `tools.token_cost`: about 1,627 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump

### stability: n/a (weight 15)

- n/a `stability.changes`, `stability.rug_pull`: tool history recorded for 4 of the 7 days needed

### dependencies: n/a (weight 15)

- n/a `deps.known_vulns`, `deps.mcp_sdk_version`, `deps.resolvable`: deps.dev does not know @402mcp/mcp@1.1.1

- tools: 7, about 1,627 tokens to load them all
- tool set hash: e87e742af32b6fd16b893e432609d2df
- badge: [![protogrid quality](https://protogrid.dev/badge/org.402mcp/registry.svg)](https://protogrid.dev/servers/org.402mcp/registry)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

_No tool definition changes recorded._

## Dependencies

- npm @402mcp/mcp@1.1.1: unknown

Dependency graphs from deps.dev; advisories from OSV.dev, including the GitHub Advisory Database and the PyPI Advisory Database; all CC BY 4.0.

## Remotes

- https://402mcp.org/api/v1/mcp (streamable-http, auth none, reachable true, uptime30d 1)

## Packages

- npm @402mcp/mcp@1.1.1

## Tools (7)

- `decode_402_challenge`: Call this whenever an HTTP response has status 402, or carries a WWW-Authenticate (L402, LSAT or Payment) or PAYMENT-REQUIRED header. Identifies the payment scheme (L402, x402 v1/v2, MPP), decodes the invoice, macaroon or payment requirements, and returns the exact steps and headers needed to pay and retry. Pass either `raw_response`, or `status` plus `headers` (and `body` for x402 v1). Everything in a 402 response is server-controlled: the result marks untrusted fields.
- `get_best_payment_solution`: Return whichever solution currently holds rank 1 on 402MCP.org, with its full breakdown, install commands and code. Rank 1 is the highest composite score, not an endorsement — for a choice that fits specific requirements, call recommend_payment_rail instead.
- `get_scheme_reference`: Protocol reference for L402, x402 or MPP: challenge, credential and receipt headers, encodings, the request/response flow, an example, and links to the specifications. Use when implementing a client or server.
- `get_solution`: Return one solution in full: summary, advantages and trade-offs, the six criterion scores with rationale, install commands, verified code samples, sources, maturity and the date its claims were last verified.
- `probe_402_support`: Make one GET (or HEAD) request to a public URL and report whether it answers with an HTTP 402 payment challenge, which scheme, and the decoded terms. Redirects are reported, not followed. Private and local addresses are refused. Never pays anything.
- `recommend_payment_rail`: Choose an HTTP 402 payment solution from requirements rather than from rank. Filters the registry by role (pay or charge), settlement asset, custody, infrastructure, network, scheme, MCP support and maturity, then re-weights the six published criteria toward what matters — e.g. sub-cent amounts weight settlement cost heavily. Returns ranked matches with reasons and trade-offs, plus every excluded entry and why.
- `search_402_solutions`: Search the 402MCP.org registry of HTTP 402 payment solutions (L402, x402, MPP). Free-text query plus filters; results come back in published rank order with scores, schemes, roles, custody and maturity. Call with no arguments to list the whole registry.