gold402-mcp
gold402-mcp
Un servidor MCP sobre gold-402 — el directorio x402 curado mantenido por 24K Labs. Proporciona a cualquier agente compatible con MCP (Claude, Cursor, o cualquier cosa que hable MCP) cuatro herramientas para encontrar servicios x402 y para verificar un endpoint antes de gastar dinero en él.
Estado: v0.1 — probado, empaquetado, aún no publicado. Se ejecuta sobre stdio.
Herramientas
Herramienta | Qué hace |
| Busca en el estante por texto libre y/o nombre de estante. Paginado. Cada respuesta indica cuántas entradas realmente buscó. |
| Los 13 estantes con sus recuentos curados reales, y cuántos de ellos se pueden buscar aquí. |
| Una entrada por nombre: URL, descripción, estante, fecha de primera inclusión, página de listado permanente. |
| Comprueba en vivo cualquier endpoint x402, esté listado o no. Una solicitud no pagada: ¿responde?, ¿es un 402 real?, ¿cuáles son los términos de pago?, ¿el origen publica un manifiesto? — además de si está en nuestro estante. |
| De pago, $0.001 USDC en Base. El veredicto editorial de 24K Labs para un recurso, más las calificaciones agregadas de evaluadores independientes. La capa de juicio: un mantenedor lo examinó y puso su nombre detrás. |
Gratis vs de pago
Cuatro de las cinco herramientas son gratuitas y seguirán siéndolo — búsqueda, estantes, consulta de entradas y verificación en vivo. Sin clave, sin cartera, sin cuenta.
gold402_verdict es de pago: 0,001 USDC en Base. Es la única que compra lo que la sonda gratuita no te da: un juicio humano. Un 402 válido demuestra que la puerta funciona; no que el servicio detrás valga la pena. gold402_verdict añade esa capa: un mantenedor lo ha revisado y pone su nombre detrás.
Este servidor no guarda carteras y nunca paga en tu nombre. Llama a gold402_verdict una vez sin payment_signature para obtener los términos x402 decodificados (precio, red, destino). Luego firma tú mismo la transacción y pásale la firma; el servidor solo la transmite.
gold402_check_endpoint es la comprobación de puerta que usan los mantenedores, ahora invocable. Funciona sobre endpoints que no están en el directorio: un agente que está a punto de pagar a un desconocido puede preguntar primero. No se envía dinero.
Related MCP server: x402 Atlas
Lo que significa el listado — y lo que no
Un listado significa que un mantenedor lo probó y respondió correctamente a una solicitud x402 en el momento de la revisión, y lo re‑probamos periódicamente. No es una auditoría del servicio, ni una garantía de que funcionará, ni un respaldo. Una solicitud 402 válida demuestra que la puerta existe y pide pago; no demuestra que el servicio que hay detrás sea bueno, esté disponible o siga ahí mañana.
Por eso gold402_verdict es de pago y es la única herramienta con juicio: un humano miró el recurso y puso su nombre detrás.
Herramientas
Herramienta | Qué hace |
| Busca en el estante por texto libre y/o nombre de estante. Paginado. Cada respuesta indica cuántas entradas buscó realmente. |
| Los 13 estantes con sus recuentos curados reales, y cuántos de cada uno se pueden buscar aquí. |
| Una entrada por nombre: URL, estante, fecha del primer listado, número de entradas y enlace permanente. |
| Sonda en vivo de cualquier endpoint x402. Una solicitud sin pago: ¿responde?, ¿es un 402 real?, ¿qué métodos acepta?, ¿tiene cabeceras |
| De pago, $0.001 USDC en Base. Veredicto editorial de 24K Labs sobre un recurso, más calificaciones agregadas de evaluadores independientes. La capa de juicio: un mantenedor lo miró y puso su nombre detrás. |
Gratis vs de pago
Cuatro de las cinco herramientas son gratuitas y seguirán siéndolo: búsqueda, estanterías, consulta de entradas y comprobación de endpoints. Sin clave, sin cartera, sin cuenta.
gold402_verdict es de pago: $0,001 USDC en Base. Es la única, y compra lo que la comprobación gratuita no da: un veredicto humano editorial sobre si un recurso merece la pena.
uvx gold402-mcp # no install step
pip install gold402-mcp # then run: gold402-mcpInstalación
python3 -m venv .venv && ./.venv/bin/pip install -e .
./.venv/bin/gold402-mcpUso
{
"mcpServers": {
"gold402": {
"command": "uvx",
"args": ["gold402-mcp"]
}
}
}Fuente de datos
https://24klabs.ai/directory.json — público, publicado, sin clave, sin scraping. Si la descarga falla y existe una copia en caché, el servidor informa de la antigüedad de la caché y aun así la sirve.
Cobertura, claramente: el servidor solo ve lo que ese JSON público expone. No adivina y nunca inventa campos. Si un campo falta en la fuente, la respuesta de la herramienta lo dice. Eso es una característica, no un error.
./.venv/bin/python test_tools.py # tool-level, incl. error paths
./.venv/bin/python test_stdio.py # end-to-end over the real MCP protocolAvailable Tools
5 toolsgold402_check_endpointARead-only
Live-probe ANY x402 endpoint — listed or not — before paying it. Sends one unpaid request and reports: whether it answered, the HTTP status, whether it returned a real 402 payment challenge, and the payment terms found (scheme, network, price, payTo, asset). Also checks the /.well-known/x402 manifest on the same origin. This is the same liveness-and-protocol check the gold-402 maintainers run at the door. It does NOT spend money and does NOT verify delivery — a valid 402 proves the door works, not that the service is good.
| Name | Required | Description | Default |
|---|---|---|---|
| params | Yes |
Output Schema
| Name | Required | Description |
|---|---|---|
| result | Yes |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description discloses specific behavioral details beyond annotations: it sends one unpaid request, does not spend money, does not verify delivery, and checks the manifest. These details are not captured by readOnlyHint or openWorldHint, adding valuable context for the agent to manage expectations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is front-loaded with the core purpose, followed by specific outputs and limitations. It is concise (five sentences) and every sentence adds value—no filler, no redundancy, and the structure flows logically.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given that an output schema exists (not shown but indicated), the description need not detail return formatting. It covers the essential output elements (status, 402 challenge, payment terms, manifest check) and clearly states constraints (does not spend money, does not verify delivery), making it complete for an agent to decide when and how to use it.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Despite the schema having descriptions for url, method, and response_format, the coverage signal is 0% (likely top-level params lacks description). The tool description does not compensate by explaining how to use these parameters; it omits any mention of method or response_format, leaving the agent to rely solely on schema descriptions for parameter guidance.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool's purpose: to live-probe any x402 endpoint, sending an unpaid request and reporting liveness, HTTP status, payment challenge, and terms. It explicitly distinguishes from siblings (search, list_sections, get_entry, verdict) by focusing on endpoint probing rather than content retrieval, and clarifies it applies to any endpoint, listed or not.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides clear context on when to use it ('before paying it') and explicitly states what it does NOT do (spend money or verify delivery). It implies this is for pre-payment validation but does not explicitly name alternative tools for delivery verification or content exploration, which minor gap prevents a 5.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
gold402_get_entryARead-onlyIdempotent
Fetch a single gold-402 entry by name (exact match preferred, falls back to partial). Returns the full record including URL, description, shelf, the date it was first listed, and the permanent listing page.
| Name | Required | Description | Default |
|---|---|---|---|
| params | Yes |
Output Schema
| Name | Required | Description |
|---|---|---|
| result | Yes |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description discloses the matching behavior (exact then partial) and lists return fields. Annotations already provide safety hints (read-only, idempotent), so the description adds meaningful behavioral detail without redundancy.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is two concise sentences, free of fluff, and clearly structured. It communicates purpose and output without unnecessary detail.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the low complexity (single entry fetch) and presence of an output schema, the description sufficiently covers the return content by listing all key fields (URL, description, shelf, date first listed, permanent listing page). No gaps found.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Both parameters have schema descriptions, and the tool description enriches the 'name' parameter by explaining the exact/partial matching semantics. The response_format parameter is adequately described in the schema, so no additional clarification is needed.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool fetches a single gold-402 entry by name, with exact match preferred and fallback to partial. This precisely defines the action and distinguishes from search-oriented siblings.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
It explicitly indicates when to use: to retrieve a single entry by name. While it doesn't contrast with sibling tools like gold402_search, the scope is unambiguous enough for the agent to select appropriately.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
gold402_list_sectionsARead-onlyIdempotent
List the shelves (categories) of the gold-402 directory with an entry count for each. Use the returned section id as the 'section' filter in gold402_search.
| Name | Required | Description | Default |
|---|---|---|---|
| params | Yes |
Output Schema
| Name | Required | Description |
|---|---|---|
| result | Yes |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare read-only/idempotent/non-destructive behavior, and the description adds beyond that by saying the tool returns counts and section IDs and how those IDs feed into search. This is useful behavioral/return context without contradicting the annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two short, purposeful sentences: the first names the action and result, the second gives the concrete integration hint. No filler, repetition, or wasted words.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple list tool with safe annotations, a one-parameter schema, and an output schema, this description is complete: it explains what the tool lists, what it returns, and how to use the result in a sibling tool. No missing contextual element is apparent.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The description is silent on the response_format parameter, but the schema itself documents that parameter thoroughly with an enum, default, and usage note. The description adds no parameter-level meaning beyond the schema, so a baseline score of 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a concrete verb and resource ('List the shelves (categories) of the gold-402 directory') and adds a useful output detail ('entry count for each'), clearly distinguishing it from the sibling search/retrieval/endpoint tools.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description tells the agent the primary downstream use ('Use the returned section id as the 'section' filter in gold402_search'), which gives clear context for when to call it. It does not explicitly say when not to use it versus alternatives, so it stops short of a 5.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
gold402_searchARead-onlyIdempotent
Search the gold-402 curated directory of x402 services, MCP servers, SDKs, facilitators and tools. Every entry was hand-probed by a maintainer and answered an x402 request correctly at the time of review. Filter by free text and/or shelf; supports pagination. Returns name, URL, description, shelf and the date first listed, with a provenance stamp.
| Name | Required | Description | Default |
|---|---|---|---|
| params | Yes |
Output Schema
| Name | Required | Description |
|---|---|---|
| result | Yes |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds context about the hand-probed, curated nature of entries and specifies output fields including provenance stamp, going beyond the annotation hints to give users confidence in reliability and result contents.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is concise, front-loaded with the primary action, and structured in three clear sentences covering purpose, curation, and features. It avoids unnecessary detail.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the detailed schema and output schema, the description provides sufficient context for usage without redundant explanations. It covers what the tool returns and the quality of entries, making it complete.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The schema already provides detailed descriptions for each parameter (limit, query, offset, section, response_format). The tool description only paraphrases filtering and pagination, adding minimal extra meaning beyond what the schema covers.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly identifies the tool's function as searching the curated x402 directory, specifying the types of entries it covers. It distinguishes itself from sibling tools like list_sections and get_entry by focusing on search.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description implies usage for searching and mentions filtering/pagination, but does not explicitly state when to prefer this tool over alternatives like list_sections. It lacks direct comparative guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
gold402_verdictARead-onlyIdempotent
PAID ($0.001 USDC on Base) — the 24K Labs editorial verdict for one x402 resource, plus aggregated independent rater grades, as JSON. This is the human judgement layer: a maintainer looked at this service and put a name behind it. Distinct from gold402_check_endpoint, which is FREE and only reports whether the door answered. Call once with no payment_signature to receive the exact payment terms; call again with the signature to settle. This server never holds a wallet — you pay 24K Labs directly from yours.
| Name | Required | Description | Default |
|---|---|---|---|
| params | Yes |
Output Schema
| Name | Required | Description |
|---|---|---|
| result | Yes |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false. The description adds meaningful behavioral context beyond those: the $0.001 USDC payment, the two-call settlement flow, and the fact that the server never holds a wallet. No contradiction with annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is dense but efficient: it front-loads the paid nature, defines the output, distinguishes the tool from a sibling, and explains the two-call flow in four short sentences. Minor redundancy with schema text on payment_signature costs it a point.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the output schema exists and the main behavioral complexity is the payment handshake, the description is largely sufficient. It explains what the verdict contains, how to pay, and what makes it different from the free check. It does not mention the markdown response_format option, but that is visible in the schema.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The description adds useful meaning about the payment_signature workflow and the resource scope, but the schema already documents resource and payment_signature semantics. The claim that output is 'as JSON' is potentially confusing because response_format defaults to markdown and allows json, and response_format is not discussed in the description.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description names a specific, differentiated purpose: 'the 24K Labs editorial verdict for one x402 resource, plus aggregated independent rater grades.' It also explicitly contrasts with gold402_check_endpoint, making the tool's role clear among its siblings.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
It gives concrete usage guidance: call once without payment_signature to receive payment terms, then call again with the signature to settle. It explicitly distinguishes from the free gold402_check_endpoint, though it does not address when to choose this over gold402_search, list_sections, or get_entry.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Tool Schema Changelog
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
5 tool updates
v0.1.0- First observed
gold402_check_endpoint - First observed
gold402_get_entry - First observed
gold402_list_sections - First observed
gold402_search - First observed
gold402_verdict
TDQS
Scored across 5 tools
Each tool targets a distinct operation: browsing shelves, searching entries, fetching one entry, live-probing an endpoint, and retrieving a paid verdict. The free technical probe and paid editorial verdict are explicitly differentiated, so there is no realistic confusion.
Most tools follow a consistent gold402_verb_noun pattern (gold402_list_sections, gold402_get_entry, gold402_check_endpoint, gold402_search). The one exception is gold402_verdict, which uses a noun instead of a verb, creating a minor but noticeable deviation.
Five tools is exactly right for this directory-style MCP server. Each tool earns its place: browse, search, detail, live verification, and paid human judgment. The scope is tight and no tool feels redundant.
The server covers the full user workflow: discover categories, search entries, retrieve full records, independently probe any endpoint, and optionally purchase an editorial verdict. The paid verdict flow with signature-based settlement is included, so there are no dead ends.
Maintenance
Related MCP Connectors
Meta-search MCP for x402 agent-payable services -- find paid APIs across every registry.
402xAgent is the check an agent calls before paying any x402 endpoint. It probes the endpoint's 402 without paying and returns a pay / skip / recheck verdict with a reason. Every check leaves a public receipt. It never pays the target.
Search 15K+ MCP services, A2A agents, and x402 APIs from 5 registries. Paid via x402 (USDC on Base).
Remote MCP utilities for agents: structured data, commerce checks, and x402 paid API discovery.
Related MCP Servers
- AlicenseNot gradedqualityCmaintenanceEnables MCP-compatible agents to discover and call x402 paid services from a directory of over 2,000 APIs.Apache 2.0
- FlicenseNot gradedqualityAmaintenanceEnables AI agents to search and verify machine-payable HTTP 402/x402 APIs using live probe data, providing ranked results by liveness, uptime, price, and trustworthiness.-

@vapi-network/mcpofficial
AlicenseNot gradedqualityBmaintenanceLets MCP clients discover x402 APIs, pay for calls from a local non-custodial wallet, and inspect balances and payment receipts.2,025Apache 2.0- AlicenseNot gradedqualityBmaintenanceExposes MCP tools that let an agent search a catalog, inspect a paid service's pricing, fetch it with payment handled automatically, and check its remaining budget and active spending limits. Payments are authorized against a signed mandate from the owner, so agents can buy API access over HTTP 402 without ever holding the owner's private key.563 npmMIT