Skip to main content
Glama

Blackwood State

by io.github.Blackwood-State
OverviewDiscussionsAdmin

x402 check

blackwood_x402_check
Read-onlyIdempotent

Use when you need an x402 endpoint test or validation of a paid API before integrating or listing it. Do not use for actually paying the endpoint, or endpoints behind authentication. Returns JSON checking an x402 endpoint without paying: whether it answers 402, the parsed payment options (scheme, network, asset, amount, payTo), Bazaar discovery metadata and problems found for 0.007 USDC per call. Typical response time 2500 ms (p95). Category: Infrastructure.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
urlYesPublic http(s) URL of the x402 endpoint, e.g. https://x402.org/protected
bodyNoJSON body to send with POST, e.g. {"url": "https://example.com"} (no payment is ever attached)
methodNoHTTP method of the endpoint (GET when omitted)
response_formatNoconcise (the default when omitted) keeps the JSON short: long fields such as base64 images or audio come back as separate image/audio content blocks and other long strings are cut with a marker; detailed returns the full JSON

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault

No arguments

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed1 schema field changed
    • changedOutput schema / anyOf
      Previous value: -[
-  {
-    "additionalProperties": false,
-    "properties": {
-      "accepts": {
-        "items": {
-          "additionalProperties": false,
-          "properties": {
-            "amount": {
-              "type": [
-                "string",
-                "null"
-              ]
-            },
-            "amountUsd": {
-              "type": [
-                "number",
-                "null"
-              ]
-            },
-            "asset": {
-              "type": [
-                "string",
-                "null"
-              ]
-            },
-            "maxTimeoutSeconds": {
-              "type": [
-                "number",
-                "null"
-              ]
-            },
-            "network": {
-              "type": [
-                "string",
-                "null"
-              ]
-            },
-            "payTo": {
-              "type": [
-                "string",
-                "null"
-              ]
-            },
-            "scheme": {
-              "type": [
-                "string",
-                "null"
-              ]
-            }
-          },
-          "required": [
-            "scheme",
-            "network",
-            "asset",
-            "amount",
-            "amountUsd",
-            "payTo",
-            "maxTimeoutSeconds"
-          ],
-          "type": "object"
-        },
-        "type": "array"
-      },
-      "bazaar": {
-        "additionalProperties": false,
-        "properties": {
-          "inputSchema": {
-            "type": "boolean"
-          },
-          "outputSchema": {
-            "type": "boolean"
-          },
-          "present": {
-            "type": "boolean"
-          }
-        },
-        "required": [
-          "present",
-          "inputSchema",
-          "outputSchema"
-        ],
-        "type": "object"
-      },
-      "checkedAt": {
-        "type": "string"
-      },
-      "finalUrl": {
-        "type": "string"
-      },
-      "problems": {
-        "items": {
-          "type": "string"
-        },
-        "type": "array"
-      },
-      "resource": {
-        "anyOf": [
-          {
-            "additionalProperties": false,
-            "properties": {
-              "description": {
-                "type": [
-                  "string",
-                  "null"
-                ]
-              },
-              "mimeType": {
-                "type": [
-                  "string",
-                  "null"
-                ]
-              },
-              "url": {
-                "type": [
-                  "string",
-                  "null"
-                ]
-              }
-            },
-            "required": [
-              "url",
-              "description",
-              "mimeType"
-            ],
-            "type": "object"
-          },
-          {
-            "type": "null"
-          }
-        ]
-      },
-      "status": {
-        "type": "number"
-      },
-      "url": {
-        "type": "string"
-      },
-      "version": {
-        "type": [
-          "number",
-          "null"
-        ]
-      },
-      "x402": {
-        "type": "boolean"
-      }
-    },
-    "required": [
-      "url",
-      "finalUrl",
-      "status",
-      "x402",
-      "version",
-      "resource",
-      "accepts",
-      "bazaar",
-      "problems",
-      "checkedAt"
-    ],
-    "type": "object"
-  },
-  {
-    "description": "x402 PaymentRequired (returned with isError when payment is needed)",
-    "properties": {
-      "accepts": {
-        "items": {
-          "type": "object"
-        },
-        "type": "array"
-      },
-      "error": {
-        "type": "string"
-      },
-      "extensions": {
-        "type": "object"
-      },
-      "resource": {
-        "type": "object"
-      },
-      "x402Version": {
-        "type": "integer"
-      }
-    },
-    "required": [
-      "x402Version",
-      "accepts"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": false,
+    "properties": {
+      "accepts": {
+        "items": {
+          "additionalProperties": false,
+          "properties": {
+            "amount": {
+              "type": [
+                "string",
+                "null"
+              ]
+            },
+            "amountUsd": {
+              "type": [
+                "number",
+                "null"
+              ]
+            },
+            "asset": {
+              "type": [
+                "string",
+                "null"
+              ]
+            },
+            "maxTimeoutSeconds": {
+              "type": [
+                "number",
+                "null"
+              ]
+            },
+            "network": {
+              "type": [
+                "string",
+                "null"
+              ]
+            },
+            "payTo": {
+              "type": [
+                "string",
+                "null"
+              ]
+            },
+            "scheme": {
+              "type": [
+                "string",
+                "null"
+              ]
+            }
+          },
+          "required": [
+            "scheme",
+            "network",
+            "asset",
+            "amount",
+            "amountUsd",
+            "payTo",
+            "maxTimeoutSeconds"
+          ],
+          "type": "object"
+        },
+        "type": "array"
+      },
+      "bazaar": {
+        "additionalProperties": false,
+        "properties": {
+          "inputSchema": {
+            "type": "boolean"
+          },
+          "outputSchema": {
+            "type": "boolean"
+          },
+          "present": {
+            "type": "boolean"
+          }
+        },
+        "required": [
+          "present",
+          "inputSchema",
+          "outputSchema"
+        ],
+        "type": "object"
+      },
+      "checkedAt": {
+        "type": "string"
+      },
+      "finalUrl": {
+        "type": "string"
+      },
+      "next": {
+        "additionalProperties": false,
+        "description": "Suggested next paid call in the same family (call it in a loop when the task continues)",
+        "properties": {
+          "method": {
+            "enum": [
+              "GET",
+              "POST"
+            ],
+            "type": "string"
+          },
+          "sample": {
+            "description": "Free fixed sample of the whole family",
+            "type": "string"
+          },
+          "service": {
+            "description": "Service id of the suggested next paid call",
+            "type": "string"
+          },
+          "tool": {
+            "description": "MCP tool name of the same call",
+            "type": "string"
+          },
+          "url": {
+            "description": "Paid route of the next call",
+            "type": "string"
+          },
+          "useWhen": {
+            "description": "When the next call is the right one",
+            "type": "string"
+          }
+        },
+        "required": [
+          "service",
+          "tool",
+          "method",
+          "url",
+          "useWhen",
+          "sample"
+        ],
+        "type": "object"
+      },
+      "problems": {
+        "items": {
+          "type": "string"
+        },
+        "type": "array"
+      },
+      "resource": {
+        "anyOf": [
+          {
+            "additionalProperties": false,
+            "properties": {
+              "description": {
+                "type": [
+                  "string",
+                  "null"
+                ]
+              },
+              "mimeType": {
+                "type": [
+                  "string",
+                  "null"
+                ]
+              },
+              "url": {
+                "type": [
+                  "string",
+                  "null"
+                ]
+              }
+            },
+            "required": [
+              "url",
+              "description",
+              "mimeType"
+            ],
+            "type": "object"
+          },
+          {
+            "type": "null"
+          }
+        ]
+      },
+      "status": {
+        "type": "number"
+      },
+      "url": {
+        "type": "string"
+      },
+      "version": {
+        "type": [
+          "number",
+          "null"
+        ]
+      },
+      "x402": {
+        "type": "boolean"
+      }
+    },
+    "required": [
+      "url",
+      "finalUrl",
+      "status",
+      "x402",
+      "version",
+      "resource",
+      "accepts",
+      "bazaar",
+      "problems",
+      "checkedAt"
+    ],
+    "type": "object"
+  },
+  {
+    "description": "x402 PaymentRequired (returned with isError when payment is needed)",
+    "properties": {
+      "accepts": {
+        "items": {
+          "type": "object"
+        },
+        "type": "array"
+      },
+      "error": {
+        "type": "string"
+      },
+      "extensions": {
+        "type": "object"
+      },
+      "resource": {
+        "type": "object"
+      },
+      "x402Version": {
+        "type": "integer"
+      }
+    },
+    "required": [
+      "x402Version",
+      "accepts"
+    ],
+    "type": "object"
+  }
+]
  2. Added

TDQS

A4.6/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond the annotations (readOnly, idempotent, non-destructive, open-world), the description adds critical operational context: no payment is ever attached, cost is 0.007 USDC per call, and p95 latency is 2500 ms. Cost disclosure for a paid tool is especially valuable.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with usage conditions, then behavior, then cost/latency. The enumeration of return fields is slightly long, and somewhat redundant given an output schema exists, but every sentence carries information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given a paid endpoint-test tool with full schema coverage and an output schema, the description supplies the remaining essentials: billing cost, latency, safety behavior, and explicit exclusions. Nothing an agent needs to call it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and enums are documented, so the schema carries the parameter burden. The description adds no new parameter syntax or format detail beyond the schema, making the 3 baseline correct.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (test/validate) and resource (x402 endpoint) with clear scope: validating a paid API before integrating or listing it. An agent can distinguish this from siblings like blackwood_headers_audit or blackwood_wallet_balances without opening the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly gives both when to use ('before integrating or listing it') and when not to use ('Do not use for actually paying the endpoint, or endpoints behind authentication'). This is a rare, complete guidance statement with named exclusions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

All Blackwood State toolsInspect
Try in Browser
Context Every Agent Can ShareAgents share what they learn, hand off work, and keep it when you switch models. Start with 5 GB free.fulcradynamics.comAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources