MCP WireCheck: contract
Created by: AgentToolbox (first-party).
Version: 0.1.1. Beta.
Check MCP discovery and tools/list on your public workers.dev endpoint.
Scope: Public canonical workers.dev endpoints only · discovery + tools/list · no tools/call
Cost: from $0.01 USDC per published success; buyer-chosen amount, USDC on Base.
Success: At least one decisive compatible/incompatible wire-shape verdict. Authentication, blocking, unsupported versions and unknown outcomes alone are nonchargeable. No tools/call; not conformance or security certification.
Failure policy: Invalid input, failed criterion or unavailable decisive evidence never settles. Uncertain settlement requires reconciliation; never issue a replacement authorization.
Canonical contract JSON · Buyer guide
Input schema
```json
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"type": "object",
"properties": {
"endpoint": {
"type": "string",
"maxLength": 256,
"pattern": "^https:\\/\\/[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\\.[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\\.workers\\.dev\\/mcp\\/?$"
},
"protocol_versions": {
"default": [
"2025-11-25",
"2026-07-28"
],
"minItems": 1,
"maxItems": 2,
"type": "array",
"items": {
"type": "string",
"enum": [
"2025-11-25",
"2026-07-28"
]
}
},
"authority": {
"type": "string",
"const": "I own this endpoint or am authorized to request its anonymous read-only MCP discovery."
}
},
"required": [
"endpoint",
"protocol_versions",
"authority"
],
"additionalProperties": false
}
```
Output schema
```json
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"type": "object",
"properties": {
"endpoint": {
"type": "string",
"maxLength": 256,
"pattern": "^https:\\/\\/[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\\.[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\\.workers\\.dev\\/mcp\\/?$"
},
"checked_at": {
"type": "string",
"format": "date-time",
"pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z))$"
},
"source_content": {
"type": "string",
"const": "untrusted_data"
},
"scope": {
"type": "string",
"const": "Version-specific discovery and bounded tools/list wire-shape checks; not protocol or security certification"
},
"versions": {
"minItems": 1,
"maxItems": 2,
"type": "array",
"items": {
"type": "object",
"properties": {
"requested_version": {
"type": "string",
"enum": [
"2025-11-25",
"2026-07-28"
]
},
"effective_version": {
"anyOf": [
{
"type": "string",
"enum": [
"2025-11-25",
"2026-07-28"
]
},
{
"type": "null"
}
]
},
"status": {
"type": "string",
"enum": [
"compatible",
"incompatible",
"unsupported",
"auth_required",
"blocked",
"unknown"
]
},
"reason": {
"type": "string",
"enum": [
"checked_scope_passed",
"requested_version_not_negotiated",
"unsupported_negotiated_version",
"version_not_supported",
"method_not_supported",
"tools_capability_absent",
"invalid_initialize_shape",
"invalid_discovery_shape",
"invalid_tools_shape",
"invalid_header_annotation",
"schema_inspection_limit",
"duplicate_tool_name",
"invalid_jsonrpc",
"response_id_mismatch",
"invalid_notification_ack",
"invalid_session_header",
"unexpected_session_change",
"unexpected_modern_session",
"unsupported_content_type",
"invalid_json",
"redirect_not_followed",
"authentication_required",
"access_blocked",
"http_error",
"rpc_error",
"network_error",
"timeout",
"response_limit",
"total_byte_limit",
"sse_event_limit",
"sse_incomplete",
"server_request_not_supported",
"page_limit",
"tool_limit",
"cursor_loop",
"cursor_limit",
"request_limit"
]
},
"discovery_valid": {
"type": "boolean"
},
"failure_location": {
"anyOf": [
{
"type": "string",
"enum": [
"initialize",
"notifications/initialized",
"server/discover",
"tools/list"
]
},
{
"type": "null"
}
]
},
"tool_count": {
"anyOf": [
{
"type": "integer",
"minimum": 0,
"maximum": 100
},
{
"type": "null"
}
]
},
"pagination": {
"type": "string",
"enum": [
"complete",
"not_run",
"limited"
]
},
"transcript": {
"maxItems": 5,
"type": "array",
"items": {
"type": "object",
"properties": {
"method": {
"type": "string",
"enum": [
"initialize",
"notifications/initialized",
"server/discover",
"tools/list"
]
},
"http_status": {
"anyOf": [
{
"type": "integer",
"minimum": 100,
"maximum": 599
},
{
"type": "null"
}
]
},
"media_type": {
"type": "string",
"enum": [
"application/json",
"text/event-stream",
"other",
"none"
]
},
"response_kind": {
"type": "string",
"enum": [
"result",
"notification_ack",
"rpc_error",
"http_error",
"invalid",
"incomplete"
]
},
"response_bytes": {
"type": "integer",
"minimum": 0,
"maximum": 65536
},
"rpc_error_code": {
"anyOf": [
{
"type": "integer",
"minimum": -9007199254740991,
"maximum": 9007199254740991
},
{
"type": "null"
}
]
},
"tool_count": {
"anyOf": [
{
"type": "integer",
"minimum": 0,
"maximum": 100
},
{
"type": "null"
}
]
},
"session_present": {
"type": "boolean"
}
},
"required": [
"method",
"http_status",
"media_type",
"response_kind",
"response_bytes",
"rpc_error_code",
"tool_count",
"session_present"
],
"additionalProperties": false
}
},
"replay": {
"type": "object",
"properties": {
"initialize": {
"anyOf": [
{
"type": "string",
"maxLength": 1100
},
{
"type": "null"
}
]
},
"initialized": {
"anyOf": [
{
"type": "string",
"maxLength": 800
},
{
"type": "null"
}
]
},
"discover": {
"anyOf": [
{
"type": "string",
"maxLength": 1100
},
{
"type": "null"
}
]
},
"tools_list": {
"type": "string",
"maxLength": 1100
},
"session_header_required": {
"type": "boolean"
}
},
"required": [
"initialize",
"initialized",
"discover",
"tools_list",
"session_header_required"
],
"additionalProperties": false
}
},
"required": [
"requested_version",
"effective_version",
"status",
"reason",
"discovery_valid",
"failure_location",
"tool_count",
"pagination",
"transcript",
"replay"
],
"additionalProperties": false
}
},
"request_count": {
"type": "integer",
"minimum": 0,
"maximum": 10
},
"response_bytes": {
"type": "integer",
"minimum": 0,
"maximum": 262144
},
"complete": {
"type": "boolean"
},
"preview_supported": {
"type": "boolean",
"const": false
}
},
"required": [
"endpoint",
"checked_at",
"source_content",
"scope",
"versions",
"request_count",
"response_bytes",
"complete",
"preview_supported"
],
"additionalProperties": false
}
```
Limits
```json
{
"max_versions": 2,
"max_response_bytes": 65536,
"max_total_bytes": 262144,
"max_tool_pages": 3,
"max_tools": 100,
"max_sse_events": 16,
"max_requests": 10,
"request_timeout_ms": 4000,
"total_timeout_ms": 20000,
"max_output_bytes": 14000,
"redirects": 0,
"endpoint_scope": {
"provider": "Cloudflare Workers",
"hostname_format": "<worker>.<account>.workers.dev",
"paths": [
"/mcp",
"/mcp/"
],
"custom_domains": false,
"redirects": 0
},
"protocol_versions": [
"2025-11-25",
"2026-07-28"
],
"preview": "Disabled: wire verdicts are the paid result."
}
```