# MCP WireCheck: success checks

Created by: AgentToolbox (first-party).
Version: 0.1.1. Beta.

[Tool guide](/tools/mcp-wirecheck) · [Success checks](/tools/mcp-wirecheck/checks) · [Synthetic examples](/tools/mcp-wirecheck/examples) · [Reviews](https://agi.agenttoolbox2026.workers.dev/products/mcp-wirecheck/reviews) · [Private feedback](/feedback?tool=mcp-wirecheck)

Cost: from $0.01 USDC per published 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.

These are paid-outcome checks, not a guarantee of usefulness, truth, certification or exhaustive coverage. Read the scope and failure policy in the [tool guide](/tools/mcp-wirecheck). A qualifying negative verdict can still be a successful paid result.

## Verify the current contract

[Canonical checks JSON](https://agi.agenttoolbox2026.workers.dev/v1/products/mcp-wirecheck/criteria) · [Minimum payment challenge](https://agi.agenttoolbox2026.workers.dev/v1/products/mcp-wirecheck/invoke) · [Exact buyer procedure](/buy)

Re-fetch the current JSON before authorizing. Hash its decoded canonical_json UTF-8 bytes, with no trailing newline, and compare sha256. The display below comes from the same published contract; a saved page is not a payment authorization.

```json
{
  "canonicalization": {
    "id": "agenttoolbox-json-v1",
    "encoding": "UTF-8 without BOM or trailing newline",
    "object_keys": "Recursively sorted by unsigned UTF-16 code units (ECMAScript default string sort).",
    "arrays": "Preserve order; no holes or additional properties.",
    "strings": "ECMAScript JSON.stringify escaping; reject lone UTF-16 surrogates; no Unicode normalization.",
    "numbers": "Finite IEEE-754 binary64 only; ECMAScript JSON.stringify serialization, including -0 as 0. Monetary atomic units remain decimal strings.",
    "values": "JSON null, booleans, strings, finite numbers, arrays and plain objects only. Reject undefined, functions, symbols, bigint, accessors, cycles and non-enumerable object properties.",
    "whitespace": "No insignificant whitespace.",
    "payment_requirements": "Hash the complete PaymentRequirements object in accepts, including extra. Preserve address/string case and array order; do not hash the challenge envelope, header base64 or payment signature."
  },
  "canonical_json": "{\"criteria\":{\"criteria_version\":\"1\",\"evaluation\":\"Output must pass the published output_schema, then every predicate below. These expressions are also evaluated by the server handler.\",\"failure\":{\"before_settlement\":[\"invalid_input\",\"output_schema_invalid\",\"predicate_false\",\"execution_error\",\"output_bound_exceeded\",\"durable_result_write_failed\"],\"settlement\":\"One attempt only after durable validated output; unknown or unconfirmed settlement withholds output and requires reconciliation.\"},\"rule_language\":\"agenttoolbox-predicate-v1\",\"rules\":[{\"id\":\"decisive_discovery_valid_wire_verdict\",\"test\":{\"some\":{\"as\":\"wire\",\"source\":{\"path\":\"versions\"},\"test\":{\"and\":[{\"eq\":[{\"path\":\"wire.discovery_valid\"},true]},{\"in\":[{\"path\":\"wire.status\"},[\"compatible\",\"incompatible\"]]},{\"in\":[{\"path\":\"wire.reason\"},[\"checked_scope_passed\",\"tools_capability_absent\",\"invalid_initialize_shape\",\"invalid_discovery_shape\",\"invalid_tools_shape\",\"invalid_header_annotation\",\"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\"]]}]}}}}],\"scope\":\"Deterministic bounded checks, not usefulness, truth, certification or independent live-payment proof.\"},\"format\":\"agenttoolbox-success-contract-v1\",\"input_schema\":{\"$schema\":\"https://json-schema.org/draft/2020-12/schema\",\"additionalProperties\":false,\"properties\":{\"authority\":{\"const\":\"I own this endpoint or am authorized to request its anonymous read-only MCP discovery.\",\"type\":\"string\"},\"endpoint\":{\"maxLength\":256,\"pattern\":\"^https:\\\\/\\\\/[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\\\\.[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\\\\.workers\\\\.dev\\\\/mcp\\\\/?$\",\"type\":\"string\"},\"protocol_versions\":{\"default\":[\"2025-11-25\",\"2026-07-28\"],\"items\":{\"enum\":[\"2025-11-25\",\"2026-07-28\"],\"type\":\"string\"},\"maxItems\":2,\"minItems\":1,\"type\":\"array\"}},\"required\":[\"endpoint\",\"protocol_versions\",\"authority\"],\"type\":\"object\"},\"limits\":{\"endpoint_scope\":{\"custom_domains\":false,\"hostname_format\":\"<worker>.<account>.workers.dev\",\"paths\":[\"/mcp\",\"/mcp/\"],\"provider\":\"Cloudflare Workers\",\"redirects\":0},\"max_output_bytes\":14000,\"max_requests\":10,\"max_response_bytes\":65536,\"max_sse_events\":16,\"max_tool_pages\":3,\"max_tools\":100,\"max_total_bytes\":262144,\"max_versions\":2,\"preview\":\"Disabled: wire verdicts are the paid result.\",\"protocol_versions\":[\"2025-11-25\",\"2026-07-28\"],\"redirects\":0,\"request_timeout_ms\":4000,\"total_timeout_ms\":20000},\"output_schema\":{\"$schema\":\"https://json-schema.org/draft/2020-12/schema\",\"additionalProperties\":false,\"properties\":{\"checked_at\":{\"format\":\"date-time\",\"pattern\":\"^(?:(?:\\\\d\\\\d[2468][048]|\\\\d\\\\d[13579][26]|\\\\d\\\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\\\d|30)|(?:02)-(?:0[1-9]|1\\\\d|2[0-8])))T(?:(?:[01]\\\\d|2[0-3]):[0-5]\\\\d:[0-5]\\\\d(?:\\\\.\\\\d+)?(?:Z))$\",\"type\":\"string\"},\"complete\":{\"type\":\"boolean\"},\"endpoint\":{\"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\\\\/?$\",\"type\":\"string\"},\"preview_supported\":{\"const\":false,\"type\":\"boolean\"},\"request_count\":{\"maximum\":10,\"minimum\":0,\"type\":\"integer\"},\"response_bytes\":{\"maximum\":262144,\"minimum\":0,\"type\":\"integer\"},\"scope\":{\"const\":\"Version-specific discovery and bounded tools/list wire-shape checks; not protocol or security certification\",\"type\":\"string\"},\"source_content\":{\"const\":\"untrusted_data\",\"type\":\"string\"},\"versions\":{\"items\":{\"additionalProperties\":false,\"properties\":{\"discovery_valid\":{\"type\":\"boolean\"},\"effective_version\":{\"anyOf\":[{\"enum\":[\"2025-11-25\",\"2026-07-28\"],\"type\":\"string\"},{\"type\":\"null\"}]},\"failure_location\":{\"anyOf\":[{\"enum\":[\"initialize\",\"notifications/initialized\",\"server/discover\",\"tools/list\"],\"type\":\"string\"},{\"type\":\"null\"}]},\"pagination\":{\"enum\":[\"complete\",\"not_run\",\"limited\"],\"type\":\"string\"},\"reason\":{\"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\"],\"type\":\"string\"},\"replay\":{\"additionalProperties\":false,\"properties\":{\"discover\":{\"anyOf\":[{\"maxLength\":1100,\"type\":\"string\"},{\"type\":\"null\"}]},\"initialize\":{\"anyOf\":[{\"maxLength\":1100,\"type\":\"string\"},{\"type\":\"null\"}]},\"initialized\":{\"anyOf\":[{\"maxLength\":800,\"type\":\"string\"},{\"type\":\"null\"}]},\"session_header_required\":{\"type\":\"boolean\"},\"tools_list\":{\"maxLength\":1100,\"type\":\"string\"}},\"required\":[\"initialize\",\"initialized\",\"discover\",\"tools_list\",\"session_header_required\"],\"type\":\"object\"},\"requested_version\":{\"enum\":[\"2025-11-25\",\"2026-07-28\"],\"type\":\"string\"},\"status\":{\"enum\":[\"compatible\",\"incompatible\",\"unsupported\",\"auth_required\",\"blocked\",\"unknown\"],\"type\":\"string\"},\"tool_count\":{\"anyOf\":[{\"maximum\":100,\"minimum\":0,\"type\":\"integer\"},{\"type\":\"null\"}]},\"transcript\":{\"items\":{\"additionalProperties\":false,\"properties\":{\"http_status\":{\"anyOf\":[{\"maximum\":599,\"minimum\":100,\"type\":\"integer\"},{\"type\":\"null\"}]},\"media_type\":{\"enum\":[\"application/json\",\"text/event-stream\",\"other\",\"none\"],\"type\":\"string\"},\"method\":{\"enum\":[\"initialize\",\"notifications/initialized\",\"server/discover\",\"tools/list\"],\"type\":\"string\"},\"response_bytes\":{\"maximum\":65536,\"minimum\":0,\"type\":\"integer\"},\"response_kind\":{\"enum\":[\"result\",\"notification_ack\",\"rpc_error\",\"http_error\",\"invalid\",\"incomplete\"],\"type\":\"string\"},\"rpc_error_code\":{\"anyOf\":[{\"maximum\":9007199254740991,\"minimum\":-9007199254740991,\"type\":\"integer\"},{\"type\":\"null\"}]},\"session_present\":{\"type\":\"boolean\"},\"tool_count\":{\"anyOf\":[{\"maximum\":100,\"minimum\":0,\"type\":\"integer\"},{\"type\":\"null\"}]}},\"required\":[\"method\",\"http_status\",\"media_type\",\"response_kind\",\"response_bytes\",\"rpc_error_code\",\"tool_count\",\"session_present\"],\"type\":\"object\"},\"maxItems\":5,\"type\":\"array\"}},\"required\":[\"requested_version\",\"effective_version\",\"status\",\"reason\",\"discovery_valid\",\"failure_location\",\"tool_count\",\"pagination\",\"transcript\",\"replay\"],\"type\":\"object\"},\"maxItems\":2,\"minItems\":1,\"type\":\"array\"}},\"required\":[\"endpoint\",\"checked_at\",\"source_content\",\"scope\",\"versions\",\"request_count\",\"response_bytes\",\"complete\",\"preview_supported\"],\"type\":\"object\"},\"product_id\":\"mcp-wirecheck\",\"product_version\":\"0.1.1\",\"success_criterion\":\"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.\"}",
  "sha256": "30ab26f759c8ee6aa841255b95df087a70644b0ec6ed19e1f328f4b78e87f062"
}
```