CrossingKey MCP

Official26 tools

by crossingkey-holdings · JavaScript

Agent-native MCP for governed commerce, x402 payments, paid capabilities, and verifiable receipts.

CrossingKey MCP for agent commerce and x402 payments. The server is described as supporting deterministic execution and producing verifiable receipts. It is identified by the slug com-crossingkeyintelligence-crossingkey-mcp and the package name com.crossingkeyintelligence/crossingkey-mcp.

🛠️ Key Features

Agent commerce integration
x402 payments support
Deterministic execution
Verifiable receipts

🚀 Use Cases

Running agent commerce workflows that require x402 payments
Use cases that depend on deterministic execution behavior
Systems that need receipts that can be verified

⚡ Developer Benefits

Predictable, deterministic execution model
Receipt outputs intended to be verifiable

⚠️ Limitations

No additional capabilities, tool count, or operational details were provided in the source data.

Topics

agent-commerceai-agentsmachine-commercemcpx402

Captured live from the server via tools/list.

marketplace.describe

FREE, read-only marketplace overview. Use this first for marketplace-specific capability commerce, fee policy, creator rights, payment rails, and active catalog counts; use provider.describe for the broader CrossingKey provider and legacy offer surface.

Parameters

No parameters.

Raw schema

{
  "type": "object",
  "properties": {},
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

provider.apply

FREE public application intake. Always pending, never creates credentials or active capabilities.

Parameters5

displayName	string	required	Public provider display name; 1-120 characters.
slug	string	required	Stable provider slug used for human-readable identity and duplicate checks.
description	string	required	Public provider description; 1-2000 characters.
website	string	optional	Optional public HTTPS/HTTP provider website URL.
contact	string	required	Private provider contact reference used for intake and operator follow-up; 3-300 characters.

Raw schema

{
  "type": "object",
  "properties": {
    "displayName": {
      "type": "string",
      "minLength": 1,
      "maxLength": 120,
      "description": "Public provider display name; 1-120 characters."
    },
    "slug": {
      "type": "string",
      "pattern": "^[A-Za-z0-9][A-Za-z0-9._:-]{0,159}$",
      "description": "Stable provider slug used for human-readable identity and duplicate checks."
    },
    "description": {
      "type": "string",
      "minLength": 1,
      "maxLength": 2000,
      "description": "Public provider description; 1-2000 characters."
    },
    "website": {
      "type": "string",
      "format": "uri",
      "maxLength": 500,
      "description": "Optional public HTTPS/HTTP provider website URL."
    },
    "contact": {
      "type": "string",
      "minLength": 3,
      "maxLength": 300,
      "description": "Private provider contact reference used for intake and operator follow-up; 3-300 characters."
    }
  },
  "required": [
    "displayName",
    "slug",
    "description",
    "contact"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

provider.get

FREE. Public active provider metadata. Pending applications require owner or administrator authorization.

Parameters1

providerId

string

required

Exact CrossingKey marketplace provider identifier.

Raw schema

{
  "type": "object",
  "properties": {
    "providerId": {
      "type": "string",
      "pattern": "^[A-Za-z0-9][A-Za-z0-9._:-]{0,159}$",
      "description": "Exact CrossingKey marketplace provider identifier."
    }
  },
  "required": [
    "providerId"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

capability.get

FREE. Use name for legacy deterministic capability metadata or capabilityId for public marketplace metadata, rights and provenance.

Parameters2

name	string	optional	Exact deterministic first-party machine capability name. Use either name or capabilityId, never both.
capabilityId	any	optional	Exact marketplace capability identifier. Use either capabilityId or name, never both.

Raw schema

{
  "type": "object",
  "properties": {
    "name": {
      "type": "string",
      "pattern": "^[A-Za-z0-9][A-Za-z0-9._:-]{0,159}$",
      "description": "Exact deterministic first-party machine capability name. Use either name or capabilityId, never both."
    },
    "capabilityId": {
      "$ref": "#/properties/name",
      "description": "Exact marketplace capability identifier. Use either capabilityId or name, never both."
    }
  },
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

capability.search

FREE MARKETPLACE FILTERED DISCOVERY ONLY. Search active public marketplace capabilities when one or more filters are known: text, category, provider, delivery type, or price. Metadata is free; purchased execution and deliverables are not. Do NOT use for unfiltered browsing; use catalog.list. Do NOT use for CrossingKey digital/service offers; use offers.list. For one exact capabilityId use capability.get.

Parameters8

query	string	optional	Optional case-insensitive search text across capability name, description, and category; maximum 160 characters.
category	string	optional	Optional exact marketplace category identifier.
provider	any	optional	Optional exact provider identifier.
deliveryType	string	optional	Optional capability delivery-type filter.
minPrice	string	optional	Optional inclusive minimum USDC price in atomic units.
maxPrice	any	optional	Optional inclusive maximum USDC price in atomic units.
offset	integer	optional	Zero-based result offset; defaults to 0.
limit	integer	optional	Maximum number of results to return; 1-100, defaults to 25.

Raw schema

{
  "type": "object",
  "properties": {
    "query": {
      "type": "string",
      "maxLength": 160,
      "description": "Optional case-insensitive search text across capability name, description, and category; maximum 160 characters."
    },
    "category": {
      "type": "string",
      "pattern": "^[A-Za-z0-9][A-Za-z0-9._:-]{0,159}$",
      "description": "Optional exact marketplace category identifier."
    },
    "provider": {
      "$ref": "#/properties/category",
      "description": "Optional exact provider identifier."
    },
    "deliveryType": {
      "type": "string",
      "enum": [
        "mcp_tool",
        "api",
        "digital_asset",
        "workflow",
        "service",
        "dataset",
        "content",
        "software",
        "other"
      ],
      "description": "Optional capability delivery-type filter."
    },
    "minPrice": {
      "type": "string",
      "pattern": "^(0|[1-9][0-9]{0,29})$",
      "description": "Optional inclusive minimum USDC price in atomic units."
    },
    "maxPrice": {
      "$ref": "#/properties/minPrice",
      "description": "Optional inclusive maximum USDC price in atomic units."
    },
    "offset": {
      "type": "integer",
      "minimum": 0,
      "maximum": 10000,
      "default": 0,
      "description": "Zero-based result offset; defaults to 0."
    },
    "limit": {
      "type": "integer",
      "minimum": 1,
      "maximum": 100,
      "default": 25,
      "description": "Maximum number of results to return; 1-100, defaults to 25."
    }
  },
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

catalog.list

FREE MARKETPLACE UNFILTERED DISCOVERY ONLY. Page through active public marketplace capabilities when no search filters are needed. Metadata is free; execution, entitlement, delivery, and purchased output remain gated. Do NOT use for filtered discovery; use capability.search. Do NOT use for CrossingKey digital/service offers; use offers.list. For one exact capabilityId use capability.get.

Parameters2

offset	integer	optional	Zero-based result offset; defaults to 0.
limit	integer	optional	Maximum number of results to return; 1-100, defaults to 25.

Raw schema

{
  "type": "object",
  "properties": {
    "offset": {
      "type": "integer",
      "minimum": 0,
      "maximum": 10000,
      "default": 0,
      "description": "Zero-based result offset; defaults to 0."
    },
    "limit": {
      "type": "integer",
      "minimum": 1,
      "maximum": 100,
      "default": 25,
      "description": "Maximum number of results to return; 1-100, defaults to 25."
    }
  },
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

commerce.quote

FREE MARKETPLACE PAYMENT QUOTE ONLY. After selecting an active marketplace capabilityId, return authoritative gross price, CrossingKey fee, provider share, and x402 v1/v2 payment requirements. A quote grants no entitlement and performs no execution. Do NOT use for first-party paid capabilities; use cost.estimate (first-party x402 capabilities have fixed catalog prices and no quote stage). Do NOT use for generic price lookup; use cost.estimate. Paid marketplace execution requires capability.purchase with authorization and verified payment.

Parameters1

capabilityId

string

required

Exact active public marketplace capability identifier to quote.

Raw schema

{
  "type": "object",
  "properties": {
    "capabilityId": {
      "type": "string",
      "pattern": "^[A-Za-z0-9][A-Za-z0-9._:-]{0,159}$",
      "description": "Exact active public marketplace capability identifier to quote."
    }
  },
  "required": [
    "capabilityId"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

creator.apply

FREE WRITE. Private creator intake for assets needing a capability model. No ownership transfer and AI training defaults false.

Parameters2

provider	object	required	Proposed provider identity for this private creator intake.
summary	string	required	Private creator intake summary describing the asset, service, or capability to evaluate; 1-4000 characters.

Raw schema

{
  "type": "object",
  "properties": {
    "provider": {
      "type": "object",
      "properties": {
        "displayName": {
          "type": "string",
          "minLength": 1,
          "maxLength": 120,
          "description": "Public provider display name; 1-120 characters."
        },
        "slug": {
          "type": "string",
          "pattern": "^[A-Za-z0-9][A-Za-z0-9._:-]{0,159}$",
          "description": "Stable provider slug used for human-readable identity and duplicate checks."
        },
        "description": {
          "type": "string",
          "minLength": 1,
          "maxLength": 2000,
          "description": "Public provider description; 1-2000 characters."
        },
        "website": {
          "type": "string",
          "format": "uri",
          "maxLength": 500,
          "description": "Optional public HTTPS/HTTP provider website URL."
        },
        "contact": {
          "type": "string",
          "minLength": 3,
          "maxLength": 300,
          "description": "Private provider contact reference used for intake and operator follow-up; 3-300 characters."
        }
      },
      "required": [
        "displayName",
        "slug",
        "description",
        "contact"
      ],
      "additionalProperties": false,
      "description": "Proposed provider identity for this private creator intake."
    },
    "summary": {
      "type": "string",
      "minLength": 1,
      "maxLength": 4000,
      "description": "Private creator intake summary describing the asset, service, or capability to evaluate; 1-4000 characters."
    }
  },
  "required": [
    "provider",
    "summary"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

provider.describe

FREE read-only provider and commerce policy discovery. Use this before selecting an offer or capability.

Parameters

No parameters.

Raw schema

{
  "type": "object",
  "properties": {},
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

offers.list

FREE read-only public offer and capability discovery. This tool never starts payment or execution.

Parameters3

query	string	optional	Optional bounded search text.
offset	integer	optional	Zero-based index of first matching record; use next_offset to retrieve the next page.
limit	integer	optional	Maximum number of public metadata records to return.

Raw schema

{
  "type": "object",
  "properties": {
    "query": {
      "type": "string",
      "maxLength": 160,
      "description": "Optional bounded search text."
    },
    "offset": {
      "type": "integer",
      "minimum": 0,
      "maximum": 1000000,
      "default": 0,
      "description": "Zero-based index of first matching record; use next_offset to retrieve the next page."
    },
    "limit": {
      "type": "integer",
      "minimum": 1,
      "maximum": 50,
      "default": 20,
      "description": "Maximum number of public metadata records to return."
    }
  },
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

requirements.check

FREE read-only requirements check. This tool never authorizes or starts payment or execution.

Parameters1

item_id

string

required

Public offer or paid capability identifier returned by offers.list.

Raw schema

{
  "type": "object",
  "properties": {
    "item_id": {
      "type": "string",
      "minLength": 1,
      "maxLength": 160,
      "description": "Public offer or paid capability identifier returned by offers.list."
    }
  },
  "required": [
    "item_id"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

cost.estimate

FREE read-only cost estimate. This tool never creates checkout, reserves funds, or contacts a facilitator.

Parameters1

item_id

string

required

Public offer or paid capability identifier returned by offers.list.

Raw schema

{
  "type": "object",
  "properties": {
    "item_id": {
      "type": "string",
      "minLength": 1,
      "maxLength": 160,
      "description": "Public offer or paid capability identifier returned by offers.list."
    }
  },
  "required": [
    "item_id"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

result.preview

FREE read-only result-shape preview. This tool never executes a capability or creates an entitlement or receipt.

Parameters1

item_id

string

required

Public offer or paid capability identifier returned by offers.list.

Raw schema

{
  "type": "object",
  "properties": {
    "item_id": {
      "type": "string",
      "minLength": 1,
      "maxLength": 160,
      "description": "Public offer or paid capability identifier returned by offers.list."
    }
  },
  "required": [
    "item_id"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

execution.preflight

FREE read-only execution preflight. Returns READY_FOR_HUMAN_AUTHORIZATION only; it never authorizes, purchases, settles, executes, or creates records.

Parameters1

item_id

string

required

Public offer or paid capability identifier returned by offers.list.

Raw schema

{
  "type": "object",
  "properties": {
    "item_id": {
      "type": "string",
      "minLength": 1,
      "maxLength": 160,
      "description": "Public offer or paid capability identifier returned by offers.list."
    }
  },
  "required": [
    "item_id"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

credits.options

FREE read-only prepaid request-credit pack options. Lists available credit packs with identifiers and credit amounts. Purchasing happens via checkout; this tool never starts payment or creates accounts.

Parameters

No parameters.

Raw schema

{
  "type": "object",
  "properties": {},
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

x402.compatibility_audit

PAID $1.00 USDC on Base via x402. Audits an x402 endpoint for v1/v2 compatibility defects. Calling this MCP tool does not spend funds; it returns the exact PAYMENT-REQUIRED challenge and canonical paid execution endpoint.

Parameters1

url

string

required

Public HTTP(S) x402 endpoint to audit.

Raw schema

{
  "type": "object",
  "properties": {
    "url": {
      "type": "string",
      "format": "uri",
      "description": "Public HTTP(S) x402 endpoint to audit."
    }
  },
  "required": [
    "url"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

mcp.schema_audit

PAID $1.00 USDC on Base via x402. Scores supplied MCP tool schemas for discoverability, descriptions, and bounded input contracts. Calling this MCP tool does not spend funds; it returns the exact PAYMENT-REQUIRED challenge and canonical paid execution endpoint.

Parameters1

tools

array

required

MCP tool definitions to audit.

Raw schema

{
  "type": "object",
  "properties": {
    "tools": {
      "type": "array",
      "items": {
        "type": "object",
        "additionalProperties": {}
      },
      "minItems": 1,
      "description": "MCP tool definitions to audit."
    }
  },
  "required": [
    "tools"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

openapi.quality_audit

PAID $1.00 USDC on Base via x402. Evaluates structural quality and required fields in an OpenAPI document. Calling this MCP tool does not spend funds; it returns the exact PAYMENT-REQUIRED challenge and canonical paid execution endpoint.

Parameters1

spec

object

required

Parsed OpenAPI document to audit.

Raw schema

{
  "type": "object",
  "properties": {
    "spec": {
      "type": "object",
      "additionalProperties": {},
      "description": "Parsed OpenAPI document to audit."
    }
  },
  "required": [
    "spec"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

machine_commerce.readiness_audit

PAID $2.00 USDC on Base via x402. Checks machine-commerce discovery and health surfaces. Calling this MCP tool does not spend funds; it returns the exact PAYMENT-REQUIRED challenge and canonical paid execution endpoint.

Parameters1

url

string

required

Base URL of the machine-commerce service to audit.

Raw schema

{
  "type": "object",
  "properties": {
    "url": {
      "type": "string",
      "format": "uri",
      "description": "Base URL of the machine-commerce service to audit."
    }
  },
  "required": [
    "url"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

artifact.integrity_manifest

PAID $0.10 USDC on Base via x402. Creates deterministic SHA-256 entries and a root manifest hash for supplied text artifacts. Calling this MCP tool does not spend funds; it returns the exact PAYMENT-REQUIRED challenge and canonical paid execution endpoint.

Parameters3

artifacts	array	required	Artifacts to include in the integrity manifest.
idempotency_key	string	optional
payment_payload	object	optional

Raw schema

{
  "type": "object",
  "properties": {
    "artifacts": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "name": {
            "type": "string",
            "minLength": 1,
            "maxLength": 300,
            "description": "Artifact name."
          },
          "content": {
            "type": "string",
            "description": "Text content to hash."
          }
        },
        "required": [
          "name",
          "content"
        ],
        "additionalProperties": false
      },
      "minItems": 1,
      "description": "Artifacts to include in the integrity manifest."
    },
    "idempotency_key": {
      "type": "string",
      "minLength": 8,
      "maxLength": 160
    },
    "payment_payload": {
      "type": "object",
      "additionalProperties": {}
    }
  },
  "required": [
    "artifacts"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

hash.encode

PAID $0.01 USDC on Base via x402. Computes a SHA-256 digest and UTF-8 byte count for supplied text. Calling this MCP tool returns a payment challenge and does not autonomously spend funds.

Parameters1

text

string

required

Input text, maximum 65536 UTF-8 bytes.

Raw schema

{
  "type": "object",
  "properties": {
    "text": {
      "type": "string",
      "maxLength": 65536,
      "description": "Input text, maximum 65536 UTF-8 bytes."
    }
  },
  "required": [
    "text"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

secret.scan

PAID $0.01 USDC on Base via x402. Detects selected credential patterns and returns classifications and positions, not matched values. Heuristic, not comprehensive. Calling this MCP tool returns a payment challenge and does not autonomously spend funds.

Parameters1

text

string

required

Input text, maximum 65536 UTF-8 bytes.

Raw schema

{
  "type": "object",
  "properties": {
    "text": {
      "type": "string",
      "maxLength": 65536,
      "description": "Input text, maximum 65536 UTF-8 bytes."
    }
  },
  "required": [
    "text"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

pii.scan

PAID $0.01 USDC on Base via x402. Detects selected personal-data patterns and returns classifications and positions, not matched values. Heuristic, not comprehensive. Calling this MCP tool returns a payment challenge and does not autonomously spend funds.

Parameters1

text

string

required

Input text, maximum 65536 UTF-8 bytes.

Raw schema

{
  "type": "object",
  "properties": {
    "text": {
      "type": "string",
      "maxLength": 65536,
      "description": "Input text, maximum 65536 UTF-8 bytes."
    }
  },
  "required": [
    "text"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

json.repair

PAID $0.01 USDC on Base via x402. Validates JSON and repairs a limited set of formatting errors. May return supplied content. Calling this MCP tool returns a payment challenge and does not autonomously spend funds.

Parameters1

text

string

required

Input text, maximum 65536 UTF-8 bytes.

Raw schema

{
  "type": "object",
  "properties": {
    "text": {
      "type": "string",
      "maxLength": 65536,
      "description": "Input text, maximum 65536 UTF-8 bytes."
    }
  },
  "required": [
    "text"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

prompt.audit

PAID $0.01 USDC on Base via x402. Scores selected prompt structure signals using deterministic heuristics. Calling this MCP tool returns a payment challenge and does not autonomously spend funds.

Parameters1

text

string

required

Input text, maximum 65536 UTF-8 bytes.

Raw schema

{
  "type": "object",
  "properties": {
    "text": {
      "type": "string",
      "maxLength": 65536,
      "description": "Input text, maximum 65536 UTF-8 bytes."
    }
  },
  "required": [
    "text"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

xkey.validate

PAID prepaid-credit XKEY intake validation. Requires an authenticated ck_ principal and commits one credit only on verified success. Discovery is free; execution is not.

Parameters2

idempotency_key	string	required	Unique client-generated idempotency key; 8-160 ASCII characters.
raw_intake	string	required	Raw intake text to validate and normalize; 2-100000 characters.

Raw schema

{
  "type": "object",
  "properties": {
    "idempotency_key": {
      "type": "string",
      "minLength": 8,
      "maxLength": 160,
      "pattern": "^[A-Za-z0-9._:-]+$",
      "description": "Unique client-generated idempotency key; 8-160 ASCII characters."
    },
    "raw_intake": {
      "type": "string",
      "minLength": 2,
      "maxLength": 100000,
      "description": "Raw intake text to validate and normalize; 2-100000 characters."
    }
  },
  "required": [
    "idempotency_key",
    "raw_intake"
  ],
  "additionalProperties": false,
  "$schema": "http://json-schema.org/draft-07/schema#"
}

README.md7 KBView on GitHub

CrossingKey MCP

Agent-native MCP for governed commerce, x402 payments, paid capabilities, and verifiable receipts.

Production

Endpoint

https://mcp.crossingkeyintelligence.com/mcp

Canonical identity

com.crossingkeyintelligence/crossingkey-mcp

Published source release

3.0.1

Current production release

3.0.1 (public endpoint verified October 12, 2026)

The published v3.0.1 source release and the deployed production runtime are distinct artifacts. On October 12, 2026, the production security update was deployed and verified through MCP initialization, public tool discovery, and HTTP 402 payment challenges. The public source release should not be assumed to contain every production-only security change.

Transport

MCP Streamable HTTP

CrossingKey MCP v3.0.1 source

CrossingKey MCP is a governed machine-commerce interface for AI agents and authorized software clients.

The public production MCP endpoint returned 26 tools during verification on October 12, 2026. The published v3.0.1 source release previously documented 21 anonymous tools:

7 free discovery and commercial-navigation tools
8 public marketplace tools
6 paid or credit-gated tools

Authenticated sessions additionally expose verification and role-gated marketplace operations.

The operating principle is:

Discovery is free. Evaluation is safe. Payment is explicit. Authority stays bounded. Execution is deterministic. Fulfillment is verifiable.

Free discovery

These seven tools can be used anonymously to understand the provider, available offers, requirements, price, expected result, authorization state, and prepaid-credit options without spending money:

provider.describe
offers.list
requirements.check
cost.estimate
result.preview
execution.preflight
credits.options

The normal discovery sequence is:

text

provider.describe
→ offers.list
→ requirements.check
→ cost.estimate
→ result.preview
→ execution.preflight
→ credits.options (when prepaid request credits are relevant)

A valid commercial flow may reach:

text

READY_FOR_HUMAN_AUTHORIZATION

and then stop at:

text

STOPPED_BEFORE_PAYMENT

until the required buyer authorization and payment conditions are satisfied.

Public marketplace discovery

The deployed production public surface includes these marketplace tools:

marketplace.describe
provider.apply
provider.get
capability.get
capability.search
catalog.list
commerce.quote
creator.apply

Discovery, catalog browsing, capability inspection, and quoting do not themselves authorize paid execution.

provider.apply and creator.apply are public intake workflows; applications remain pending and grant no credentials, ownership transfer, or active commercial authority. provider.register is an authenticated administrator operation, not advertised in the anonymous production tool catalog.

Paid and gated execution

These six tools perform valuable computation, validation, or artifact generation and are payment- or credit-gated:

x402.compatibility_audit
mcp.schema_audit
openapi.quality_audit
machine_commerce.readiness_audit
artifact.integrity_manifest
xkey.validate

Current payment models include x402 Base USDC exact-payment flows and prepaid request credits where applicable.

Free discovery does not consume paid execution credits.

Authenticated verification

Authenticated sessions can expose read-only verification tools including:

approval.verify
idempotency.inspect
receipt.verify
entitlement.inspect

Marketplace sessions may additionally expose role-gated job, receipt, purchase, provider, capability, and settlement operations.

Approval minting remains a local operator action and is not exposed over MCP.

Commercial flow

The governed machine-commerce path is:

text

discover
→ inspect requirements
→ estimate cost
→ preview result
→ preflight
→ authorize
→ pay
→ verify settlement
→ execute
→ issue result
→ bind entitlement
→ issue verifiable receipt

Payment alone does not create unrestricted authority.

Authorization, payment verification, execution, fulfillment, entitlement creation, and receipt generation remain separate governed stages.

Human authorization

CrossingKey does not treat an LLM-supplied boolean such as approved: true as buyer authorization.

Where human authorization is required, approval is bound to the relevant commercial context, including the buyer, capability, inputs, quote, idempotency state, and expiration conditions.

Paid execution does not occur merely because an agent asks for it.

MCP resources

The v3.0.1 source exposes public MCP resources for agent comprehension:

crossingkey://discovery-guide
crossingkey://commerce-policy
crossingkey://capability/{name}

These describe the free discovery sequence, commerce policy, and per-capability instructions.

Machine commerce

CrossingKey supports governed machine-payment infrastructure including:

x402 v1
x402 v2
Base USDC
prepaid request credits where supported
settlement verification
entitlements
result-bound receipts
idempotent execution
replay protection

The CrossingKey seller wallet boundary is receiver-only.

Agents are not granted unrestricted wallet signing, sending, swapping, bridging, or autonomous seller-spend authority.

Security properties

The production design includes:

bounded input validation
strict capability schemas
SSRF protections
DNS and address validation
response-size controls
authorization boundaries
approval binding
idempotency protection
payment replay protection
duplicate-settlement protection
deterministic result hashing
entitlement binding
receipt verification
receiver-only seller wallet policy
explicit uncertain-settlement handling

No private keys, wallet secrets, Stripe secrets, API keys, seed phrases, mnemonics, or private customer information belong in this repository.

Agent discovery

Recommended entry point:

provider.describe

Canonical MCP endpoint:

https://mcp.crossingkeyintelligence.com/mcp

Canonical identity:

com.crossingkeyintelligence/crossingkey-mcp

Official MCP Registry identity:

com.crossingkeyintelligence/crossingkey-mcp

Website:

https://www.crossingkeyintelligence.com

HAAR research: https://github.com/crossingkey-holdings/crossingkey-public-research/blob/main/research/HAAR.md
Professional evidence: https://github.com/crossingkey-holdings/experience
Developer documentation: https://github.com/crossingkey-holdings/crossingkey-developer-documentation
Open specifications: https://github.com/crossingkey-holdings/crossingkey-open-specifications

HAAR and CrossingKey MCP share concerns such as bounded authority, idempotency, state verification, reconciliation, receipts, and entitlements. HAAR remains a research architecture; this repository and its releases remain authoritative for what CrossingKey MCP actually implements.

CrossingKey Intelligence

Operating online under the handle crossingkey_.

intelligence is the standard.

Install

Tools (26)

marketplace.describeprovider.applyprovider.getcapability.getcapability.searchcatalog.listcommerce.quotecreator.apply

Remote endpoint

Streamable HTTP

Hosted server - connect over the network, no local install.

url

https://mcp.crossingkeyintelligence.com/mcp

Add to VS Code Add to Cursor

claude_desktop_config.json

json

{
  "mcpServers": {
    "crossingkey-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://mcp.crossingkeyintelligence.com/mcp"
      ]
    }
  }
}

Desktop config is stdio-only; this bridges via mcp-remote. Native remote: Settings > Connectors.

🛠️ Key Features

🚀 Use Cases

⚡ Developer Benefits

⚠️ Limitations

Topics

marketplace.describe

provider.apply

provider.get

capability.get

capability.search

catalog.list

commerce.quote

creator.apply

provider.describe

offers.list

requirements.check

cost.estimate

result.preview

execution.preflight

credits.options

x402.compatibility_audit

mcp.schema_audit

openapi.quality_audit

machine_commerce.readiness_audit

artifact.integrity_manifest

hash.encode

secret.scan

pii.scan

json.repair

prompt.audit

xkey.validate

CrossingKey MCP

Production

CrossingKey MCP v3.0.1 source

Free discovery

Public marketplace discovery

Paid and gated execution

Authenticated verification

Commercial flow

Human authorization

MCP resources

Machine commerce

Security properties

Agent discovery

Related public architecture

CrossingKey Intelligence

Install

Remote endpoint

Related servers