aid: kgninja-dev
name: KG-NINJA
description: >-
  KG-NINJA is the operator identity (GitHub user KG-NINJA, Osaka; Cloudflare Wallet handle @kgninja) behind
  Agent Verification Utility at agent-economy.kgninja.dev, a Cloudflare Workers service (v0.4.3) that runs
  bounded deterministic checks (SHA-256 equality, JSON Pointer existence/equality/type) over caller-supplied
  inline JSON and returns an Ed25519-signed execution record, sold to agents per call
  for 10000 atomic USDC ($0.01) on Base through x402 v2 with no account, API key or OAuth. One origin
  exposes the product three ways — a 44-operation OpenAPI 3.1.0 contract at /openapi.json, a remote
  Streamable HTTP MCP server at /mcp answering an anonymous tools/list (five tools, one paid), and an A2A 1.0
  agent card at /.well-known/agent-card.json with JSON-RPC at /a2a — plus an RFC 9727 API catalog, an MCP
  Registry server.json, a provider-published Agent Skill, a JWKS, an x402 manifest, llms.txt and
  Content-Signal. The apex kgninja.dev has no A record; the subdomain is its only web presence.
url: https://raw.githubusercontent.com/api-evangelist/kgninja-dev/refs/heads/main/apis.yml
image: https://agent-economy.kgninja.dev/icon.svg
x-type: company
x-source: harvest:a2a-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-09-19 (local-v3; was a2a-registry harvest stub)
specificationVersion: '0.20'
created: '2026-09-19'
modified: '2026-09-19'
tags:
- Agents
- Agentic Commerce
- A2A
- MCP
- x402
- Verification
- JSON
- Cryptography
- Cloudflare Workers
- Agent-Native
- Japan
tags_raw:
- Agents
- Agent commerce
- A2A
- MCP
- x402
- Verification
- JSON
- Cryptography
- Cloudflare Workers
- Agent-native
- Japan
- Agent Commerce
- agent-native
apis:
- aid: kgninja-dev:agent-verification-utility-mcp-server
  name: Agent Verification Utility MCP Server
  image: https://agent-economy.kgninja.dev/icon.svg
  description: >-
    Remote Model Context Protocol server at https://agent-economy.kgninja.dev/mcp — stateless Streamable
    HTTP, POST only (GET returns 405), serverInfo dev.kgninja/agent-verification-utility 0.4.3, protocol
    version 2025-06-18 negotiated live and 2026-07-28 declared on the server card. initialize and tools/list
    answer anonymously with five tools carrying real inputSchemas and MCP annotations: four free (describe_verify_evidence,
    get_revenue_goal_status, quote_verify_evidence, prepare_verify_evidence_purchase) and one paid (verify_evidence),
    whose unpaid call returns an x402 v2 PaymentRequired document in _meta["x402/error"] and is retried
    with _meta["x402/payment"]. resources/list and prompts/list are not implemented. Published alongside
    it: an MCP Registry server.json, an experimental MCP Server Card, a Cloudflare Agent Readiness card
    at /.well-known/mcp/server-card.json (aliased at /.well-known/mcp.json), a registry HTTP ownership
    proof and a browser WebMCP bridge (webmcp.js).
  humanURL: https://agent-economy.kgninja.dev/docs/mcp-x402-interoperability
  baseURL: https://agent-economy.kgninja.dev/mcp
  tags:
  - MCP
  - Agent-Native
  - x402
  tags_raw:
  - MCP
  - agent-native
  - x402
  properties:
  - type: MCPServer
    url: mcp/kgninja-dev-mcp.yml
  - type: MCPServer
    name: MCP endpoint (Streamable HTTP)
    url: https://agent-economy.kgninja.dev/mcp
  - type: ToolCrosswalk
    url: mcp/kgninja-dev-tool-crosswalk.yml
  - type: Documentation
    url: https://agent-economy.kgninja.dev/docs/mcp-x402-interoperability
- aid: kgninja-dev:agent-verification-utility-a2a-agent
  name: Agent Verification Utility A2A Agent
  image: https://agent-economy.kgninja.dev/icon.svg
  description: >-
    Agent2Agent (A2A) 1.0 surface: an agent card served from https://agent-economy.kgninja.dev/.well-known/agent-card.json
    (supportedInterfaces[] JSONRPC at https://agent-economy.kgninja.dev/a2a, protocolVersion 1.0, version
    0.4.3, provider KG-NINJA) declaring one skill, prepare-json-evidence-verification, which revalidates
    a prechecked paid intent, creates or reuses an idempotent bound quote and returns exact x402 and MCP
    purchase instructions as a direct Message. The adapter is stateless and synchronous: it never creates
    Tasks, never executes paid work, and declares streaming, push notifications and extended cards unsupported.
    The endpoint enforces the A2A-Version header (0.3 is rejected with -32009 VERSION_NOT_SUPPORTED; 1.0
    is required).
  humanURL: https://agent-economy.kgninja.dev/docs/mcp-x402-interoperability
  baseURL: https://agent-economy.kgninja.dev/a2a
  tags:
  - A2A
  - Agent-Native
  - x402
  tags_raw:
  - A2A
  - agent-native
  - x402
  properties:
  - type: AgentCard
    url: a2a/kgninja-dev-a2a.yml
  - type: AgentCard
    name: A2A Agent Card (provider-hosted)
    url: https://agent-economy.kgninja.dev/.well-known/agent-card.json
- aid: kgninja-dev:kgninja-dev-a2a-api
  name: KG-NINJA A2a API
  description: Synchronous A2A 1.0 JSON-RPC quote preparation
  humanURL: https://agent-economy.kgninja.dev/
  baseURL: https://agent-economy.kgninja.dev/mcp
  tags:
  - a2a
  properties:
  - type: OpenAPI
    url: openapi/kgninja-dev-a2a-api-openapi.yml
  - type: Documentation
    url: https://agent-economy.kgninja.dev/docs/deterministic-json-verification
  - type: APIReference
    url: https://agent-economy.kgninja.dev/openapi.json
  - type: GettingStarted
    url: https://agent-economy.kgninja.dev/index.md
  - type: Conventions
    url: conventions/kgninja-dev-conventions.yml
  - type: ErrorCatalog
    url: errors/kgninja-dev-problem-types.yml
  - type: DataModel
    url: data-model/kgninja-dev-data-model.yml
- aid: kgninja-dev:kgninja-dev-decision-support-api
  name: KG-NINJA Decision Support API
  description: Free use-case selection and request validation before payment
  humanURL: https://agent-economy.kgninja.dev/
  baseURL: https://agent-economy.kgninja.dev/mcp
  tags:
  - decision-support
  properties:
  - type: OpenAPI
    url: openapi/kgninja-dev-decision-support-api-openapi.yml
  - type: Documentation
    url: https://agent-economy.kgninja.dev/docs/deterministic-json-verification
  - type: APIReference
    url: https://agent-economy.kgninja.dev/openapi.json
  - type: GettingStarted
    url: https://agent-economy.kgninja.dev/index.md
  - type: Conventions
    url: conventions/kgninja-dev-conventions.yml
  - type: ErrorCatalog
    url: errors/kgninja-dev-problem-types.yml
  - type: DataModel
    url: data-model/kgninja-dev-data-model.yml
- aid: kgninja-dev:kgninja-dev-discovery-api
  name: KG-NINJA Discovery API
  description: Machine-readable service discovery
  humanURL: https://agent-economy.kgninja.dev/
  baseURL: https://agent-economy.kgninja.dev/mcp
  tags:
  - discovery
  properties:
  - type: OpenAPI
    url: openapi/kgninja-dev-discovery-api-openapi.yml
  - type: Documentation
    url: https://agent-economy.kgninja.dev/docs/deterministic-json-verification
  - type: APIReference
    url: https://agent-economy.kgninja.dev/openapi.json
  - type: GettingStarted
    url: https://agent-economy.kgninja.dev/index.md
  - type: Conventions
    url: conventions/kgninja-dev-conventions.yml
  - type: ErrorCatalog
    url: errors/kgninja-dev-problem-types.yml
  - type: DataModel
    url: data-model/kgninja-dev-data-model.yml
- aid: kgninja-dev:kgninja-dev-goals-api
  name: KG-NINJA Goals API
  description: Goal-driven revenue measurement and improvement recommendations
  humanURL: https://agent-economy.kgninja.dev/
  baseURL: https://agent-economy.kgninja.dev/mcp
  tags:
  - goals
  properties:
  - type: OpenAPI
    url: openapi/kgninja-dev-goals-api-openapi.yml
  - type: Documentation
    url: https://agent-economy.kgninja.dev/docs/deterministic-json-verification
  - type: APIReference
    url: https://agent-economy.kgninja.dev/openapi.json
  - type: GettingStarted
    url: https://agent-economy.kgninja.dev/index.md
  - type: Conventions
    url: conventions/kgninja-dev-conventions.yml
  - type: ErrorCatalog
    url: errors/kgninja-dev-problem-types.yml
  - type: DataModel
    url: data-model/kgninja-dev-data-model.yml
- aid: kgninja-dev:kgninja-dev-mcp-api
  name: KG-NINJA MCP API
  description: Stateless MCP Streamable HTTP transport
  humanURL: https://agent-economy.kgninja.dev/
  baseURL: https://agent-economy.kgninja.dev/mcp
  tags:
  - mcp
  properties:
  - type: OpenAPI
    url: openapi/kgninja-dev-mcp-api-openapi.yml
  - type: Documentation
    url: https://agent-economy.kgninja.dev/docs/deterministic-json-verification
  - type: APIReference
    url: https://agent-economy.kgninja.dev/openapi.json
  - type: GettingStarted
    url: https://agent-economy.kgninja.dev/index.md
  - type: Conventions
    url: conventions/kgninja-dev-conventions.yml
  - type: ErrorCatalog
    url: errors/kgninja-dev-problem-types.yml
  - type: DataModel
    url: data-model/kgninja-dev-data-model.yml
- aid: kgninja-dev:kgninja-dev-operations-api
  name: KG-NINJA Operations API
  description: Availability and operational status
  humanURL: https://agent-economy.kgninja.dev/
  baseURL: https://agent-economy.kgninja.dev/mcp
  tags:
  - operations
  properties:
  - type: OpenAPI
    url: openapi/kgninja-dev-operations-api-openapi.yml
  - type: Documentation
    url: https://agent-economy.kgninja.dev/docs/deterministic-json-verification
  - type: APIReference
    url: https://agent-economy.kgninja.dev/openapi.json
  - type: GettingStarted
    url: https://agent-economy.kgninja.dev/index.md
  - type: Conventions
    url: conventions/kgninja-dev-conventions.yml
  - type: ErrorCatalog
    url: errors/kgninja-dev-problem-types.yml
  - type: DataModel
    url: data-model/kgninja-dev-data-model.yml
- aid: kgninja-dev:kgninja-dev-purchase-api
  name: KG-NINJA Purchase API
  description: Quote and paid verification operations
  humanURL: https://agent-economy.kgninja.dev/
  baseURL: https://agent-economy.kgninja.dev/mcp
  tags:
  - purchase
  properties:
  - type: OpenAPI
    url: openapi/kgninja-dev-purchase-api-openapi.yml
  - type: Documentation
    url: https://agent-economy.kgninja.dev/docs/deterministic-json-verification
  - type: APIReference
    url: https://agent-economy.kgninja.dev/openapi.json
  - type: GettingStarted
    url: https://agent-economy.kgninja.dev/index.md
  - type: Conventions
    url: conventions/kgninja-dev-conventions.yml
  - type: ErrorCatalog
    url: errors/kgninja-dev-problem-types.yml
  - type: DataModel
    url: data-model/kgninja-dev-data-model.yml
- aid: kgninja-dev:kgninja-dev-registration-api
  name: KG-NINJA Registration API
  description: Optional anonymous, short-lived agent registration
  humanURL: https://agent-economy.kgninja.dev/
  baseURL: https://agent-economy.kgninja.dev/mcp
  tags:
  - registration
  properties:
  - type: OpenAPI
    url: openapi/kgninja-dev-registration-api-openapi.yml
  - type: Documentation
    url: https://agent-economy.kgninja.dev/docs/deterministic-json-verification
  - type: APIReference
    url: https://agent-economy.kgninja.dev/openapi.json
  - type: GettingStarted
    url: https://agent-economy.kgninja.dev/index.md
  - type: Conventions
    url: conventions/kgninja-dev-conventions.yml
  - type: ErrorCatalog
    url: errors/kgninja-dev-problem-types.yml
  - type: DataModel
    url: data-model/kgninja-dev-data-model.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: DomainSecurity
  url: security/kgninja-dev-domain-security.yml
- type: AgenticAccess
  url: agentic-access/kgninja-dev-agentic-access.yml
- type: Authentication
  url: authentication/kgninja-dev-authentication.yml
- type: Website
  url: https://agent-economy.kgninja.dev/
- type: Documentation
  url: https://agent-economy.kgninja.dev/docs/deterministic-json-verification
- type: GettingStarted
  url: https://agent-economy.kgninja.dev/index.md
- type: APIReference
  url: https://agent-economy.kgninja.dev/openapi.json
- type: FAQ
  url: https://agent-economy.kgninja.dev/faq
- type: Pricing
  name: Published price (agent manifest payment block)
  url: https://agent-economy.kgninja.dev/agent.json
- type: GitHubOrganization
  url: https://github.com/KG-NINJA
- type: AgentCard
  url: a2a/kgninja-dev-a2a.yml
- type: MCPServer
  url: mcp/kgninja-dev-mcp.yml
- type: ToolCrosswalk
  url: mcp/kgninja-dev-tool-crosswalk.yml
- type: WellKnown
  url: well-known/kgninja-dev-well-known.yml
- type: APICatalog
  url: well-known/kgninja-dev-api-catalog.json
- type: ContentSignal
  url: https://agent-economy.kgninja.dev/robots.txt
- type: LLMsTxt
  url: llms/kgninja-dev-llms.txt
- type: LLMsTxt
  name: llms.txt (provider-hosted)
  url: https://agent-economy.kgninja.dev/llms.txt
- type: AgentSkill
  url: skills/_index.yml
- type: AgentSkill
  name: verify-json-evidence SKILL.md (provider-hosted)
  url: https://agent-economy.kgninja.dev/.well-known/agent-skills/verify-json-evidence/SKILL.md
- type: Conventions
  url: conventions/kgninja-dev-conventions.yml
- type: Idempotency
  url: conventions/kgninja-dev-conventions.yml
- type: ErrorCatalog
  url: errors/kgninja-dev-problem-types.yml
- type: DataModel
  url: data-model/kgninja-dev-data-model.yml
- type: RateLimits
  url: rate-limits/kgninja-dev-rate-limits.yml
- type: Plans
  url: plans/kgninja-dev-plans-pricing.yml
- type: Sandbox
  url: sandbox/kgninja-dev-sandbox.yml
- type: Conformance
  url: conformance/kgninja-dev-conformance.yml
- type: Lifecycle
  url: lifecycle/kgninja-dev-lifecycle.yml
- type: Overlay
  url: overlays/kgninja-dev-openapi-overlay.yaml
x-enrichment:
  date: '2026-09-19'
  status: enriched
  artifacts_added: 37
  pass: local-v3
x-a2a:
  verified: true
  probed: '2026-09-26'
  url: "https://agent-economy.kgninja.dev/.well-known/agent-card.json"
  grade: "flavored"
  protocol_version: "1.0"
  control: 404