CHP is the governed execution layer of the agentic web. This API exposes a natural-language query endpoint (/ask), the well-known discovery manifests, and the MCP server endpoint. For full tool invocation, connect over MCP at /api/mcp.
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{
"openapi": "3.1.0",
"info": {
"title": "Capability Host Protocol — Public API",
"version": "0.8.0",
"summary": "Query CHP, discover its capabilities, and connect agents.",
"description": "CHP is the governed execution layer of the agentic web. This API exposes a natural-language query endpoint (/ask), the well-known discovery manifests, and the MCP server endpoint. For full tool invocation, connect over MCP at /api/mcp.",
"contact": {
"name": "Capability Host Protocol",
"url": "https://capabilityhostprotocol.com"
},
"license": {
"name": "Apache-2.0",
"identifier": "Apache-2.0"
}
},
"servers": [
{
"url": "https://capabilityhostprotocol.com"
}
],
"paths": {
"/ask": {
"get": {
"operationId": "ask",
"summary": "Natural-language query over CHP knowledge",
"description": "Returns the best-matching concept, definition, FAQ, and capabilities for a query. Structured retrieval over real CHP content.",
"parameters": [
{
"name": "q",
"in": "query",
"required": false,
"schema": {
"type": "string"
},
"description": "The question, e.g. \"how does CHP prove what an agent did\"."
}
],
"responses": {
"200": {
"description": "A structured answer.",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/AskResponse"
}
}
}
},
"400": {
"description": "Bad request.",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
}
}
},
"post": {
"operationId": "askPost",
"summary": "Natural-language query (POST)",
"requestBody": {
"required": false,
"content": {
"application/json": {
"schema": {
"type": "object",
"properties": {
"q": {
"type": "string"
}
}
}
}
}
},
"responses": {
"200": {
"description": "A structured answer.",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/AskResponse"
}
}
}
},
"400": {
"description": "Bad request.",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
}
}
}
},
"/api/mcp": {
"post": {
"operationId": "mcp",
"summary": "MCP server (Model Context Protocol, streamable HTTP)",
"description": "JSON-RPC 2.0 over streamable HTTP. Tools: explain, define, how_to_adopt, get_example, faq, list_capabilities, get_capability, list_adapters, search. Resources: chp://glossary, chp://concepts, chp://quickstart, chp://capabilities. Every tool call is wrapped as hash-chained CHP evidence. See /.well-known/mcp.json.",
"requestBody": {
"required": true,
"content": {
"application/json": {
"schema": {
"type": "object",
"description": "A JSON-RPC 2.0 request."
}
}
}
},
"responses": {
"200": {
"description": "A JSON-RPC 2.0 response (application/json or text/event-stream)."
}
}
}
},
"/.well-known/agent-card.json": {
"get": {
"operationId": "agentCard",
"summary": "A2A agent card (capability manifest)",
"responses": {
"200": {
"description": "The A2A agent card.",
"content": {
"application/json": {}
}
}
}
}
},
"/.well-known/mcp.json": {
"get": {
"operationId": "mcpManifest",
"summary": "MCP discovery manifest",
"responses": {
"200": {
"description": "MCP endpoint, transport, and tools.",
"content": {
"application/json": {}
}
}
}
}
},
"/.well-known/capabilities.json": {
"get": {
"operationId": "capabilities",
"summary": "CHP capability discovery manifest",
"responses": {
"200": {
"description": "The declared capability surface.",
"content": {
"application/json": {}
}
}
}
}
}
},
"components": {
"schemas": {
"AskResponse": {
"type": "object",
"properties": {
"query": {
"type": "string"
},
"answer": {
"type": [
"object",
"null"
],
"properties": {
"type": {
"type": "string",
"enum": [
"concept",
"definition",
"faq"
]
},
"title": {
"type": "string"
},
"text": {
"type": "string"
},
"learnMore": {
"type": "string",
"format": "uri"
}
}
},
"related": {
"type": "object"
},
"sources": {
"type": "object"
}
}
},
"Error": {
"type": "object",
"required": [
"error"
],
"properties": {
"error": {
"type": "object",
"required": [
"code",
"message"
],
"properties": {
"code": {
"type": "string",
"example": "invalid_request"
},
"message": {
"type": "string"
},
"hint": {
"type": "string"
}
}
}
}
}
}
}
}