RealWorldAPIs
Evidence-first registry of real-world APIs for AI agents, with verified metadata and comparison.
Should I use this
Quality & Safety
A
Based on automated analysis of tool definitions and protocol compliance.
Context Cost
~2,794Tokens (tool definitions)
~7.4 KBTypical response size
Significant attention impact (2.18% of 128k context)
This is the approximate number of tokens consumed each time the server's tools are loaded into a model's context. Higher counts reduce the attention available for other tasks.
Install
One-Click Install
Add this to your `claude_desktop_config.json` file:
{
"mcpServers": {
"realworldapis": {
"url": "https://realworldapis-api.realworldapis.workers.dev/mcp"
}
}
}Remote endpoints
https://realworldapis-api.realworldapis.workers.dev/mcpstreamable-httphttps://mcp.realworldapis.com/mcpstreamable-httpWhat it can do
Tool inventory
Tools (4)
🟢 Read-only🟡 Write🔴 Delete⚪ Unknown
🟢find_api_for_task(task, requirements, limit)
Find the best APIs for a natural-language physical-world task. Use this for open-ended task or outcome-based recommendations; use search_apis when you already know exact filters, get_api for one known API, or compare_apis for known candidates. Returns an authoritative canonical structured_results shortlist plus a best-effort AI comparison restricted to that shortlist. The canonical browser-parity flow always returns five structured candidates: limit is retained only for backward compatibility. requirements.categories, capabilities, mcp, openapi and auth are added as task hints; free_tier and min_readiness are accepted for compatibility but are not hard filters. Unknown remains Unknown.
Input Schema
{
"type": "object",
"properties": {
"task": {
"type": "string",
"maxLength": 1000,
"description": "Required natural-language goal or workflow, for example 'connect to a car and predict weather on the route'. Describe the desired outcome rather than naming a specific API."
},
"requirements": {
"type": "object",
"additionalProperties": false,
"description": "Optional compatibility hints appended to the task before canonical ranking. categories, capabilities, mcp, openapi and auth influence the effective query. free_tier and min_readiness are accepted for backward compatibility but are not hard filters; use search_apis when you need strict field filtering.",
"properties": {
"categories": {
"type": "array",
"items": {
"type": "string"
},
"description": "Preferred catalog categories, such as Geospatial, Weather or Mobility. These are ranking hints, not strict filters."
},
"capabilities": {
"type": "array",
"items": {
"type": "string",
"enum": [
"observe",
"locate",
"predict",
"plan",
"control",
"act"
]
},
"description": "Desired agent capability dimensions. These are appended as ranking hints, not strict filters."
},
"mcp": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
],
"description": "Compatibility hint for MCP support. Only Yes becomes an explicit 'Must support MCP' task hint; use search_apis for exact Yes/No/Unknown filtering."
},
"openapi": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
],
"description": "Compatibility hint for OpenAPI support. Only Yes becomes an explicit task hint; use search_apis for exact Yes/No/Unknown filtering."
},
"free_tier": {
"type": "boolean",
"description": "Backward-compatible field only. The canonical recommendation engine does not currently hard-filter on free-tier availability."
},
"auth": {
"type": "string",
"enum": [
"none",
"api_key",
"oauth",
"client_credentials",
"bearer",
"jwt",
"basic"
],
"description": "Preferred authentication method, appended to the effective task as a ranking hint."
},
"min_readiness": {
"type": "integer",
"minimum": 0,
"maximum": 100,
"description": "Backward-compatible field only. It does not hard-filter the canonical top five; use search_apis for a strict minimum readiness threshold."
}
}
},
"limit": {
"type": "integer",
"minimum": 1,
"maximum": 5,
"default": 5,
"description": "Backward-compatible parameter. The canonical browser-parity workflow always produces five structured candidates before the AI comparison, even when another value is supplied."
}
},
"required": [
"task"
],
"additionalProperties": false
}Output Schema
{
"type": "object",
"properties": {
"name": {
"type": "string"
},
"engine_version": {
"type": "string"
},
"method": {
"type": "string"
},
"task": {
"type": "string"
},
"effective_query": {
"type": "string"
},
"snapshot_date": {
"type": [
"string",
"null"
]
},
"coverage_status": {
"type": "string"
},
"coverage_warnings": {
"type": "array",
"items": {
"type": "string"
}
},
"structured_results": {
"type": "array",
"description": "Canonical deterministic shortlist. This is the authoritative result set.",
"items": {
"type": "object",
"additionalProperties": true
}
},
"ai_comparison": {
"type": [
"object",
"null"
],
"additionalProperties": true,
"description": "Best-effort grounded explanation of only the structured_results candidates."
},
"ai": {
"type": "object",
"additionalProperties": true
},
"compatibility_warnings": {
"type": "array",
"items": {
"type": "string"
}
},
"source_endpoints": {
"type": "object",
"additionalProperties": true
},
"grounding_policy": {
"type": "object",
"additionalProperties": true
},
"timing_ms": {
"type": "object",
"additionalProperties": true
}
},
"required": [
"name",
"task",
"structured_results",
"ai",
"grounding_policy"
],
"additionalProperties": true
}🟢search_apis(query, categories, capabilities, agent_capabilities, openapi, ...)
Search the canonical registry when you already know keywords or exact requirements. All supplied filter groups combine with AND logic; array capability filters require every supplied value, and protocol fields match the exact Yes/No/Unknown status, so Unknown never satisfies Yes. Results are sorted by agent_readiness_score descending and then API name, with 1–20 results returned (default 10); total_matches reports the complete match count and there is no pagination. Use find_api_for_task for open-ended task recommendations, get_api for one known API, and compare_apis for side-by-side inspection.
Input Schema
{
"type": "object",
"properties": {
"query": {
"type": "string",
"maxLength": 300,
"description": "Optional case-insensitive text search across API name, provider, category, description, capabilities, agent capabilities and authentication fields."
},
"categories": {
"type": "array",
"items": {
"type": "string"
},
"description": "Exact category names. Supplying multiple category values allows a record to match any listed category; this category condition still combines with every other supplied filter group using AND logic."
},
"capabilities": {
"type": "array",
"items": {
"type": "string"
},
"description": "Capability terms that must all be present in the record's verified capabilities. Matching is case-insensitive and allows a capability string to contain the supplied term."
},
"agent_capabilities": {
"type": "array",
"items": {
"type": "string",
"enum": [
"observe",
"locate",
"predict",
"plan",
"control",
"act"
]
},
"description": "Agent capability dimensions that must all be explicitly present on a record."
},
"openapi": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
],
"description": "Exact OpenAPI evidence status required for a match."
},
"mcp": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
],
"description": "Exact MCP evidence status required for a match."
},
"a2a": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
],
"description": "Exact A2A evidence status required for a match."
},
"x402": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
],
"description": "Exact x402 evidence status required for a match."
},
"llms_txt": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
],
"description": "Exact llms.txt evidence status required for a match."
},
"min_readiness": {
"type": "integer",
"minimum": 0,
"maximum": 100,
"description": "Strict minimum agent-readiness score. Records below this score are excluded."
},
"agent_actionable": {
"type": "boolean",
"description": "When true, require agent_actionable = true. False does not exclude actionable records; omit this field unless you need the positive requirement."
},
"limit": {
"type": "integer",
"minimum": 1,
"maximum": 20,
"default": 10,
"description": "Maximum number of matching records returned. Results are sorted by readiness descending then API name. total_matches still reports the full count. No pagination is currently exposed."
}
},
"additionalProperties": false
}Output Schema
{
"type": "object",
"properties": {
"name": {
"type": "string"
},
"method": {
"type": "string"
},
"query": {
"type": "string"
},
"filters": {
"type": "object",
"additionalProperties": true
},
"total_matches": {
"type": "integer",
"minimum": 0
},
"returned": {
"type": "integer",
"minimum": 0
},
"results": {
"type": "array",
"items": {
"type": "object",
"additionalProperties": true,
"properties": {
"slug": {
"type": "string"
},
"name": {
"type": "string"
},
"provider": {
"type": "string"
},
"category": {
"type": "string"
},
"description": {
"type": "string"
},
"capabilities": {
"type": "array",
"items": {
"type": "string"
}
},
"agent_capabilities": {
"type": "array",
"items": {
"type": "string"
}
},
"auth_methods": {
"type": "array",
"items": {
"type": "string"
}
},
"openapi": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
]
},
"mcp": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
]
},
"a2a": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
]
},
"x402": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
]
},
"llms_txt": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
]
},
"agent_readiness_score": {
"type": "number",
"minimum": 0,
"maximum": 100
},
"public_documentation": {
"type": "boolean"
},
"authentication_verified": {
"type": "boolean"
},
"agent_actionable": {
"type": "boolean"
},
"website": {
"type": [
"string",
"null"
]
},
"docs_url": {
"type": [
"string",
"null"
]
}
}
}
},
"evidence_policy": {
"type": "string"
}
},
"required": [
"name",
"method",
"filters",
"total_matches",
"returned",
"results",
"evidence_policy"
],
"additionalProperties": false
}🟢get_api(identifier)
Retrieve one canonical verified API record when you already know its name or slug. Exact slug or exact API name is preferred; a partial identifier is accepted only when it uniquely resolves to one record. Missing or ambiguous identifiers return an error directing the agent to search_apis. Use compare_apis instead when you want fields from multiple known APIs.
Input Schema
{
"type": "object",
"properties": {
"identifier": {
"type": "string",
"maxLength": 200,
"description": "Required API slug or API name. Exact matches are preferred; a unique case-insensitive partial slug/name match is accepted. If it is ambiguous or missing, use search_apis to find the exact identifier."
}
},
"required": [
"identifier"
],
"additionalProperties": false
}Output Schema
{
"type": "object",
"properties": {
"name": {
"type": "string"
},
"record": {
"type": "object",
"additionalProperties": true,
"properties": {
"slug": {
"type": "string"
},
"name": {
"type": "string"
},
"provider": {
"type": "string"
},
"category": {
"type": "string"
},
"description": {
"type": "string"
},
"capabilities": {
"type": "array",
"items": {
"type": "string"
}
},
"agent_capabilities": {
"type": "array",
"items": {
"type": "string"
}
},
"auth_methods": {
"type": "array",
"items": {
"type": "string"
}
},
"openapi": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
]
},
"mcp": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
]
},
"a2a": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
]
},
"x402": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
]
},
"llms_txt": {
"type": "string",
"enum": [
"Yes",
"No",
"Unknown"
]
},
"agent_readiness_score": {
"type": "number",
"minimum": 0,
"maximum": 100
},
"public_documentation": {
"type": "boolean"
},
"authentication_verified": {
"type": "boolean"
},
"agent_actionable": {
"type": "boolean"
},
"website": {
"type": [
"string",
"null"
]
},
"docs_url": {
"type": [
"string",
"null"
]
}
}
},
"source": {
"type": "string"
},
"evidence_policy": {
"type": "string"
}
},
"required": [
"name",
"record",
"source",
"evidence_policy"
],
"additionalProperties": false
}🟢compare_apis(apis, fields)
Compare 2–8 already-known APIs side by side using only canonical RealWorldAPIs fields. Use this after find_api_for_task or search_apis has produced candidates; use get_api when only one record is needed. If fields is omitted, the tool returns the default core comparison fields: provider, category, capabilities, agent capabilities, authentication, protocol statuses, readiness and verification/actionability fields, excluding long description and URLs. Unresolved names/slugs are listed in unresolved; at least two identifiers must resolve. No missing value is inferred and Unknown remains Unknown.
Input Schema
{
"type": "object",
"properties": {
"apis": {
"type": "array",
"minItems": 2,
"maxItems": 8,
"items": {
"type": "string"
},
"description": "Required list of 2–8 API slugs or names. Exact matches are preferred; unique partial matches are accepted. Unresolved identifiers are reported separately, and the call fails if fewer than two records resolve."
},
"fields": {
"type": "array",
"uniqueItems": true,
"description": "Optional fields to compare. If omitted or empty, the tool uses the default core fields: provider, category, capabilities, agent_capabilities, auth_methods, openapi, mcp, a2a, x402, llms_txt, agent_readiness_score, public_documentation, authentication_verified and agent_actionable.",
"items": {
"type": "string",
"enum": [
"provider",
"category",
"description",
"capabilities",
"agent_capabilities",
"auth_methods",
"openapi",
"mcp",
"a2a",
"x402",
"llms_txt",
"agent_readiness_score",
"public_documentation",
"authentication_verified",
"agent_actionable",
"website",
"docs_url"
]
}
}
},
"required": [
"apis"
],
"additionalProperties": false
}Output Schema
{
"type": "object",
"properties": {
"name": {
"type": "string"
},
"method": {
"type": "string"
},
"fields": {
"type": "array",
"items": {
"type": "string"
}
},
"records": {
"type": "array",
"items": {
"type": "object",
"additionalProperties": false,
"required": [
"slug",
"name",
"values"
],
"properties": {
"slug": {
"type": "string"
},
"name": {
"type": "string"
},
"values": {
"type": "object",
"additionalProperties": true
}
}
}
},
"unresolved": {
"type": "array",
"items": {
"type": "string"
}
},
"evidence_policy": {
"type": "string"
}
},
"required": [
"name",
"method",
"fields",
"records",
"unresolved",
"evidence_policy"
],
"additionalProperties": false
}Community
Evidence
Recent observations
verifiedversion not recorded4 tools
verifiedversion not recorded4 tools
verifiedversion not recorded1 tools