openapi: 3.0.7 info: title: 'IPGeolocation.io: ASN Lookup API' version: "3.0" description: | Retrieve Autonomous System Number (ASN) information associated with an IPv4 address, IPv6 address, or a specific ASN. The ASN Lookup API returns detailed information about an Autonomous System including the ASN number, organization name, country of registration, domain, ASN type, allocation date, and the Regional Internet Registry (RIR) responsible for assigning the ASN. Additional routing intelligence can also be retrieved including: - Peering relationships - Upstream and downstream connections - IPv4 and IPv6 routing prefixes - Raw WHOIS registry data This information helps organizations analyze internet routing, identify network operators, and understand how Autonomous Systems interconnect across the internet. One endpoint is available: - **ASN lookup** (`GET /v3/asn`) returns ASN information for a single IPv4 address, IPv6 address, or ASN number per request. Use query parameters to control which fields are returned, include routing relationships, or exclude fields to reduce response payload size. ## Authentication Two authentication methods are supported: ### API Key Pass your API key as the `apiKey` query parameter on every request. You can find your key in the [IPGeolocation dashboard](https://app.ipgeolocation.io/). Store it in server-side environment variables. Avoid exposing it in client-side JavaScript. ### Request Origin (CORS) Available on paid plans only. Whitelist your domain in the dashboard under the "API Keys" section. Once configured, requests from that domain (and all its subdomains) are accepted without passing `apiKey`. Enter your root domain (e.g. `example.com`), not the full URL. Each plan has a limit on the number of extra API keys and request origins: | Plan | Extra API Keys + Request Origins | |---|---| | Starter (150K requests) | 1 | | Core (250K requests) | 1 | | Plus (500K requests) | 2 | | Pro (1M requests) | 2 | | Business (2M requests) | 3 | | Premium (5M requests) | 3 | Additional keys or origins can be added for $2.50 per month each. ## Response Formats The API supports JSON (default) and XML output. - Set the `output` query parameter to `json` or `xml`. - Alternatively, set the `Accept` header to `application/json`, `application/xml`, or `text/xml`. If neither is specified, the response is returned as JSON. XML responses use a `LinkedHashMap` root element. ## Credit Usage Credits are charged only for successful **HTTP 200** responses. The exact number of credits consumed by a request is returned in the `X-Credits-Charged` response header. A **single ASN lookup** (`GET /v3/asn`) consumes **1 credit** per request. ## Field Filtering Use `fields` to cherry-pick specific fields, or `excludes` to drop fields you do not need. Both accept dot-notation for nested fields (e.g. `asn.as_number`, `asn.organization`). The `ip` field is always present regardless of filters. ## Parameter Name Casing Query parameter names are case-sensitive. Use exact names such as `apiKey`, `ip`, `fields`, `include`, `excludes`, and `output`. ## Include Additional ASN Data The `include` parameter can be used to retrieve additional routing information related to the ASN. Supported values include: - `peers` - `downstreams` - `upstreams` - `routes` - `whois_response` Multiple values must be comma-separated. ## Parameter Name Casing Query parameter names are case-sensitive. Use exact names such as `apiKey`, `ip`, `asn`, `include`, `fields`, `excludes`, and `output`. ## ASN Data Availability Basic ASN information is also included in the IP Geolocation API (`/v3/ipgeo`). Field availability differs depending on the endpoint and subscription plan. | Field | /v3/ipgeo (Free) | /v3/ipgeo (Paid) | /v3/asn | |---|---|---|---| | asn.as_number | ✓ | ✓ | ✓ | | asn.organization | ✓ | ✓ | ✓ | | asn.country | ✓ | ✓ | ✓ | | asn.type | ✗ | ✓ | ✓ | | asn.domain | ✗ | ✓ | ✓ | | asn.date_allocated | ✗ | ✓ | ✓ | | asn.rir | ✗ | ✓ | ✓ | | asn.asn_name | ✗ | ✗ | ✓ | | asn.allocation_status | ✗ | ✗ | ✓ | | asn.num_of_ipv4_routes | ✗ | ✗ | ✓ | | asn.num_of_ipv6_routes | ✗ | ✗ | ✓ | | asn.peers | ✗ | ✗ | ✓ | | asn.downstreams | ✗ | ✗ | ✓ | | asn.upstreams | ✗ | ✗ | ✓ | | asn.routes | ✗ | ✗ | ✓ | | asn.whois_response | ✗ | ✗ | ✓ | The `/v3/ipgeo` endpoint is recommended when you need IP geolocation data together with basic ASN information. The `/v3/asn` endpoint should be used when detailed ASN intelligence is required, including routing relationships, routes, and WHOIS registry data. ## Usage Limits Paid subscriptions do not enforce fixed daily or hourly rate limits. If the monthly request quota is exceeded, requests continue and a surcharge may be applied depending on the subscribed plan. Requests made using invalid API keys or unsupported subscriptions return **HTTP 401 Unauthorized**. contact: name: IPGeolocation Support url: https://ipgeolocation.io/contact.html email: support@ipgeolocation.io termsOfService: https://ipgeolocation.io/tos.html license: name: Proprietary url: https://ipgeolocation.io/tos.html externalDocs: description: IPGeolocation ASN Lookup API documentation url: https://ipgeolocation.io/documentation/asn-api.html servers: - url: https://api.ipgeolocation.io description: Production security: - ApiKeyAuth: [] paths: /v3/asn: get: operationId: lookupASN summary: IPGeolocation.io ASN Lookup description: | Returns ASN details for a single IPv4 address, IPv6 address, or ASN number. The response contains information about the Autonomous System responsible for routing the queried IP address or ASN. Basic ASN metadata is always returned, while additional routing relationships such as peers, upstreams, downstreams, routes, and WHOIS data can be retrieved using the `include` parameter. When the lookup is performed using the `asn` parameter, the `ip` field is not included in the response. Each successful lookup consumes **1 credit**. Use the `fields`, `excludes`, and `include` parameters to customize the response. tags: - ASN Lookup parameters: - $ref: "#/components/parameters/Ip" - $ref: "#/components/parameters/Asn" - $ref: "#/components/parameters/Include" - $ref: "#/components/parameters/Fields" - $ref: "#/components/parameters/Excludes" - $ref: "#/components/parameters/Output" responses: "200": description: ASN information for the requested IP address. headers: X-Credits-Charged: description: Number of API credits consumed by this request. schema: type: number example: 1 content: application/json: schema: $ref: "#/components/schemas/ASNLookupResponse" example: asn: as_number: "AS24940" organization: "Hetzner Online GmbH" country: "DE" type: "HOSTING" domain: "hetzner.com" date_allocated: "2002-06-03" asn_name: "HETZNER-AS" allocation_status: "ASSIGNED" num_of_ipv4_routes: "84" num_of_ipv6_routes: "6" rir: "RIPE" peers: - as_number: "AS58057" description: "Securebit A" country: "CH" - as_number: "AS28792" description: "Public Internet Ltd" country: "GB" routes: - "78.46.0.0/15" - "138.199.128.0/17" upstreams: - as_number: "AS12552" description: "GlobalConnect AB" country: "SE" - as_number: "AS58057" description: "Securebit AG" country: "CH" downstreams: - as_number: "AS209148" description: "Securepoint GmbH" country: "DE" - as_number: "AS198167" description: "Apptc.me s.r.o." country: "CZ" whois_response: | # # ARIN WHOIS data and services are subject to the Terms of Use # ASNumber: 24940 ASName: HETZNER-AS OrgName: Hetzner Online GmbH Country: DE ... application/xml: schema: $ref: "#/components/schemas/ASNLookupResponse" example: | AS24940 Hetzner Online GmbH DE HOSTING hetzner.com 2002-06-03 HETZNER-AS ASSIGNED 84 6 RIPE AS58057 Securebit AG CH AS28792 Public Internet Ltd GB 78.46.0.0/15 138.199.128.0/17 AS12552 GlobalConnect AB SE AS58057 Securebit AG CH AS209148 Securepoint GmbH DE AS198167 Apptc.me s.r.o. CZ ASNumber: 24940 OrgName: Hetzner Online GmbH Country: DE ... "400": $ref: "#/components/responses/BadRequest" "401": $ref: "#/components/responses/Unauthorized" "404": $ref: "#/components/responses/NotFound" "405": $ref: "#/components/responses/MethodNotAllowed" "423": $ref: "#/components/responses/Locked" "429": $ref: "#/components/responses/TooManyRequests" "499": $ref: "#/components/responses/ClientClosedRequest" "500": $ref: "#/components/responses/InternalServerError" "502": $ref: "#/components/responses/BadGateway" "503": $ref: "#/components/responses/ServiceUnavailable" "504": $ref: "#/components/responses/GatewayTimeout" "505": $ref: "#/components/responses/HttpVersionNotSupported" x-microcks-operation: delay: 0 dispatcher: FALLBACK components: parameters: Ip: name: ip in: query required: false description: | An IPv4 address or IPv6 address to look up. When omitted, the API resolves the public IP of the requesting client. If the `asn` parameter is provided, the `ip` parameter must not be used, because the lookup will be performed directly using the specified ASN. Empty or whitespace-only values are treated the same as omission and resolve the caller IP. Pass `ip` only once. If multiple `ip` query parameters are sent, values may be merged and treated as invalid input (HTTP 400). schema: type: string examples: none: summary: No IP address provided value: "" ipv4: summary: IPv4 address value: "91.128.103.196" ipv6: summary: IPv6 address value: "2607:fb91:16c6:8860:e531:2d1d:4944:6c7c" Asn: name: asn in: query required: false description: | An Autonomous System Number (ASN) to look up. When provided, the lookup is performed directly using the specified ASN, and the `ip` parameter must not be included in the request. The API returns detailed information about the ASN including the organization name, country of registration, ASN type, routing statistics, and other related network metadata. Pass `asn` only once. If multiple `asn` query parameters are sent, values may be merged and treated as invalid input (HTTP 400). schema: type: string examples: none: summary: No ASN provided value: "" numeric: summary: ASN number value: "24940" prefixed: summary: ASN with prefix value: "AS24940" Include: name: include in: query required: false description: | Comma-separated list of optional data modules to add to the response. These are not returned by default. Supported ASN modules include: - `peers` - `downstreams` - `upstreams` - `routes` - `whois_response` If multiple values are provided, they must be comma-separated. For additional query parameters (`include`, `fields`, `excludes`, `output`), unknown values are ignored. The API still returns HTTP 200 and applies only recognized values. schema: type: string examples: none: summary: Do not include any optional modules value: "" peers: summary: Include ASN peer relationships value: "peers" multiple: summary: Include peers and downstream connections value: "peers,downstreams" routingData: summary: Include routing relationships and routes value: "peers,downstreams,upstreams,routes" all: summary: Include all ASN modules value: "peers,downstreams,upstreams,routes,whois_response" Fields: name: fields in: query required: false description: | Comma-separated list of fields or objects to return. Everything else is omitted. The `ip` field is always returned when the lookup is performed using an IP address. Supports dot-notation for nested fields: `asn.organization`, `asn.domain`. If the same field or object is specified in both `fields` and `excludes`, the object is still returned, but it will be empty. If you list both an object key and one of its nested fields separated by comma (e.g. `asn,asn.organization`), the full object is returned. Unknown field paths are ignored. The API still returns HTTP 200. Available on all plans including Free. schema: type: string examples: none: summary: Return the full response (no field filtering) value: "" countryOnly: summary: Return only the ASN country field value: "asn.country" moreThanOneFields: summary: Return specific ASN fields value: "asn.organization,asn.country" Excludes: name: excludes in: query required: false description: | Comma-separated list of fields or objects to remove from the response. The `ip` field cannot be excluded. Supports dot-notation for nested fields: `asn.domain`. If the same field or object is specified in both `fields` and `excludes`, the object is still returned, but it will be empty. Unknown fields or object keys in `excludes` are ignored. The API still returns HTTP 200. Available on all plans including Free. schema: type: string examples: none: summary: Do not exclude any fields value: "" excludeObjects: summary: Exclude ASN allocation metadata value: "asn.date_allocated,asn.allocation_status" Output: name: output in: query required: false description: | Desired response format. Defaults to `json` if not specified. You can also control the format using the `Accept` header (`application/json`, `application/xml`, or `text/xml`). If both are provided, the `output` parameter takes precedence. If `output` is unknown or unsupported, it is ignored and the response defaults to JSON (`application/json`) with HTTP 200. schema: type: string enum: [json, xml] default: json responses: BadRequest: description: | Bad request. Returned for one of the following reasons: - The provided IPv4 address or IPv6 address is invalid. - Special characters such as ( ) [ ] { } | ^ ` are present in the API URL, either in a parameter name or its value (especially in the API key). content: application/json: schema: $ref: "#/components/schemas/ErrorResponse" examples: invalidIp: summary: Invalid IPv4/IPv6 input value: message: "Provided name, service or IP address '999.999.999.999' is not valid." specialCharacters: summary: Special characters in API URL or key value: message: "Invalid character found in the request target." Unauthorized: description: | Unauthorized. Returned for one of the following reasons: - The `apiKey` URL parameter is missing. - An invalid (random or incorrect) API key is provided. - The account has been disabled or locked due to abuse or illegal activity. - The API request is made using an API key for a database subscription. - The API request is made using a free subscription API key. - The subscription is in a 'paused' state. - The subscription trial has expired. - The account’s active-until date has passed and renewal or upgrade is required. content: application/json: schema: $ref: "#/components/schemas/ErrorResponse" examples: missingApiKey: summary: Missing API key value: message: "Please provide an API key (as 'apiKey=YOUR_API_KEY' URL parameter) to use IPGeolocation API. To get your free API Key, sign up at https://app.ipgeolocation.io/login" invalidApiKey: summary: Invalid API key value: message: "Provided API key is not valid. Contact technical support for assistance at support@ipgeolocation.io" lockedAccount: summary: Account locked or disabled value: message: "Your account has been locked to use IPGeolocation API. Contact technical support for assistance at support@ipgeolocation.io" databaseSubscriptionKey: summary: Database subscription API key used for REST API value: message: "You cannot query IPGeolocation API on a database plan subscription. " freePlanAccess: summary: Free subscription used for ASN lookup API value: message: "ASN Lookup is not supported on your current subscription. This feature is available to Paid subscriptions only." pausedSubscription: summary: Subscription is paused value: message: "Your subscription has been paused. Please resume your subscription to use IPGeolocation API." expiredSubscription: summary: Subscription expired or trial ended value: message: "Your subscription has expired at DATE. Please subscribe to a paid plan to continue using IPGeolocation API without interruption or contact technical support for assistance at support@ipgeolocation.io" NotFound: description: | Not found. Returned for one of the following reasons: - A syntactically valid IPv4, IPv6, or ASN does not exist in the IPGeolocation database. - An IPv4, IPv6, or ASN is passed as a path variable instead of as a URL query parameter (e.g., using `/v3/ipgeo/8.8.8.8` instead of `/v3/ipgeo?ip=8.8.8.8`). - A non-existent or incorrect API endpoint is called. Invalid or malformed IPv4, IPv6, or domain input returns HTTP 400 instead. content: application/json: schema: $ref: "#/components/schemas/ErrorResponse" examples: ipNotInDatabase: summary: IPv4/IPv6/ASN not found in database value: message: "Provided ASN or IP Address does not exist in our database." ipAsPathVariable: summary: IP passed as path variable instead of query parameter value: message: "No endpoint GET /v3/ipgeo/8.8.8.8." asnAsPathVariable: summary: ASN passed as path variable instead of query parameter value: message: "No endpoint GET /v3/ipgeo/24940." wrongEndpoint: summary: Incorrect or non-existent endpoint value: message: "No endpoint GET /v3/asn-invalid." MethodNotAllowed: description: | Method Not Allowed. Returned when an unsupported HTTP method is used to call an endpoint. Only the **GET** method is supported for the ASN lookup API endpoint. Any other HTTP method results in HTTP 405. content: application/json: schema: $ref: "#/components/schemas/ErrorResponse" examples: postNotAllowed: summary: POST method used value: message: "Request method 'POST' is not supported" unsupportedMethod: summary: Unsupported HTTP method value: message: "Request method is not supported" Locked: description: | Locked. The provided IP address belongs to a bogon IP range or a private network and cannot be looked up. content: application/json: schema: $ref: "#/components/schemas/ErrorResponse" example: message: "'10.0.0.1' is a bogon IP address." TooManyRequests: description: | Too Many Requests. Returned for one of the following reasons: - The API usage limit has been reached for a Paid subscription with status 'past due', 'deleted', or 'trial expired'. - The surcharge API usage limit has been reached for the subscribed plan. content: application/json: schema: $ref: "#/components/schemas/ErrorResponse" examples: usageLimitReached: summary: API usage limit reached value: message: "You have exceeded the limit of PLAN_USAGE_LIMIT requests per PLAN_INERVAL for your subscribed PLAN plan. Please throttle your requests or upgrade your plan to continue using IPGeolocation API without interruption." surchargeLimitReached: summary: Surcharge usage limit reached value: message: "You have reached the surcharge amount limit of PLAN_USAGE_LIMIT_AND_SURCHARGE_LIMIT on your subscribed PLAN plan. Please throttle your requests or upgrade your plan to continue using IPGeolocation API without interruption." ClientClosedRequest: description: | The client closed the connection before the server finished processing the request. This usually happens when the client sets a very short request or connection timeout. Increase the timeout on the client side. content: application/json: schema: $ref: "#/components/schemas/ErrorResponse" example: message: "Client closed the request before the server could respond." InternalServerError: description: | Internal Server Error. The server encountered an unexpected condition that prevented it from fulfilling the request. If the issue persists, contact support@ipgeolocation.io. content: application/json: schema: $ref: "#/components/schemas/ErrorResponse" example: message: "Something went wrong on the server side." BadGateway: description: | Bad Gateway. The API server received an invalid response from an upstream server while processing the request. This is usually temporary. content: application/json: schema: $ref: "#/components/schemas/ErrorResponse" example: message: "Upstream service error. Please try again later." ServiceUnavailable: description: | Service Unavailable. The API is temporarily unavailable due to maintenance or overload. Please try again later. content: application/json: schema: $ref: "#/components/schemas/ErrorResponse" example: message: "Service temporarily unavailable. Please try again later." GatewayTimeout: description: | Gateway Timeout. The API server did not receive a timely response from an upstream server. content: application/json: schema: $ref: "#/components/schemas/ErrorResponse" example: message: "The server timed out while processing the request." HttpVersionNotSupported: description: | HTTP Version Not Supported. The server does not support the HTTP protocol version used in the request. content: application/json: schema: $ref: "#/components/schemas/ErrorResponse" example: message: "HTTP version not supported." schemas: ErrorResponse: type: object description: | Returned for any non-200 response. Contains only a human-readable `message`. Message text can vary by status and condition; examples in this spec are representative, not exhaustive, and should not be treated as stable machine codes. required: - message properties: message: type: string description: Human-readable explanation of what went wrong. Use HTTP status for control flow. example: "Provided name, service or IP address '999.999.999.999' is not valid." ASNLookupResponse: type: object xml: name: LinkedHashMap description: | Response returned by the ASN Lookup API. Contains the queried IP address (when an IP lookup is performed) and the ASN information associated with the network responsible for routing that IP address. When the lookup is performed using the `asn` parameter, the `ip` field is not included in the response. properties: ip: type: string description: | The IP address for which ASN details are returned. This field appears only when the lookup is performed using an IP address. example: "49.12.0.0" asn: $ref: "#/components/schemas/ASN" ASN: type: object description: | ASN information describing the Autonomous System responsible for routing the queried IP address or the specified ASN. Costs 1 credit. properties: as_number: type: string description: Complete Autonomous System Number that was looked up. example: "AS24940" organization: type: string description: Name of the organization to which the ASN is assigned. example: "Hetzner Online GmbH" country: type: string description: ISO 3166-1 alpha-2 country code where the ASN is registered. example: "DE" asn_name: type: string description: Official ASN handle. example: "HETZNER-AS" type: type: string description: | ASN category. Possible values include `ISP`, `HOSTING`, `BUSINESS`, `EDUCATION`, or `GOVERNMENT` when available. example: "HOSTING" domain: type: string description: Domain associated with the ASN. example: "hetzner.com" date_allocated: type: string description: Date when the ASN was originally allocated. example: "2002-06-03" rir: type: string description: | Regional Internet Registry that allocated the ASN. Examples include `RIPE`, `ARIN`, `APNIC`, `LACNIC`, `AFRINIC`, etc. example: "RIPE" allocation_status: type: string description: Current allocation status of the ASN. example: "ASSIGNED" num_of_ipv4_routes: type: string description: Number of IPv4 prefixes announced by this ASN. example: "84" num_of_ipv6_routes: type: string description: Number of IPv6 prefixes announced by this ASN. example: "6" peers: type: array description: Directly connected peer ASNs. items: $ref: "#/components/schemas/ASNConnection" downstreams: type: array description: Downstream (customer) ASNs connected to this ASN. items: $ref: "#/components/schemas/ASNConnection" upstreams: type: array description: Upstream provider ASNs used for internet connectivity. items: $ref: "#/components/schemas/ASNConnection" routes: type: array description: IPv4 and IPv6 prefixes announced by this ASN. items: type: string examples: - "192.76.177.0/24" - "2607:f600::/32" whois_response: type: string description: Raw WHOIS registry record text returned for the ASN. example: "ASNumber: 24940\nOrgName: Hetzner Online GmbH\nCountry: DE" ASNConnection: type: object description: | Represents a connected Autonomous System such as a peer, upstream provider, or downstream customer. properties: as_number: type: string description: Autonomous System Number of the connected network. example: "AS3356" description: type: string description: Name or description of the connected network operator. example: "Level 3 Parent, LLC" country: type: string description: Country code of the connected ASN. example: "US" securitySchemes: ApiKeyAuth: type: apiKey in: query name: apiKey description: | API key passed as the `apiKey` query parameter. Get yours from the [IPGeolocation dashboard](https://app.ipgeolocation.io/). For client-side usage, consider using Request Origin (CORS) authentication instead to avoid exposing your key. tags: - name: ASN Lookup description: | API endpoint for retrieving Autonomous System Number (ASN) information associated with IPv4 addresses, IPv6 addresses, or specific ASN numbers. The response includes ASN metadata such as the ASN number, organization name, country of registration, ASN type, domain, allocation details, routing statistics, and the Regional Internet Registry (RIR) responsible for the allocation. Additional routing intelligence such as peers, upstreams, downstreams, announced routes, and raw WHOIS registry data can also be retrieved using the `include` parameter. This information helps analyze internet routing, identify network operators, and understand how Autonomous Systems interconnect across the internet. externalDocs: description: ASN Lookup API documentation url: https://ipgeolocation.io/documentation/asn-api.html