> ## Documentation Index > Fetch the complete documentation index at: https://unkey.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Apply rate limiting > Check and enforce rate limits for any identifier (user ID, IP address, API client, etc.). Use this for rate limiting beyond API keys - limit users by ID, IPs by address, or any custom identifier. Supports namespace organization, variable costs, and custom overrides. **Response Codes**: Rate limit checks return HTTP 200 regardless of whether the limit is exceeded — check the `success` field in the response to determine if the request should be allowed. A 429 may be returned if the workspace exceeds its API rate limit. Other 4xx responses indicate auth, namespace existence/deletion, or validation errors (e.g., 410 Gone for deleted namespaces). 5xx responses indicate server errors. **Required Permissions** Your root key must have one of the following permissions: - `ratelimit.*.limit` (to check limits in any namespace) - `ratelimit..limit` (to check limits in a specific namespace) ## OpenAPI ````yaml https://spec.speakeasy.com/unkey/unkey/openapi-json-with-code-samples post /v2/ratelimit.limit openapi: 3.1.0 info: description: >- Unkey's API provides programmatic access for all resources within our platform. ### Authentication # This API uses HTTP Bearer authentication with root keys. Most endpoints require specific permissions associated with your root key. When making requests, include your root key in the `Authorization` header: ``` Authorization: Bearer unkey_xxxxxxxxxxx ``` All responses follow a consistent envelope structure that separates operational metadata from actual data. This design provides several benefits: - Debugging: Every response includes a unique requestId for tracing issues - Consistency: Predictable response format across all endpoints - Extensibility: Easy to add new metadata without breaking existing integrations - Error Handling: Unified error format with actionable information ### Success Response Format: ```json { "meta": { "requestId": "req_123456" }, "data": { // Actual response data here } } ``` The meta object contains operational information: - `requestId`: Unique identifier for this request (essential for support) The data object contains the actual response data specific to each endpoint. ### Paginated Response Format: ```json { "meta": { "requestId": "req_123456" }, "data": [ // Array of results ], "pagination": { "cursor": "next_page_token", "hasMore": true } } ``` The pagination object appears on list endpoints and contains: - `cursor`: Token for requesting the next page - `hasMore`: Whether more results are available ### Error Response Format: ```json { "meta": { "requestId": "req_2c9a0jf23l4k567" }, "error": { "detail": "The resource you are attempting to modify is protected and cannot be changed", "status": 403, "title": "Forbidden", "type": "https://unkey.com/docs/errors/unkey/application/protected_resource" } } ``` Error responses include comprehensive diagnostic information: - `title`: Human-readable error summary - `detail`: Specific description of what went wrong - `status`: HTTP status code - `type`: Link to error documentation - `errors`: Array of validation errors (for 400 responses) This structure ensures you always have the context needed to debug issues and take corrective action. title: Unkey API version: 2.0.0 servers: - url: https://api.unkey.com security: - rootKey: [] tags: - description: Analytics query operations name: analytics - description: API management operations name: apis - description: Deployment operations name: deploy - description: Identity management operations name: identities - description: API key management operations name: keys - description: Health check operations name: liveness - description: Permission and role management operations name: permissions - description: Customer Portal session management name: portal - description: Rate limiting operations name: ratelimit paths: /v2/ratelimit.limit: post: tags: - ratelimit summary: Apply rate limiting description: > Check and enforce rate limits for any identifier (user ID, IP address, API client, etc.). Use this for rate limiting beyond API keys - limit users by ID, IPs by address, or any custom identifier. Supports namespace organization, variable costs, and custom overrides. **Response Codes**: Rate limit checks return HTTP 200 regardless of whether the limit is exceeded — check the `success` field in the response to determine if the request should be allowed. A 429 may be returned if the workspace exceeds its API rate limit. Other 4xx responses indicate auth, namespace existence/deletion, or validation errors (e.g., 410 Gone for deleted namespaces). 5xx responses indicate server errors. **Required Permissions** Your root key must have one of the following permissions: - `ratelimit.*.limit` (to check limits in any namespace) - `ratelimit..limit` (to check limits in a specific namespace) operationId: ratelimit.limit requestBody: content: application/json: examples: basic: summary: Basic rate limit check value: duration: 60000 identifier: user_abc123 limit: 100 namespace: api.requests ipLimit: summary: IP-based rate limiting value: duration: 60000 identifier: 203.0.113.42 limit: 5 namespace: auth.login weightedCost: summary: Operation with variable cost value: cost: 5 duration: 3600000 identifier: user_def456 limit: 50 namespace: api.heavy_operations schema: $ref: '#/components/schemas/V2RatelimitLimitRequestBody' required: true responses: '200': content: application/json: examples: allowed: summary: Request allowed value: data: limit: 100 remaining: 99 reset: 1714582980000 success: true meta: requestId: req_01H9TQPP77V5E48E9SH0BG0ZQX limitReached: summary: Rate limit exceeded value: data: limit: 100 remaining: 0 reset: 1714582980000 success: false meta: requestId: req_01H9TQPP77V5E48E9SH0BG0ZQY withOverride: summary: With custom override applied value: data: limit: 1000 overrideId: ovr_2cGKbMxRyIzhCxo1Idjz8q remaining: 995 reset: 1714582980000 success: true meta: requestId: req_01H9TQPP77V5E48E9SH0BG0ZQZ schema: $ref: '#/components/schemas/V2RatelimitLimitResponseBody' description: > Rate limit check completed successfully. Check the `success` field to determine if the request is allowed. '400': content: application/json: schema: $ref: '#/components/schemas/BadRequestErrorResponse' description: Bad request '401': content: application/json: schema: $ref: '#/components/schemas/UnauthorizedErrorResponse' description: Unauthorized '403': content: application/json: schema: $ref: '#/components/schemas/ForbiddenErrorResponse' description: Forbidden '404': content: application/json: schema: $ref: '#/components/schemas/NotFoundErrorResponse' description: Not Found '410': content: application/json: schema: $ref: '#/components/schemas/GoneErrorResponse' description: Gone - Namespace has been deleted '429': content: application/problem+json: schema: $ref: '#/components/schemas/TooManyRequestsErrorResponse' description: Too Many Requests '500': content: application/json: schema: $ref: '#/components/schemas/InternalServerErrorResponse' description: Internal server error security: - rootKey: [] x-codeSamples: - lang: go label: Go (SDK) source: "package main\n\nimport(\n\t\"context\"\n\t\"os\"\n\tunkey \"github.com/unkeyed/sdks/api/go/v2\"\n\t\"github.com/unkeyed/sdks/api/go/v2/models/components\"\n\t\"log\"\n)\n\nfunc main() {\n ctx := context.Background()\n\n s := unkey.New(\n unkey.WithSecurity(os.Getenv(\"UNKEY_ROOT_KEY\")),\n )\n\n res, err := s.Ratelimit.Limit(ctx, components.V2RatelimitLimitRequestBody{\n Namespace: \"api.requests\",\n Cost: unkey.Pointer[int64](5),\n Duration: 60000,\n Identifier: \"user_abc123\",\n Limit: 100,\n })\n if err != nil {\n log.Fatal(err)\n }\n if res.V2RatelimitLimitResponseBody != nil {\n // handle response\n }\n}" - lang: python label: Python (SDK) source: |- from unkey.py import Unkey with Unkey( root_key="", ) as unkey: res = unkey.ratelimit.limit(namespace="api.requests", duration=60000, identifier="user_abc123", limit=100, cost=5) # Handle response print(res) - lang: typescript label: Typescript (SDK) source: |- import { Unkey } from "@unkey/api"; const unkey = new Unkey({ rootKey: process.env["UNKEY_ROOT_KEY"] ?? "", }); async function run() { const result = await unkey.ratelimit.limit({ namespace: "api.requests", cost: 5, duration: 60000, identifier: "user_abc123", limit: 100, }); console.log(result); } run(); components: schemas: V2RatelimitLimitRequestBody: additionalProperties: false properties: namespace: type: string minLength: 1 maxLength: 255 description: The id or name of the namespace. example: sms.sign_up cost: type: integer format: int64 minimum: 0 default: 1 description: > Sets how much of the rate limit quota this request consumes, enabling weighted rate limiting. Use higher values for resource-intensive operations and 0 for tracking without limiting. When accumulated cost exceeds the limit within the duration window, subsequent requests are rejected. Essential for implementing fair usage policies and preventing resource abuse through expensive operations. example: 5 duration: type: integer format: int64 minimum: 1000 maximum: 2592000000 description: > Sets the rate limit window duration in milliseconds after which the counter resets. Shorter durations enable faster recovery but may be less effective against sustained abuse. Common values include 60000 (1 minute), 3600000 (1 hour), and 86400000 (24 hours). Balance user experience with protection needs when choosing window sizes. example: 60000 identifier: type: string minLength: 1 maxLength: 255 description: > Defines the scope of rate limiting by identifying the entity being limited. Use user IDs for per-user limits, IP addresses for anonymous limiting, or API key IDs for per-key limits. Accepts letters, numbers, underscores, dots, colons, slashes, and hyphens for flexible identifier formats. The same identifier can be used across different namespaces to apply multiple rate limit types. Choose identifiers that provide appropriate granularity for your rate limiting strategy. example: user_12345 limit: type: integer format: int64 minimum: 1 description: > Sets the maximum operations allowed within the duration window before requests are rejected. When this limit is reached, subsequent requests fail with `RATE_LIMITED` until the window resets. Balance user experience with resource protection when setting limits for different user tiers. Consider system capacity, business requirements, and fair usage policies in limit determination. example: 1000 required: - namespace - identifier - limit - duration type: object V2RatelimitLimitResponseBody: type: object required: - meta - data properties: meta: $ref: '#/components/schemas/Meta' data: $ref: '#/components/schemas/V2RatelimitLimitResponseData' BadRequestErrorResponse: type: object required: - meta - error properties: meta: $ref: '#/components/schemas/Meta' error: $ref: '#/components/schemas/BadRequestErrorDetails' description: >- Error response for invalid requests that cannot be processed due to client-side errors. This typically occurs when request parameters are missing, malformed, or fail validation rules. The response includes detailed information about the specific errors in the request, including the location of each error and suggestions for fixing it. When receiving this error, check the 'errors' array in the response for specific validation issues that need to be addressed before retrying. UnauthorizedErrorResponse: type: object required: - meta - error properties: meta: $ref: '#/components/schemas/Meta' error: $ref: '#/components/schemas/BaseError' description: >- Error response when authentication has failed or credentials are missing. This occurs when: - No authentication token is provided in the request - The provided token is invalid, expired, or malformed - The token format doesn't match expected patterns To resolve this error, ensure you're including a valid root key in the Authorization header. ForbiddenErrorResponse: type: object required: - meta - error properties: meta: $ref: '#/components/schemas/Meta' error: $ref: '#/components/schemas/BaseError' description: >- Error response when the provided credentials are valid but lack sufficient permissions for the requested operation. This occurs when: - The root key doesn't have the required permissions for this endpoint - The operation requires elevated privileges that the current key lacks - Access to the requested resource is restricted based on workspace settings To resolve this error, ensure your root key has the necessary permissions or contact your workspace administrator. NotFoundErrorResponse: type: object required: - meta - error properties: meta: $ref: '#/components/schemas/Meta' error: $ref: '#/components/schemas/BaseError' description: >- Error response when the requested resource cannot be found. This occurs when: - The specified resource ID doesn't exist in your workspace - The resource has been deleted or moved - The resource exists but is not accessible with current permissions To resolve this error, verify the resource ID is correct and that you have access to it. GoneErrorResponse: type: object required: - meta - error properties: meta: $ref: '#/components/schemas/Meta' error: $ref: '#/components/schemas/BaseError' description: >- Error response when the requested resource has been soft-deleted and is no longer available. This occurs when: - The resource has been marked as deleted but still exists in the database - The resource is intentionally unavailable but could potentially be restored - The resource cannot be restored through the API or dashboard To resolve this error, contact support if you need the resource restored. TooManyRequestsErrorResponse: type: object required: - meta - error properties: meta: $ref: '#/components/schemas/Meta' error: $ref: '#/components/schemas/BaseError' description: >- Error response when the client has sent too many requests in a given time period. This occurs when you've exceeded a rate limit or quota for the resource you're accessing. The rate limit resets automatically after the time window expires. To avoid this error: - Implement exponential backoff when retrying requests - Cache results where appropriate to reduce request frequency - Check the error detail message for specific quota information - Contact support if you need a higher quota for your use case InternalServerErrorResponse: type: object required: - meta - error properties: meta: $ref: '#/components/schemas/Meta' error: $ref: '#/components/schemas/BaseError' description: >- Error response when an unexpected error occurs on the server. This indicates a problem with Unkey's systems rather than your request. When you encounter this error: - The request ID in the response can help Unkey support investigate the issue - The error is likely temporary and retrying may succeed - If the error persists, contact Unkey support with the request ID Meta: type: object required: - requestId properties: requestId: description: >- A unique id for this request. Always include this ID when contacting support about a specific API request. This identifier allows Unkey's support team to trace the exact request through logs and diagnostic systems to provide faster assistance. example: req_123 type: string additionalProperties: false description: >- Metadata object included in every API response. This provides context about the request and is essential for debugging, audit trails, and support inquiries. The `requestId` is particularly important when troubleshooting issues with the Unkey support team. V2RatelimitLimitResponseData: type: object properties: limit: description: >- The maximum number of operations allowed within the time window. This reflects either the default limit specified in the request or an override limit if one exists for this identifier. This value helps clients understand their total quota for the current window. format: int64 type: integer remaining: description: >- The number of operations remaining in the current window before the rate limit is exceeded. Applications should use this value to: - Implement client-side throttling before hitting limits - Display usage information to end users - Trigger alerts when approaching limits - Adjust request patterns based on available capacity When this reaches zero, requests will be rejected until the window resets. format: int64 type: integer reset: description: >- The Unix timestamp in milliseconds when the rate limit window will reset and 'remaining' will return to 'limit'. This timestamp enables clients to: - Calculate and display wait times to users - Implement intelligent retry mechanisms - Schedule requests to resume after the reset - Implement exponential backoff when needed The reset time is based on a sliding window from the first request in the current window. format: int64 type: integer success: description: >- Whether the request passed the rate limit check. If true, the request is allowed to proceed. If false, the request has exceeded the rate limit and should be blocked or rejected. You MUST check this field to determine if the request should proceed, as the endpoint always returns `HTTP 200` even when rate limited. type: boolean overrideId: description: >- If a rate limit override was applied for this identifier, this field contains the ID of the override that was used. Empty when no override is in effect. This can be useful for: - Debugging which override rule was matched - Tracking the effects of specific overrides - Understanding why limits differ from default values type: string x-go-type-skip-optional-pointer: true x-go-type-skip-optional-pointer-with-omitzero: true required: - limit - remaining - reset - success BadRequestErrorDetails: allOf: - $ref: '#/components/schemas/BaseError' - type: object properties: errors: description: >- List of individual validation errors that occurred in the request. Each error provides specific details about what failed validation, where the error occurred in the request, and suggestions for fixing it. This granular information helps developers quickly identify and resolve multiple issues in a single request without having to make repeated API calls. items: $ref: '#/components/schemas/ValidationError' type: array required: - errors description: >- Extended error details specifically for bad request (400) errors. This builds on the BaseError structure by adding an array of individual validation errors, making it easy to identify and fix multiple issues at once. BaseError: properties: detail: description: >- A human-readable explanation specific to this occurrence of the problem. This provides detailed information about what went wrong and potential remediation steps. The message is intended to be helpful for developers troubleshooting the issue. example: Property foo is required but is missing. type: string status: description: >- HTTP status code that corresponds to this error. This will match the status code in the HTTP response. Common codes include `400` (Bad Request), `401` (Unauthorized), `403` (Forbidden), `404` (Not Found), `409` (Conflict), and `500` (Internal Server Error). example: 404 format: int type: integer title: description: >- A short, human-readable summary of the problem type. This remains constant from occurrence to occurrence of the same problem and should be used for programmatic handling. example: Not Found type: string type: description: >- A URI reference that identifies the problem type. This provides a stable identifier for the error that can be used for documentation lookups and programmatic error handling. When followed, this URI should provide human-readable documentation for the problem type. example: https://unkey.com/docs/errors/unkey/resource/not_found type: string required: - title - detail - status - type type: object additionalProperties: false description: >- Base error structure following Problem Details for HTTP APIs (RFC 7807). This provides a standardized way to carry machine-readable details of errors in HTTP response content. ValidationError: additionalProperties: false properties: location: description: >- JSON path indicating exactly where in the request the error occurred. This helps pinpoint the problematic field or parameter. Examples include: - 'body.name' (field in request body) - 'body.items[3].tags' (nested array element) - 'path.apiId' (path parameter) - 'query.limit' (query parameter) Use this location to identify exactly which part of your request needs correction. type: string example: body.permissions[0].name message: description: >- Detailed error message explaining what validation rule was violated. This provides specific information about why the field or parameter was rejected, such as format errors, invalid values, or constraint violations. type: string example: Must be at least 3 characters long fix: description: >- A human-readable suggestion describing how to fix the error. This provides practical guidance on what changes would satisfy the validation requirements. Not all validation errors include fix suggestions, but when present, they offer specific remediation advice. type: string example: >- Ensure the name uses only alphanumeric characters, underscores, and hyphens required: - location - message type: object description: >- Individual validation error details. Each validation error provides precise information about what failed, where it failed, and how to fix it, enabling efficient error resolution. securitySchemes: rootKey: bearerFormat: root key description: >- Unkey uses API keys (root keys) for authentication. These keys authorize access to management operations in the API. To authenticate, include your root key in the Authorization header of each request: ``` Authorization: Bearer unkey_123 ``` Root keys have specific permissions attached to them, controlling what operations they can perform. Key permissions follow a hierarchical structure with patterns like `resource.resource_id.action` (e.g., `apis.*.create_key`, `apis.*.read_api`). Security best practices: - Keep root keys secure and never expose them in client-side code - Use different root keys for different environments - Rotate keys periodically, especially after team member departures - Create keys with minimal necessary permissions following least privilege principle - Monitor key usage with audit logs. scheme: bearer type: http ````