> For the complete documentation index, see [llms.txt](https://developers-apps-in-toss.toss.im/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developers-apps-in-toss.toss.im/api/en/user-key.md).

# User identification key

## Verify anonymous user identification key

> Verifies whether the anonymous user identification key passed in the x-anon-key header is valid.\
> \
> \### Business error code\
> \
> The errors below are returned with HTTP 200 and \`resultType: FAIL\`.\
> \
> \| errorCode | Description                                     |\
> \| --------- | ----------------------------------------------- |\
> \| \`4010\`       | Authentication information could not be found.  |\
> \| \`4095\`       | Request limit exceeded. Please try again later. |\
> \
> \*\*Request limit\*\*: 3,000 times per minute per app

```json
{"openapi":"3.1.0","info":{"title":"Apps in Toss partner API","version":"1.0.0"},"tags":[{"description":"This is the API used when verifying the user identification key in a partner app.","name":"user-key"}],"servers":[{"description":"Operations (simple login, message sending, Toss points payouts, etc.)","url":"https://apps-in-toss-api.toss.im"}],"security":[{"mutualTLS":[]}],"components":{"securitySchemes":{"mutualTLS":{"description":"This is client-certificate-based mTLS authentication issued to the partner. The mini app is identified by the certificate's CN. Refer to the [Use the server API](https://developers-apps-in-toss.toss.im/documentation/api-and-sdk-en/integration/server-api) document for how to issue and manage certificates.","type":"mutualTLS"}},"schemas":{"TossApiSuccessBoolean":{"description":"This is the success response envelope.","properties":{"resultType":{"description":"This is the processing result. If successful, it is `SUCCESS`.","enum":["SUCCESS"],"type":"string"},"success":{"description":"This is the actual response data on success.","type":"boolean"}},"required":["resultType","success"],"type":"object"},"TossApiFail":{"description":"This is the failure response envelope. Business errors are returned with HTTP 200, so be sure to check `resultType`.","properties":{"error":{"$ref":"#/components/schemas/TossApiError"},"resultType":{"description":"This is the processing result. Treat any value other than `SUCCESS` as a failure. It is usually `FAIL`.","enum":["FAIL","HTTP_TIMEOUT","NETWORK_ERROR","EXECUTION_FAIL","INTERRUPTED","INTERNAL_ERROR"],"type":"string"},"success":{"description":"It is always null on failure."}},"required":["error","resultType"],"type":"object"},"TossApiError":{"description":"This is detailed error information.","properties":{"data":{"description":"This is additional error information. When the request limit is exceeded, `retryAfterSeconds` is included.","type":"object"},"errorCode":{"description":"This is the error code. Refer to each API's business error code table.","type":"string"},"errorType":{"description":"This is the internal error classification value. Use `errorCode` for error categorization.","format":"int32","type":"integer"},"reason":{"description":"This is a human-readable error description.","type":"string"},"title":{"description":"This is the error title. It is usually null.","type":"string"}},"required":["errorCode","reason"],"type":"object"},"TossApiValidationFail":{"description":"This is the response when request field validation fails.","properties":{"error":{"$ref":"#/components/schemas/TossApiValidationFailError"},"resultType":{"description":"This is the processing result. Treat any value other than `SUCCESS` as a failure. It is usually `FAIL`.","enum":["FAIL","HTTP_TIMEOUT","NETWORK_ERROR","EXECUTION_FAIL","INTERRUPTED","INTERNAL_ERROR"],"type":"string"},"success":{"description":"It is always null on failure."}},"required":["error","resultType"],"type":"object"},"TossApiValidationFailError":{"description":"This is detailed error information.","properties":{"data":{"description":"This is additional error information. When the request limit is exceeded, `retryAfterSeconds` is included.","properties":{"errorDetails":{"description":"This is a detailed list of field-by-field validation failures.","items":{"$ref":"#/components/schemas/TossApiFieldError"},"type":"array"}},"type":"object"},"errorCode":{"description":"This is the error code. Refer to each API's business error code table.","type":"string"},"errorType":{"description":"This is the internal error classification value. Use `errorCode` for error categorization.","format":"int32","type":"integer"},"reason":{"description":"This is a human-readable error description.","type":"string"},"title":{"description":"This is the error title. It is usually null.","type":"string"}},"required":["errorCode","reason"],"type":"object"},"TossApiFieldError":{"description":"This is a detailed list of field-by-field validation failures.","properties":{"field":{"description":"This is the name of the field that failed validation.","type":"string"},"message":{"description":"This is the reason for validation failure.","type":"string"},"rejectedValue":{"description":"This is the rejected input value."}},"type":"object"}}},"paths":{"/api-partner/v1/apps-in-toss/users/anon-key/verify":{"post":{"description":"Verifies whether the anonymous user identification key passed in the x-anon-key header is valid.\n\n### Business error code\n\nThe errors below are returned with HTTP 200 and `resultType: FAIL`.\n\n| errorCode | Description                                     |\n| --------- | ----------------------------------------------- |\n| `4010`       | Authentication information could not be found.  |\n| `4095`       | Request limit exceeded. Please try again later. |\n\n**Request limit**: 3,000 times per minute per app","operationId":"verifyAnonKey","parameters":[{"description":"It's a key for authenticating users. You can issue it with the [User.getAnonymousKey](https://developers-apps-in-toss.toss.im/documentation/api-and-sdk-en/sdk/domains-api/user/user.getanonymouskey) function in the mini app SDK","in":"header","name":"x-anon-key","required":true,"schema":{"type":"string"}}],"responses":{"200":{"content":{"application/json":{"schema":{"discriminator":{"mapping":{"FAIL":"#/components/schemas/TossApiFail","SUCCESS":"#/components/schemas/TossApiSuccessBoolean"},"propertyName":"resultType"},"oneOf":[{"$ref":"#/components/schemas/TossApiSuccessBoolean"},{"$ref":"#/components/schemas/TossApiFail"}]}}},"description":"The anonymous user identification key verification result is returned as true or false."},"400":{"content":{"application/json":{"schema":{"$ref":"#/components/schemas/TossApiValidationFail"}}},"description":"Request format is invalid. `error.data` is an empty object, and `error.reason` is returned as `Unknown Error`. Missing the `x-anon-key` header is not returned in this response, but as an HTTP 200 business error (`4010`)."},"500":{"content":{"application/json":{"schema":{"$ref":"#/components/schemas/TossApiFail"}}},"description":"This is an unclassified server error. If it keeps failing, please contact the partner support channel."}},"summary":"Verify anonymous user identification key","tags":["user-key"]}}}}
```


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