> For the complete documentation index, see [llms.txt](https://fusionauth.io/docs/llms.txt)

# Generate a Key

API documentation for the FusionAuth Generate a Key API.

# Generate a Key

This API is used to generate a new Key.

[!Global API Key Authentication](https://fusionauth.io/docs/apis/authentication.md#global-api-key-authentication)

Generate a new Key with a randomly generated Id

POST/api/key/generate

OpenAPI Spec

[!Global API Key Authentication](https://fusionauth.io/docs/apis/authentication.md#global-api-key-authentication)

Generate a new Key with the provided unique Id

POST/api/key/generate/{keyId}

OpenAPI Spec

## Request

### Request Parameters

`keyId`UUIDoptionalDefaults to secure random UUID

The Id to use for the new key. If not specified a secure random UUID will be generated.

### Request Body

`key.algorithm`Stringrequired

The algorithm used to generate the Key. The following values represent algorithms supported by FusionAuth:

*   `Ed25519` - EdDSA using the Ed25519 parameter set Available since 1.62.0
*   `ES256` - ECDSA using P-256 curve and SHA-256 hash algorithm
*   `ES384` - ECDSA using P-384 curve and SHA-384 hash algorithm
*   `ES512` - ECDSA using P-521 curve and SHA-512 hash algorithm
*   `RS256` - RSA using SHA-256 hash algorithm
*   `RS384` - RSA using SHA-384 hash algorithm
*   `RS512` - RSA using SHA-512 hash algorithm
*   `HS256` - HMAC using SHA-256 hash algorithm
*   `HS384` - HMAC using SHA-384 hash algorithm
*   `HS512` - HMAC using SHA-512 hash algorithm

`key.issuer`Stringoptional

The issuer of the certificate.

If omitted, this value will default to the value of **tenant.issuer** on the default tenant. For HMAC keys, this field does not apply and will be ignored if specified, and no default value will be set.

`key.name`Stringrequired

The name of the Key.

`key.length`Stringoptional

The length of the RSA or EC certificate. This field is required when generating RSA key types.

For RSA, possible values are: `2048`, `3072` or `4096`.

For EC, possible values are: `256`, `384`, or `521`.

*Example Request JSON*

```json
{
  "key": {
    "algorithm": "RS256",
    "issuer": "piedpiper.com",
    "name": "SHA-256 with RSA",
    "length": 2048
  }
}
```

## Response

The response for this API contains the Key that was generated.

*Response Codes*

| Code | Description |
| --- | --- |
| 200 | The request was successful. The response will contain a JSON body. |
| 400 | The request was invalid and/or malformed. The response will contain an [Errors](https://fusionauth.io/docs/apis/errors.md) JSON Object with the specific errors. This status will also be returned if a paid FusionAuth license is required and is not present. |
| 401 | You did not supply a valid Authorization header. The header was omitted or your API key was not valid. The response will be empty. See [Authentication](https://fusionauth.io/docs/apis/authentication.md). |
| 500 | There was an internal error. A stack trace is provided and logged in the FusionAuth log files. The response will be empty. |
| 503 | The search index is not available or encountered an exception so the request cannot be completed. The response will contain a JSON body. |

#### Response Body

`key.algorithm`String

The algorithm used to generate the key. For Secrets, this value will be `None`.

`key.certificate`String

The X.509 certificate. This field is omitted for HMAC keys and Secrets.

`key.certificateInformation`Map<String, Object>

The RSA or EC certificate information. This field is omitted for HMAC keys and Secrets.

`key.certificateInformation.issuer`String

The issuer of the certificate. This field is omitted for HMAC keys and Secrets.

`key.certificateInformation.md5Fingerprint`String

The md5 fingerprint of the certificate. This field is omitted for HMAC keys and Secrets.

`key.certificateInformation.serialNumber`String

The serial number of the certificate. This field is omitted for HMAC keys and Secrets.

`key.certificateInformation.sha1Fingerprint`String

The SHA-1 fingerprint of the certificate. This field is omitted for HMAC keys and Secrets.

`key.certificateInformation.sha1Thumbprint`String

The SHA-1 thumbprint of the certificate. This field is omitted for HMAC keys and Secrets.

`key.certificateInformation.sha256Fingerprint`String

The SHA-256 fingerprint of the certificate. This field is omitted for HMAC keys and Secrets.

`key.certificateInformation.sha256Thumbprint`String

The SHA-256 thumbprint of the certificate. This field is omitted for HMAC keys and Secrets.

`key.certificateInformation.subject`String

The subject of the certificate. This field is omitted for HMAC keys and Secrets.

`key.certificateInformation.validFrom`Integer

The UNIX time in milliseconds marking the start of the certificate validity period. This field is omitted for HMAC keys and Secrets.

`key.certificateInformation.validTo`Integer

The UNIX time in milliseconds marking the expiration certificate. This field is omitted for HMAC keys and Secrets.

`key.expirationInstant`Integer

The [instant](https://fusionauth.io/docs/reference/data-types.md#instants) marking the expiration certificate. This field is omitted for HMAC keys and Secrets.

`key.hasPrivateKey`Boolean

Because the private key will never be returned in the API response, this value will indicate if the private key is stored in FusionAuth. This field is omitted for HMAC keys and Secrets.

`key.id`UUID

The Id of the Key.

`key.insertInstant`Long

The [instant](https://fusionauth.io/docs/reference/data-types.md#instants) that the key was added to the FusionAuth database.

`key.issuer`String

The issuer of the certificate. This field is omitted for HMAC keys and Secrets.

`key.kid`String

The key identifier 'kid'.

`key.lastUpdateInstant`Long

The [instant](https://fusionauth.io/docs/reference/data-types.md#instants) that the key was updated in the FusionAuth database.

`key.length`String

The length of the certificate. This field is omitted for HMAC keys and Secrets.

`key.name`String

The name of the key.

`key.publicKey`String

The certificate public key. This field is omitted for HMAC keys and Secrets.

`key.type`String

The key type. The possible values are:

*   `EC`
*   `OKP` Available since 1.62.0
*   `RSA`
*   `HMAC`
*   `Secret` Available since 1.64.0

*Example HMAC Key Response JSON*

```json
{
  "key": {
    "algorithm": "HS256",
    "id": "092dbedc-30af-4149-9c61-b578f2c72f59",
    "insertInstant": 1562171137000,
    "kid": "10d51735a5",
    "lastUpdateInstant": 1595361143101,
    "name": "OpenID Connect compliant HMAC using SHA-256",
    "type": "HMAC"
  }
}
```

*Example RSA Key Response JSON*

```json
{
  "key": {
    "algorithm": "RS256",
    "certificate": "-----BEGIN CERTIFICATE-----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\nkUlBh6gSyN7SGJBvWEh6+zZF\n-----END CERTIFICATE-----",
    "certificateInformation": {
      "issuer": "CN=acme.com",
      "md5Fingerprint": "FC:36:CD:0B:9C:B7:62:F0:A9:16:AE:72:8E:F8:7D:D8",
      "serialNumber": "78:0E:1D:5B:EE:3B:43:B2:AE:C8:DB:99:B9:9A:DC:4E",
      "sha1Fingerprint": "CD:A9:80:5F:4D:37:EB:CD:B4:45:42:DF:76:35:15:E9:89:21:61:B6",
      "sha1Thumbprint": "zamAX0036820RULfdjUV6YkhYbY",
      "sha256Fingerprint": "33:7C:CB:4C:23:3B:F5:22:49:2F:68:C5:FA:D1:6E:3C:72:54:CB:3C:E6:D1:70:08:55:FC:43:24:9A:98:05:CF",
      "sha256Thumbprint": "M3zLTCM79SJJL2jF-tFuPHJUyzzm0XAIVfxDJJqYBc8",
      "subject": "CN=acme.com",
      "validFrom": 1562189072183,
      "validTo": 1877808272183
    },
    "expirationInstant": 1877808272183,
    "hasPrivateKey": false,
    "id": "780e1d5b-ee3b-43b2-aec8-db99b99adc4e",
    "insertInstant": 1562189072183,
    "issuer": "acme.com",
    "kid": "zamAX0036820RULfdjUV6YkhYbY",
    "lastUpdateInstant": 1595361143101,
    "length": 2048,
    "name": "SHA-256 with RSA",
    "publicKey": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAnbNGwtU33S4vbipGeIwe\n/DhLEfc5FaEOHK4WeQ3QF8zZGyI09bNQdkp8uNTFfVehIgmvYHmJWPeaNrYK//qj\nWAsSvYYoytj1j4BywI8uLSjt8QvzaoFUMOi1cBbXM2586R7yTRm7jMk91MLM101z\nkrf1cmFdRUwTpeJjw66XG3JlTGZCmZsJG7m6+nbe5LHt4CiufmJHujGeFzgwby3j\nXZtuK1y3ua3380Fv95JyG3TucnMwEw5EYQ8Q+dZzNC8OSaKrgmnN0gWdsJ7P7vu6\nlMy6sXKhvcxo1p+tXywYPFJahxA+rZDG16RLbUppCx10q8tIcFKeAyl4eywzBaBL\nxwIDAQAB\n-----END PUBLIC KEY-----",
    "type": "RSA"
  }
}
```

*Example EC Key Response JSON*

```json
{
  "key": {
    "algorithm": "ES256",
    "certificate": "-----BEGIN CERTIFICATE-----\nMIIBJzCBy6ADAgEBAhEAwUtQ5YaLTb6fPAKM0FFbETAMBggqhkjOPQQDAgUAMBMx\nETAPBgNVBAMTCGFjbWUuY29tMB4XDTIxMTAwMjEzNDE1MVoXDTMxMTAwMjEzNDE1\nMVowEzERMA8GA1UEAxMIYWNtZS5jb20wWTATBgcqhkjOPQIBBggqhkjOPQMBBwNC\nAARPysdu/AKSICtkZa9hlBGb7vJHJ0GHWYXEeyTYDCPd2XoT5icVAZQ5GVU1q2WV\nEaVJRmlFuGqWElvYLIRYrce2MAwGCCqGSM49BAMCBQADSQAwRgIhAJCXC5Ys25Wk\nYXeC1bWjyt71p8Yn1B//DZo+SzQrBVF+AiEA3u6an0m+wsO1dnNN1wtXdUsa5Avo\nOjME4ZLJHhtGQ1I=\n-----END CERTIFICATE-----",
    "certificateInformation": {
      "issuer": "CN=acme.com",
      "md5Fingerprint": "E5:50:70:3A:88:56:7C:BE:CB:FA:50:29:19:B5:CE:2D",
      "serialNumber": "00:C1:4B:50:E5:86:8B:4D:BE:9F:3C:02:8C:D0:51:5B:11",
      "sha1Fingerprint": "2F:22:15:AC:7C:2A:67:E8:F3:AB:87:97:3A:E0:84:58:79:A3:35:7F",
      "sha1Thumbprint": "LyIVrHwqZ-jzq4eXOuCEWHmjNX8",
      "sha256Fingerprint": "D5:B0:B5:5E:07:1D:2B:84:A8:7C:5F:89:B7:74:62:2F:8C:57:A8:66:A1:D5:A2:F1:A9:94:70:8F:D3:0D:64:0F",
      "sha256Thumbprint": "1bC1XgcdK4SofF-Jt3RiL4xXqGah1aLxqZRwj9MNZA8",
      "subject": "CN=acme.com",
      "validFrom": 1633182111000,
      "validTo": 1948714911000
    },
    "expirationInstant": 1948714911000,
    "hasPrivateKey": true,
    "id": "c14b50e5-868b-4dbe-9f3c-028cd0515b11",
    "insertInstant": 1633182111648,
    "issuer": "acme.com",
    "kid": "LyIVrHwqZ-jzq4eXOuCEWHmjNX8",
    "lastUpdateInstant": 1633182111648,
    "length": 256,
    "name": "ECDSA using P-256 curve and SHA-256",
    "publicKey": "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAET8rHbvwCkiArZGWvYZQRm+7yRydB\nh1mFxHsk2Awj3dl6E+YnFQGUORlVNatllRGlSUZpRbhqlhJb2CyEWK3Htg==\n-----END PUBLIC KEY-----",
    "type": "EC"
  }
}
```

*Example EdDSA Key Response JSON*

```json
{
  "key": {
    "algorithm": "Ed25519",
    "certificate": "-----BEGIN CERTIFICATE-----\nMIHsMIGfoAMCAQECEQDqdRGGNnhIwI8IEfDjwZN7MAUGAytlcDAYMRYwFAYDVQQD\nEw1mdXNpb25hdXRoLmlvMB4XDTI1MTIxODE2MDUyNVoXDTM1MTIxODE2MDUyNVow\nGDEWMBQGA1UEAxMNZnVzaW9uYXV0aC5pbzAqMAUGAytlcAMhAI+wTC3wU30tqiGR\n8RsFrAYl++dNZTRIdwUqPmMv3xeqMAUGAytlcANBANiOCGE+XoUorYo13gor1PWM\n6sL7j2oDBbSExzThihvYXyO7Lx7s8ZCgJ8rIcxgDQRJbhq1n5oxMAvGnzezDMwQ=\n-----END CERTIFICATE-----",
    "certificateInformation": {
      "issuer": "CN=fusionauth.io",
      "md5Fingerprint": "74:19:09:95:D9:6F:52:D9:83:D5:CD:48:D2:26:34:A2",
      "serialNumber": "00:EA:75:11:86:36:78:48:C0:8F:08:11:F0:E3:C1:93:7B",
      "sha1Fingerprint": "AB:6D:71:A6:B6:36:BA:D3:00:7D:1D:E8:CB:08:25:6F:46:13:EF:51",
      "sha1Thumbprint": "q21xprY2utMAfR3oywglb0YT71E",
      "sha256Fingerprint": "1A:BE:72:43:9A:B6:06:D5:08:32:06:28:A8:1B:DF:73:A2:99:5E:82:FF:C4:A3:FD:F3:9B:5F:5F:80:4A:27:D4",
      "sha256Thumbprint": "Gr5yQ5q2BtUIMgYoqBvfc6KZXoL_xKP985tfX4BKJ9Q",
      "subject": "CN=fusionauth.io",
      "validFrom": 1766073925573,
      "validTo": 2081606725573
    },
    "expirationInstant": 2081606725573,
    "hasPrivateKey": true,
    "id": "ea751186-3678-48c0-8f08-11f0e3c1937b",
    "insertInstant": 1766073925573,
    "issuer": "fusionauth.io",
    "kid": "q21xprY2utMAfR3oywglb0YT71E",
    "lastUpdateInstant": 1766073925573,
    "length": 32,
    "name": "EdDSA using the Ed25519 parameter set",
    "publicKey": "-----BEGIN PUBLIC KEY-----\nMCowBQYDK2VwAyEAj7BMLfBTfS2qIZHxGwWsBiX7501lNEh3BSo+Yy/fF6o=\n-----END PUBLIC KEY-----",
    "type": "OKP"
  }
}
```