b2_create_key
- 11 Sep 2026
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b2_create_key
- Updated on 11 Sep 2026
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Post
/b2api/v4/b2_create_key
Creates a new application key
There is a limit of 100 million key creations per account.
NOTE:
This API endpoint can be called using a GET request by converting the parameters in the request body to query parameters.
API Versions
v4 b2_create_key (April 24, 2025)
Please note: to allow for the creation of Multi-Bucket Application Keys v4 b2_create_key now includes the bucketIds field in the request and response. The bucketId field has been removed in the request and response.
For information on all API versions, view our API changelog.
Header parameters
Authorization
stringRequired
An account authorization token, obtained from b2_authorize_account.
The token must have the writeKeys capability.
Body parameters
object
accountId
string Required
Your account ID.
ExampleACCOUNT_ID
capabilities
Array of string Required
A list of strings, each one naming a capability the new key should have.
Example[ "listKeys", "writeKeys" ]
string
Valid values[ "listKeys", "writeKeys", "deleteKeys", "listAllBucketNames", "listBuckets", "readBuckets", "writeBuckets", "deleteBuckets", "readBucketRetentions", "writeBucketRetentions", "readBucketEncryption", "writeBucketEncryption", "writeBucketNotifications", "listFiles", "readFiles", "shareFiles", "writeFiles", "deleteFiles", "readBucketNotifications", "readFileLegalHolds", "writeFileLegalHolds", "readFileRetentions", "writeFileRetentions", "bypassGovernance", "readBucketLogging", "writeBucketLogging" ]
keyName
string Required
The name for this key. There is no requirement for the key name to be unique. Key names are limited to 100 characters and can contain letters, numbers, and "-", but not I18N characters, such as é, à , and ü.
Please note: The key name cannot be used to look up the key.
Max length100
PatternA-Za-z0-9\-]+
Examplekey-0003
validDurationInSeconds
integer
When provided, the key will expire after the given number of seconds, and will have expirationTimestamp set. Value must be a positive integer, and must be less than 1000 days (in seconds).
Minimum0
Maximum86400000
bucketIds
Array
When provided, the new key can only access the specified buckets.
Example[ "ca1edec684c1f8805b570c17" ]
namePrefix
string
When provided, this parameter limits access to files with names starting with the specified prefix. By default, the restriction is applied to all buckets unless a bucketId is included in the request.
Examplefoo
Responses
200
Successful operation
object
keyName
string
The name assigned when the key was created.
Examplekey-0003
applicationKeyId
string
The ID of the newly created key
Example00512f95cf4dcf0000000004z
applicationKey
string
The secret part of the key. This is the only time it will be returned, so you need to keep it. This is not returned when you list the keys in your account.
ExampleK0041ZMxZEop4JkYUJqEei1ZSep14zz
capabilities
Array of string
list of strings, each one naming a capability the key has. This list could include: listKeys, writeKeys, deleteKeys, listAllBucketNames, listBuckets, readBuckets, writeBuckets, deleteBuckets, readBucketRetentions, writeBucketNotifications, writeBucketRetentions, readBucketEncryption, writeBucketEncryption, listFiles, readFiles, shareFiles, writeFiles, deleteFiles, readFileLegalHolds, writeFileLegalHolds, readFileRetentions, writeFileRetentions, bypassGovernance, readBucketNotifications, readBucketReplications, writeBucketReplications, readBucketLogging, and writeBucketLogging.
Example[ "listKeys", "readFiles" ]
string
Valid values[ "listKeys", "writeKeys", "deleteKeys", "listAllBucketNames", "listBuckets", "readBuckets", "writeBuckets", "deleteBuckets", "readBucketRetentions", "writeBucketRetentions", "readBucketEncryption", "writeBucketEncryption", "writeBucketNotifications", "listFiles", "readFiles", "shareFiles", "writeFiles", "deleteFiles", "readBucketNotifications", "readFileLegalHolds", "writeFileLegalHolds", "readFileRetentions", "writeFileRetentions", "bypassGovernance" ]
accountId
string
The account that this application key is for.
ExampleACCOUNT_ID
expirationTimestamp
integer
When present, says when this key will expire, in milliseconds since 1970.
Minimum0
Example1671147546259
bucketIds
Array
When present, restricts access to the buckets in the array.
Example[ "ca1edec684c1f8805b570c17" ]
namePrefix
string
When present, restricts access to files whose names start with the prefix
Examplefoo
options
Array of string
When present, contains a set of strings. Reserved for future use.
Example[ "s3" ]
string
Valid values[ "s3" ]
400
| status | code | description |
|---|---|---|
| 400 | bad_bucket_id | The requested bucket ID does not match an existing bucket. |
| 400 | bad_request | The request had the wrong fields or illegal values. The message returned with the error will describe the problem. |
object
status
integer
The numeric HTTP status code. Always matches the status in the HTTP response.
Example400
code
string
A single-identifier code that identifies the error.
Exampleinvalid_bucket_name
message
string
A human-readable message, in English, saying what went wrong.
Examplebucket name is too long
401
| status | code | description |
|---|---|---|
| 401 | bad_auth_token | The auth token used is not valid. Call b2_authorize_account again to either get a new one, or an error message describing the problem. |
| 401 | expired_auth_token | The auth token used has expired. Call b2_authorize_account again to get a new one. |
| 401 | unauthorized | The auth token used is valid, but does not authorize this call with these parameters. The capabilities of an auth token are determined by the application key used with b2_authorize_account. |
object
status
integer
The numeric HTTP status code. Always matches the status in the HTTP response.
Example400
code
string
A single-identifier code that identifies the error.
Exampleinvalid_bucket_name
message
string
A human-readable message, in English, saying what went wrong.
Examplebucket name is too long
403
| status | code | description |
|---|---|---|
| 403 | transaction_cap_exceeded | Transaction cap exceeded. Daily transaction caps apply to non-paying accounts. To view or adjust your caps, sign in to your B2 Cloud Storage account online and select the Caps & Alerts link in the B2 Cloud Storage section of the sidebar. |
object
status
integer
The numeric HTTP status code. Always matches the status in the HTTP response.
Example400
code
string
A single-identifier code that identifies the error.
Exampleinvalid_bucket_name
message
string
A human-readable message, in English, saying what went wrong.
Examplebucket name is too long
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