Presign an upload or download for an object in a bucket
API Reference / Buckets / Presign an upload or download for an object in a bucket
POST /projects//branches//buckets//objects//presign
Section titled “POST /projects//branches//buckets//objects//presign”Returns a presigned URL that transfers bytes directly to or from the
object's bucket on the specified branch, without the caller ever
handling S3 credentials. The operation field selects the direction:
uploadreturns a presignedPUTURL (the callerPUTs the file bytes straight tourlwith the returnedheaders). Authorized with project write access.downloadreturns a presignedGETURL (the callerGETs the bytes straight fromurl). Authorized with project read access.
The platform mints a short-lived credential and builds the SigV4-signed URL against the branch's S3 data-plane host, returning it together with the HTTP method, any headers the caller must echo, and the URL's expiry.
Served by the user's session (no customer S3 credentials required).
Note: This endpoint is currently in Beta.
Parameters
Section titled “Parameters”project_id(string, path, required) The Neon project IDbranch_id(string, path, required) The Neon branch IDbucket_name(string, path, required) The bucket nameobject_key(string, path, required) The object key. Keys may contain/; the/characters of nested keys must be percent-encoded (%2F) in the path segment.
Request body
Section titled “Request body”-
operation(string, required) The transfer direction.uploadreturns a presignedPUTURL;downloadreturns a presignedGETURL.Possible values:
upload,download -
content_type(string, optional) TheContent-Typeto bind into the signed request. Only meaningful forupload: when set, the caller MUST send the sameContent-Typeheader on thePUT, and the value is echoed back in the responseheaders. Ignored fordownload. -
expires_in_seconds(integer, optional, format: int64) How long the presigned URL stays valid, in seconds. Defaults to 900 (15 minutes); capped at 604800 (7 days).Default:
900
Response (200)
Section titled “Response (200)”{
"url": "https://br-young-forest-a5b6c7d8.storage.c-5.us-east-2.aws.neon.tech/user-uploads-ms9mbu2o16/uploads/hello.txt?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=nak_live_00000000000000000000000000000000%2Fus-east-2&X-Amz-Date=20250115T103000Z&X-Amz-Expires=900&X-Amz-Signature=0000000000000000000000000000000000000000000000000000000000000000&X-Amz-SignedHeaders=host",
"method": "GET",
"headers": {},
"expires_at": "2025-02-15T10:30:00Z"
}Code examples
Section titled “Code examples”curl "https://console.neon.tech/api/v2/projects/$PROJECT_ID/branches/$BRANCH_ID/buckets/$BUCKET_NAME/objects/$OBJECT_KEY/presign" \
-X POST \
-H "Authorization: Bearer $NEON_API_KEY"import { createNeonClient, raw } from '@neon/sdk';
const neon = createNeonClient({ apiKey: process.env.NEON_API_KEY });
const { data } = await raw.presignProjectBranchBucketObject({
client: neon.client,
path: {
project_id: process.env.PROJECT_ID,
branch_id: process.env.BRANCH_ID,
bucket_name: process.env.BUCKET_NAME,
object_key: process.env.OBJECT_KEY
}
});Errors
Section titled “Errors”404 Bucket or branch not found
-
request_id(string, optional) Unique identifier for the request, useful for debugging. You can set this value manually by including anX-Request-IDheader in the request. If not provided, the value will be generated automatically. -
code(string, required) Machine-readable code classifying the error type. Seemessagefor a human-readable explanation. Default: `` -
message(string, required) Error message
default General Error.
The request may or may not be safe to retry, depending on the HTTP method, response status code, and whether a response was received.
- If no response is returned from the API, a network error or timeout likely occurred.
- In some cases, the request may have reached the server and been successfully processed, but the response failed to reach the client. As a result, retrying non-idempotent requests can lead to unintended results.
The following HTTP methods are considered non-idempotent: POST, PATCH, DELETE, and PUT. Retrying these methods is generally not safe.
The following methods are considered idempotent: GET, HEAD, and OPTIONS. Retrying these methods is safe in the event of a network error or timeout.
Any request that returns a 503 Service Unavailable response is always safe to retry.
Any request that returns a 423 Locked response is safe to retry. 423 Locked indicates that the resource is temporarily locked, for example, due to another operation in progress.
-
request_id(string, optional) Unique identifier for the request, useful for debugging. You can set this value manually by including anX-Request-IDheader in the request. If not provided, the value will be generated automatically. -
code(string, required) Machine-readable code classifying the error type. Seemessagefor a human-readable explanation. Default: `` -
message(string, required) Error message