Presign an upload or download for an object in a bucket

POST/projects/{project_id}/branches/{branch_id}/buckets/{bucket_name}/objects/{object_key}/presignPresign an upload or download for an object in a bucket

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:

upload returns a presigned PUT URL (the caller PUTs the file

bytes straight to url with the returned headers). Authorized with project write access.

download returns a presigned GET URL (the caller GETs the

bytes straight from url). 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

project_idstringpathrequired

The Neon project ID

pattern ^[a-z0-9-]{1,60}$

branch_idstringpathrequired

The Neon branch ID

pattern ^[a-z0-9-]{1,60}$

bucket_namestringpathrequired

The bucket name

maxLength 255 · minLength 1

object_keystringpathrequired

The object key. Keys may contain `/`; the `/` characters of nested keys must be percent-encoded (`%2F`) in the path segment.

maxLength 1024 · minLength 1

Request body

required

application/json

objectPresignRequest

Options for the presigned URL. The `operation` selects upload (`PUT`) or download (`GET`); the remaining fields are optional.

content_typestring

The `Content-Type` to bind into the signed request. Only meaningful for `upload`: when set, the caller MUST send the same `Content-Type` header on the `PUT`, and the value is echoed back in the response `headers`. Ignored for `download`.

expires_in_secondsinteger · int64

How long the presigned URL stays valid, in seconds. Defaults to 900 (15 minutes); capped at 604800 (7 days).

default 900 · maximum 604800 · minimum 1

operationstringrequired

The transfer direction. `upload` returns a presigned `PUT` URL; `download` returns a presigned `GET` URL.

one of "upload", "download"

Example request

{
  "content_type": "string",
  "expires_in_seconds": 900,
  "operation": "download"
}

Responses

objectPresignResponse

expires_atstring · date-timerequired

When the presigned URL stops being valid.

headersobjectrequired

Headers the caller MUST send verbatim on the request (e.g. `Content-Type` when it was signed on an upload). May be empty.

methodstringrequired

The HTTP method to use against `url`: `PUT` for an upload, `GET` for a download.

urlstringrequired

The presigned URL. Transfer the object bytes by issuing `method url` with the returned `headers`.

Example response

{
  "expires_at": "2026-06-09T00:00:00Z",
  "headers": {
    "additionalProp1": "string"
  },
  "method": "string",
  "url": "string"
}

objectGeneralError

codestringrequired

default ""

messagestringrequired

Error message

request_idstring

Unique identifier for the request, useful for debugging. You can set this value manually by including an `X-Request-ID` header in the request. If not provided, the value will be generated automatically.

Example response

{
  "code": "",
  "message": "string",
  "request_id": "string"
}

defaultGeneral 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. application/json

objectGeneralError

codestringrequired

default ""

messagestringrequired

Error message

request_idstring

Example response

{
  "code": "",
  "message": "string",
  "request_id": "string"
}

Examples

project_idrequiredpath parameter

branch_idrequiredpath parameter

bucket_namerequiredpath parameter

object_keyrequiredpath parameter

curl -X POST 'https://console.neon.tech/api/v2/projects/string/branches/string/buckets/string/objects/string/presign' \
  -H 'Content-Type: application/json' \
  -d '{"content_type":"string","expires_in_seconds":900,"operation":"download"}'

const response = await fetch('https://console.neon.tech/api/v2/projects/string/branches/string/buckets/string/objects/string/presign', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({"content_type":"string","expires_in_seconds":900,"operation":"download"}),
});
const data = await response.json();

const response = await fetch('https://console.neon.tech/api/v2/projects/string/branches/string/buckets/string/objects/string/presign', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: "{\"content_type\":\"string\",\"expires_in_seconds\":900,\"operation\":\"download\"}" });
console.log(await response.json());

import requests

response = requests.request(
    "POST",
    "https://console.neon.tech/api/v2/projects/string/branches/string/buckets/string/objects/string/presign",
    headers={"Content-Type": "application/json"},
    data='{"content_type":"string","expires_in_seconds":900,"operation":"download"}',
)
print(response.json())

package main

import (
	"context"
	"net/http"
	"strings"
)

func main() {
	ctx := context.Background()
	body := strings.NewReader(`{"content_type":"string","expires_in_seconds":900,"operation":"download"}`)
	req, err := http.NewRequestWithContext(ctx, "POST", "https://console.neon.tech/api/v2/projects/string/branches/string/buckets/string/objects/string/presign", body)
	if err != nil {
		panic(err)
	}
	req.Header.Set("Content-Type", "application/json")
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer resp.Body.Close()
}

<?php
$request = curl_init("https://console.neon.tech/api/v2/projects/string/branches/string/buckets/string/objects/string/presign");
curl_setopt($request, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($request, CURLOPT_POSTFIELDS, "{\"content_type\":\"string\",\"expires_in_seconds\":900,\"operation\":\"download\"}");
curl_setopt($request, CURLOPT_HTTPHEADER, ['Content-Type: application/json']);
$response = curl_exec($request);
curl_close($request);

var request = HttpRequest.newBuilder(URI.create("https://console.neon.tech/api/v2/projects/string/branches/string/buckets/string/objects/string/presign"))
    .method("POST", HttpRequest.BodyPublishers.noBody())
    .header("Content-Type", "application/json")
    .method("POST", HttpRequest.BodyPublishers.ofString("{\"content_type\":\"string\",\"expires_in_seconds\":900,\"operation\":\"download\"}"))
    .build();
var response = HttpClient.newHttpClient().send(request, HttpResponse.BodyHandlers.ofString());

require 'net/http'

uri = URI("https://console.neon.tech/api/v2/projects/string/branches/string/buckets/string/objects/string/presign")
request = Net::HTTPGenericRequest.new("POST", true, true, uri)
request['Content-Type'] = 'application/json'
request.body = "{\"content_type\":\"string\",\"expires_in_seconds\":900,\"operation\":\"download\"}"
response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |http| http.request(request) }

using var client = new HttpClient();
using var request = new HttpRequestMessage(HttpMethod.Post, "https://console.neon.tech/api/v2/projects/string/branches/string/buckets/string/objects/string/presign");
request.Content = new StringContent("{\"content_type\":\"string\",\"expires_in_seconds\":900,\"operation\":\"download\"}", Encoding.UTF8, "application/json");
using var response = await client.SendAsync(request);

{
  "expires_at": "2026-06-09T00:00:00Z",
  "headers": {
    "additionalProp1": "string"
  },
  "method": "string",
  "url": "string"
}

{
  "code": "",
  "message": "string",
  "request_id": "string"
}

{
  "code": "",
  "message": "string",
  "request_id": "string"
}