---
title: "Pre-sign a signature image upload for a public proposal"
method: POST
path: "/api/v2/public/proposals/{uuid}/file_presign"
tags: ["Proposals"]
---

# Pre-sign a signature image upload for a public proposal

`POST /api/v2/public/proposals/{uuid}/file_presign`

## Request

- Base URL: `https://developer.productive.io` (the document declares no server; this is the origin it was published from)
- URL: `https://developer.productive.io/api/v2/public/proposals/{uuid}/file_presign`
- Auth: none required

## Path parameters

- `uuid` string, required

## Headers

- `X-Proposal-Token` string

## Request body

- object
  - `data` object
    - `attributes` object
      - `file_name` string: Signature image file name; .jpg, .jpeg or .png
    - `type` 'proposals'

## Response `201`

Pre-signed S3 upload form fields for the signature image

- object
  - `data` object: Upload form fields (policy, signature, key, ...)
  - `links` object
  - `meta` object
    - `page_size` integer

## Other responses

- `400`: Bad Request
- `401`: Unauthorized
- `404`: Not Found
- `408`: Request Timeout
- `415`: Unsupported Media Type
- `422`: Unprocessable Content
- `423`: Locked
- `429`: Too Many Requests
- `500`: Internal Server Error

## Changes

- **2026-11-02** `fa3060fd0144`: 3 warning, 6 info
  - added the new `bad_decimal_format` enum value to the `errors/items/code` response property for the response status `422`
  - added the new `non_finite_number` enum value to the `errors/items/code` response property for the response status `422`
  - added the new `null_bytes_in_params` enum value to the `errors/items/code` response property for the response status `422`
  - added the non-success response with the status `400`
  - …5 more
- **2026-10-27** `f11a8740641a`: 1 info
  - endpoint added
  - …this revision’s changelog is incomplete

[Operation history](https://skmtc.dev/productive/apis/api-documentation/changes/api/v2/public/proposals/:uuid/file_presign/post.md)

---

[API](https://skmtc.dev/productive/apis/api-documentation.md) - [All operations](https://skmtc.dev/productive/apis/api-documentation/llms.txt) - [OpenAPI document](https://skmtc.dev/productive/apis/api-documentation/revisions/e7bdfdf6cba3?raw)