---
title: "Declare an upload: {key, size_bytes} → a presigned PUT"
method: POST
path: "/preview/storage/{bucket}/objects"
tags: ["storage"]
---

# Declare an upload: {key, size_bytes} → a presigned PUT

`POST /preview/storage/{bucket}/objects`

## Request

- Base URL: `https://autoresearch.sfcompute.com`
- URL: `https://autoresearch.sfcompute.com/preview/storage/{bucket}/objects`
- Auth: HTTP bearer

Declare an upload: {key, size_bytes} → a presigned PUT

## Path parameters

- `bucket` string, required

## Query parameters

- `workspace` string

## Request body

- object
  - `key` string, required
  - `size_bytes` integer, required: Declared upload size; the commit verifies the store agrees.

## Response `200`

The capability's JSON result.

- Result: The capability's result: the same object the MCP tool returns as structuredContent. Resources carry an `object` type discriminator and an immutable id; money is integer micro-dollars in `*_usd_micros` fields.
  - `object` string: The resource type, when the result is one resource.

## Other responses

- `400`: Malformed request: bad JSON, a parameter that does not parse, or a value outside its range. Code `invalid`.
- `401`: No bearer token, or one this API cannot verify. Code `unauthenticated`.
- `403`: Authenticated, but the token's scopes or the account's role do not reach this operation. The message names the scope word to request. Code `forbidden`.
- `404`: No such route. Code `not_found`; the body names the OpenAPI document.
- `422`: A well-formed request the platform declined: no such node, a cap reached, a state that forbids the move. The message says which, and what to do instead. Code `refused`.
- `429`: Over this door's per-customer budget. Wait `Retry-After` seconds. Code `rate_limited`.
- `500`: Our fault. Retry; if it persists, quote the request-id. Code `internal`.

---

[API](https://skmtc.dev/givemeanode/apis/autoresearch-customer-api.md) · [All operations](https://skmtc.dev/givemeanode/apis/autoresearch-customer-api/llms.txt) · [OpenAPI document](https://skmtc.dev/givemeanode/apis/autoresearch-customer-api/revisions/f88dcb70ac6c?raw)