# Replace the storefront builder draft

`PUT /api/v1/online-store/draft`

Replaces the working draft. The live storefront is untouched until you publish. THE WHOLE DOCUMENT REPLACES THE STORED ONE. There is no merge and no partial update: read GET /api/v1/online-store, change what you mean to change, and send the result back. expected_updated_at IS REQUIRED. This document is a singleton, so you, the merchant's dashboard and every other integration are writers on one row, and a write naming no version would overwrite work nobody knows was lost. Send null only when you believe the store has no configuration at all; otherwise send the updated_at you last read. A mismatch is 409 config_modified, and the fix is always the same: re-read, re-apply your change, re-send.

## Headers

- `Idempotency-Key` (string, required) — A unique key per logical write. Replaying a request with the same key returns the first response byte for byte instead of applying the write twice.

## Request body

Required.

- `schema_version` (integer, required) — The builder document format. A version this backend does not know is a 400 rather than a document stored and rendered as nothing.
- `draft` (object, required) — The whole builder document, which REPLACES the stored draft. It is opaque to this API: no field of it is validated beyond being a JSON object within the 512 KB bound, and nothing is merged. Read GET /api/v1/online-store, edit, send it all back.
- `expected_updated_at` (string | null, required) — The updated_at you last read. NULL asserts that this store has no configuration at all, which is the only way a first write can name a version that does not exist; it is refused the moment a row does exist, so it cannot be used to skip the check. A mismatch is 409 config_modified.

## Responses

- `200` — Success
- `400` — The request was refused before any state changed. `code` is one of:

`invalid_body`, a write body this route will not take. `reason` partitions it
and `field` names the key when one key is at fault.
`invalid_query`, a query parameter, including limit and after.
`invalid_text`, a NUL byte or bytes that are not valid UTF-8 anywhere in the
path, the query or the body. Strip control characters before sending.
`idempotency_key_required`, a write sent without the Idempotency-Key header.
`invalid_request`, an Idempotency-Key longer than 255 bytes.

Routes add their own codes for rules only they know. Switch with a default arm.
- `401` — No credential, or one this API does not accept. `code` is always
`unauthorized`.

THE BODY IS DELIBERATELY UNINFORMATIVE. An expired key, a revoked key, a
publishable key, a key belonging to another merchant and a key that never
existed are all refused with the same bytes, so this response cannot be used to
probe which keys exist. Check the key's state in the dashboard rather than
inferring it here.

Send the key as `Authorization: Bearer <key>` or as `X-API-Key: <key>`. It is
never accepted in a query string.
- `403` — The key lacks the write_storefront scope. `code` is `insufficient_scope` and the message names the scope to ask the merchant for.
- `409` — The request is well formed and the store's current state refuses it.

EVERY WRITE CAN ANSWER TWO OF THESE, whatever it does:
`idempotency_key_reused`, this Idempotency-Key already served a different
method, path or body. The key namespace is per store and not per endpoint, so a
key built from a business id collides across routes; use a fresh key per
logical write.
`idempotency_key_in_progress`, an identical request is still running. Retry
after a short delay; exactly one of the racing calls will have applied.

`not_configured` means the merchant has not set something up yet, with
`resource` naming what. The remaining codes are the per-route state rules named
on the operation.
- `413` — The request body exceeded the cap named in the message. `code` is
`payload_too_large`. Nothing was read and nothing was recorded, so the same
Idempotency-Key may be reused once the body is smaller.
- `415` — The body was not declared as `application/json`. `code` is
`unsupported_media_type`.

This API reads ONE media type. The `+json` structured suffixes are refused
too, because they name semantics (merge-patch in particular) this API does
not implement, and reading such a body as plain JSON would be a silent
misreading. A write that carries NO body needs no Content-Type at all.
- `422` — An id INSIDE the request resolves to nothing on this store. `code` is
`unprocessable_reference`, `resource` names the kind of thing that did not
resolve and `field` names where it arrived, so the fix is mechanical.

Distinct from 404, which is about the url, and from 400, which is about the
bytes. The message stays generic about WHY the id did not resolve: an id owned
by another merchant must read identically to one that never existed.
- `429` — Too many requests. `code` is `rate_limited`.

Two limits apply independently: one on the credential and the route family,
one on the client address. The headers describe whichever has less left, so
honouring Retry-After always clears the window that bound.
- `default` — Any status this operation does not list, in the same envelope.

A 5xx means the request may or may not have applied. Retry it with the SAME
Idempotency-Key: that is the only way to find out without risking a duplicate,
and it is what the key is for.

A few 4xx conditions arrive here rather than as a listed status because they
depend on the merchant's plan or on a module being wired: 402 when a quota or a
plan limit is reached, and 503 when a capability the route needs is not
configured on this deployment. Both carry a `code` naming which.

## Example

```bash
curl --request PUT \
  --url 'https://api.mercemur.com/api/v1/online-store/draft' \
  --header 'Authorization: Bearer <token>'
```