---
title: "Set the authenticated user's preferred email locale"
method: POST
path: "/auth/set-locale"
tags: ["Auth"]
---

# Set the authenticated user's preferred email locale

`POST /auth/set-locale`

## Request

- Base URL: `https://api.mnemom.ai/v1`
- URL: `https://api.mnemom.ai/v1/auth/set-locale`
- Auth: API key in cookie `mnemom_session`

Updates `user_metadata.locale` on the Supabase auth user. Locale-aware send paths (billing webhooks, licensing expiry, auth send-email-hook) read this field to choose between English (default), French, German, Italian, and Spanish copy. Cookie session auth required; the change is effective immediately for subsequent email sends.

## Request body

- object
  - `locale` 'en' | 'fr' | 'de' | 'it' | 'es', required: Preferred email locale. Values outside this enum are rejected with `unsupported_locale`.

## Response `200`

Locale updated.

- object
  - `ok` boolean, required
  - `locale` 'en' | 'fr' | 'de' | 'it' | 'es', required

## Other responses

- `400`: Bad request
- `401`: Authentication required
- `403`: Cross-origin write refused (`cross_origin_rejected`). A state-changing request that carries the browser session cookie must come from a first-party origin (`Origin`, or failing that `Referer`) and must not send a form-style body (text/plain, urlencoded, multipart) the operation does not declare. Bearer and API-key callers are never subject to this check.
- `429`: Rate-limit exceeded. The global per-IP limiter (100 requests/minute, applied to every `/v1/*` route) rejected this request. Back off until the window resets — `Retry-After` carries the cooldown in seconds and `X-RateLimit-Reset` the absolute reset time.
- `500`: Server error — request was well-formed but the server failed to fulfill it. Typically a downstream dependency (DB / RPC / external API) returned an unexpected error.
- `503`: An upstream dependency is currently unavailable. The request was not processed; retry after the cooldown window.

---

[API](https://skmtc.dev/mnemom/apis/mnemom-api.md) · [All operations](https://skmtc.dev/mnemom/apis/mnemom-api/llms.txt) · [OpenAPI document](https://skmtc.dev/mnemom/apis/mnemom-api/revisions/274b7a6ea182?raw)