---
title: "OAuth 2.1 token endpoint (code exchange + refresh)"
method: POST
path: "/oauth/token"
tags: ["OAuth"]
---

# OAuth 2.1 token endpoint (code exchange + refresh)

`POST /oauth/token`

## Request

- Base URL: `https://api.mnemom.ai/v1`
- URL: `https://api.mnemom.ai/v1/oauth/token`
- Auth: none required

Exchanges an authorization code (+ PKCE code_verifier) for a short-lived opaque access token and a rotating refresh token, or rotates a refresh token. Authorization codes are single-use; refresh tokens are single-use (rotated on every exchange). Public-client posture: no client authentication (token_endpoint_auth_method=none).

## Response `200`

Token response (RFC 6749 §5.1).

- object
  - `access_token` string, required
  - `token_type` 'Bearer', required
  - `expires_in` integer, required
  - `refresh_token` string
  - `scope` string

## Other responses

- `400`: OAuth error (invalid_request / invalid_grant / unsupported_grant_type / authorization_pending / slow_down / expired_token / access_denied).
- `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.

---

[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)