n8n-nodes-jumia

Custom n8n community node for the Jumia Vendor API, with automatic
access-token refresh using Jumia's rotating refresh token flow.

How the token rotation works

Jumia's flow:

1. You register your app and get a client_id + an initial refresh_token.
2. Exchanging a refresh token for an access token also returns a new
   refresh token — the one you used is now invalid.
3. So every refresh must persist the new refresh token, or the next
   refresh attempt will fail.

This package handles that with n8n's preAuthentication hook on the
credential type (JumiaOAuth2Api.credentials.ts):

• Before every API call, it checks if the cached access token is expired
  (or about to expire, with a 60s buffer).
• If so, it calls Jumia's token endpoint using the currently stored
  refresh token (falling back to the initial one on first run).
• It returns the new accessToken, refreshToken, and expiresAt —
  n8n automatically merges these into the encrypted credential and
  persists them, so the next execution (even in a different workflow)
  picks up the latest rotated token.

You don't need any manual refresh logic in the node itself — every node
that uses the jumiaOAuth2Api credential gets this for free.

Token endpoint (confirmed against Jumia's docs)

• Endpoint: POST https://vendor-api.jumia.com/token
• Content type: application/x-www-form-urlencoded
• Request fields: grant_type=refresh_token, client_id, refresh_token
  (no client_secret — this is the "Self Authorization" flow, distinct
  from the Web Application/authorization_code flow which never receives
  a refresh token at all)
• Response fields: access_token, refresh_token, expires_in,
  refresh_expires_in

The code also tracks refresh_expires_in and logs a warning if the
refresh token itself is within 24h of expiring — a sign the credential
hasn't been used recently and may need re-authorizing from the Manage
Applications screen in Jumia's vendor UI.

The example Jumia.node.ts only implements a placeholder "Get Order" /
"Get Many Orders" operation to prove the credential wiring works end to
end. Add whatever resources/operations (products, orders, returns, etc.)
you actually need.

Build & install (self-hosted n8n)

npm install
npm run build

Then either:

• Publish to npm and install via n8n's Settings → Community Nodes, or
• For local dev: symlink or copy the built package into your n8n instance's
  custom nodes directory (~/.n8n/custom/ by default) and restart n8n.

Setting up the credential

In n8n, create a new Jumia OAuth2 API credential:

• Client ID: from your Jumia app registration
• Initial Refresh Token: the refresh token Jumia gave you at registration

Leave the auto-managed fields (Access Token, Refresh Token, Expires At,
Refresh Token Expires At) empty — the node fills them in on first use and
keeps them updated.

There's no "Test" button behavior on this credential (n8n's built-in
credential tester doesn't run preAuthentication first, so it can't
exercise the refresh flow correctly). Verify a new credential by running
the Jumia node once instead.

Caveat

This relies on n8n's credential store being writable from
preAuthentication (standard in modern n8n, self-hosted or cloud). If
you're on an older n8n version that doesn't support preAuthentication,
you'd need to fall back to manual token handling inside the node's
execute() method plus n8n's REST API to persist credential updates.