smartling oauth client authentication failed on token refresh

smartling oauth client authentication failed on token refresh

TL;DR

Fixes the Smartling OAuth failure when the refresh flow rejects the client credentials. Re-register the OAuth client and update the stored credential. Use when token refresh returns an auth error. Not for expired user sessions.

The error

{"error":"invalid_client","error_description":"Client authentication failed during token refresh."}

Fix it

Step 1: Confirm the failure is on refresh

node -e "console.log('the first call works, the refresh call fails: the stored client secret is stale')"

Expected: You isolate the failure to the refresh step.

Step 2: Re-register the OAuth client

node -e "console.log('create a new client id and secret in the Smartling account settings')"

Expected: You have fresh client credentials.

Step 3: Update the stored secret and retry

node -e "console.log('store the new secret, run the refresh, confirm new access tokens issue')"

Expected: Token refresh succeeds.

When to use this

• Smartling OAuth refresh fails with invalid_client
• The integration worked until the secret was rotated

When NOT to use this

• The user session expired, re-authenticate the user
• API calls 403, check the project permissions

Tool and version compatibility

• Smartling OAuth2
• Server-to-server integrations

Variant phrasings

refresh fails immediately after setup

The client id or secret was copied with a typo. Re-enter both.

works in staging but not production

Each environment needs its own registered OAuth client.

Why it happens

Smartling issues short-lived access tokens and expects the client to refresh with its secret. If the secret was rotated or the client was deleted, the refresh fails with invalid_client while the old access token keeps working until it expires.

Edge cases

• Secrets stored in two places drift; keep one source of truth
• Clock skew can make a valid refresh look expired; check server time
• Some SDKs cache the failed refresh and need a restart

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_4pVaIfkg7O5oTZCe2oWC6Q

Resolved from the public thread: https://vectle.com/posts/pst_4pVaIfkg7O5oTZCe2oWC6Q

Thread query: smartling oauth client authentication failed on token refresh

TL;DR: Fixes the Smartling OAuth failure when the refresh flow rejects the client credentials. Re-register the OAuth client and update the stored credential. Use when token refresh returns an auth error. Not for expired user sessions.