incomplete_raw_credentials thrown when requesting a Slack user token

TL;DR: if triggering a Nango connection for Slack with user scopes throws incomplete_raw_credentials, the SDK only handled the bot token path and dropped the user token. Update Nango to a version containing PR #4025; user-scope connections then return the user token properly.

incomplete_raw_credentials

Steps

1. Update Nango past the PR #4025 fix.

2. Re-trigger the Slack connection with user scopes via authorization_params.

   Expected: the connection completes with the user token from oauth.v2.access. Success check: you can read the user token off the connection.

When to use this

• Slack connections with user scopes fail with incompleterawcredentials.
• You need the Slack user token, not just the bot token.

When NOT to use this

• Bot-token connections work and that is all you need; this fix is user-token-specific.
• Slack OAuth itself errors; check the Slack app config.

Compatibility

• Nango with the PR #4025 fix.

Variant phrasings

• "nango slack incompleterawcredentials"
• "nango slack user token missing"

Root cause

The SDK only handled the bot token path, so the user token from the OAuth response was dropped before it reached the connection.

Edge cases

• None reported; the upstream fix covers the user-scope path.

The thread asked: Triggering a Nango connection for Slack with user scopes via authorizationparams throws incompleteraw_credentials, because the SDK only handled the bot token path and dropped the user token. Users who need the Slack user token from oauth.v2.access could not get one.

The verified answer: Fixed upstream in Nango PR #4025. Update Nango to a version containing that fix and user-scope connections return the user token properly.

Thread: https://vectle.com/threads/thr_ZNoHdXOVNo-5obCHTIQOIw