How can I dynamically authenticate Salesforce in n8n using credentials from PostgreSQL?

Below is one approach to automating Salesforce authentication without manual login in n8n:

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1. Use a Non-Interactive Authentication Flow

Instead of relying on the built-in username/password prompt, use a flow that works totally in the background. n8n supports non-interactive Salesforce authentication via either JWT Bearer Flow or OAuth2:

• JWT Bearer Flow: This method uses a signed JWT (with a private key) to request an access token. After you set up a Connected App in Salesforce and generate your digital certificate, you can configure a Salesforce credential in n8n with the required fields (Client ID, username, and private key). Once set, Salesforce will automatically validate your signature and return a token on each run.

• OAuth2 Flow: When configured correctly, OAuth2 can also be automated so that no manual login prompt appears on every run. (Be sure to disable settings such as PKCE or secret requirements if they are not needed.)

Reference: See the Salesforce credentials documentation for detailed steps on both flows.

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2. Dynamically Fetching Credentials from PostgreSQL

Because you maintain multiple schemas with Salesforce credentials stored in your database, you can use this strategy:

1. Fetch Credentials Using a Postgres Node:
   Use a Postgres node to run a SQL query (like your provided example) and pull the necessary Salesforce credential fields (e.g. Client ID, OAuth token, or private key).
   For example:

   SQLCopied
   SELECT username, client_id, private_key FROM app_config WHERE organization_id = $json["organization_id"];

2. Pass the Credentials to a Function or HTTP Request Node:
   Since n8n’s built-in Salesforce node currently expects statically configured credentials, you can build a dynamic solution by:

   • Using a Function or Code node to construct and sign a JWT (if using JWT Bearer Flow) or to construct the OAuth2 request.
   • Then, use an HTTP Request node to call Salesforce endpoints (such as to fetch leads) with the token you obtained in your dynamic authentication step.

   This “manual” approach in the workflow allows you to use credentials fetched from the database without pre-setting them on the Salesforce node.

3. Storing the Fetched Data:
   Once Salesforce data (like leads) is fetched via the HTTP Request or a custom integration, use another Postgres node to insert the data into the organization’s corresponding schema.

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3. Example Workflow Outline

Below is an outline of how your workflow could be structured:

1. Postgres – Get Salesforce Credentials:
   Fetch the necessary authentication details from the organization’s app_config table.

2. Function Node – Build Authentication Request:
   Use JavaScript code to create the JWT assertion (or the OAuth2 refresh request) using the fetched fields.

3. HTTP Request Node – Get Access Token:
   Call the Salesforce token endpoint using your JWT assertion to receive an access token.

4. HTTP Request Node – Fetch Leads Data:
   With the token included in the request header, call the Salesforce API to fetch leads.

5. Postgres – Insert Lead Data:
   Insert the fetched data into the corresponding organization’s schema.

Note: The built-in Salesforce node in n8n uses pre-configured credentials. If you need to pass dynamic tokens, consider using a combination of HTTP Request and Function nodes as shown above.

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Summary

To automate data fetching from Salesforce without manual login, configure your Salesforce authentication to use a background flow like JWT Bearer Flow or a fully automated OAuth2. Since n8n’s built-in Salesforce node does not support dynamically loaded credentials from a database, you can implement a custom sub-workflow that:

• Retrieves the credentials from PostgreSQL,
• Uses these credentials to request an access token,
• Calls Salesforce’s API via an HTTP Request node, and
• Finally inserts the returned data into the appropriate PostgreSQL schema.

This approach keeps your process fully automated from start to finish.

For step-by-step details on setting up Salesforce authentication, refer to the official Salesforce credentials documentation.