Salesforce Custom REST API Endpoint Caller

Overview

A generic, reusable Power Automate cloud flow that acts as a thin wrapper around the Salesforce connector's HttpRequest action. It accepts a REST endpoint path, HTTP method, and optional JSON body as manual trigger inputs, calls any Salesforce REST API (standard, Apex, Chatter, Bulk, Metadata, Tooling, Analytics), and writes a full audit record of the call to a Dataverse log table.

Because the Salesforce connector handles authentication, this flow can call any Salesforce REST endpoint without ever embedding OAuth tokens, session IDs, or security tokens in the flow definition. It turns Power Automate into a zero-config "Salesforce REST console."

Use Case

Every call is logged to a Dataverse table — endpoint, method, request body, response body, status code, timestamp — giving you an audit history without instrumenting individual flows.

The flow is ideal for teams that:

• Custom Apex REST endpoints — call /services/apexrest/MyService/doWork without building a dedicated flow per service.
• Connector gap-filling — hit any REST API the Salesforce connector doesn't expose as a first-class operation (Metadata API, Tooling API, Chatter, Analytics, Bulk v2).
• Ad-hoc admin queries — run arbitrary SOQL via /services/data/{v}/query?q=... when you don't want to build a flow around one-off data pulls.
• Diagnostic tooling — support engineers can POST to /services/data/{v}/sobjects/... to repair records with a full audit trail, instead of logging into Salesforce directly.
• Integration prototyping — quickly test the shape of a Salesforce API response before wiring it into a larger flow.

Flow Architecture

Environment Variables

Connectors & Connections

Note — All connections are referenced as solution connection references; the flow is portable between environments as long as a connection is mapped at import time.

Customization Guide

Almost every realistic variant of this flow can be implemented by changing environment variable values. A few cases require small edits inside the flow definition — those are called out explicitly below.

Change the Salesforce API version

Update the default value of flowlibs_SalesforceRestApiVersion in each environment where the solution is imported. Callers are responsible for embedding the version in their endpoint paths; the variable exists as a documented anchor.

Log failures as well as successes

Change the Log_Call_To_Dataverse action's runAfter clause to include Failed, and swap the status code expression for one that reads from the error output when the call fails.

Add header support

The Salesforce connector's HttpRequest operation exposes a Headers parameter. Wire a fourth trigger input or a variable to pass custom headers (e.g. Sforce-Auto-Assign: FALSE, or a custom locale).

Return the response to the caller

Append a Response (HTTP response) action that returns outputs('Call_Salesforce_Rest_Api')?['body'] with status @{outputs('Call_Salesforce_Rest_Api')?['statusCode']}. This lets you wrap the flow as a callable HTTP endpoint.

Restrict who can call arbitrary endpoints

A button trigger is only as secure as the people with access to run it. For untrusted callers, replace the manual trigger with a solution-aware HTTP trigger and validate the incoming method/endpoint against an allowlist before the Salesforce call.

Extend the log schema

Add columns for CalledByUser (bound to @{triggerOutputs()?['headers']?['x-ms-user-email-encoded']}) or CorrelationId for cross-system tracing.

Key Expressions

The flow is intentionally light on Power Fx / WDL gymnastics — the heaviest expressions are the branch-name concatenation and the approval outcome check. They are listed below in the order they appear in the flow.

@triggerBody()?['text']
@triggerBody()?['text_1']
@triggerBody()?['text_2']

@toUpper(triggerBody()?['text_1'])

@coalesce(triggerBody()?['text_2'], '')

@substring(string(outputs('Call_Salesforce_Rest_Api')?['body']), 0, min(length(string(outputs('Call_Salesforce_Rest_Api')?['body'])), 99000))

@coalesce(outputs('Call_Salesforce_Rest_Api')?['statusCode'], 200)

@concat(variables('varMethod'), ' ', variables('varEndpoint'), ' @ ', utcNow())