How many API calls does OutboundSync use?
When to use this guide: Use this guide when configuring or validating CRM integration behavior.
Some customers ask about OutboundSync’s API utilization to better understand any potential impact on their Salesforce billing or daily API limits.
Summary
Section titled “Summary”OutboundSync uses 2–4 Salesforce API requests per webhook payload it receives. How many payloads you generate depends on which engagement events you enable (sends, replies, opens, clicks, bounces, lead categories, and so on).
As a planning rule of thumb, teams often round up to about 6 API calls per sent email when counting sends plus typical replies, categorizations, and engagement events. For Salesforce edition limits and tier fit, see the Salesforce tier guide.
Per-event request breakdown
Section titled “Per-event request breakdown”| Step | Typical requests | When it happens |
|---|---|---|
| Find Contact/Lead (email or object lookup ID) | 1 | Every payload that needs a person match |
| Create Email or Task activity | 1 | After a match (or after create) |
| Update Contact/Lead fields | +1 | When the sync writes engagement fields on the person |
| Find Company by domain | +1 | When the person is missing and account matching is required |
| Create Contact and/or Company (or attach Company) | +1 | When OutboundSync creates missing records |
Minimum path: find + create activity = 2 requests.
Heavier path: missing contact, company lookup, creates, and field updates = up to 4 requests on a single payload.
You can reduce lookups by pre-loading Contacts and Leads in Salesforce before a campaign starts, so OutboundSync mostly appends activity instead of creating people and accounts. See How OutboundSync queues and prioritizes webhook payloads.
Volume example
Section titled “Volume example”If you send 100 emails, Email Sent events alone are roughly 200–400 API calls (2–4 per payload).
Add replies and lead-category updates — for example a 10% reply rate (10 payloads) plus 10 category updates (10 more). At about 2 requests each for those 20 payloads, that is roughly 80 additional calls.
Opens, link clicks, bounces, and unsubscribes add more payloads. In one illustrative mix that might be another ~120 calls.
Rounded up, that lands near ~600 API calls per 100 emails sent, or about 6 calls per sent email on average when those event types are enabled.
How to check usage in Salesforce
Section titled “How to check usage in Salesforce”- In Salesforce Setup, search for Company Information (or open System Overview, depending on your edition and UI).
- Review API Requests, Last 24 Hours (and related API usage fields) against your org’s daily limit.
- Watch for spikes that line up with large campaign sends or newly enabled high-volume event types (opens/clicks).
- If you are near the limit, reduce optional event types in your engagement webhook config, pre-import contacts, or confirm your Salesforce edition has enough headroom in the Salesforce tier guide.
