Salesforce API Guide for Contractors

One-line verdict: One of the most complete APIs on earth — behind one hard gate: your edition. Below Enterprise, API access is a paid add-on, not a switch. Openness: 4 / 5 — rated 4 because Salesforce documents full read/write API access with events and published limits, held back from 5 by the edition gate that decides whether the API exists for you at all.

The connection that works

Rung 1 — Direct connection. Salesforce’s REST API is documented to the last detail: records can be created, read, updated, upserted, and deleted; queries run in SOQL across standard and custom objects. For a contractor, the standard objects that matter — Accounts (your companies), Contacts, Leads, and Opportunities — all ride the same documented CRUD pattern, with worked examples in Salesforce’s own developer guide (create an account, create a contact, link them). Sign-in runs through OAuth 2.0 via a Connected App or External Client App your admin sets up, and the connecting user’s own permissions decide what it can touch.

The edition gate, in Salesforce’s own words: “API access is enabled by default in Enterprise, Performance, Unlimited, and Developer Edition orgs. Professional Edition orgs can add API access as an add-on.” An org without API access doesn’t degrade gracefully — it returns an error (API_DISABLED_FOR_ORG). Limits are published with equal clarity: a rolling 24-hour call allowance that scales with your licences (for example, Enterprise and Professional-with-API start at 100,000 calls plus 1,000 per licence), and 25 concurrent long-running requests in production.

Events, Salesforce-style: Salesforce doesn’t do classic outbound webhooks; it runs an event system. Its Pub/Sub API publishes and subscribes to platform events and Change Data Capture events — when a record changes, subscribers hear about it — across the same top editions. Functionally that’s your instant trigger; it just arrives wearing a different name, so make any builder quote it by its real one.

Bridge apps: both bridges are real — Zapier lists Salesforce triggers (New Lead, New Contact, New Record, Updated Record — polling) and record actions; Make lists a full module set including Watch Records and Make an API Call. On a platform this open, bridges are convenience, not necessity.

Can automate

• The whole pipeline, both directions — leads, accounts, contacts, and opportunities can be created, updated, and read by your other systems; nothing about the front office has to be re-typed.
• Change-driven follow-up — platform events and Change Data Capture mean a stage change or a new lead can start work elsewhere in near real time.
• Custom objects — if your org models jobs, crews, or properties as custom objects, the same API covers them; the API doesn’t care that Salesforce didn’t invent the object.
• Bulk movement — documented bulk APIs handle the big syncs (imports, reporting pulls) that would choke a record-at-a-time connection.

Can’t automate

• Anything, on an edition without API access — Professional without the add-on gets an error, not a connection. Confirm the edition before quoting any build.
• Core-platform invoicing — UNVERIFIED. No general invoices read/write is verified from the core REST guide in our pass; Salesforce’s billing and invoicing objects belong to separate Salesforce products and editions. Don’t let “Salesforce does invoicing” slide into “the API we have does invoicing.”
• “Webhooks,” by that name — the documented mechanism is Pub/Sub platform events and Change Data Capture. A proposal promising Salesforce webhooks is using the wrong vocabulary for this platform.
• Unlimited calls — the 24-hour allowance is real and licence-scaled; a sloppy sync can burn it and stall every integration at once.

Hidden gate: Your Salesforce edition decides everything — if you’re not on Enterprise or above, the API is a paid add-on, not a switch. Check the edition line on your contract before anyone scopes an integration.

Build fit — what this platform supports well

• Speed-to-Lead — strong fit: leads are first-class API objects, and events make follow-up near-instant.
• Estimate Follow-Up — workable where estimates live as opportunities or custom objects in your org; the API covers the objects, your org’s data model does the rest.
• Invoice Chase / AR — depends on which Salesforce products you actually own; the core platform claim is UNVERIFIED, so the chase usually keys off your accounting system instead.
• Review Engine — like every platform here, Salesforce has no verified reviews API in the documentation we reviewed, so the review ask runs on our system triggered by a job-completion signal.

What this means for your shop

Most small contractors meet Salesforce as the CRM somebody sold them, not a construction tool — but if it’s already your system of record, openness isn’t your problem. Your problem is the edition line and the admin who controls the Connected App. Confirm both, and Salesforce will connect to practically anything you own. Skip the check, and the first invoice you get is for the add-on that makes the API exist.