eFax APIConnect eFax without building on its API
eFax has a REST API (the eFax Enterprise API) with webhooks. eFax opens the Enterprise API to eFax Corporate accounts and trusted partners rather than to anyone with a developer login. Each integration gets an API key and App ID, which it exchanges for a bearer token. If you're reading the docs because you need eFax to talk to the rest of your stack, Caddi does that without you writing or maintaining integration code: you show the job on a screenshare or describe it in chat, and it runs across eFax and your other tools.
The differenceBuilding on the eFax API gets you one connection your team then maintains. Caddi runs the whole job across eFax and every tool it touches, including the screens with no API, and keeps it running when fields change.
- APIREST (JSON)
- AuthOAuth 2.0
- AccesseFax Corporate accounts
What the eFax API gives you
- Type
- REST (JSON)
- Authentication
- OAuth 2.0 (API key and App ID exchanged for a bearer token)
- Who can get access
- eFax opens the Enterprise API to eFax Corporate accounts and trusted partners rather than to anyone with a developer login. Each integration gets an API key and App ID, which it exchanges for a bearer token.
- What it covers
- Sending faxes, downloading fax images and metadata, searching sent and received faxes, deleting faxes, and webhooks for inbound and outbound fax notifications; a separate Admin API handles account provisioning and numbers.
Official docs: docs.efaxcorporate.com. Checked October 2026. Vendors change access terms, so confirm with eFax before you build.
Building on the eFax API vs. having Caddi run it
| The job | Build it on the API | With Caddi |
|---|---|---|
| Getting access | Register an app, get eFax credentials, and manage tokens and refreshes. | Connect your eFax account once. Caddi holds the connection. |
| Writing the integration | A developer maps fields, handles pagination, retries and rate limits, and writes the sync. | You show Caddi the eFax task the way you'd train a new hire. It writes verified code for it. |
| Steps the API doesn't cover | Screens with no endpoint stay manual, or need a separate RPA tool. | Caddi uses a secure, audited browser session where there's no API, in the same automation. |
| The other systems in the loop | Each extra tool is another API, another set of credentials, another integration to own. | One automation runs across all the tools the job touches. |
| Keeping it running | Someone owns the code when the API version, fields or your process change. | Every automation is reviewed before it runs in production, and every run is logged. |
Building on the API is the right call when you have engineers and the integration is your product. When the goal is getting eFax work off someone's desk, the build is the slow part.
What teams usually want the eFax API for
File inbound faxes
Caddi reads each inbound eFax, identifies the client or matter, and files it in the right system.
Extract and update records
Caddi pulls the fields from a faxed form and updates the client record in the CRM.
Send from workflow
Caddi sends the outbound eFax and confirms delivery back in Outlook.
eFax API questions
Does eFax have an API?
Yes. eFax has a REST API (the eFax Enterprise API) with webhooks, authenticated with OAuth 2.0 (API key and App ID exchanged for a bearer token). The official documentation is at https://docs.efaxcorporate.com/API/content/index.htm.
How do I get access to the eFax API?
eFax opens the Enterprise API to eFax Corporate accounts and trusted partners rather than to anyone with a developer login. Each integration gets an API key and App ID, which it exchanges for a bearer token.
Can I connect eFax to my other tools without writing code against its API?
Yes. With Caddi you show the eFax task once, the way you'd train a new hire, and Caddi builds it as verified code that runs across eFax and the other tools the job touches. Where a step has no API, Caddi uses a secure, audited browser session in the same automation.
Do I need a developer to automate eFax with Caddi?
No. There is no integration code for you to write or maintain. Every automation Caddi builds for eFax is reviewed before it runs in production, and every run is logged.
Connect eFax without the build.
Drop your work email and pick a time. We'll show you Caddi running your eFax workflow end to end.