ERP & accounting
Sage Intacct Construction API and integration guide
Sage Intacct (including the construction edition) is cloud accounting with a REST API, which Sage recommends for new work, and a legacy XML Web Services API. Concurrency, not requests per minute, is the limit you hit first.
Last verified October 2026 against the sources below. Confirm details with Sage before you build.
At a glance
- Category
- ERP & accounting · Sage
- API style
- REST (recommended; Sage says new objects and features ship in REST) plus the legacy XML Web Services gateway, which accepts POST only.
- Authentication
- REST: OAuth 2.0. XML: a Web Services sender ID and password plus company credentials or a session ID. Either way, each customer company must authorize the sender ID under Company > Security > Web Services authorizations.
- Sandbox / developer program
- Sage says the Web Services license is available to Sage Intacct customers and partners; a customer sandbox is an additional module on the subscription. Confirm partner sandbox terms with Sage.
- Webhooks / events
- Partial: Smart Events and platform triggers can send outbound HTTP requests. Sage describes Smart Events as fire-and-forget, with no error feedback or retry.
- Rate limits
- Concurrency by level of service. Under Standard, each company may run one API transaction job and one offline report job at a time; a further request waits 30 seconds and then errors. Higher performance tiers allow more concurrency.
- Exports and files
- CSV imports and exports in the application. Not researched further.
- Marketplace / partner program
- Sage Intacct Marketplace Partner Program.
Key objects for construction workflows
- Projects and tasks
- Cost types
- Standard tasks and cost types
- Change requests
- Project estimates
- Project change orders
- Project contracts
- Vendors
- AP bills
- Purchasing documents
- Timesheets
Notes and gotchas
- The sender ID must be authorized separately in every customer company; a missing authorization fails with “Invalid Web Services Authorization” and is a common go-live blocker.
- Concurrency is per company and shared with the customer's other integrations, so a nightly extract can queue behind someone else's job.
- XML gets no new enhancements; build new work on REST.
Sources
Frequently asked questions
Should I use the Sage Intacct REST or XML API?
Sage recommends REST for new work and says new objects and features are released there. XML still works and remains common in older integrations.
Why does my Sage Intacct integration fail with “Invalid Web Services Authorization”?
The customer company hasn't authorized your sender ID. An admin adds it under Company > Security > Web Services authorizations, in every company you connect to.
What are the Sage Intacct API limits?
Limits are about concurrency. Under the Standard level of service, each company runs one API transaction job and one offline report job at a time; higher performance tiers allow more.
Next step
Connecting Sage Intacct Construction to your other systems?
Bring the systems and the report or workflow you want to fix. We'll walk through what moves, who owns each record, and what to check first.