Overview
Siteline integrates with Foundation to help subcontractors streamline billing workflows without double entry. With this integration, teams can:
Import projects from Foundation into Siteline
Optionally import SOVs and change orders
Manage billing and pay apps in Siteline
Sync invoices back to Foundation via API
Use file-based exports for advanced or AIA-level detail when needed
Siteline is designed to be the system of record for billing workflows, while Foundation remains the system of record for accounting and posting.
This integration supports both hosted (cloud) and on-premise Foundation instances and is powered by a third-party API provider, Agave.
Ideal Workflow: Foundation <> Siteline
High-level flow
Foundation >> Siteline
Link an existing Foundation job during project creation
Import project data (job number, name, GC, address, terms)
Import contract retention
Optionally import SOVs and change orders
Siteline
Complete project setup
Manage SOVs, change orders, and billing
Generate pay apps and invoices
Siteline >> Foundation
Sync invoices via API (summary-level by design)
Retention amounts are included on synced invoices
Post invoices in Foundation
Retention-only invoices are not supported due to Foundation API limitations
This workflow keeps project teams and AR teams working in Siteline, while accounting maintains posting control in Foundation.
Importing Projects from Foundation
Linking a project
When creating a new project in Siteline:
Select + New Project, choose Project Type, and select Foundation as the ERP
2. Search for an existing Foundation job
3. Click Import project(s).
Siteline pulls in available project data automatically.
Imported project data includes
Job number > Internal Project #
Job description > Project name
Customer > General contractor
Job address > Project address
Payment terms > Net terms
Contract retention %
SOVs & Change Orders: How They’re Handled
SOV import (supported, with caveats)
If a Foundation job is set up for AIA billing, Siteline can import the SOV during project onboarding.
Important caveats to understand:
SOV import is supported
API invoice sync does not write back to Foundation’s AIA billing module
Because of this, many customers prefer to:
Build or refine their SOV directly in Siteline
Use Siteline as the source of truth for ongoing billing
Bottom line: SOV import works and can be useful for onboarding, but Siteline is designed to own the billing structure going forward.
Change orders
Change orders can be imported from Foundation
Imported change orders appear as SOV line items in Siteline
Ongoing billing and changes should be managed in Siteline after import
Syncing Invoices from Siteline to Foundation (API)
Once billing is complete in Siteline, invoices can be synced directly to Foundation using the API-based integration.
How invoice sync works
Open the project in Siteline
Open the pay app you want to sync and head to the Invoice tab
3. Click Sync invoice to Foundation
4. Review and confirm invoice details
5. Click Sync
Siteline sends the invoice to Foundation, where it can then be reviewed and posted by accounting.
Invoice details you’ll confirm during sync
During the sync dialog, Siteline prompts you to confirm or select:
Invoice date
Due date
Defaults based on the payment terms imported from Foundation
Can be adjusted before syncing
Invoice number
Default: generated by Siteline using project number + pay app number
Optional: click Generate from Foundation to use the next available Foundation invoice number
GL account
Income type (e.g., Commercial, T&M)
Once selected, the GL account and income type are remembered for future pay apps on the same project, reducing repeat setup.
Summary-level sync (by design)
Invoice syncing via API is summary-first by design:
SOV line items are collapsed
Foundation receives invoice totals grouped by ledger and cost type
This ensures reliable posting while keeping Siteline as the billing system of record
Customers who require full AIA-style line detail in Foundation should use the file-based export options described later in this guide.
Retention handling
Retention behavior is important to understand:
Siteline calculates and displays retention accurately
Retention-held amounts are included directly on invoices synced to Foundation
Retention percent and amount are written to the Foundation invoice during sync
What to know about limitations:
Retention values cannot be adjusted programmatically after syncing
Retention-only invoices cannot be synced via API due to Foundation limitations
All retention must be billed as part of a standard invoice, not separately
Editing or re-syncing an invoice
If an invoice needs to be changed after syncing:
Void the invoice in Foundation
Revert the pay app to Draft in Siteline
Make updates
Sync again
If you want to reuse the same invoice number, the original invoice must be voided first in Foundation before re-syncing.
Field Mapping Summary
Foundation >> Siteline (Project Import)
Foundation Field | Siteline Field | Notes |
Job Number | Internal Project # | Primary identifier |
Job Description | Project Name | Editable post-import |
Customer | General Contractor | Required |
Job Address | Project Address | Must exist for bulk import |
Payment Terms | Net Terms | Drives due date logic |
Retainage % | Contract Retention | Imported automatically |
Siteline >> Foundation (Invoice Sync)
Siteline Field | Foundation Target | Notes |
Invoice number | AR Invoice | Siteline-generated/ Foundation-generated |
Invoice date | Invoice Date | Editable at sync |
Due date | Due Date | Based on terms |
Invoice total | Invoice Amount | Summary-level |
GL account | GL Income | Selected at sync |
Income type | Income Type | Persisted per project |
Retention | Retention field | Must be applied manually |
Advanced Option: File-Based Invoice Exports (Optional)
Some customers require more granular invoice detail in Foundation, especially when continuing to rely on Foundation’s AIA Billing module.
For these cases, Siteline supports file-based exports, which are separate from the API workflow.
When to use file-based exports
Use file-based exports if you:
Need AIA-style line-item detail in Foundation
Rely on Foundation’s A/R AIA Billing module
Want a fallback or transitional workflow
Option 1: FSI Importer (Total-only invoices)
Best for customers who:
Post invoices in Foundation using totals only
Do not maintain detailed SOVs in Foundation
Workflow:
Open a pay app in Siteline
Click Invoice >> Export >> Export to Foundation Software
Select FSI Importer
Download the CSV
Import using Foundation’s FSI Importer tool
This creates a standard A/R invoice using the total amount only.
Option 2: Import Genies (AIA Billing detail)
Best for customers who:
Use Foundation’s Add/Edit AIA Billings
Need line-item detail per SOV line
One-time setup:
Import the Siteline AIA Import Genie (.FGF file) into Foundation
Ongoing workflow:
Export pay app from Siteline using Genie Import
Open Foundation >> Accounts Receivable >> Add/Edit AIA Billings
Select the job
Import the CSV using the Siteline AIA Import Genie
Review and post
This preserves AIA-style billing detail in Foundation.
FAQ
Do I need to import SOVs from Foundation?
No. SOV import is supported, but many customers prefer to build and manage SOVs directly in Siteline.
Can Siteline sync detailed AIA billing via API?
Not currently. API sync is summary-level by design.
Can I export retention-only invoices?
No. Foundation limitations prevent exporting retention-only invoices.
Can I link multiple Foundation contracts to one Siteline project?
No. One Siteline project links to one Foundation job.
What happens if bulk import fails?
Bulk import requires a job address in Foundation. Single-project imports may still succeed without one.
Appendix: Screenshot Field Mapping
This is what a job looks like in Foundation before importing into Siteline:
These screenshots show what the above project looks like when imported from Foundation into Siteline. (To import a project, select “New project” on the homepage. Next, in the modal box that pops up: select the project type, select the ERP you want to import the project from, and then search for your desired project in the search bar.):
This is where the SOV is imported from in Foundation (if applicable — some customers do not track their SOVs in Foundation at all):
This is what the imported SOV looks like in Siteline:
This screenshot shows what an invoice looks like after updating billing in Siteline and before syncing over to Foundation (To sync an invoice, you can click the “Sync invoice to Foundation” button shown in the top right corner of the screenshot below):
These screenshots show what newly generated invoices look like in Foundation after syncing from Siteline
This screenshot shows what a Vendor would look like after importing from Foundation to Siteline:
The following screenshots show how Siteline can import posted AP invoices from Foundation for your associated vendors. The screenshots show what a posted invoice looks like in Foundation, and the flow for importing that invoice into Siteline:
