Why does this integration use Stampli's SFTP instead of a REST API?

Stampli does not publish a public REST API; file-based SFTP integration is the only third-party path available without a formal partnership agreement. ml-connector polls Stampli's SFTP outbound directory on a schedule and translates CSV payloads into Sage 300's REST schema on each pull.

How does Sage 300's HTTP Basic Auth work in this integration?

Every Sage 300 API call requires an Authorization header with base64-encoded USERNAME:PASSWORD credentials; both must be uppercase. ml-connector stores the credentials encrypted, prepends the Basic Auth header on every request, and validates that the Sage 300 user account is configured in Administrative Services with the Web API security group assigned.

How are vendors and GL accounts mapped between the two systems?

ml-connector aligns vendor master data first before posting invoices, matching Stampli vendor names to Sage 300 APVendor records by name or external ID. GL account codes on each invoice line are validated against Sage 300's GLAccounts before posting; mismatches are logged and can be corrected and replayed without re-processing the entire file.

Sage 300Stampli

Sage 300 and Stampli integration

Sage 300 runs your accounting and procurement. Stampli automates your invoice capture and approval workflows. Connecting the two moves approved invoices from Stampli directly into Sage 300 without manual re-entry, and sends payment confirmations back to Stampli so your AP process is end-to-end. ml-connector handles the SFTP-to-REST bridge and keeps both systems in sync on your schedule.

How Sage 300 works

Sage 300 exposes vendors, AP invoices, payments, GL accounts, purchase orders, and items through REST and OData endpoints hosted on your own Windows IIS server. The API uses HTTP Basic Authentication with base64-encoded USERNAME:PASSWORD credentials sent with every request; both username and password must be uppercase. The API requires an Sage 300 user account configured in Administrative Services with the Web API security group assigned. The API supports OData filtering ($filter), pagination ($skip, $top), and ordering on list endpoints. Sage 300 has no webhook or change-data-capture system, so integration requires polling on a defined schedule.

How Stampli works

Stampli provides invoice, vendor, and payment data through SFTP-only file-based integration; Stampli does not publish a public REST API. Customers pull exported invoices and payment records from Stampli's SFTP outbound directory as flat files in CSV or XML format on a polling interval. Stampli maintains no sandbox environment for third-party testing, and all partner access requires coordination with Stampli support. Stampli includes built-in duplicate detection for invoices, but file-based integrations should implement their own dedup logic. Authentication is SFTP credentials (hostname, port, username, password) only; there is no API key or OAuth2 option for file-based integrations.

What moves between them

The main flow is Stampli into Sage 300. After Stampli's approval workflows complete, ml-connector polls Stampli's SFTP directory for newly exported invoice CSV files, translates them to Sage 300 APInvoiceBatches, and posts them into Sage 300's general ledger via REST. Vendor master data is synced first, ensuring every invoice references a valid Sage 300 APVendor. Payment confirmations flow back from Sage 300 into Stampli via CSV files deposited in Stampli's inbound SFTP directory so Stampli's records reflect which invoices have been paid. The polling cadence is configurable (typically every 15 minutes) and independent of either system's internal refresh rates.

How ml-connector handles it

ml-connector stores Sage 300 HTTP Basic Auth credentials and Stampli SFTP credentials encrypted. On each poll interval, it connects to Stampli's SFTP server, retrieves new invoice and payment export files, parses the CSV payload, and translates each row to a Sage 300 APInvoice entity. It then calls Sage 300's REST API with Basic Auth headers, matching Stampli vendors to Sage 300 APVendors by name or external ID and validating GL account codes before posting. Because both systems are poll-only, ml-connector watches for duplicate invoices using an internal dedup key (Stampli invoice ID + vendor) and skips re-posting if a match is found. Vendor master data is aligned first so invoice posting succeeds; GL account mismatches are logged and can be corrected and replayed. SFTP connectivity issues trigger exponential backoff retries, and every invoice carry a full audit trail recording the Stampli source file, the API calls made, and the Sage 300 batch and document IDs assigned.

A real-world example

A mid-sized manufacturing distributor runs Sage 300 for AP, GL, and POs, and uses Stampli to automate invoice receipt and approval. Before the integration, the AP team exported approved invoices from Stampli weekly and manually entered them into Sage 300, a process that introduced re-keying errors and delayed GL posting. The finance team spent week-end time chasing invoice discrepancies and month-end close was delayed waiting for all invoices to be hand-entered. With Stampli and Sage 300 connected, approved invoices post directly into Sage 300's GL on the same day Stampli approves them, payments flow back to Stampli so the approval chain stays current, and month-end close begins with all invoices already in the ledger.

What you can do

Poll Stampli SFTP for approved invoices and translate CSV payloads into Sage 300 APInvoiceBatches posted to the general ledger.
Keep Sage 300 vendors aligned with Stampli vendor master data so invoices post to valid AP accounts.
Send payment confirmations from Sage 300 back to Stampli via SFTP so Stampli's records reflect paid invoices.
Authenticate Sage 300 with HTTP Basic Auth and Stampli with SFTP credentials, both encrypted.
Detect and skip duplicate invoices across polls, with a full audit trail of every CSV record translated and every REST call made.

Questions

Why does this integration use Stampli's SFTP instead of a REST API?: Stampli does not publish a public REST API; file-based SFTP integration is the only third-party path available without a formal partnership agreement. ml-connector polls Stampli's SFTP outbound directory on a schedule and translates CSV payloads into Sage 300's REST schema on each pull.
How does Sage 300's HTTP Basic Auth work in this integration?: Every Sage 300 API call requires an Authorization header with base64-encoded USERNAME:PASSWORD credentials; both must be uppercase. ml-connector stores the credentials encrypted, prepends the Basic Auth header on every request, and validates that the Sage 300 user account is configured in Administrative Services with the Web API security group assigned.
How are vendors and GL accounts mapped between the two systems?: ml-connector aligns vendor master data first before posting invoices, matching Stampli vendor names to Sage 300 APVendor records by name or external ID. GL account codes on each invoice line are validated against Sage 300's GLAccounts before posting; mismatches are logged and can be corrected and replayed without re-processing the entire file.

Connect Sage 300 and Stampli

Free to use. Add your credentials, ping your real systems, and see if we fit.

Get started