A bridge between Sage 50 and your cloud app.

Sage 50 is accounting software that lives on a Windows PC in your customer's office. It has no web API, so cloud products can't reach it. AcctRelay puts a small agent on that PC and gives your app a REST API to it.

See what it does

Sales Journal — Northwind Supply▫▫✕

FileEditMaintainReports

Invoice	Customer	Amount
10480	Harbour Foods	1,940.00
10481	Maple Tool & Die	812.50
10482	Lakeside Clinic	4,280.00
10483	Bow River Supply	2,105.75
10484	Prairie Dental	655.20

GET /v1/companies/northwind/invoices

{ "number": "10482",

"customer": "Lakeside Clinic",

"total": 4280.00,

"currency": "CAD",

"status": "open" }

What AcctRelay is

The situation

Thousands of small and mid-sized businesses keep their books in Sage 50 desktop — more than 160,000 in Canada alone.¹ Unlike QuickBooks Online or Xero, Sage 50 has no web API. It can only be reached by software running on the same Windows machine.

What happens today

When one of those businesses uses your product, the “integration” is usually a CSV file. Someone exports a report from Sage 50, fixes the columns in Excel and uploads it to your app — every week, by hand.

What AcctRelay does

We're building the missing piece: an agent that runs next to Sage 50 and talks to it through Sage's official SDK, and a cloud API that your app calls like any other. Your app gets customers, invoices, bills and payments as JSON.

Who it's for

SaaS teams whose customers run Sage 50:

Accounts payable and bill pay
Expense and corporate cards
Payroll and time tracking
Field service and construction
B2B ordering and inventory
CRM and reporting tools

How it works

Your customer installs the agent

They click a connect link inside your app and install AcctRelay on the PC or server where Sage 50 runs. It's designed to take a couple of minutes.

They approve access in Sage 50

Sage 50 asks them to allow the connection. They can revoke it at any time. The agent only makes outbound connections — no open ports, no VPN.

Your app calls the API

You read and write Sage 50 data through a normal REST API, and get notified when records change. Your team never touches Windows code.

What it looks like for your developers

REST and JSON: Cursor pagination, clear error messages, a separate key for each connected company.
No Windows code on your side: The agent is built to handle Sage 50's company-file locks, version changes and reconnects.
Change notifications: Webhooks when invoices, bills or payments change — planned for design partners.
Canada first, US next: We start with Sage 50 Canadian Edition. US Edition will use the same endpoints.

# Unpaid invoices from a customer's Sage 50
curl https://api.acctrelay.com/v1/companies/northwind/invoices \
  -G -d status=open \
  -H "Authorization: Bearer $ACCTRELAY_KEY"

# Record a payment back into Sage 50
curl https://api.acctrelay.com/v1/companies/northwind/payments \
  -H "Authorization: Bearer $ACCTRELAY_KEY" \
  -d invoice=10482 -d amount=4280.00 -d date=2026-11-20

const res = await fetch(
  "https://api.acctrelay.com/v1/companies/northwind/invoices?status=open",
  { headers: { Authorization: `Bearer ${process.env.ACCTRELAY_KEY}` } }
);
const { data } = await res.json();

for (const invoice of data) {
  console.log(invoice.number, invoice.customer, invoice.total);
}

import os, requests

r = requests.get(
    "https://api.acctrelay.com/v1/companies/northwind/invoices",
    params={"status": "open"},
    headers={"Authorization": f"Bearer {os.environ['ACCTRELAY_KEY']}"},
)

for invoice in r.json()["data"]:
    print(invoice["number"], invoice["customer"], invoice["total"])

First to build: reading customers, vendors, chart of accounts, items, sales invoices, bills and payments. After that: writing invoices, bills and payments back.

These examples show the planned API. Design partners get a key when their first company is connected.

Why it helps your business

You stop losing Sage 50 prospects

“We support QuickBooks and Xero” is where many Sage 50 deals end. With AcctRelay you can say yes.

The CSV support tickets go away

No more failed imports because a column moved or a date was formatted the wrong way. Data syncs on its own.

Your engineers stay on your product

No one on your team has to learn a 32-bit Windows SDK or keep it working through every new Sage 50 release. That's our job.

Your customers stay in control

They approve access inside Sage 50 and can revoke it any time. AcctRelay passes data through and doesn't keep copies of their books.

Why now

A short note from the person building it.

Hi — I'm Stepan, and I'm building AcctRelay.

Most people assume desktop accounting is disappearing. In Canada it's the opposite. Intuit stopped selling QuickBooks Desktop Pro and Premier to new Canadian customers in April 2025,² and Sage retires BusinessVision at the end of 2026, pointing those customers to Sage 50.³ More of your prospects will be on Sage 50 next year, not fewer.

Yet connecting to Sage 50 still means either CSV files or months of Windows engineering. I think that should take an afternoon, the same way it does for QuickBooks Online.

That's what AcctRelay is for. If you have customers on Sage 50, write to me — email or Telegram — and tell me how you connect to them today.

Stepan Eremin, founder · stepan@acctrelay.com

Is it safe to install?

An unknown program next to the books is a fair worry. So the agent is designed to need as little trust as possible — and your customer decides how far to go.

How the agent is secured

Step 1
Sage demo company
Try everything on the sample company that ships with Sage 50. No real data at all.
No risk
Step 2
A copy of the books
Restore a backup on a spare PC or virtual machine. The live file is never touched.
No risk to live books
Step 3
Live, read-only
Connect the real company through a Sage 50 user with read-only rights. Pick which records to share.
Read-only, chosen data
Step 4
Write back
Turn on creating invoices or payments, one type at a time, when you're ready.
Full integration

Sage enforces the limits

Read-only is a permission on the Sage 50 user, so Sage itself blocks changes — not just our code.

No way in from outside

The agent only connects out to api.acctrelay.com over HTTPS. No open ports, no VPN, no remote desktop.

Visible and reversible

A local log shows every request. Pause or revoke access in one click; uninstall like any Windows program.

What it costs compared with building it

Move the slider to the number of your customers on Sage 50. The invoice shows what AcctRelay would cost you per month.

Building in-house usually means an engineer for about a quarter, plus upkeep for every Sage 50 release
That's roughly $40,000+ in the first year (our estimate)
With AcctRelay you pay only for companies that are connected

Invoice

AcctRelay
No. 0001 · monthly

Item	Amount
Connected Sage 50 companies × $59 20	$1,180.00
Platform fee	$0.00
Setup fee per customer	$0.00

Total per month$1,180

About $14,160 a year, compared with roughly $40,000+ to build and maintain it yourself in the first year.

Questions

Is AcctRelay available today?

Not for production yet. We're building the first version now with a small group of design partners. Pilots start on Sage 50 demo data, then on a copy of the books — never on live data until everyone is ready.

What does my customer need?

A Windows PC or server running Sage 50 Canadian Edition, and a few minutes to install the agent. US Edition comes next.

What happens when Sage releases a new version?

We'll test each new release and update the agent, so your integration keeps working without changes on your side.

How is this different from a local API?

Local APIs run on each customer's server and need network access from your cloud to every installation. AcctRelay's agent connects out to us, so your app calls one endpoint for all customers.

Does it work with Remote Data Access or hosted Sage 50?

A server with the agent installed works the same way as a PC. Remote Data Access and hosted setups still need testing — tell us about your customers' setup.

Is AcctRelay made by Sage?

No. AcctRelay is an independent product built on Sage's official SDK. It is not affiliated with or endorsed by The Sage Group plc.

Start as a design partner

We're taking on 10 SaaS teams for early access. You get the API free while we build it together; after launch it's $59 per connected company, per month.

Become a design partner Message us on Telegram

You get

Free API access during early access
A direct line to the founder
A say in which features come next
Launch pricing locked in

After launch

$59 per connected company / month
No platform fee, no setup fee
Volume pricing from 25 companies
Cancel any time, 14-day refund