Build Production-Grade Accounting Automation with Python
Yes, you can replace accounting workflows with custom Python automation for greater reliability and control. This approach connects systems via direct API calls, not a third-party platform that charges per task.
Scope depends on the number of systems and the complexity of the business logic. Reconciling invoices from Stripe against QuickBooks is simpler than a three-way match between a custom ERP, bank statements, and a supplier portal. We work best with systems that have modern APIs.
We built a reconciliation system for a 15-person e-commerce business processing 3,000 orders per month. Their two-day manual process to match Shopify payouts, Stripe fees, and QuickBooks entries was a bottleneck. Our Python service automated it, running in 90 seconds, and was deployed in three weeks.
What Problem Does This Solve?
Point-and-click automation tools are great for simple triggers, like posting a Slack message when an invoice is paid. But they fail with multi-step financial logic. Error handling is often limited to "retry once, then stop," which is insufficient for business-critical processes like month-end close. A single failed step can halt the entire workflow with no clear path to resume.
A 20-person agency tried to automate invoice creation. When a project was marked "complete," a workflow was supposed to create a QuickBooks invoice, calculate a 5% commission, and schedule a payment. The platform's QuickBooks connector timed out on invoices with more than 30 line items. The logic for calculating tiered commissions required nested conditional paths that became an unmanageable, 50-step visual diagram.
These platforms charge per "task" or "operation." A single reconciliation workflow that reads 100 transactions, checks each against an accounting ledger, and logs the result can burn through 200 tasks. At 500 invoices a month, this becomes 100,000 tasks, pushing you into an expensive enterprise plan for what is functionally a small script. The business model penalizes volume and complexity.
How Does It Work?
We start by mapping your entire accounting process, field by field. We use httpx to make asynchronous calls directly to the APIs for your ERP (like NetSuite) and payment processor (like Stripe). We build a data model using Pydantic to validate every transaction record, catching formatting errors that would crash a less resilient system. This initial mapping takes about 3 days.
The core logic is a set of Python functions orchestrated by a FastAPI service. For a three-way reconciliation, one function fetches Shopify payout reports, another pulls Stripe transaction data, and a third queries QuickBooks invoices. We handle API rate limits with exponential backoff and cache immutable data like product SKUs in a Supabase Postgres database to reduce API calls by up to 70%.
The FastAPI application is deployed as a container on AWS Lambda, triggered on a schedule or by a webhook. This serverless architecture means you pay only for the 90 seconds it runs each day, often under $20 per month. We implement structured logging with structlog, sending detailed error reports with transaction IDs directly to a dedicated Slack channel for immediate, actionable alerts.
For one client, we processed 15,000 transactions from their bank feed against 4,000 invoices in their custom ERP. The full reconciliation runs in under 2 minutes. The system identifies discrepancies down to the cent, flagging them for manual review. The previous manual process took a staff accountant 8 hours every week. The error rate from manual data entry dropped from 4% to less than 0.1%.
What Are the Key Benefits?
Your Process, Not a Platform's UI
Logic is written in Python, not constrained by a visual builder's limitations. Tiered commissions or multi-stage approvals are simple if/else statements.
Pay for Compute, Not Tasks
A typical reconciliation job costs under $20/month on AWS Lambda. You escape per-task pricing that punishes your growth.
Full Ownership of Your Code
You receive the complete Python source code in your company's GitHub repository. There is no vendor lock-in.
Alerts That Actually Help
When an API key expires or a transaction fails validation, structlog sends a Slack alert with the exact record ID and error message for immediate triage.
Connects to Any Modern API
We use httpx to integrate with any modern REST API, from QuickBooks and Stripe to legacy internal ERPs with custom authentication.
What Does the Process Look Like?
API Access & Workflow Audit (Week 1)
You provide read-only API credentials for your accounting, payment, and CRM systems. We deliver a detailed workflow diagram and a data validation report.
Core Logic & Integration Build (Week 2)
We build the core Python application and connect to each API endpoint. You receive a private GitHub repository with the initial commit history.
Staging Deployment & Testing (Week 3)
We deploy the system to a staging environment and run it against a full day's worth of your production data. You receive a validation report comparing the output to your manual process.
Production Go-Live & Monitoring (Week 4+)
After your sign-off, we deploy to production. For the first 30 days, we monitor daily runs and provide a runbook for your team to take over maintenance.
Frequently Asked Questions
- What does a typical accounting automation build cost?
- Pricing is based on the number of systems to integrate and the complexity of the business logic. A two-system reconciliation (e.g., Stripe to QuickBooks) is a standard 2-week build. A three-way match involving a custom ERP and bank feeds is a 4-week project. We provide a fixed-price quote after a 30-minute discovery call.
- What happens if an external API like Stripe's changes or breaks?
- Our code is built with versioned API calls and Pydantic data validation. If Stripe changes a field, Pydantic will raise a validation error, and the system will alert us immediately instead of processing bad data. The optional monthly maintenance plan covers updates to accommodate breaking API changes from third-party vendors.
- How is this different from hiring an accounting firm to do this?
- Accounting firms typically use off-the-shelf automation tools or manual processes. They solve the bookkeeping problem but do not deliver a software asset. Syntora builds a custom system that you own. It runs on your infrastructure, and the code is in your GitHub. It is a permanent engineering solution, not a managed service.
- Can this handle sensitive financial data securely?
- Yes. We never store raw financial data. The system processes data in-memory on AWS Lambda and only stores IDs or status flags in its Supabase database. All API keys and credentials are encrypted and stored in AWS Secrets Manager, not in the code. You retain full control over access in your own AWS account.
- My accounting system doesn't have a modern API. Can you still connect to it?
- It depends. If the system can export a CSV or XML file to a specific location like an S3 bucket or SFTP server, we can build the automation to trigger off that file drop. This is common for legacy ERPs. However, if the only way in is through screen scraping or a desktop client, that is not a project we would take on.
- What kind of team is needed to maintain this after handoff?
- No dedicated team is required for day-to-day operation. For maintenance, a generalist developer with Python experience can handle common tasks like updating an API key. The provided runbook covers these scenarios. We also offer a flat monthly support plan for teams with no engineering resources.
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