Simple Budget API integration & OpenData export services

Transaction history API

Read the user's expense and income entries with pagination, date-range filters, and category filters. Each row carries amount, currency, category, note, recurring-flag, and timestamp — the same fields users see in Simple Budget's daily and weekly views. Useful for reconciliation against bank statements or tax export.

Budget & cap query

Surface the user's flexible budgets — overall caps and per-category caps — together with their remaining headroom and period progress. Pairs naturally with the Forecast Budget feature to project end-of-month positions, the way the in-app weekly report does.

Recurring & future payments

Pull the user's scheduled bills, subscriptions, and any future-dated expenses they have entered. Returned as a calendar-style structure so cash-flow tools can show upcoming payments and how each will impact the running balance.

Categories & breakdown

Export the user's custom category tree (add / edit / remove operations are mirrored) plus the percentage-wise expense breakdown that powers Simple Budget's pie views. Suitable for personal-finance dashboards and category-mapping into ERP charts of accounts.

Backup ingestion & restore

Ingest the app's automatic cloud-backup payload (the same one Simple Budget uses for "restore on any phone anywhere"), parse it server-side, and re-emit normalized JSON. Lets enterprise users archive personal-finance history away from a single device.

Reminder & insight webhooks

Forward the in-app daily and weekly reminder events to your backend so a CRM, Slack channel, or savings agent can react when the user records a new transaction or hits a budget threshold.

1. Accountant export bridge

An independent accountant manages many self-employed clients who track day-to-day spending in Simple Budget. We build a bridge that pulls each client's monthly transaction history through the export API, maps Simple Budget categories to the accountant's chart of accounts, and pushes ready-to-import CSVs into QuickBooks, Xero, or a local tax tool. This mirrors the export flow that personal-finance tools such as Lunch Money and Koody already standardize on CSV-based hand-off, so accountants get a familiar workflow.

2. Couples / household roll-up

Two partners each run Simple Budget on their own phones. The integration ingests both users' cloud backups (with consent), de-duplicates shared expenses by note & timestamp, and produces a unified household statement and a shared budget view. Field-level mapping covers amount, category, note, and occurred_at from each side.

3. Savings-goal automation

A neobank or savings agent listens to webhook events emitted whenever a Simple Budget user records a transaction. When monthly spend in the "Eating out" category crosses 80% of the user's flexible budget, the agent triggers an automatic transfer to a savings sub-account. The trigger uses the same threshold logic the app uses for its daily reminders, so user-facing behavior stays consistent.

4. Open-banking augmentation

An OpenBanking aggregator already pulls bank-side transactions under PSD2 in the EU. Many small purchases are still tagged manually in Simple Budget by the user. We provide an enrichment API that joins bank-feed transactions to the user's Simple Budget notes and categories on amount and date, returning a richer, human-labeled feed for budgeting UIs.

5. Compliance archival for regulated freelancers

Some jurisdictions require self-employed individuals to keep expense records for 5–10 years. We ship a scheduled job that snapshots a user's Simple Budget cloud backup, encrypts it, stores it in long-term object storage, and exposes a read-only API for auditor access — answering the GDPR right-to-portability question with structured JSON exports.

Authorization & backup ingestion

// Step 1: register a Simple Budget user with their consent
POST /api/v1/simple-budget/auth/register
Content-Type: application/json

{
  "user_ref": "alice@example.com",
  "package_id": "gplx.simple.budgetapp",
  "backup_provider": "google_drive",
  "consent_scope": ["transactions", "budgets", "categories"]
}

// Response
{
  "user_id": "u_8f2a1c",
  "access_token": "sb_at_...",
  "expires_at": "2026-05-28T00:00:00Z"
}

Transaction list with pagination

GET /api/v1/simple-budget/transactions
  ?from=2026-04-01&to=2026-04-30
  &category=eating_out
  &limit=100&cursor=eyJpZCI6...
Authorization: Bearer sb_at_...

// Response
{
  "items": [
    {
      "id": "t_01H...",
      "amount": -12.50,
      "currency": "USD",
      "category": "eating_out",
      "note": "Lunch with team",
      "is_recurring": false,
      "occurred_at": "2026-04-12T12:31:00Z"
    }
  ],
  "next_cursor": "eyJpZCI6..."
}

Budgets & webhook subscription

// Read the user's budgets
GET /api/v1/simple-budget/budgets?period=monthly
Authorization: Bearer sb_at_...

// Subscribe to "transaction recorded" events
POST /api/v1/simple-budget/webhooks
{
  "event": "transaction.recorded",
  "url": "https://your.app/hooks/sb",
  "secret": "whsec_..."
}

// Error contract is consistent across endpoints
{ "error": { "code": "consent_revoked",
             "message": "User has revoked the categories scope.",
             "retry_after": null } }

Compliance & privacy

Simple Budget itself never asks for bank credentials, which keeps the integration surface narrow. Our delivery still follows the standards that apply to any personal-finance data flow:

• GDPR — Lawful basis is explicit user consent at registration; we ship Article 15 (access) and Article 20 (portability) endpoints out of the box, and all storage uses EU regions when the end-user is in the EEA.
• PSD2 / OpenBanking — Where the integration joins Simple Budget data with bank-feed data, we keep the AISP and budgeting paths separate, in line with PSD2's strong-customer-authentication and consent-renewal cadence (every 90 / 180 days).
• CCPA & regional laws — California, Brazilian LGPD, and UK GDPR variants are handled through regionally-routed consent records.
• Apache License 2.0 — Because Simple Budget's upstream codebase is open source, our protocol analysis is fully auditable and we respect attribution requirements in derivative work.

Data flow / architecture

A typical pipeline for a Simple Budget integration looks like this:

1. Client — Simple Budget on Android writes transactions locally and triggers automatic backups to the user's personal cloud (e.g. Google Drive).
2. Ingestion — Our connector polls or receives the backup payload, validates the schema, and decrypts it with the user-supplied key.
3. Normalization & storage — Records are mapped to a canonical OpenFinance shape and stored in a tenanted database; PII fields are tokenized.
4. API / outputs — REST endpoints serve transactions, budgets, recurring schedules, and reports. CSV, Excel, and JSON export targets and outbound webhooks fan-out events to your stack.

Market positioning & user profile

Simple Budget targets consumers who explicitly do not want to give a third-party app access to their bank account. Its primary user profile is a privacy-conscious, mobile-first individual on Android who wants daily and weekly reminders, weekly/monthly auto-generated reports, and a personal cloud backup they fully own. Rough segmentation we see in similar apps (Goodbudget, Spendee, Koody, MoneyManager EX): self-employed freelancers, students managing tight cash flow, dual-income couples splitting expenses, and small-business owners who file taxes once a year. Reach is global with strong adoption in regions where bank-API openness is uneven (parts of LATAM, South-East Asia, Africa) — making manual-entry tools a stable choice. The 2024 shutdown of Mint pushed many users to similar offline-first or open-source options, broadening the addressable audience for Simple Budget integrations.

Recent context (2024–2025)

The personal-finance app landscape shifted sharply in 2024 when Intuit retired Mint in March, redirecting tens of millions of users toward alternatives. In parallel, the Simple Budget upstream codebase (open-sourced as SimplePlanningStudio/EasyBudget on GitHub) continued to receive feature updates, including expense breakdown views and improved recurring-payment handling. Across competing apps, AI-assisted insights and spending-recap features (added by Monarch Money and YNAB during 2024–2025) have set new user expectations — making structured data export from offline-first apps like Simple Budget more valuable, not less, since those AI features need a clean, machine-readable feed to operate on.

Deliverables checklist

• OpenAPI / Swagger spec covering transactions, budgets, recurring, categories, reports
• Protocol & data-format report for the Simple Budget cloud-backup payload
• Runnable source code (Python or Node.js) for ingestion, normalization, and the export API
• Postman collection and automated integration tests
• Docker compose for local replay against sample backups
• Compliance package: consent record schema, GDPR data-subject endpoints, retention defaults

Engagement models

Two ways to work with us, both ungated by upfront fees:

• Source-code delivery from $300 — runnable API source plus documentation; you pay after delivery once you have validated the build.
• Pay-per-call hosted API — call our managed Simple Budget endpoints and pay only for the calls you make; ideal when you do not want to operate ingestion infrastructure yourself.

About us

We are an independent technical studio focused on App interface integration and authorized API integration for global clients. Engineers on the team have shipped backends for retail banks, payment gateways, accounting platforms, and consumer-finance apps; we know how mobile ledgers, OAuth flows, cloud-backup payloads, and OpenBanking AISP feeds are stitched together in production.

• Protocol analysis, app interface refactoring, and OpenData integration
• Android & iOS targets; Python, Node.js, and Go reference implementations
• Workflow: protocol analysis → API design → build → validation → compliance review
• NDA available; clean-room implementation when license terms require it

Contact

Send us the target app name, the data you need (transactions, budgets, categories, reports), and any sample cloud-backup file or sandbox account you can share. We will reply with scope, timeline, and a quote within one business day.

Open contact page

Engagement workflow

1. Scope confirmation: target data classes (transactions, budgets, categories, recurring) and target output (REST, CSV export, webhook).
2. Protocol analysis on the Simple Budget backup payload and the open-source upstream code (2–4 business days).
3. API design plus build & internal validation against sample accounts (4–7 business days).
4. Documentation, OpenAPI spec, Postman collection, automated tests (1–2 business days).
5. Hand-off; pay on satisfaction. Typical first delivery 5–13 business days.

FAQ

Does Simple Budget have an official public API?

Will the user's bank account be touched?

What about data retention?

How long does delivery take?