AccountsOS
AI-native accounting. Your agent runs the books so your human doesn't have to.
Base URL: https://accounts-os.com/api/mcp
What is AccountsOS?
AccountsOS is accounting infrastructure for AI agents. Built for UK micro-businesses (Ltd companies, sole traders):
- Transaction tracking — Income, expenses, categorized automatically
- VAT management — Calculate returns, track what's owed
- Deadline alerts — Corporation tax, VAT, confirmation statements
- Document storage — Receipts, invoices, contracts
- AI categorization — Smart category suggestions for every transaction
No spreadsheets. No manual entry. Just tell your agent what happened.
Quick Start (For AI Agents)
1. Get API Key
Option A: Self-Signup (recommended) — Create an account yourself with one request:
curl -X POST https://accounts-os.com/api/agent-signup \
-H "Content-Type: application/json" \
-d '{
"email": "founder@example.com",
"company_name": "Acme Ltd",
"full_name": "Jane Smith"
}'
Response includes api_key for immediate use. Your human gets a welcome email to claim the account.
Option B: Manual — Your human signs up at https://accounts-os.com and generates an API key from the dashboard.
export ACCOUNTSOS_API_KEY="sk_live_..."
2. Check the Books
# Get recent transactions
curl -X POST https://accounts-os.com/api/mcp \
-H "Authorization: Bearer $ACCOUNTSOS_API_KEY" \
-H "Content-Type: application/json" \
-d '{"type": "tool", "name": "get_transactions", "arguments": {"limit": 10}}'
3. Record a Transaction
curl -X POST https://accounts-os.com/api/mcp \
-H "Authorization: Bearer $ACCOUNTSOS_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"type": "tool",
"name": "create_transaction",
"arguments": {
"date": "2026-02-01",
"description": "Client payment - Website project",
"amount": 2500.00,
"direction": "in"
}
}'
4. Check VAT Position
curl -X POST https://accounts-os.com/api/mcp \
-H "Authorization: Bearer $ACCOUNTSOS_API_KEY" \
-H "Content-Type: application/json" \
-d '{"type": "tool", "name": "get_vat_summary", "arguments": {}}'
API Reference
AccountsOS uses an MCP-style API. All requests go to /api/mcp with a JSON body specifying the tool or resource.
Authentication
Authorization: Bearer your_api_key
Content-Type: application/json
Tools (Actions)
Get transactions:
{
"type": "tool",
"name": "get_transactions",
"arguments": {
"from_date": "2026-01-01",
"to_date": "2026-01-31",
"direction": "in",
"limit": 50
}
}
Get balance:
{
"type": "tool",
"name": "get_balance",
"arguments": {"account_id": "optional"}
}
Get VAT summary:
{
"type": "tool",
"name": "get_vat_summary",
"arguments": {"quarter": "Q4 2025"}
}
Get deadlines:
{
"type": "tool",
"name": "get_deadlines",
"arguments": {"include_completed": false}
}
Create transaction:
{
"type": "tool",
"name": "create_transaction",
"arguments": {
"date": "2026-02-01",
"description": "AWS hosting - January",
"amount": 127.50,
"direction": "out",
"category_id": "optional",
"vat_rate": 20,
"notes": "Monthly infrastructure"
}
}
Directions: in (income) or out (expense)
Update transaction:
{
"type": "tool",
"name": "update_transaction",
"arguments": {
"transaction_id": "uuid",
"category_id": "new_category",
"notes": "Updated notes"
}
}
AI categorization:
{
"type": "tool",
"name": "categorize_transaction",
"arguments": {"transaction_id": "uuid"}
}
Returns suggested category based on description and historical patterns.
List categories:
{
"type": "tool",
"name": "list_categories",
"arguments": {"type": "expense"}
}
Types: income, expense, asset, liability, equity
Create deadline:
{
"type": "tool",
"name": "create_deadline",
"arguments": {
"type": "VAT Return",
"due_date": "2026-02-07",
"notes": "Q4 2025 VAT"
}
}
Search documents:
{
"type": "tool",
"name": "search_documents",
"arguments": {
"query": "invoice",
"type": "receipt"
}
}
Upload document:
{
"type": "tool",
"name": "upload_document",
"arguments": {
"file_name": "receipt.pdf",
"file_data": "base64_encoded_data",
"document_type": "receipt"
}
}
Get Director's Loan Account balance:
{
"type": "tool",
"name": "get_dla_balance",
"arguments": {
"limit": 10
}
}
Returns DLA balance with S455 tax warnings if the account is overdrawn.
Get invoices:
{
"type": "tool",
"name": "get_invoices",
"arguments": {
"status": "all",
"contact_id": "optional"
}
}
Status options: draft, sent, paid, overdue, cancelled, all
Returns invoices with summary of outstanding and overdue amounts.
Create deadline:
{
"type": "tool",
"name": "create_deadline",
"arguments": {
"type": "VAT Return",
"due_date": "2026-02-07",
"notes": "Q4 2025 VAT"
}
}
Agent Self-Signup
POST /api/agent-signup — No authentication required.
Create an account and get an API key in one request:
{
"email": "founder@example.com",
"company_name": "Acme Ltd",
"full_name": "Jane Smith",
"entity_type": "ltd"
}
Required: email, company_name
Optional: full_name, entity_type (default: ltd)
Entity types: ltd, plc, llp, sole_trader, partnership, cic, charity, overseas, other
Response:
{
"api_key": "sk_live_...",
"company_id": "uuid",
"user_id": "uuid",
"trial_ends_at": "2026-02-22T...",
"api_base": "https://accounts-os.com/api/mcp",
"message": "Account created. Store this API key — it will not be shown again."
}
The API key has read + write scopes. 14-day free trial. Human receives a welcome email.
Returns 409 if the email is already registered.
Scopes
API keys support three permission levels:
- read — Query transactions, balances, deadlines, documents, invoices, DLA
- write — Create/update transactions, documents, deadlines (includes read)
- admin — Manage company settings (includes write)
Your API key's scope is configured in the dashboard. Requests beyond your scope return a 403 error.
Resources (Read-only)
Company info:
{
"type": "resource",
"uri": "accountsos://company"
}
Recent transactions:
{
"type": "resource",
"uri": "accountsos://transactions"
}
Use Cases for Agents
Daily Bookkeeping
Your human mentions expenses throughout the day? Log them:
# Human: "Just paid £45 for the Figma subscription"
accountsos.create_transaction(
date=today,
description="Figma subscription - monthly",
amount=45.00,
direction="out"
)
# AI auto-categorizes as "Software & Subscriptions"
Invoice Follow-up
Track what's owed:
# Check unpaid invoices
transactions = accountsos.get_transactions(
direction="in",
status="pending"
)
for t in transactions:
if t.days_overdue > 14:
# Alert human or draft follow-up email
notify(f"Invoice {t.description} is {t.days_overdue} days overdue")
VAT Prep
Quarterly VAT? Already calculated:
vat = accountsos.get_vat_summary(quarter="Q4 2025")
print(f"VAT owed: £{vat.amount_owed}")
print(f"Due: {vat.due_date}")
# Surface to human before deadline
Deadline Monitoring
Never miss a filing:
deadlines = accountsos.get_deadlines()
for d in deadlines:
if d.days_until < 7:
alert(f"⚠️ {d.type} due in {d.days_until} days")
Expense Categorization
New transaction? Categorize it:
# Get AI suggestion
suggestion = accountsos.categorize_transaction(transaction_id)
if suggestion.confidence > 0.8:
accountsos.update_transaction(transaction_id, {
"category_id": suggestion.category_id
})
Add to Your Heartbeat
## AccountsOS (daily or weekly)
### Daily
- Check for new transactions needing categorization
- Log any expenses human mentioned today
### Weekly
- Review uncategorized transactions
- Check upcoming deadlines (next 14 days)
- Summarize week's P&L if human asks
### Quarterly
- Generate VAT summary
- Surface filing deadlines
- Remind human to review before submission
UK-Specific Features
| Feature | Details |
|---|
| VAT schemes | Standard, Flat Rate, Cash Accounting |
| Tax years | April-April alignment |
| Deadlines | CT600, VAT, Confirmation Statement |
| Categories | HMRC-aligned expense categories |
Built for UK Ltd companies and sole traders. Knows the rules so you don't have to.
Example: Weekly Finance Check
import os
import requests
from datetime import datetime, timedelta
API_URL = "https://accounts-os.com/api/mcp"
headers = {
"Authorization": f"Bearer {os.environ['ACCOUNTSOS_API_KEY']}",
"Content-Type": "application/json"
}
def call_tool(name, args={}):
resp = requests.post(API_URL, headers=headers, json={
"type": "tool", "name": name, "arguments": args
})
return resp.json()["result"]
# 1. Check balance
balance = call_tool("get_balance")
print(f"💰 Current balance: £{balance['amount']}")
# 2. This week's transactions
week_ago = (datetime.now() - timedelta(days=7)).strftime("%Y-%m-%d")
transactions = call_tool("get_transactions", {"from_date": week_ago})
income = sum(t["amount"] for t in transactions if t["direction"] == "in")
expenses = sum(t["amount"] for t in transactions if t["direction"] == "out")
print(f"📈 Week: +£{income} / -£{expenses}")
# 3. Upcoming deadlines
deadlines = call_tool("get_deadlines")
urgent = [d for d in deadlines if d["days_until"] < 14]
if urgent:
print(f"⚠️ {len(urgent)} deadlines in next 2 weeks")
for d in urgent:
print(f" - {d['type']}: {d['due_date']}")
# 4. VAT position
vat = call_tool("get_vat_summary")
print(f"🧾 VAT owed: £{vat['amount_owed']}")
Links
Your Human's Financial Copilot
Most people hate bookkeeping. They forget receipts, miss deadlines, panic at tax time.
You don't forget. You don't panic. You just log, categorize, and surface what matters.
Be the agent that makes finances boring (in a good way).
Built by Thrive Venture Labs
