• QBO International (UK, CA, AU, IE, ZA, Global) — fully supported, manual tax codes
• QBO-US legacy manual sales tax — supported
• QBO-US with Automated Sales Tax (AST) — not supported. The middleware detects AST at init and raises QBOUnsupportedConfigError; catch this in your onboarding flow and block the integration.

1. Sign in at developer.intuit.com and go to My Apps → Create an app
2. Pick QuickBooks Online and Payments
3. Under Scopes, enable com.intuit.quickbooks.accounting
4. Add your OAuth2 redirect URI and copy your Client ID + Client Secret from Keys & credentials

Use Intuit's OAuth 2.0 Playground or your own server to walk the user through authorization. You will end up with four values: realm_id, access_token (~1h), refresh_token (~100d, rotates on use), and expires_in. Persist all four in your secrets store.

pip install httpx

from qbo_middleware import QBOTaxMiddleware, QBOUnsupportedConfigError

middleware = QBOTaxMiddleware(
    taxai_url="https://determinedai.co",
    taxai_api_key="txai_live_...",
    qbo_client_id="YOUR_INTUIT_CLIENT_ID",
    qbo_client_secret="YOUR_INTUIT_CLIENT_SECRET",
    environment="production",  # or "sandbox"
)

# This probes CompanyInfo + Preferences; raises
# QBOUnsupportedConfigError if the org is QBO-US with AST on.
try:
    await middleware.set_tokens(
        realm_id=stored["realm_id"],
        access_token=stored["access_token"],
        refresh_token=stored["refresh_token"],
        expires_in=stored["expires_in"],
    )
except QBOUnsupportedConfigError as e:
    return error_response(str(e))

result = await middleware.create_invoice_with_tax(
    doc_number="INV-2024-042",
    customer_ref="42",
    customer_name="Acme GmbH",
    bill_country="DE",
    customer_tax_id="DE123456789",  # B2B -> EU reverse charge
    currency_code="EUR",
    line_items=[{
        "description": "Cloud analytics - annual SaaS",
        "amount": 1188.00,
        "quantity": 1,
        "item_ref": "SAAS-001",
    }],
)
invoice_id = result["Invoice"]["Id"]

QBO TaxCode numeric IDs are company-specific. On set_tokens() the middleware caches the name → id lookup for the org's active tax codes. If your company's tax code names don't match what DeterminedAI returns, configure the mapping via POST /v1/setup/erp-mapping with erp_system: "quickbooks".

See connectors/quickbooks/SETUP.md for the complete guide including AST detection internals, error handling, production checklist, and the live sandbox validation notes.

1. Go to developer.xero.com/app/manage and click New App
2. Integration type: Web app
3. Set a redirect URI under your control (e.g. https://yourapp.com/xero/callback)
4. Copy the Client ID and Client Secret

At minimum:

openid profile email offline_access accounting.transactions accounting.settings

pip install httpx

from xero_middleware import XeroTaxMiddleware

middleware = XeroTaxMiddleware(
    taxai_api_url=os.environ["TAXAI_API_URL"],
    taxai_api_key=os.environ["TAXAI_API_KEY"],
    xero_client_id=os.environ["XERO_CLIENT_ID"],
    xero_client_secret=os.environ["XERO_CLIENT_SECRET"],
)

# After OAuth2:
await middleware.set_tokens(
    tenant_id=stored["tenant_id"],
    access_token=stored["access_token"],
    refresh_token=stored["refresh_token"],
    expires_in=stored["expires_in"],
)

See connectors/xero/SETUP.md.

1. In the NetSuite File Cabinet, create SuiteScripts/TaxAI/
2. Upload TaxAI_SuiteTax_Plugin.js
3. Go to Customization → Scripting → Scripts → New, select the file, set Script Type: Custom Plug-in Implementation

custscript_taxai_api_url   = https://determinedai.co
custscript_taxai_api_key   = txai_live_xxxxxxxx...
custscript_taxai_timeout   = 15000
custscript_taxai_fallback  = T   # zero-rate if API down

1. Go to Setup → Accounting → Tax Calculation Plug-in
2. Pick customscript_taxai_suitetax as the Custom Tax Engine Plug-in
3. Select subsidiaries and transaction types (Sales Order, Invoice, etc.)

See connectors/netsuite/SETUP.md.

• ABAP BAdI (S/4HANA On-Premise, Private Cloud, ECC 6.0) — you write a ~50-line BAdI implementation that calls the middleware over HTTPS
• BTP Tax Service external provider (S/4HANA Public Cloud) — configure the middleware URL as the external provider in your BTP Tax Service tenant
• CPI / Integration Suite iFlow — intercept the tax service call and forward to the middleware

Run sap_middleware.py on a host reachable from SAP (e.g. Azure App Service, a VM inside your SAP network, or BTP). Configure with your DeterminedAI API key:

from sap_middleware import SAPTaxMiddleware

middleware = SAPTaxMiddleware(
    taxai_url="https://determinedai.co",
    taxai_api_key=os.environ["TAXAI_API_KEY"],
)

1. Transaction SM59 → HTTP Connection to External Server
2. Name: ZDETERMINEDAI_TAX, Target Host: your middleware host, Service: 443
3. Trust the certificate in transaction STRUST

Your BAdI implementation serializes the document to JSON, calls the middleware's /calculate_tax endpoint via cl_http_client, and writes the response into SAP's pricing structures. A reference Z-function (Z_TAXAI_CALCULATE_TAX) is included in the SETUP guide.

See connectors/sap/SETUP.md for the complete ABAP template, BTP provider configuration, and iFlow pattern.

An X++ extension subscribes to TaxCalculation.onCalculating inside your D365 environment. On every sales order or invoice post, the extension serializes the document to JSON, calls the Python middleware over HTTPS, and writes the returned tax amounts into F&O's pricing structures. The flow is transparent to end users — they just see the correct tax on the document.

• D365 F&O environment with Visual Studio + D365 Developer Tools access (usually a Tier-1 dev environment via LCS)
• Python 3.10+ environment with httpx to run the middleware
• HTTPS endpoint reachable from your D365 environment
• D365 F&O admin role

from d365_middleware import D365TaxMiddleware

middleware = D365TaxMiddleware(
    taxai_url="https://determinedai.co",
    taxai_api_key=os.environ["TAXAI_API_KEY"],
)

Expose /calculate_tax via FastAPI, Azure Functions, or your framework of choice.

Subscribe to TaxCalculation.onCalculating (or implement a plug-in for TaxCalculationEngine). On each sales order / invoice post, serialize the document to JSON, POST to the middleware, and write the response into F&O's tax structures. A reference template is in the SETUP guide.

See connectors/dynamics365/SETUP.md for the X++ extension template, authentication options, and deployment guidance.

Your backend receives Stripe webhooks (invoice.created) or serves a /create-checkout-session endpoint. The middleware translates the Stripe payload into a call to POST /v1/erp/stripe/calculate, then writes the returned tax back to Stripe via the stripe-python SDK. B2B reverse charge is detected automatically from customer.tax_ids.

• Stripe account with API keys and webhook secret (Dashboard → Developers)
• Python 3.10+ backend running pip install stripe httpx
• DeterminedAI API key

from connectors.stripe.stripe_middleware import (
    StripeMiddleware, StripeMiddlewareConfig, verify_webhook_signature,
)

mw = StripeMiddleware(StripeMiddlewareConfig.from_env())

# Mode A: pre-finalization invoice
mw.apply_tax_to_draft_invoice(invoice_id="in_123")

# Mode B: Checkout Session
rate_ids = mw.build_checkout_session_tax_rates(
    customer=customer_obj, cart_lines=lines, currency="eur",
)

51 verified jurisdictions plus full EU reverse-charge logic. Stripe's tax_type enum is mapped automatically (vat / gst / jct / igst / hst / sales_tax) from the determined jurisdiction.

See connectors/stripe/SETUP.md.