tangentopay 0.1.6

Official Python SDK for the TangentoPay API

tangentopay-python

Official Python SDK for the TangentoPay API — accept payments, issue refunds, manage wallets, and verify webhooks with a clean, type-safe interface.

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Table of contents

• Requirements
• Installation
• Quick start
• Authentication
• Resources
• Wallet top-up
• Payment methods
• Async support
• Error handling
• Webhook verification
• Supported currencies
• Security
• License

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Requirements

• Python 3.9 or higher
• httpx — installed automatically as a dependency

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Installation

pip install tangentopay

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Quick start

1. Accept a customer payment (storefront)

Use ServiceClient with your public service key (pk_live_...). Get it from: TangentoPay Dashboard → Services → your service → API Keys.

import tangentopay

client = tangentopay.ServiceClient("pk_live_your_service_key")

session = client.checkout.create(
    products=[
        {"name": "Pro Plan", "price": 49.99, "quantity": 1},
    ],
    currency_code="USD",
    customer_email="[e-mail]",
    return_url="https://myshop.com/thank-you",
    cancel_url="https://myshop.com/cart",
)

# Redirect your customer to the hosted checkout page
redirect(session.redirect_url)

2. Confirm payment before fulfilling an order

# On your /thank-you page the URL contains ?session_id=...
# Poll until the payment is confirmed (up to 60 seconds)

status = client.checkout.wait_for_completion(transaction_uid, timeout=60)
if status.is_completed:
    fulfill_order()

3. Manage payments on the backend (merchant)

Use MerchantClient with your API token — keep this server-side only, never expose it in a browser.

import os
import tangentopay

merchant = tangentopay.MerchantClient(api_token=os.environ["TANGENTOPAY_API_TOKEN"])

# List recent payments
page = merchant.payments.list(per_page=20)
for txn in page.data:
    print(txn.transaction_uid, txn.transaction_status, txn.final_amount)

# Issue a refund
refund = merchant.refunds.create(
    transaction_uid="TXN-ABC123",
    amount=49.99,
    reason="Customer request",
    pin="1234",
    recipient_type="stripe",
)

# Check wallet balance
balance = merchant.wallets.main_balance()
print(balance.available_balance, balance.currency_code)

4. Verify incoming webhooks

Always verify the HMAC signature before trusting any webhook payload.

import os
import tangentopay

WEBHOOK_SECRET = os.environ["TANGENTOPAY_WEBHOOK_SECRET"]

def handle_webhook(raw_body: bytes, signature_header: str):
    try:
        event = tangentopay.Webhook.construct_event(
            payload=raw_body,
            signature=signature_header,
            secret=WEBHOOK_SECRET,
        )
    except tangentopay.WebhookSignatureError:
        return 400  # reject tampered or replayed events

    if event.event == "transaction.payment_completed":
        fulfill_order(event.payload["transaction_uid"])

    return 200

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Authentication

TangentoPay uses two separate credentials depending on what you are doing:

Client	Credential	Header sent	When to use
ServiceClient	Service key (pk_live_...)	X-Service-Key	Creating checkout sessions, checking payment status — storefront / frontend server
MerchantClient	API token (Bearer)	Authorization: Bearer	Everything sensitive — payments, refunds, payouts, wallets, analytics — backend only

Getting your credentials

1. Log in to the TangentoPay Dashboard
2. Go to Services and open your service
3. Click API Keys
4. Copy the Service Key and API Token
5. Store them as environment variables — never commit them to git

# .env (never commit this file)
TANGENTOPAY_SERVICE_KEY=pk_live_xxxxxxxxxxxxxxxxxxxxxxxx
TANGENTOPAY_API_TOKEN=eyJhbGciOiJIUzI1NiIsInR5cCI6...
TANGENTOPAY_WEBHOOK_SECRET=whsec_xxxxxxxxxxxxxxxxxxxxxxxx

Obtaining a token programmatically

# Step 1 — submit credentials (triggers OTP to your registered device)
token = tangentopay.login(
    email="[e-mail]",
    password="secret",
    otp="123456",
)

merchant = tangentopay.MerchantClient(api_token=token)

The token does not expire automatically. Call merchant.auth.logout() to revoke it.

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Resources

ServiceClient resources

Resource	Methods	Description
checkout	create(), get_status(), wait_for_completion()	Hosted Stripe checkout sessions

MerchantClient resources

Resource	Methods	Description
auth	login(), verify_otp(), me(), logout(), change_password()	Authentication and profile
payments	list(), get(), create_manual()	View and record payments
refunds	create(), list()	Issue and list refunds
topups	create(), list()	Add funds to a wallet
payouts	create(), bulk(), list()	Send funds to recipients
transfers	to_main(), list()	Move funds between wallets
wallets	main_balance(), service_balance(), manual_balance()	Check balances
services	list(), get(), create(), update(), delete(), create_api_key(), list_api_keys(), revoke_api_key(), update_webhook(), list_payment_methods(), set_payment_method(), set_payment_methods()	Manage services, keys, and payment methods
customers	list(), get(), create(), update(), delete(), import_csv()	Customer management
analytics	dashboard(), payments_chart(), gross_volume(), total_payouts()	Reporting and analytics

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Wallet top-up

Top-up lets authenticated merchants add funds to their TangentoPay wallet via Stripe Checkout. It uses the MerchantClient.

Why idempotency_key is required

Every call to topups.create() is an independent Python function call. If you retry after a network failure without passing the same key, the server sees a completely new request and creates a second Stripe Checkout Session — potentially charging the user twice.

The rule is simple: generate the key once, store it, reuse it on every retry of the same top-up intent.

import tangentopay

merchant = tangentopay.MerchantClient(api_token=os.environ["TANGENTOPAY_API_TOKEN"])

# Step 1 — generate ONCE and store in your session / database
key = tangentopay.generate_idempotency_key()

# Step 2 — initiate the top-up (safe to retry with the same key)
session = merchant.topups.create(
    amount=50.00,
    currency_code="USD",
    idempotency_key=key,          # required
    return_url="https://app.com/topup/success",
    cancel_url="https://app.com/topup/cancel",
)

# Step 3 — redirect the user to complete payment
redirect(session.redirect_url)

On retry (network timeout, double-tap):

# Same key → server returns the existing session, no new charge
session = merchant.topups.create(
    amount=50.00,
    currency_code="USD",
    idempotency_key=key,   # same key as before
    return_url="https://app.com/topup/success",
)
# session.redirect_url is the same Stripe URL — user continues where they left off

Async variant:

session = await async_merchant.topups.create(
    amount=50.00,
    currency_code="USD",
    idempotency_key=key,
    return_url="https://app.com/topup/success",
)

Top-up without products

Unlike checkout sessions, top-ups do not require a products array. Pass amount + currency_code directly — the payment line item is created automatically.

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Payment methods

Each service has its own set of enabled payment methods. Cards (Visa/Mastercard) are always enabled. Company accounts that have completed KYB verification can enable additional Stripe methods (Google Pay, Apple Pay, Alipay, WeChat Pay) per service via the SDK.

Method	Default	Availability
Visa / Mastercard / Amex (card)	✅ Always enabled	All account types
Google Pay	Off	Company accounts with KYB verification
Apple Pay	Off	Company accounts with KYB verification
Alipay	Off	Company accounts with KYB verification
WeChat Pay	Off	Company accounts with KYB verification
MoMo (Mobile Money)	Coming soon	Will be added as a native TangentoPay method

Managing payment methods per service

# List all payment methods for a service (with enabled/locked/reason status)
methods = merchant.services.list_payment_methods(service_id)
# [ServicePaymentMethod(slug='card', enabled=True, locked=False), ...]

# Toggle a single method on or off
merchant.services.set_payment_method(service_id, 'google_pay', enabled=True)

# Replace the entire set of enabled methods at once
# card must always be included
merchant.services.set_payment_methods(service_id, ['card', 'apple_pay', 'alipay'])

Checkout sessions for that service will only show the methods you have enabled. If the account is not KYB-verified, non-card methods are returned as locked=True with a human-readable reason.

MoMo note: Mobile Money support is on the roadmap and will be integrated as a first-class TangentoPay payment method, separate from Stripe.

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Async support

Every client has an async counterpart — AsyncServiceClient and AsyncMerchantClient — with identical methods that return awaitables. Use these with FastAPI, Starlette, or any asyncio-based framework.

import asyncio
import tangentopay

async def main():
    client = tangentopay.AsyncServiceClient("pk_live_your_service_key")

    session = await client.checkout.create(
        products=[{"name": "Pro Plan", "price": 49.99, "quantity": 1}],
        currency_code="USD",
        return_url="https://myshop.com/thank-you",
        cancel_url="https://myshop.com/cart",
    )
    print(session.redirect_url)

asyncio.run(main())

# FastAPI example
from fastapi import FastAPI, Request
import tangentopay

app = FastAPI()
merchant = tangentopay.AsyncMerchantClient(api_token=os.environ["TANGENTOPAY_API_TOKEN"])

@app.get("/payments")
async def list_payments():
    page = await merchant.payments.list(per_page=20)
    return {"total": page.total, "data": [p.transaction_uid for p in page.data]}

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Error handling

All SDK errors inherit from tangentopay.TangentoPayError so you can catch everything with one clause or be specific.

try:
    refund = merchant.refunds.create(
        transaction_uid="TXN-001",
        amount=9999.00,
        reason="test",
        pin="wrong",
        recipient_type="stripe",
    )
except tangentopay.ValidationError as e:
    # Server-side field validation failed
    print(e.errors)           # {"amount": ["exceeds original transaction amount"]}
except tangentopay.AuthenticationError:
    # Token is invalid or expired — re-authenticate
    print("Invalid or expired token")
except tangentopay.PermissionError:
    # Authenticated but not allowed to perform this action
    print("Insufficient permissions")
except tangentopay.NotFoundError:
    print("Transaction not found")
except tangentopay.RateLimitError as e:
    # SDK already retried with exponential backoff and gave up
    print(f"Rate limited — retry after {e.retry_after}s")
except tangentopay.ServerError:
    # 5xx — SDK retried 3 times automatically before raising
    print("TangentoPay server error")
except tangentopay.NetworkError:
    # Timeout, DNS failure, connection refused
    print("Network error — check your connection")
except tangentopay.TangentoPayError as e:
    # Catch-all for any other SDK error
    print(f"Error {e.http_status}: {e.message}")

Exception reference

Exception	HTTP status	Notes
AuthenticationError	401	Invalid or expired API key / token
PermissionError	403	Authenticated but not authorised
NotFoundError	404	Resource does not exist
ValidationError	422	Field-level errors in e.errors dict
RateLimitError	429	After all retries exhausted; e.retry_after seconds
ServerError	5xx	After 3 automatic retries
NetworkError	—	Timeout, DNS, connection error
WebhookSignatureError	—	Invalid HMAC, tampered payload, or replay attack

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Webhook verification

TangentoPay signs every webhook with HMAC-SHA256 and includes a timestamp to prevent replay attacks. The SDK verifies both automatically.

from tangentopay.webhook import Webhook
import tangentopay

event = Webhook.construct_event(
    payload=raw_body,           # bytes or str — the raw request body
    signature=sig_header,       # value of the X-TangentoPay-Signature header
    secret=webhook_secret,      # whsec_... from your dashboard
    timestamp_tolerance_seconds=300,  # default — reject events older than 5 minutes
)

Signature header format:

X-TangentoPay-Signature: t=1716134400,sha256=abcdef1234...

Django example:

from django.http import HttpResponse
from django.views.decorators.csrf import csrf_exempt
from tangentopay.webhook import Webhook
import tangentopay

@csrf_exempt
def webhook(request):
    try:
        event = Webhook.construct_event(
            payload=request.body,
            signature=request.headers.get("X-TangentoPay-Signature", ""),
            secret=settings.TANGENTOPAY_WEBHOOK_SECRET,
        )
    except tangentopay.WebhookSignatureError as e:
        return HttpResponse(str(e), status=400)

    match event.event:
        case "transaction.payment_completed":
            handle_payment(event.payload["transaction_uid"])
        case "transaction.refund_completed":
            handle_refund(event.payload["transaction_uid"])

    return HttpResponse(status=200)

Flask example:

from flask import Flask, request, abort
from tangentopay.webhook import Webhook
import tangentopay

app = Flask(__name__)

@app.post("/webhooks/tangentopay")
def webhook():
    try:
        event = Webhook.construct_event(
            payload=request.data,
            signature=request.headers.get("X-TangentoPay-Signature", ""),
            secret=app.config["TANGENTOPAY_WEBHOOK_SECRET"],
        )
    except tangentopay.WebhookSignatureError:
        abort(400)

    if event.event == "transaction.payment_completed":
        handle_payment(event.payload["transaction_uid"])

    return "", 200

Supported webhook events

Event	When it fires
transaction.payment_completed	Payment successfully processed
transaction.payment_failed	Payment attempt failed
transaction.refund_completed	Refund issued successfully
transaction.payout_completed	Payout sent to recipient
transaction.topup_completed	Wallet top-up completed

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Supported currencies

TangentoPay supports Stripe's full currency list. Commonly used currencies:

Code	Currency
USD	US Dollar
EUR	Euro
GBP	British Pound
XAF	Central African CFA Franc (Cameroon, Chad, Congo, Gabon…)
NGN	Nigerian Naira
GHS	Ghanaian Cedi
KES	Kenyan Shilling
ZAR	South African Rand

XAF note: Amounts in XAF are zero-decimal — pass 500 not 5.00. The SDK handles this automatically when you provide currency_code="XAF".

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Contributing

See CONTRIBUTING.md for development setup, branch naming, commit conventions, code style, and release instructions.

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Security

Security issues should not be reported via public GitHub issues.

Please report vulnerabilities by emailing [e-mail]. We will acknowledge within 48 hours and aim to release a fix within 7 days for critical issues.

See SECURITY.md for the full security policy.

Security features built into this SDK

• HTTPS enforced — the SDK rejects any base_url that does not use https://, preventing accidental credential leakage over plain HTTP
• Header injection protection — credentials are validated for CR/LF characters at construction time, preventing HTTP header injection attacks
• Webhook replay protection — construct_event() rejects events with timestamps outside a configurable tolerance window (default 5 minutes)
• Payload size limit — webhook payloads over 10 MB are rejected before any HMAC computation
• Credential masking — API keys and tokens are masked in repr() output so they do not appear in logs or debug output
• Capped retry backoff — the Retry-After value from the server is capped at 60 seconds to prevent server-controlled denial-of-service
• Protected auth headers — extra_headers cannot override Authorization or X-Service-Key

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License

MIT — see LICENSE for the full text.

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Built with ❤️ by the TangentoPay team