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Why satim-sdk?

• Zero runtime dependencies. Just the Web Fetch API. No transitive supply chain.
• Runs everywhere fetch runs. Node 20+, Bun, Deno, Cloudflare Workers, Vercel Edge.
• Strictly immutable, fluent API. Every setter returns a new instance — no cross-request state leaks.
• Security in depth by default. SSRF guards, credential isolation in a module-private WeakMap, terminal-ID injection prevention, IEEE 754-safe currency conversion, and a deliberately conservative retry policy that never double-charges.
• Typed gateway errors. Discriminated SatimError subclasses with localized messages and a sanitized raw payload for logs (PII redacted).
• Zero-trust webhooks. Built-in HMAC verification, replay protection, and rate limiting — designed for distributed deployments.
• Strict TypeScript. Full type coverage, no any escape hatches in the public API.

Compatibility

Runtime	Version	Notes
Node.js	≥ 20	Native fetch required
Bun	≥ 1.0
Deno	≥ 1.28
Cloudflare Workers	All	Edge-runtime safe
Vercel / Netlify Edge	All

Install

npm install satim-module
# or
bun add satim-module
# or
pnpm add satim-module
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Quick Start

import { Satim } from 'satim-module';

const satim = new Satim({
  username: process.env.SATIM_USERNAME!,
  password: process.env.SATIM_PASSWORD!,
  terminalId: process.env.SATIM_TERMINAL_ID!,
});

// Register a payment
const payment = await satim
  .amount(1500)
  .returnUrl('https://your-app.com/callback')
  .register();

// Redirect the customer to the hosted payment page
return payment.redirectResponse(); // standard Web API Response (302)
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Verifying a Payment

const response = await satim.confirm(orderId, expectedCartTotal);

if (response.isSuccessful()) {
  // Amount verification is automatic for successful payments
  console.log(response.getSuccessMessage());
} else if (response.isPending()) {
  console.log('Payment not yet completed');
} else if (response.isCancelled()) {
  console.log('Customer cancelled the payment');
} else if (response.isExpired()) {
  console.log('Payment session expired');
} else {
  console.log(response.getErrorMessage());
}
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API

Core Methods

Method	Endpoint	Returns	Description
register()	/register.do	RegisterResponse	Register a payment order.
confirm(orderId, amount)	/confirmOrder.do	ConfirmResponse	Confirm and deposit a payment.
status(orderId)	/getOrderStatus.do	ConfirmResponse	Query the current status of an order.
refund(orderId, amount)	/refund.do	ConfirmResponse	Refund a captured payment.
registerPreAuth()	/registerPreAuth.do	RegisterResponse	Hold funds without capturing.
reverseOrder(orderId)	/reverse.do	ConfirmResponse	Void a transaction before settlement.

Configuration (Fluent Immutable API)

The configuration is strictly immutable. Calling a setter returns a NEW instance.

Method	Description
amount(n)	Payment amount in major currency units (e.g. DZD).
returnUrl(url)	Redirect URL after payment.
failUrl(url)	Redirect URL on failure (defaults to returnUrl).
description(text)	Text shown on the payment page (max 598 chars).
language(lang)	Payment page language: "FR", "AR", or "EN".
currency(code)	"DZD", "USD", or "EUR".
orderNumber(n)	Custom 10-digit order number.
timeout(seconds)	Session timeout (600 – 86400).
userDefinedFields()	Custom metadata forwarded in jsonParams.
dynamicCallbackUrl()	Server-to-server webhook for status notifications.
setTestMode(bool)	Route requests to test.satim.dz.

Status Predicates (on ConfirmResponse)

All predicates are mutually exclusive — at most one terminal-state predicate will return true for any given response.

Method	Condition
isSuccessful()	Payment deposited (OrderStatus 2).
isPending()	Registered but not yet paid (OrderStatus 0).
isReversed()	Authorization reversed/voided (OrderStatus 3).
isFailed()	Terminal failure (not successful, refunded, or pending).
isRejected()	Declined by the issuing bank.
isRefunded()	Refunded (OrderStatus 4).
isCancelled()	Customer cancelled before completing.
isExpired()	Session timed out (actionCode -2007).

Response Accessors

Available on RegisterResponse or ConfirmResponse:

Method	Available On	Returns
getOrderId()	RegisterResponse	Order identifier
getUrl()	RegisterResponse	Hosted payment form URL
redirectResponse()	RegisterResponse	Web API 302 Response
getIpAddress()	ConfirmResponse	Cardholder IP
getCardHolderName()	ConfirmResponse	Name on card
getCardExpiry()	ConfirmResponse	Expiration (YYYYMM)
getCardPan()	ConfirmResponse	Masked PAN
getApprovalCode()	ConfirmResponse	Issuer approval code
getAmount()	ConfirmResponse	Payment amount captured
getOrderNumber()	ConfirmResponse	Verified order number
verifyAmount(n)	ConfirmResponse	Security assertion
getSuccessMessage()	ConfirmResponse	Localized success text
getErrorMessage()	ConfirmResponse	Localized error text
getRawResponse()	Both	Sanitized raw gateway response (PII redacted)

Error Handling

All errors extend SatimError for unified catching:

import { SatimError, SatimGatewayError } from 'satim-module';

try {
  await satim.register();
} catch (err) {
  if (err instanceof SatimGatewayError) {
    // Typed BPC gateway error with err.errorCode and err.errorMessage
    // Code 1 = Duplicate order, 3 = Unknown currency,
    // 4 = Missing parameter, 7 = System error
  }
  if (err instanceof SatimError) {
    // SatimMissingDataError        - required field not set
    // SatimInvalidArgumentError    - validation failure
    // SatimInvalidCredentialsError - wrong username/password/terminal
    // SatimUnexpectedResponseError - network or malformed response
    // SatimGatewayError            - typed BPC gateway errors (1,3,4,7)
  }
}
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Security

The SDK ships with the following protections enabled by default:

• Credential isolation — Credentials live in a module-private WeakMap and never appear as enumerable properties. JSON.stringify() and console.log() automatically redact them. (The SATIM API requires credentials as POST form parameters on every request — make sure reverse proxies, WAFs, and APM tools do not log raw request bodies.)
• SSRF protection — All URLs are validated against private IP ranges (IPv4/IPv6), cloud metadata endpoints, and non-standard IP encodings (decimal, octal, hex).
• Terminal-ID injection prevention — force_terminal_id is always set by the SDK and cannot be overridden via userDefinedFields.
• IEEE 754-safe currency conversion — Amounts are converted to minor units using toPrecision(12) to avoid floating-point drift. Sub-centime amounts that would round to zero are rejected. The precision guard caps at ~10 billion major units.
• Safe retry policy — Financial mutations (register, confirm, refund, reverseOrder) never retry on transient errors, preventing double-charges or double-refunds. Only idempotent queries (status) retry automatically.
• Immutable API — Every setter returns a new instance, preventing cross-request state leaks.

Best practices

1. Always verify server-side. Never trust client-side redirect parameters. Use confirm() or status() to verify outcomes from your backend.
2. Always verify amounts. Call verifyAmount() to detect partial-payment manipulation.
3. Use environment variables. Never hardcode credentials. Load them from process.env or a secrets manager.
4. Never log request bodies. Outgoing POST bodies contain credentials; ensure logging middleware excludes them.
5. Keep TLS valid. Never set NODE_TLS_REJECT_UNAUTHORIZED=0 in production.

For the full threat model, see SECURITY.md.

Documentation

• ARCHITECTURE.md — system topology, request lifecycle, technical constraints, state machine, predicate contract.
• src/README.md — module map and dependency order.
• src/responses/README.md — response wrappers and the status predicate contract.
• src/webhook/README.md — zero-trust verification flow and distributed deployment notes.
• SECURITY.md — threat model, mitigations, known limitations.
• API reference — generated locally with npm run docs (outputs to docs/api/).

Development

bun install       # install dev dependencies
bun test          # run the unit test suite (vitest)
npm run typecheck # strict type checking (any runtime)
npm run build     # compile to dist/
npm run docs      # generate TypeDoc API reference
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Contributing

Contributions are welcome. Please open an issue first for anything beyond a small fix so we can align on scope. PRs should:

1. Keep the zero-dependency rule intact.
2. Pass npm run typecheck and the full test suite.
3. Include tests for behavioral changes.
4. Follow the existing immutable, fluent API style.

License

Released under the MIT License.