> ## Documentation Index > Fetch the complete documentation index at: https://docs.crypto.westminister.tech/llms.txt > Use this file to discover all available pages before exploring further. # Send USDT Payment To Escrow Or Destination Address > Initiates USDT transfer from user's EmaalCoin wallet to the destination address. Supports both on-ramp (ON_RAMP_BUY) and off-ramp (OFF_RAMP_SELL) orders. **For Off-Ramp Orders:** - Transfers USDT from customer's wallet to escrow address - Used when customer wants to send crypto in-app (no external wallet needed) - Network and destination are determined from order's escrow details **For On-Ramp Orders:** - Transfers USDT from customer's wallet to their own wallet address - Typically not used (vendor sends USDT after mobile money payment) - Network is detected from customer's wallet address - Supported for alternative flows or pre-funding scenarios **Security:** - Wallet must belong to the order's customer - Wallet network must match order's required network - Requires explicit confirmation (`confirm: true`) - Private keys are decrypted server-side only ## OpenAPI ````yaml /openapi.yaml post /api/v1/auth/orders/{order_id}/send-payment openapi: 3.1.0 info: title: EmaalCoin API description: > EmaalCoin API reference. These APIs power cryptocurrency exchange between USDT and Fiat trading. - **On-Ramp**: Buy USDT with fiat (KES) via mobile money (STK Push for Kenya) - **Off-Ramp**: Sell USDT for KES with mobile money payout (Kenya) - **Ethereum, TRON, and Solana**: Multi-chain wallet support - **Merchant Offers**: Create and manage trading offers - **OTC Flows**: Bank and mobile money deposits/withdrawals for merchants - **Pricing engine**: FX quotes and fee profiles for quote-backed orders and transfers - **P2P/B2B transfers**: Internal and external stablecoin sends (USDT/USDC) with optional pricing snapshots - **Stablecoin swaps**: Treasury-backed two-leg USDT ↔ USDC conversion with BitGo confirmation, inventory reservation, and automatic refunds - **Multisig**: Collaborative and platform-managed multisig flows for high-value B2B version: 1.1.0 servers: - url: https://crypto.westminister.tech description: Production API (requires DNS for this hostname). - url: http://13.42.110.185:8080 description: >- UAT on EC2 (direct). Use this base when building proof PDF URLs if the production hostname does not resolve. security: [] tags: - name: Pricing description: >- Commercial pricing profiles and FX rate quotes (admin). Used with orders and transfers for auditable snapshots. - name: Transfers description: >- P2P and B2B stablecoin transfers (USDT/USDC). Optional fiat-equivalent pricing fields. B2B multisig behavior depends on wallet registration (synchronous completion vs proposal flow). - name: Stablecoin Swaps description: >- Treasury-backed USDT ↔ USDC conversions for BitGo provider-managed wallets on `tron`, `ethereum`, or `solana`. Collection confirms before treasury payout starts. Completion requires both legs and dual-asset balance synchronization. - name: Multisig description: >- Multisig wallet registration and TRON proposal/confirm flows (vendor/admin). - name: Escrow Wallets description: Escrow pool wallet metadata for off-ramp and operations. - name: Users description: >- User-related operations (registration, lookup, updates, counts, status changes) - name: Wallets-Users description: User wallet operations (create, manage, query balances) - name: Offers description: Offer operations (create, read, list, counts) - name: Orders description: Order operations (create, update, list, counts, stats) - name: Payment description: Payment initiation operations - name: Merchants description: > Merchant (vendor) onboarding and hierarchy operations. USE **GET /API/V1/AUTH/MERCHANTS** WITH **PAGE_ID** AND **PAGE_SIZE** TO PAGE MASTER VENDORS. USE **GET /API/V1/AUTH/MERCHANTS/{MERCHANT_ID}** FOR ONE MASTER VENDOR, **MERCHANT_WALLETS**, AND ALL **SUBVENDOR** ROWS WITH **WALLETS** (FULL TREE). - name: OTC Deposits description: > OTC fiat-to-crypto deposits (bank or mobile money). Rows live in **`otc_deposits`**. Merchants create drafts or one-shot deposits. **admin**, **otc_officer**, or **treasury** list all deposits. B2B bank flow uses draft, quote, submit, proof, assign, claim, settlement, and audit. **`credited_to_address`** is the merchant on-chain wallet treasury credits (resolved from the default wallet for **`requested_network`** on the master merchant ledger user or any **sub-vendor** under that merchant). **`GET /api/v1/auth/otc/deposits`** backfills missing **`credited_to_address`**/**`to_wallet_id`** when a wallet can be resolved. One-shot **`POST /api/v1/auth/otc/deposits`** persists the payout address when **`requested_network`** is sent. Bank proof PDFs upload via `POST .../proof` and are viewed at **`GET /otc-deposits-proof/{deposit_id}/{file}.pdf`** (relative **`proof_url`**/**`file_url`** plus API base URL). Merchants may edit tab-1 draft fields with **`PATCH /api/v1/auth/otc/deposits/{id}/draft`** while **`status`** is **`draft`**. - name: OTC Withdrawals description: >- OTC crypto-to-fiat withdrawals (bank or mobile money). Merchants create. Admin approves and executes. - name: OTC Config description: OTC display config (bank details, mobile money paybill) for merchant UI - name: Fiat Currencies description: > Shared platform **fiat_currencies** catalog. **GET /api/v1/auth/fiat-currencies** lists active rows for UI pickers. **GET /api/v1/auth/fiat-currencies/admin** lists all rows including inactive (admin). Admin manages rows with **GET /api/v1/auth/fiat-currencies/{id}**, **POST /api/v1/auth/fiat-currencies**, **PATCH /api/v1/auth/fiat-currencies/{id}**, and **DELETE /api/v1/auth/fiat-currencies/{id}**. Use for OTC, pricing, orders, remittance, and backoffice — not under **`/otc/...`**. Prefer **PATCH** with **`is_active: false`** over delete when a currency is referenced. - name: Countries description: >- Shared platform **countries** catalog. Public **GET /api/v1/countries** lists active rows for pickers. Auth **GET /api/v1/auth/countries** returns the same active catalog. Admin manages rows with **GET /api/v1/auth/countries/admin**, **GET /api/v1/auth/countries/{id}**, **POST /api/v1/auth/countries**, **PATCH /api/v1/auth/countries/{id}**, and **DELETE /api/v1/auth/countries/{id}**. - name: Files description: Authenticated file uploads for OTC receipts and proof artifacts. paths: /api/v1/auth/orders/{order_id}/send-payment: post: tags: - Orders summary: Send USDT Payment To Escrow Or Destination Address description: > Initiates USDT transfer from user's EmaalCoin wallet to the destination address. Supports both on-ramp (ON_RAMP_BUY) and off-ramp (OFF_RAMP_SELL) orders. **For Off-Ramp Orders:** - Transfers USDT from customer's wallet to escrow address - Used when customer wants to send crypto in-app (no external wallet needed) - Network and destination are determined from order's escrow details **For On-Ramp Orders:** - Transfers USDT from customer's wallet to their own wallet address - Typically not used (vendor sends USDT after mobile money payment) - Network is detected from customer's wallet address - Supported for alternative flows or pre-funding scenarios **Security:** - Wallet must belong to the order's customer - Wallet network must match order's required network - Requires explicit confirmation (`confirm: true`) - Private keys are decrypted server-side only parameters: - name: order_id in: path required: true schema: type: string format: uuid description: Order ID requestBody: required: true content: application/json: schema: type: object required: - wallet_id - confirm properties: wallet_id: type: string format: uuid description: Wallet ID to send USDT from (must belong to order customer) example: a4a7e9af-3e09-4c49-9cd7-d9e69500e4a4 confirm: type: boolean description: Confirmation flag (must be true to proceed) example: true responses: '200': description: Payment initiated successfully content: application/json: schema: type: object properties: transaction_hash: type: string description: Blockchain transaction hash example: 0xabc123def456... status: type: string description: Transaction status enum: - pending - confirmed example: pending estimated_confirmations: type: integer description: Estimated number of confirmations required example: 20 network: type: string description: Blockchain network example: tron message: type: string description: Status message example: >- USDT transfer initiated successfully. Waiting for blockchain confirmation. examples: tron: summary: Tron Transfer Initiated value: transaction_hash: 0xabc123def456... status: pending estimated_confirmations: 20 network: tron message: >- USDT transfer initiated successfully. Waiting for blockchain confirmation. ethereum: summary: Ethereum Transfer Initiated value: transaction_hash: 0xdef456abc123... status: pending estimated_confirmations: 10 network: ethereum message: >- USDT transfer initiated successfully. Waiting for blockchain confirmation. '400': description: >- Bad request (invalid order type, network mismatch, confirmation required, etc.) '403': description: Forbidden (wallet does not belong to order customer) '404': description: Order or wallet not found '500': description: Internal server error (transfer failed, decryption failed, etc.) security: - bearerAuth: [] components: securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: PASETO ````