> ## Documentation Index > Fetch the complete documentation index at: https://docs.rach.finance/llms.txt > Use this file to discover all available pages before exploring further. # Send to any phone or wallet (instant, on-chain) > Moves USDC between two customer SCWs on Polygon PoS via an ERC-4337 UserOperation. Settlement is on-chain and final within seconds — no banks, no correspondents, no cut-off times. **Addressing:** `sender_phone` and `recipient_phone` each accept EITHER an E.164 phone number (`+2250700000001`) OR a 0x-prefixed 40-character SCW wallet address — the format is auto-detected, so there is no separate field to learn. Use whichever identifier you already have for that party. **Sender** must be a user affiliated with your business (provisioned under or adopted by your account). **Recipient can be ANY phone number or existing wallet address** — system-wide, merchant-agnostic. If the recipient belongs to another business, their business is notified by webhook. If addressed by phone and that number has never been provisioned by anyone, Rach creates an unaffiliated wallet on the fly (`recipient_status: PROVISIONED_ON_THE_FLY`) and notifies the recipient by SMS with instructions to access their money via Rach's USSD service. Addressing by wallet address requires that wallet to already exist — it cannot be auto-provisioned, since there's no phone number to derive a fresh identity from. For fiat-denominated transfers supply a valid quote_id from POST /v1/fx/quote. For direct crypto amounts use quote_id format `DIRECT_CRYPTO:USDC:{amount}` (e.g. `DIRECT_CRYPTO:USDC:10.50`). AML daily/monthly limits apply per sender. ## OpenAPI ````yaml /api-reference/caas-openapi.json post /v1/transfers/send openapi: 3.0.0 info: description: >- Rach CaaS is the stablecoin infrastructure layer for African fintechs and financial institutions. It enables any business to offer their customers non-custodial USDC and USDT wallets, instant on-chain transfers, and fiat ↔ stablecoin conversion in any supported currency (XOF, XAF, NGN, GHS, ...) — without building blockchain infrastructure. **Stablecoins:** USDC and USDT are supported equally everywhere. On any endpoint that moves value — `POST /v1/users/fund`, `POST /v1/transfers/send`, `POST /v1/users/withdraw` — set the token (`target_token` / `token`, or the ticker inside a `DIRECT_CRYPTO:{USDC|USDT}:{amount}` quote). `GET /v1/users/balance` returns both `balance_usdc` and `balance_usdt`. **System-wide phone addressing:** wallets are keyed by phone number and belong to the system, not to any one business. Money moves freely across businesses — and to phone numbers that have never been provisioned: Rach creates the wallet on the fly and notifies the recipient by SMS with USSD access instructions. **Network:** Polygon PoS (Chain ID 137). All smart contract wallets, transfers, and withdrawals settle on Polygon mainnet. Test environments use Sepolia (Chain ID 11155111). ## Authentication **B2B API endpoints** (`/v1/users/*`, `/v1/transfers/*`, `/v1/fx/*`) use API Key authentication. Pass your key in the `X-API-Key` header. Keys are prefixed `rach_sk_live_` (mainnet) or `rach_sk_test_` (sandbox — no on-chain execution). **Dashboard endpoints** (`/v1/dashboard/*`) use JWT Bearer authentication. Your JWT must include `business_id` and the `waas` permission scope. ## Sandbox Mode All B2B endpoints honour test-mode API keys (`rach_sk_test_*`). In sandbox mode every operation returns an immediate success response (`SANDBOX_SIMULATED`) without touching the blockchain or debiting your treasury balance. Use sandbox keys for integration testing and CI. ## Typical Integration Flow 1. `POST /v1/users/provision` — create a non-custodial SCW for each end-user (offline, no gas) 2. Collect fiat from customer → deposit to Rach bank account → `POST /v1/dashboard/treasury/topup` 3. Rach confirms XOF receipt → `POST /v1/dashboard/treasury/topup/{id}/confirm` (credits your USDC balance) 4. `POST /v1/users/fund` — transfer USDC from your treasury balance to the customer SCW on-chain 5. `GET /v1/users/balance` — read live on-chain USDC balance via Polygon RPC 6. `POST /v1/transfers/send` — instant peer-to-peer USDC transfer between customer SCWs (ERC-4337 UserOp) 7. `POST /v1/users/withdraw` — off-ramp: sweep USDC from SCW back to Rach treasury; Rach pays out XOF via mobile money ## System-Wide Wallets & Multi-Membership A wallet is keyed by phone number and belongs to the **system**, not to any one business. Several businesses can operate the same wallet — but only with the customer's consent. **Provisioning outcomes** (`POST /v1/users/provision`): - `PROVISIONED` — new wallet created; you are its first member. - `ADOPTED` — the phone had an unaffiliated wallet (created on the fly by an inbound transfer); you are now its primary member. - `ALREADY_EXISTS` — the wallet exists and you already operate it. - `LINK_REQUIRED` — the wallet belongs to another business. You get the same address back but **no operating rights**. Start the consent flow to gain them. **Consent-based linking** (to operate a wallet another business created): 1. `POST /v1/users/link/request` — a one-time code is SMSed to the customer. 2. `POST /v1/users/link/confirm` — submit the code the customer gives you; you become a member. Existing members receive a `user.linked` webhook. **Money-in is open, money-out is gated.** Any business can fund a wallet or send money to it (paid from the sender's own ledger). Only a **member** may originate transfers, withdraw, or change the phone number for a wallet. **Consent-gated phone change** (`POST /v1/users/phone-change/request` → `/confirm`): a one-time code is SMSed to the NEW number (proving SIM control). The SCW address, balance and history are preserved; every member receives a `user.phone_changed` webhook. ## Webhook Events Signed with HMAC-SHA256 over the body in the `X-Rach-Signature: sha256=...` header (key = your webhook secret). - `transfer.received` — a wallet you operate received an inbound transfer. - `user.linked` — a new business was granted operating rights on a wallet you operate. - `user.phone_changed` — the phone number of a wallet you operate was re-keyed (address unchanged). ## Multi-Currency Rach moves any fiat; USDC is the settlement rail. Rates are per-currency (XOF, XAF, NGN, GHS, ...). See `GET /v1/dashboard/rates`. Topup quotes and withdrawals carry a `currency_code` / `payout_currency`. ## Status Lifecycles **Deposit:** `QUEUED` → `SETTLED` **Transfer:** `QUEUED` → `SUBMITTED` → `SETTLED` **Withdrawal:** `PENDING` → `SUBMITTED` → `CRYPTO_RECEIVED` → `COMPLETED` title: Rach CaaS — Crypto-as-a-Service API contact: name: Rach Finance Support url: https://rach.finance version: 1.0.1 servers: - url: https://api.rach.finance/caas/api security: [] paths: /v1/transfers/send: post: tags: - B2B - Transfers summary: Send to any phone or wallet (instant, on-chain) description: >- Moves USDC between two customer SCWs on Polygon PoS via an ERC-4337 UserOperation. Settlement is on-chain and final within seconds — no banks, no correspondents, no cut-off times. **Addressing:** `sender_phone` and `recipient_phone` each accept EITHER an E.164 phone number (`+2250700000001`) OR a 0x-prefixed 40-character SCW wallet address — the format is auto-detected, so there is no separate field to learn. Use whichever identifier you already have for that party. **Sender** must be a user affiliated with your business (provisioned under or adopted by your account). **Recipient can be ANY phone number or existing wallet address** — system-wide, merchant-agnostic. If the recipient belongs to another business, their business is notified by webhook. If addressed by phone and that number has never been provisioned by anyone, Rach creates an unaffiliated wallet on the fly (`recipient_status: PROVISIONED_ON_THE_FLY`) and notifies the recipient by SMS with instructions to access their money via Rach's USSD service. Addressing by wallet address requires that wallet to already exist — it cannot be auto-provisioned, since there's no phone number to derive a fresh identity from. For fiat-denominated transfers supply a valid quote_id from POST /v1/fx/quote. For direct crypto amounts use quote_id format `DIRECT_CRYPTO:USDC:{amount}` (e.g. `DIRECT_CRYPTO:USDC:10.50`). AML daily/monthly limits apply per sender. requestBody: content: application/json: schema: $ref: '#/components/schemas/cmd_api.TransferRequest' description: Transfer payload required: true responses: '202': description: Accepted content: application/json: schema: $ref: '#/components/schemas/cmd_api.TransferResponse' '400': description: Invalid payload or expired FX quote content: application/json: schema: type: object additionalProperties: true '401': description: Invalid or missing API key content: application/json: schema: type: object additionalProperties: true '404': description: Sender or recipient wallet not provisioned content: application/json: schema: type: object additionalProperties: true '409': description: Duplicate idempotency key content: application/json: schema: type: object additionalProperties: true '410': description: FX quote expired content: application/json: schema: type: object additionalProperties: true '429': description: 'AML block: daily or monthly limit exceeded' content: application/json: schema: type: object additionalProperties: true security: - ApiKeyAuth: [] components: schemas: cmd_api.TransferRequest: type: object required: - idempotency_key - local_fiat_amount - quote_id - recipient_phone - sender_phone - target_token properties: idempotency_key: type: string example: txn_ref_abc123 local_fiat_amount: type: string example: '5500.00' quote_id: type: string example: DIRECT_CRYPTO:USDC:0.50 recipient_phone: description: >- RecipientPhone identifies the recipient — same dual format. Addressing by phone allows on-the-fly provisioning for a never-seen number; addressing by wallet address requires that wallet to already exist. type: string example: '+2250700000002' sender_phone: description: >- SenderPhone identifies the sender — accepts EITHER an E.164 phone number (+2250700000001) OR a 0x-prefixed wallet address. No separate field needed: the format is auto-detected. type: string example: '+2250700000001' target_token: type: string enum: - USDT - USDC example: USDC cmd_api.TransferResponse: type: object properties: created_at: type: string message: type: string recipient_status: description: >- RecipientStatus is "EXISTING" when the recipient already had a wallet, or "PROVISIONED_ON_THE_FLY" when Rach auto-created an unaffiliated wallet for their phone number (recipient gets an SMS with USSD access instructions). type: string example: EXISTING status: type: string transfer_id: type: string securitySchemes: ApiKeyAuth: description: >- Your Rach B2B API key. Use `rach_sk_live_*` for production (on-chain) or `rach_sk_test_*` for sandbox (no-chain simulation). type: apiKey name: X-API-Key in: header ````