Developer documentation

Build carbon-negative cross-border payments in one API call.

Keep whatever payment provider you already use. Point a payment intent at the AfriCredit corridor API and SynapticChain resolves the optimal route, settles atomically in under a second, and retires carbon on-chain — returning a verifiable certificate with every transaction.

Quickstart Live demo

Overview

Introduction

AfriCredit is the settlement layer for African stablecoins, running on SynapticChain. A single REST endpoint turns a payment intent into an atomic on-chain settlement: mint, route through the aUSD hub or a direct pair, off-ramp, and retire carbon — all in one transaction that finalizes in well under a second.

Base URL

api.synapticchain.xyz

Protocol fee

0.01%

Carbon levy

0.01%

Every settlement is carbon-negative by default. You never opt in — the 0.01% levy buys and burns tCC credits atomically and returns a certificate you can surface to your users.

Getting started

Quickstart

Send your first cross-border settlement in three steps. The example moves 150,000 NGN to a Kenyan recipient in KES.

1Grab a secret key from the dashboard. Test keys are prefixed sk_test_afc.
2POST a payment intent to the corridor endpoint.
3Read the settlement + carbon certificate from the response.

cURL

curl -X POST https://api.synapticchain.xyz/settle \
  -H "X-API-Key: your_api_key_here" \
  -H "Content-Type: application/json" \
  -d '{
    "source": "NGN",
    "destination": "KES",
    "amount": 150000,
    "recipient": "syn1q9recipient…",
    "provider": "flutterwave"
  }'

Node.js

import { AfriCredit } from '@africredit/sdk'

const afc = new AfriCredit({ apiKey: process.env.SYNAPTICCHAIN_API_KEY })

const settlement = await afc.corridors.settle({
  source: 'NGN',
  destination: 'KES',
  amount: 150_000,
  recipient: 'syn1q9recipient…',
  provider: 'flutterwave',
})

console.log(settlement.certificate.certificateId)
// -> tCC-9F2A-C7B1  (carbon retired atomically)

Security

Authentication

Authenticate every request with a bearer token in the Authorization header. Keys are environment-scoped — never ship a live key to a browser or mobile client.

request header

X-API-Key: your_api_key_here

The RPC endpoint at api.synapticchain.xyz/rpc uses the same X-API-Key header. The public /health endpoint requires no key.

X-API-Key: test_…

Simulated corridors and certificates. No real value moves.

X-API-Key: live_…

Production settlements against live vaults and oracles on mainnet-beta.

Core API

Corridor API

POST/settle

Resolve the best route between two markets and settle atomically. Source and destination accept either a fiat code (NGN) or its stablecoin (cNGN).

Body parameters

sourcestringrequired

Origin market — fiat code or stablecoin ticker.

destinationstringrequired

Target market. Must differ from the source market.

amountnumberrequired

Notional in the source currency. Must be greater than zero.

recipientstringoptional

Destination wallet address. Defaults to a generated demo wallet.

providerstringoptional

Label for your upstream provider, echoed into the event stream.

Response

Returns the resolved route, the amount that lands, timing, and an embedded carbon certificate.

200 OK · application/json

{
  "ok": true,
  "settlementId": "scs_8fk2p1az",
  "txHash": "0x7c3f…e91a",
  "corridor": "NGN→KES",
  "path": "hub",
  "amountIn": 150000,
  "currencyIn": "NGN",
  "amountOut": 12184.55,
  "currencyOut": "KES",
  "effectiveRate": 0.0812,
  "feePct": 0.01,
  "finalityMs": 397,
  "youGainPct": 7.9,
  "hops": ["NGN", "cNGN", "aUSD", "cKES", "KES"],
  "carbon": {
    "carbonFeeUsd": 0.0094,
    "tccRetired": 0.0947,
    "co2Tonnes": 0.000947,
    "co2Kg": 0.947
  },
  "certificate": {
    "certificateId": "tCC-9F2A-C7B1",
    "retirementHash": "0x1b8c…",
    "gescoStatus": "pending-quarterly-audit",
    "ncmcStandard": "NCMC-CA-2026 · national carbon accounting"
  },
  "explorer": "https://explorer.synapticchain.xyz/tx/0x7c3f…e91a"
}

Core API

Webhooks

Rather than polling, subscribe to settlement lifecycle events. AfriCredit POSTs a signed JSON payload to your endpoint as each stage completes — the same event stream you see in the live demo.

Event	Fires when
`settlement.created`	Payment intent accepted and route solved.
`settlement.routed`	Corridor path locked against oracle marks.
`settlement.retired`	tCC purchased and burned; certificate minted.
`settlement.settled`	Funds landed in the recipient wallet.
`settlement.failed`	Route became unfillable; funds unwound atomically.

Example payload

POST · your-endpoint

// POST from AfriCredit -> your endpoint
{
  "event": "settlement.retired",
  "settlementId": "scs_8fk2p1az",
  "corridor": "NGN→KES",
  "amountOut": 12184.55,
  "currencyOut": "KES",
  "certificate": {
    "certificateId": "tCC-9F2A-C7B1",
    "co2Kg": 0.947,
    "gescoStatus": "pending-quarterly-audit"
  },
  "signature": "t=1751760000,v1=8d5f…"
}

Verifying signatures

Every request carries an AfriCredit-Signature header. Compute an HMAC-SHA256 over `${timestamp}.${body}` and compare in constant time.

TypeScript

import crypto from 'node:crypto'

export function verify(payload: string, header: string) {
  const [t, v1] = header.split(',').map((p) => p.split('=')[1])
  const signed = `${t}.${payload}`
  const digest = crypto
    .createHmac('sha256', process.env.AFC_WEBHOOK_SECRET!)
    .update(signed)
    .digest('hex')
  return crypto.timingSafeEqual(Buffer.from(digest), Buffer.from(v1))
}

Reference

Errors

Errors return a non-2xx status with { ok: false, error, message }. The error field is a stable machine code.

Code	Status	Meaning
`invalid_json`	400	Request body was not valid JSON.
`unauthorized`	401	Missing or invalid API key.
`unroutable`	422	Source/destination are equal, unknown, or amount ≤ 0.
`insufficient_depth`	409	Vault depth too shallow for the notional.
`rate_limited`	429	Too many requests — back off and retry.

Protocol

Carbon & certificates

Carbon retirement is constitutional to the protocol. The carbon and certificate objects on every settlement are your ESG audit trail: certificate ID, retirement hash, tCC burned, CO₂ offset, and GESCO verification status against the NCMC-CA-2026 standard.

The Retirement Vault has no withdrawal function — burned credits can never re-enter circulation, so retirement is provably permanent and safe to report against GRI, SASB, and TCFD frameworks.

Open the retirement station

Reference

Supported corridors

12 live markets, each with an on-chain stablecoin and an over-collateralized vault. Any pair is routable — directly or through the aUSD hub.

Market	Fiat	Stablecoin	Vault depth
Nigeriahub	NGN	cNGN	$214M
Kenyahub	KES	cKES	$168M
South Africahub	ZAR	cZAR	$231M
Tanzania	TZS	cTZS	$96M
Ghana	GHS	cGHS	$84M
Egypthub	EGP	cEGP	$142M
Zambia	ZMW	cZMW	$41M
Uganda	UGX	cUGX	$52M
Morocco	MAD	cMAD	$73M
Senegal	XOF	cXOF	$58M
Rwanda	RWF	cRWF	$33M
Ethiopia	ETB	cETB	$47M