Stream USDC Payments to Any Recipient in Real Time

Payment streaming replaces lump-sum or scheduled transfers with a continuous, per-second USDC flow. The sender deposits USDC upfront into the streaming contract on Arc testnet, and the contract releases funds to the recipient at a fixed rate every second. Recipients can withdraw their vested balance at any time — they never have to wait until the end of the stream — and senders can stop the stream early to reclaim unstreamed USDC.

Use Cases

Contractor & Freelancer Payroll

Pay contributors by the second for time worked — no invoicing cycles, no delayed wire transfers.

Subscription Billing

Let subscribers pay continuously as they consume your service, with automatic stop if they cancel.

Grant Disbursement

Release grant funds over a defined vesting period so recipients earn as they deliver milestones.

AI Agent Compensation

Pay autonomous agents for completed compute tasks in real time, tied to their on-chain wallet.

How Streaming Works

Deposit — The sender locks a total USDC amount into the streaming contract.
Stream — The contract releases funds to the recipient at ratePerSecond every second.
Withdraw — The recipient calls withdraw at any time to claim their vested balance.
Stop — The sender can stop the stream; unstreamed USDC is returned to the sender.

Creating a Stream

REST API Parameters

string

required

The wallet address of the sender. This wallet must hold sufficient USDC to cover totalDeposited.

string

required

The wallet address of the recipient. They will withdraw vested USDC to this address.

string

required

USDC released to the receiver per second, expressed as a 6-decimal string, e.g. "0.000193".

string

required

Total USDC to lock into the stream, e.g. "500.00". The stream ends naturally when this balance is exhausted.

string

URL to receive stream lifecycle events. See Webhook Events below.

Managing a Stream

Stop a Stream

The sender calls the stop endpoint to halt the flow. Unstreamed USDC is returned to the sender’s wallet.

curl -X POST https://flarehq.xyz/api/payments/stream/stop \
  -H "Authorization: Bearer fhq_sec_..." \
  -H "Content-Type: application/json" \
  -d '{
    "reference": "stream_m3n7p1x9_ab12cd",
    "callerSCA": "0xYourSenderWalletAddress"
  }'

Withdraw Vested Balance

The recipient withdraws all USDC that has vested since the stream started (or since their last withdrawal).

curl -X POST https://flarehq.xyz/api/payments/stream/withdraw \
  -H "Authorization: Bearer fhq_sec_..." \
  -H "Content-Type: application/json" \
  -d '{
    "reference": "stream_m3n7p1x9_ab12cd",
    "receiverSCA": "0x71C...B39"
  }'

List Streams

Query active or historical streams by sender, receiver, or status.

# All active streams for a sender
curl "https://flarehq.xyz/api/payments/stream?sender=0xYourSenderWalletAddress&status=ACTIVE" \
  -H "Authorization: Bearer fhq_sec_..."

# A specific stream by reference
curl "https://flarehq.xyz/api/payments/stream?reference=stream_m3n7p1x9_ab12cd" \
  -H "Authorization: Bearer fhq_sec_..."

The response includes live metrics computed at request time:

number

USDC already streamed to the receiver as of now.

number

USDC still locked in the contract.

number

Estimated seconds until the stream exhausts the deposit.

number

Percentage of the total deposit that has been streamed.

Stream Lifecycle

ACTIVE ──── sender stops early ──→ STOPPED
  │
  └──── deposit exhausted ────────→ COMPLETED

Status	Description
`ACTIVE`	Stream is live and USDC is flowing per second
`STOPPED`	Sender stopped the stream; remaining USDC returned
`COMPLETED`	Deposit fully exhausted; stream ended naturally

Webhook Events

Event	Fired when
`stream.created`	Stream is confirmed onchain and is `ACTIVE`
`stream.stopped`	Sender calls stop; unstreamed USDC has been returned
`stream.completed`	Deposit balance reaches zero and the stream closes

Example Payload — `stream.created`

{
  "event": "stream.created",
  "reference": "stream_m3n7p1x9_ab12cd",
  "senderSCA": "0xYourSenderWalletAddress",
  "receiverSCA": "0x71C...B39",
  "ratePerSecond": 0.000193,
  "totalDeposited": 500.0,
  "currency": "USDC",
  "estimatedDurationSeconds": 2590674,
  "estimatedEndTime": "2025-02-14T10:00:00.000Z",
  "txHash": "0xabc123...",
  "explorerUrl": "https://testnet.arcscan.app/tx/0xabc123...",
  "createdAt": "2025-01-15T10:00:00.000Z"
}

Minimum deposit and rate precision. USDC on Arc testnet uses 6 decimal places. Express all amounts and rates to at most 6 decimal places. The minimum meaningful ratePerSecond is 0.000001 USDC/s (1 micro-USDC per second). Rates with more than 6 decimal places are truncated by the contract.

Get Started

Payments

x402 Protocol

Agentic Finance

Developer Guide

Stream USDC Payments to Any Recipient in Real Time

Use Cases

Contractor & Freelancer Payroll

Subscription Billing

Grant Disbursement

AI Agent Compensation

How Streaming Works

Creating a Stream

REST API Parameters

Managing a Stream

Stop a Stream

Withdraw Vested Balance

List Streams

Stream Lifecycle

Webhook Events

Example Payload — `stream.created`

​Use Cases

Contractor & Freelancer Payroll

Subscription Billing

Grant Disbursement

AI Agent Compensation

​How Streaming Works

​Creating a Stream

​REST API Parameters

​Managing a Stream

​Stop a Stream

​Withdraw Vested Balance

​List Streams

​Stream Lifecycle

​Webhook Events

​Example Payload — stream.created

Use Cases

How Streaming Works

Creating a Stream

REST API Parameters

Managing a Stream

Stop a Stream

Withdraw Vested Balance

List Streams

Stream Lifecycle

Webhook Events

Example Payload — `stream.created`