Overview & Concepts

For a one-time transaction, an agent signs a payment and the exchange clears in a single HTTP round trip - that's Move Onchain Money. Streaming works differently: an agent signs one authorization with a spending cap, and zerohash's Payments Streaming Engine meters actual usage and settles in increments as the session runs - crediting the business in near real-time and never charging beyond what was consumed.

The solution encompasses the following steps:

1. Configure the zerohash x402 middleware connector for your Platform's to support streaming
2. Configure merchants x402 payins parameters such as defining a metering unit (per second, token, or megabyte), a price-per-unit, a maximum session spend cap, and a settlement/increment period.
3. Integrate to the Agentic Streaming integration guide, below.
4. Start accepting streaming agentic payments.

zerohash is applying this streaming payments rail to:

• Streaming and metered access: Live data feeds, running model output, and video or audio streams billed by the second, the token, or the megabyte.
• Creator and publisher paywalls: Per-article, per-video, or per-download pricing collected at the moment of access, with no subscription required.
• Public API monetization for AI agents: Market data, inference, geolocation, or search APIs that charge per call instead of running on API keys and postpaid invoices.
• Agentic commerce for platforms: Marketplaces and SaaS platforms exposing usage-based tools directly to autonomous agents, on the same settlement model as their existing merchants.

Roles

1. Shopper's Agent initiates an x402 request. The agent calls the x402-enabled endpoint directly: GET /forecast?city=chicago . The merchant can configure the x402 payins parameters such as price-per-endpoint-access, maximum spend limits, and specific asset & network acceptance either through your own x402 middleware or zerohash's middleware solution.
2. Merchant returns payment requirements in response to Shopper's Agent. The merchant's middleware responds with 402 Payment Required with the KYA requirements to onboard a Shopper's agent, price to access the endpoint requested, supported assets, amount limits, chains, and destination address for payment.
3. Shopper's Agent resubmits x402 request with payment & KYA requirements - Shopper's agent includes all requirements in X-PAYMENT header of request.
4. zerohash authorize's the payment via POST /verify. The Platform submits the payment and KYA requirements to zerohash's /verify endpoint on the agent's behalf. zerohash checks the request against the merchant's configured product_permissions and transaction limits (see Set agent permissions and limits) and confirms whether it's authorized - no funds move at this step.

Streaming Integration Guide

The agent's session spend cap is enforced against merchant's x402 streaming configuration. A session cap is the maximum amount a merchant wants an agent to spend within a given frame.

x402 streaming occurs either through the zerohash middleware or through your own middleware that uses zerohash as a payment facilitator. The spend sessions are defined at first x402 request, and settlement terms are done in batches according to the merchant's configuration.

How a streaming session completes:

1 - Shopper's Agent initiates an x402 request - The agent calls the merchant's x402 streaming enabled endpoint, requesting access: GET /stream/market-data

2 - Merchant returns streaming payment requirements in response to Shopper's Agent. The merchant's middleware responds with 402 Payment Required with the KYA requirements to onboard a Shopper's agent, metering unit, price-per-unit, and maximum cap it will accept.

  {
    //KYA requirements
		"accepts": [
      {
        "scheme": "upto",
        "network": "base",
        "asset": "USDC",
        "price_per_unit": "0.0001",
        "unit": "second",
        "max_session_amount": "5.00",
        "pay_to": "0xSkylineAddress"
      }
    ]
  }

3 - Authorize the session via POST /verify: The Platform submits the proposed cap to zerohash, referencing the agent's participant_code and account_label. zerohash checks the cap against the agent's existing product_permissions and transaction limits (same check as Move) and, if authorized, opens a session - reserving the ceiling, not charging it.

Response:

{
    "status": "verified",
    "session_id": "SESSION-8821",
    "participant_code": "CUST01",
    "account_label": "AGENT01"
  }

4 - Usage accrues. As the agent consumes the metered resource, usage is tracked against the price-per-unit for the duration of session_id.

5 - Increments settle via POST /settle. Rather than a single settlement, /settle is called once per settlement period (e.g., every 60 seconds) for the duration of the session, each call debiting only what's been consumed since the last increment. As with Move, this is a free internal ledger transfer if the merchant is also zerohash-custodied, or a real onchain transfer otherwise.

POST /settle call:

  {
    "session_id": "SESSION-8821",
    "participant_code": "CUST01",
    "account_label": "AGENT01",
    "increment_amount": "0.006",
    "asset": "USDC.BASE"
  }

Response:

{
    "status": "settled",
    "settlement_type": "internal_ledger",
    "session_id": "SESSION-8821",
    "cumulative_amount": "0.006",
    "remaining_cap": "4.994",
    "settled_at": "2026-07-29T12:01:00Z"
  }

6 - Session closes: When the agent's task ends, or the cap is reached, the Platform (or the merchant, or an idle timeout) closes the session. A final /settle call reconciles any remaining metered usage since the last increment; the unspent portion of the cap is never charged.

{
  "participant_code": "CUST01",
  "account_label": "AGENT01",
  "wallet_address": "0xAgentExternalAddress",
  "network": "base",
  "wallet_type": "smart_account"
}

"I grant a session key authority to spend up to 5.00 USDC to 0xSkylineAddress,
expiring at [timestamp]."

GET /stream/market-data
Header: SESSION-GRANT: <base64-encoded session key grant>

{
  "accepts": [
    {
      "scheme": "upto",
      "network": "base",
      "asset": "USDC",
      "price_per_unit": "0.0001",
      "unit": "second",
      "max_session_amount": "5.00",
      "pay_to": "0xSkylineAddress"
    }
  ]
}

{
  "session_grant": "<base64-encoded session key grant>",
  "session_requirements": {
    "asset": "USDC.BASE",
    "max_session_amount": "5.00",
    "price_per_unit": "0.0001",
    "unit": "second",
    "pay_to": "0xSkylineAddress",
    "scheme": "upto"
  }
}

{
  "status": "verified",
  "session_id": "SESSION-9042",
  "payer_address": "0xAgentExternalAddress"
}

{
  "session_id": "SESSION-9042",
  "increment_amount": "0.006",
  "asset": "USDC.BASE"
}

{
  "status": "settled",
  "settlement_type": "onchain",
  "session_id": "SESSION-9042",
  "transaction_hash": "0xdef456...",
  "cumulative_amount": "0.006",
  "remaining_cap": "4.994",
  "settled_at": "2026-07-29T12:01:00Z"
}