There are three ways to build on SohoPay, depending on which side of the payment you sit on. This page helps you pick one and tells you exactly which guides to follow, in order. If you haven’t run the Quickstart yet, do that first — every path assumes you have a working sandbox API key.

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The three paths

Merchant Integration

Accept payments from AI agents. You onboard as a merchant, manage an allowlist, and receive USDC settlements. ~3–5 days.

Agent Setup

Operate agents that pay merchants. You provision credit lines, fund a vault, and handle signing. ~2–3 days.

Full End-to-End

Run both sides — a platform where your own agents pay your own merchants. Do merchant first, then agent, then the payment flow. ~5–7 days.

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Compare the paths

The 5% transaction fee is always charged to the operator’s credit line — merchants receive the full order amount. Details in Fees.

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Which path am I?

Answer in order — the first “yes” is your path:
  • Do you sell a product or API that AI agents should pay for? You’re a merchant → Merchant Integration.
  • Do you run agents that need to buy things autonomously? You’re an operator → Agent Setup.
  • Are you a platform doing both — your agents paying merchants you onboard? Full End-to-End: complete the merchant track, then the agent track, then Payment Flow.
  • Just evaluating the protocol? Skip integration for now and read x402 and the trust model.

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What each path looks like

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Path 1: Merchant Integration (3–5 days)

You expose orders, decide which agents may pay you, and receive settlements.
  1. Merchant Integration — the end-to-end walkthrough.
  2. Merchant Onboarding — account setup; KYB when you go to mainnet.
  3. Allowlist Management — approve the agents allowed to pay you.
  4. Settlements & Payouts — reconciliation and fee breakdowns.
  5. Webhooks — react to payment.settled and merchant.settlement.completed instead of polling.

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Path 2: Agent Setup (2–3 days)

You create agents with credit lines and let them spend within limits you set.
  1. Agent Setup — create agents, set credit_limit and daily_limit, accept operator liability.
  2. Key Management — how the 2-of-3 MPC signing model works and what you hold.
  3. Vault Funding — deposit USDC collateral; vault balance is your borrowing capacity.
As the operator you are liable for your agents’ transactions — agent creation requires operator_acknowledgment: true. Read Operator Liability before going live.

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Path 3: Full End-to-End (5–7 days)

Do the two tracks sequentially, then connect them:
  1. Complete the merchant track above — you need a live merchant with an allowlist before any agent can pay it.
  2. Complete the agent track — create agents and allowlist them against your merchant.
  3. Payment Flow — the full order → sign → settle loop, including the 10-minute order TTL.
  4. Error Handling — declines, expirations, and retries across both sides.
  5. Testing — exercise the whole loop in sandbox before requesting mainnet access.

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Next steps

Merchant Integration

Start the merchant track.

Agent Setup

Start the agent track.

Payment Flow

See how the two sides meet.