Start here · Sellers
Audience: You run a normal web API (REST, GraphQL, etc.) in any language and want paid access without becoming a blockchain developer.
Goal: Integrate against Mainnet (https://ipay.sh) and accept real payments. Devnet (https://preview.ipay.sh) is an optional rehearsal if you want zero financial risk while learning the steps.
You keep your API. You add HTTP 402 + forward payment proof to pr402. You never run any blockchain inside your server.
Ready to code? → Hands-on seller lab (Express weather API, steps 1–6) · Integrate your API (~30 minutes, language examples). Already know x402? → Quick reference · 5 steps.
Documentation map
| When you want… | Read |
|---|---|
| Prerequisites + pick rail (this page) | Start here |
| New web2 seller (hands-on) | Hands-on seller lab |
| Full walkthrough + Rust / Python / JS / Go samples | Integrate your API |
Minimal cheat-sheet (exact rail only) | Quick reference · 5 steps |
| Sovereign fees, JIT provisioning, oracle profiles | Onboarding guide |
Facilitators vs buyer tools (CDP, x402.org, pay CLI) | Choosing x402 on Solana · Appendix B below |
| Machine-readable contract | GET /openapi.json on your facilitator host |
Facilitator hosts: Mainnet https://ipay.sh · Devnet https://preview.ipay.sh. Use one origin everywhere ($BASE). Confirm cluster with GET $BASE/api/v1/facilitator/health.
Prerequisites (before code)
Check these off:
- [ ] An HTTP API you control (Node, Python, Go, Rust, Java, Ruby, PHP, …).
- [ ] A Solana wallet (your seller identity):
- Browser (typical): Phantom or Solflare — install the extension, create or import a wallet, copy your public address.
- Server / CI only: install Solana CLI, then run
solana-keygen new -o seller.json— store the keypair safely; publish only the pubkey (solana-keygen pubkey seller.json).
- [ ] Mainnet SOL in that wallet (recommended, not required): ~0.1 SOL is enough if you use Activate on ipay.sh to self-provision your SplitVault before the first sale. That unlocks the sovereign protocol fee tier (90 bps vs 100 bps standard). If you skip Activate, pr402 can still JIT-provision your vault on the first paid transaction — you keep 100 bps fees and pay no upfront SOL.
- [ ] Do not hardcode mints or PDAs from blog posts — copy live values from
GET $BASE/api/v1/facilitator/capabilitiesor/supported.
You do not need a blockchain SDK in your API server.
Optional — rehearse on Devnet first: Point $BASE at https://preview.ipay.sh and use preview.ipay.sh (not Mainnet ipay.sh) for Preview / Activate. Devnet test funds:
- SOL: switch your wallet to Devnet, then open faucet.solana.com — paste your wallet address, select an amount, and airdrop. CLI:
solana config set --url devnet, thensolana airdrop 2 YOUR_PUBKEY. - USDC (optional, recommended): faucet.circle.com — select USDC and Solana Devnet, paste your wallet address. Creates/funds your Devnet USDC token account before your first sale.
Only Devnet Activate needs SOL; your API server never spends it.
Pick your rail
exact (UniversalSettle) | sla-escrow (SLA-Escrow) | |
|---|---|---|
| Best for | Instant access, API calls, payments from ~5¢ upward | High value, slow fulfillment, refunds / delivery proofs |
| Buyer experience | Pay once → content immediately | Pay into escrow → you deliver → oracle / release path |
| Your integration size | Smaller (402 + settle) | Larger (SLA terms, oracle, fulfillment) |
| Next step | Integrate your API | Onboarding guide · SLA-Escrow, then integration guide |
Default for first integration: exact. Switch to sla-escrow when buyers need escrow protection on high-value or slow-fulfillment work.
Before you set prices, skim Appendix A · Protocol fees (optional reference).
When you are stuck
| Symptom | Likely fix |
|---|---|
| Buyers pay wrong address | payTo must be vault PDA from /payment-required/enrich or /sellers/{wallet}/rails/{scheme}, not bare wallet |
| Mixed Devnet / Mainnet | One $BASE everywhere — 402 body, settle, health check |
| Settle fails quickly on Solana | Call /settle promptly; do not verify-then-wait-then-settle with long gaps |
| Fee eats most of a micro-payment | Raise price or see Appendix A · Protocol fees |
| Need audit / correlation IDs | Optional POST /verify before /settle — see Integrate your API |
Deep reference: Agent integration runbook · API overview
Supplemental reference
Optional reading — pricing math and facilitator comparisons. Not required to complete integration.
Appendix A · Protocol fees & pricing
pr402 deducts a protocol fee from each payment at settlement. Treat GET $BASE/api/v1/facilitator/capabilities as authoritative if numbers drift; the table below matches the live ipay.sh deployment today.
exact | sla-escrow | |
|---|---|---|
| Standard rate | 100 bps (1.00%) | 100 bps (1.00%) on protocol fee |
Sovereign rate (exact only) | 90 bps (0.90%) after self-provision via Activate | — |
| Minimum protocol fee (USDC rail) | $0.01 (1 cent) | $0.10 (10 cents) |
| Oracle tip | none | 100 bps (1.00%) when an oracle renders a verdict — no floor |
How the floor bites on small exact payments: fee = max(1% × amount, $0.01). Examples on USDC:
| Price per call | Protocol fee | Fee as % of your revenue |
|---|---|---|
| $0.01 | $0.01 | 100% |
| $0.02 | $0.01 | 50% |
| $0.05 | $0.01 | 20% |
| $0.10+ | scales with 1% | ≤ 10% and falling |
Rough pricing guidance:
exact: aim for ≥ ~$0.05 USDC per call so the $0.01 floor is not more than ~20% of revenue. Below ~$0.02, more than half of each payment can go to protocol fees. pr402 is not optimized for sub-cent micro-payments — unlike some large facilitators we do not fully subsidize tx gas, and we enforce a 1 cent protocol floor to cover running costs.sla-escrow: aim for ≥ ~$10 USDC per payment (escrow + oracle economics). For smaller tickets,exactis usually the better rail.
Why offer sla-escrow? Buyers get on-chain escrow protection — funds are not released until delivery terms are met or an oracle rules. Standard x402 facilitators today only offer instant-settle rails like exact; pr402 is the only facilitator shipping this escrow model, which matters for high-value or slow-fulfillment services where buyers need refund/release guarantees.
These are recommendations, not hard limits. You choose price and rail; just understand the fee math before you launch.
Sovereign discount: Self-provision via Activate (~0.1 SOL one-time) drops exact protocol fee from 100 bps → 90 bps. Skip Activate and pr402 JIT-provisions on first settle at 100 bps — your choice.
The $0.01 floor exists because the Facilitator must cover operational costs during initial go-live. It may decrease as the ecosystem matures; treat GET …/capabilities as authoritative for current values.
Appendix A2 · Payout sweeps (when USDC reaches your wallet)
Each exact payment settles into your on-chain SplitVault. The Facilitator transfers accumulated USDC to your merchant wallet only when a sweep threshold is met — each on-chain sweep costs the Facilitator SOL.
| Environment | Sweep threshold | Notes |
|---|---|---|
| Mainnet (ipay.sh) | $3.00 USDC accumulated | Production default; batches payouts |
| Preview / Devnet (preview.ipay.sh) | $0.10 USDC accumulated | Demo only — experience a real sweep without waiting for $3 |
Devnet fee policy: preview uses the same $0.01 protocol fee floor as Mainnet. Only the sweep threshold is lowered on Devnet — not the per-payment fee — so pricing math matches production.
Hands-on lab: seller-lab · Protocol fees and payouts.
Appendix B · Why pr402 vs other facilitators
Other x402 facilitators exist (notably Coinbase CDP and x402.org). Solana Foundation’s pay CLI is a buyer client, not a facilitator like ipay.sh — see Choosing x402 on Solana.
Preview rehearsal (preview.ipay.sh)
| pr402 | CDP / x402.org (facilitators) | pay CLI (buyer client) | |
|---|---|---|---|
| Solana Devnet for x402 | Yes | Yes | Demos / local tooling only |
| Paired prod ↔ preview hostnames | ipay.sh ↔ preview.ipay.sh | CDP: one URL + network; x402.org: testnet URL | N/A — not a facilitator |
| Signup required for public Devnet | No (just access preview.ipay.sh) | CDP: API keys; x402.org: no signup | N/A |
sla-escrow on Devnet | Yes | exact only on Solana | N/A |
| Seller lifecycle UI on Devnet | Yes | No | No |
Preview rehearsal is a full production mirror (including both rails, the seller UI and one-URL migration), so you can test it without risking your real SOL or USDC on Solana Mainnet.
For sellers (resource providers)
| Differentiator | What it means |
|---|---|
| No chain code in your API | Return 402, forward PAYMENT-SIGNATURE to /settle. pr402 verifies and executes on-chain. |
/payment-required/enrich + discovery | No hand-built extra or vault PDA math — facilitator injects institutional accepts[]. |
| Two settlement rails | exact (UniversalSettle, instant) and sla-escrow (on-chain escrow + oracle). CDP/x402.org Solana today is exact only. |
| Sovereign fee tier | Self-provision via Activate qualifies 90 bps protocol fee tier vs 100 bps JIT standard on exact. |
Blockhash-safe /settle | Verification runs inside /settle before broadcast — avoids verify→deliver→settle gaps that break on Solana (~60s blockhash). |
SplitVault payTo model | Buyers pay program PDAs, not your bare wallet — enforced by UniversalSettle + facilitator verify. |
| Honest fee floors | $0.01 min on exact, $0.10 on sla-escrow protocol fee — we do not subsidize sub-cent micro-payments like some large facilitators. |
Seller rehearsal path: integrate on https://preview.ipay.sh, then switch to https://ipay.sh and re-run /payment-required/enrich for Mainnet mints/PDAs.
For buyers (payer agents)
| Differentiator | What it means |
|---|---|
sla-escrow buyer protection | Funds stay in on-chain escrow until delivery terms are met or an oracle verdict — refund/release paths are program-enforced. No standard x402 facilitator offers an equivalent escrow rail today. |
| Tx builders on the facilitator | POST /build-exact-payment-tx and POST /build-sla-escrow-payment-tx return unsigned txs + verifyBodyTemplate — no guessing instruction layout. |
| Open buyer tooling | @pr402/client, pr402-client (Rust), x402-buyer-starter. |
| Choose your oracle | On sla-escrow, buyers pick oracle_authority from seller-advertised profiles or GET /capabilities → slaEscrowOracleProfiles[]. |
| Zero-risk rehearsal | Point builders/settle at preview.ipay.sh with Devnet USDC — same flow as production. |
pay CLI complements pr402 on the buyer side — it can call APIs that settle via ipay.sh.
For oracles (operators & developers)
| Differentiator | What it means |
|---|---|
| First x402 escrow oracle economy | The on-chain sla-escrow program is hash-agnostic; oracles implement off-chain evaluation and submit ConfirmOracle on-chain. pr402 is the facilitator wired to this rail. |
| Open-source reference workspace | miraland-labs/oracles — shared oracle-common library plus three sibling binaries: api-quality, onchain-transfer, file-delivery. |
| Profile discovery via facilitator | GET /capabilities → slaEscrowOracleProfiles[] advertises canonical profile ids, operator pubkeys, and normative spec URLs. |
| Verdict-neutral oracle tips | Oracle tip is paid when a verdict is rendered — adjudication work, not outcome (release vs refund). |
| Built-in operator option | pr402 deployments may operate x402/oracles/onchain-transfer/v1 as a default for SPL transfer delivery; other profiles are ecosystem-operated. |
| Full pipeline in the template | Chain monitor → hash-bound SLA/delivery registry → evaluate → settle — documented in the oracles repo. |
Full comparison guide: Choosing x402 on Solana