Base
Base mainnet
- Network
- eip155:8453
- Settlement
- accepted
- Facilitator
- https://api.cdp.coinbase.com/platform/v2/x402
- Seller wallet compatible
- Yes
Current live paid settlement rail with confirmed unpaid 402, paid 200, and USDC settlement proof.
Guarded multichain and agent-wallet expansion
Base stays proven. Polygon and Solana are staged.
Agent Research Desk is now multichain-aware without silently changing the working checkout. Current accepted paid settlement remains Base mainnet; Polygon requires an explicit experimental flag; Solana uses the official SVM x402 package behind a separate SVM flag and Solana seller address; Stripe Link and Kite Passport are buyer-side compatibility only.
Base
Base Sepolia
- Network
- eip155:84532
- Settlement
- testnet
- Facilitator
- https://x402.org/facilitator
- Seller wallet compatible
- Yes
Testnet rail for local and development checks; not used for production revenue.
Polygon
Polygon mainnet
- Network
- eip155:137
- Settlement
- candidate
- Facilitator
- Not configured
- Seller wallet compatible
- Yes
- Activation flag
- X402_ENABLE_EXPERIMENTAL_RAILS=true
Polygon is code-recognized but disabled until the operator intentionally enables experimental payment rails.
Solana
Solana mainnet
- Network
- solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp
- Settlement
- watch-only
- Facilitator
- Not configured
- Seller wallet compatible
- No
- Activation flag
- X402_ENABLE_EXPERIMENTAL_RAILS=true, X402_ENABLE_SVM_RAILS=true, SOLANA_PAY_TO_ADDRESS=<solana-address>
Solana stays watch-only until SVM rails are explicitly enabled and a Solana seller address is configured.
Polygon Rail Proof Pack
Payment rail risk is active, but paid proof still needs approval.
Move Polygon from vague future option to an auditable proof checklist while keeping Base as the live paid rail.
- Candidate
- Polygon mainnet
- Required flag
- X402_ENABLE_EXPERIMENTAL_RAILS=true
- Paid proof
- Requires separate approval
- Production switch
- Blocked
The protected endpoint still returns HTTP 402 with Polygon network metadata in the challenge.
An explicitly approved buyer request pays once and receives HTTP 200 JSON.
The seller wallet receives the expected USDC settlement on Polygon.
Discovery surfaces list the route with the intended Polygon rail after proof.
Removing the experimental flags returns the service to the proven Base rail.
Solana SVM Proof Pack
Solana is code-wired behind flags, not silently accepted.
The service can register the official @x402/svm exact SVM x402 scheme for a separate proof deployment. It still requires a seller-controlled Solana address and its own unpaid 402, paid 200, settlement, and rollback proof before public production claims.
- Package
- @x402/svm 2.11.0
- Network
- solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp
- Status
- watch-only
- Production switch
- Blocked
The server can register the official @x402/svm exact scheme without touching the Base EVM route.
A protected endpoint returns HTTP 402 with Solana CAIP-2 network metadata and a Solana seller address.
An explicitly approved buyer request pays once over SVM x402 and receives HTTP 200 JSON.
The configured Solana seller address receives the expected USDC settlement.
Removing the SVM flags returns the service to the proven Base rail.
Kite Passport x402 Readiness
Buyer-side delegation is exposed without changing settlement.
Kite Passport fits ApexScout as a buyer-side delegated wallet path: a human approves the spending session, the agent probes ARD unpaid, then the buyer's own payment client retries the same x402 route.
- Status
- buyer-controlled-compatibility
- Kite settlement
- not-enabled
- Production switch
- Blocked
- Auto session
- Disabled
- Kite Passport buyer agents can inspect /instant-x402, copy a route payload, and send the unpaid probe.
- The expected first result remains HTTP 402 with the ARD payment requirement.
- A buyer-controlled x402 client can retry the same route after the buyer approves its own spending session.
- Public metrics remain aggregate-only and do not expose buyer prompts, wallet history, or paid response contents.
- ARD does not create Kite Passport accounts, agents, sessions, passkeys, or OAuth flows.
- ARD does not hold buyer funds or ask buyers to fund an ARD-controlled wallet.
- ARD does not auto-pay any route from the public testbench.
- ARD does not accept Kite mainnet settlement until a separate proof window is approved and verified.
- Official Kite mainnet service-provider requirement format is inspected.
- An ARD proof deployment emits the intended Kite/x402 402 challenge without breaking Base.
- One separately approved paid proof returns HTTP 200 JSON.
- Settlement reaches the seller-controlled wallet on the intended Kite rail.
- Rollback returns public checkout to the proven Base rail.
Stripe Link Agent Wallet Readiness
Buyer-side Link approvals are watched without accepting card settlement.
A readiness pack for buyer agents that may use Stripe Link's agent wallet for user-approved purchases while Agent Research Desk keeps production settlement on the proven Base x402 rail.
- Status
- watched buyer-wallet lane
- Stripe settlement
- Not accepted
- Checkout Sessions
- Not created by ARD
- Tempo payments
- Not enabled
- Use Link on the buyer side if your agent already has a user-approved Link wallet flow.
- Inspect /docs.json, choose an ARD route, and send the normal unpaid probe first.
- Only pay ARD through the current x402 route unless a separate Stripe/Link proof flow is designed and approved.
- Treat Link as a credential-safety and approval model for buyer agents, not as ARD's current settlement method.
- Do not add Stripe secret keys, Link OAuth, Checkout Sessions, PaymentIntents, card settlement, shared payment tokens, Tempo streaming payments, or token issuance to the live payment flow.
- Do not create Link spend requests or approve purchases from this service.
- Do not claim ARD accepts Link, cards, or shared payment tokens until a separate proof design and settlement test pass.
- Do not change the working Base mainnet x402 middleware, facilitator, seller wallet, endpoint paths, or route prices.
- Do not expose buyer prompts, wallet-level request history, raw feedback comments, watched subjects, or paid response contents.
- Official Link agent wallet provider requirements are reviewed for API-service purchases.
- A Link-controlled buyer agent can still read ARD's normal HTTP 402 challenge without breaking Base.
- A separate proof plan defines whether Link pays a card route, an x402 route, or a future protocol bridge.
- Any non-x402 Link proof settles into a seller-controlled account with clear receipts and rollback.
- Base remains the default active rail after the proof window is removed.
Expansion policy
- Base mainnet remains the proven production rail.
- Polygon mainnet can only be enabled by explicitly setting X402_ENABLE_EXPERIMENTAL_RAILS=true and X402_NETWORK=eip155:137.
- The Polygon proof pack is active as a bounded risk, but paid proof and production promotion still require separate approval.
- Solana mainnet can only be enabled by explicitly setting X402_ENABLE_EXPERIMENTAL_RAILS=true, X402_ENABLE_SVM_RAILS=true, X402_NETWORK=solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp, and SOLANA_PAY_TO_ADDRESS.
- The Solana SVM proof pack uses the official @x402/svm package, but paid proof and production promotion still require separate approval.
- Kite Passport is exposed as a buyer-controlled delegated-payment compatibility lane, not as an accepted ARD settlement rail.
- Stripe Link Agent Wallet is exposed as a buyer-controlled approval and one-time credential compatibility lane, not as an accepted ARD settlement rail.
- Agent Messenger is exposed as an optional inbound inbox/discovery layer, not as a payment rail, spending authority, or outbound automation channel.
- ERC-8004 identity readiness is exposed as a manual registration path, not as automatic registration or a verified token claim.
- The legacy /agent-discovery surface is inbound-only and limited to ApexScout-owned public docs, public agent cards, manual testing, and manually supplied partner URLs if provided later.
- x402 chain, language, and framework expansion is tracked as watch-only protocol intelligence, not as a production payment change.
- Solana mainnet is not treated as production-ready until a separate Solana unpaid 402, paid 200, USDC settlement, discovery, and rollback proof passes.