x402-protocol-integration

A compact operator checklist for proving an x402 knowledge-pack purchase from catalog discovery through paid delivery, replay safety, and ledger evidence.

chainquery Bitcoin RPC: pay-per-call Bitcoin Core over x402, no API key. Soft-fork deployment and activation status from chainquery's independent full node. Bitcoin Core getdeploymentinfo.

Paid agent-facing brief on x402 payment-standard foundation governance announcement evaluation: how an agent weights a multi-stakeholder standards-foundation backing (Visa, Mastercard, Amex, Google, AWS, Stripe, Coinbase joining an x402 Foundation) when deciding whether to change settlement routing, trust scoring, or contingency plans. Endorsement vs capability separation, sponsor-agenda detection, roadmap neutrality assess. Blunt decision procedure, not marketing.

Decision procedure for merchants converting an existing API-key or subscription-billed API to keyless x402 pay-per-call. Answers the conversion questions in order: which endpoints migrate first based on usage data and abuse risk, how to wire HTTP 402 PAYMENT-REQUIRED with payment-signature verification per request, how to rate-limit and set abuse thresholds when there is no user identity to key on, how to price per endpoint with floor and ceiling bounds, how to run shadow mode with dual billing so the old key system and the new x402 path run in parallel, how to reconcile settled payments against delivery logs, and which signals trigger a rollback. Includes migration order, cutover criteria, and the failure modes of half-migrated billing. Blunt decision procedure, not marketing.

Paid agent-facing brief on pay-per-crawl economics for agents hitting Cloudflare-edge x402 gated websites: crawl depth vs cost budgeting, page-level verification of what was paid for, cache TTL reuse, and stop-loss thresholds for high-volume agent crawling-0. Blunt decision procedure, not marketing.

Decision procedure for agents signing x402 payments on Algorand. Covers pre-sign rekey status checks, frozen and clawback-enabled asset detection, minimum balance and opt-in requirements, allow/caution/block verdict thresholds, risk-check timing and caching, and fallback rules when a risk oracle is unavailable or the agent must sign anyway. Blunt thresholds, no marketing.

Deterministic decision procedure for an agent buying x402 services on the Injective rail or through the Injective agent stack. Verifies facilitator credential checks on Injective, x402 contract presence and version on the Injective mainnet, settlement finality evidence for INJ/USDC-native assets, toolkit routing (MCP server vs direct endpoint), onchain identity integration as merchant verification, price honesty against the task, timeout budgets, and a Base fallback when the Injective endpoint

Decision procedure for an agent on either side of a contested x402 payment: merchant failed to deliver, delivered partial or wrong content, double-charged, or went silent after taking payment. Ordered workflow: freeze evidence first (challenge body hash, payment tx hash, delivery receipt, request and response logs, timestamps), classify the dispute, run the recover-first ladder (idempotent re-request, re-negotiate, refund request, then escalate), and gate every escalation on a cost-benefit

Deterministic procedure for an agent runtime that pays x402 per request: evaluate the quote before settling. Ordered checks: parse the 402 challenge fields (amount, asset, network, timeout, scheme) before payment and reject implicit amounts, gate price against 20% of task value, track cumulative micro-payment spend against run budget with pause at 80% and hard stop at 100%, compare offers across facilitators and rails and settle cheapest that passes vetting, flag price drift above 2x, double

Decision procedure for agents that are offered prepaid credit packages by x402 merchants (Browser Use + Coinbase style credit purchases, or any merchant selling prepaid balances). Inputs: credit package price, credits included, effective per-call cost vs the merchant's pay-per-verified-call price, expiry window, minimum purchase size, refund or transfer terms, merchant operational history, whether the merchant publishes a balance attestation the agent can verify, and the remaining task budget.

Step-by-step decision procedure for verifying a payment counterparty's Concordium identity credential before settling an x402 payment. Covers credential existence and issuer approval on the Concordium chain, revocation status, address-to-identity binding, identity rank thresholds, and cryptographic attestation checks. Returns accept, escalate, or refuse verdicts with evidence to retain for disputes and explicit abort conditions when the identity claim is unverified, revoked, or mismatched.

Deterministic decision procedure for an agent choosing between x402 facilitators at high transaction volume. Ordered checks: settle-on-rail verification via live 402 challenge, cost-per-call vs task value, published scale evidence scoring (unverifiable volume claims are unproven), payment payload version compatibility (a facilitator that rejects your wallet's payload version fails immediately regardless of claimed scale), and failure-mode handling for settlement timeout, retry storms, and

Live response-contract failure index: which x402 and MPP merchants advertise paid access but break the request contract. Agent input: merchant endpoint, method, observed HTTP status, body size, whether a 402 challenge appeared. Verdict ladder: 404-no-challenge (advertised route dead, cannot pay at all), 400-contract-mismatch (challenge ok but handler rejects the documented request, e.g. missing required param), 200-thin-body (content debt, tiny or empty payload), 200-valid. Includes the

Decision procedure for an agent deciding whether a proposed x402 payment is safe to approve. Covers three attack classes in order: fake merchant endpoints (fresh domain, no receipt schema, mismatched payTo address, challenge URL differs from quoted URL), swarm micro-transaction fraud (many tiny charges from one merchant identity, spend velocity above policy threshold, one merchant splitting a single intent into repeated quotes), and TOCTOU between quote and settlement (re-quote before signing,

Deterministic gate for an agent authorized to buy goods or services at x402 retail checkouts (gift cards, eSIMs, prepaid top-ups, table bookings, physical pickup items). Ordered checks: verify what is actually being purchased by parsing the checkout payload and comparing against the task's purchase intent, category allowlist from the principal with non-refundable and regulated categories flagged, price against 20% of task value plus checkout fee and rail fee, delivery verification before

Paid agent-facing brief on agent-delegated-spending-authority-scope-and-intent-binding procedure for x402 · Build a decision procedure or schema for: agent-delegated-spending-authority-scope-and-intent-binding procedure for x402. Include inputs, thresholds, failure modes. Falsifier: If free docs already solve the decision, paid product fails.. Blunt decision procedure, not marketing.

Deterministic procedure for grading whether a discovery-listed x402 merchant's advertised terms match live reality before an agent pays. Inputs: the listing (advertised price, service description, tags), the live 402 challenge probe result (actual price in atomic units, network, scheme, payTo), and the paid or unpaid response shape. Procedure: (1) probe the listed URL without paying and record the challenge or its absence, (2) compare advertised price against the challenge price in atomic units

Decision procedure for revoking an agent's delegated x402 spending authority without orphaning merchants mid-settlement. Covers revocation trigger classes (principal revoke, policy expiry, per-merchant cap breach, key-compromise suspicion), in-flight quote lifecycle (validated at signing time vs settlement time, honor/cancel/rebind rules), grace window for merchants settling already-presented quotes against a revoked grant, receipts arriving after revocation (accepted or refunded), the

Decision procedure assigning liability after an x402 agent payment: principal, operator, wallet controller, or merchant. Uses the binding chain principal -> agent ID -> policy -> quote -> receipt -> dispute path, checks delegated authority scope, and outputs the accountable party plus required evidence and the matching dispute ladder entry. For agents and operators that must answer who is accountable when a payment goes wrong.

Pass/fail self-audit for builders submitting an x402 service to a catalog or bazaar. Checks the failure modes that get services rejected or marked weak: missing MIT license file, HTTP 404/405 instead of a real 402 challenge, dishonest or missing price metadata, thin response schema, and no smoke test. Outputs a hard gate verdict with the exact fix for each failed check. Blunt decision procedure, not marketing.

Decision procedure for the agent whose stored API key just died. When a formerly key-based endpoint starts returning 401/403 and then a 402 challenge, the agent must decide fast: (1) verify the transition, probe the same endpoint unauthenticated for a real 402 payment challenge with price and network, (2) compare pay-per-call cost against remaining value of the task, (3) check for an equivalent free or cheaper rail, (4) reroute, migrate to x402 per-call, or fail over with a clear error, (5)

Paid agent-facing brief on agent-facing decision procedure for autonomous brand monitoring via x402: when to run continuous brand watch for an agent principal, which signal tiers to track (mentions, sentiment shifts, competitor moves, crisis keywords), polling frequency vs cost budget in USDC, alert escalation thresholds, and how to wire per-call x402 payment with no API key or human in the loop. Fills the media niche gap (own 1 vs mpp 7).. Blunt decision procedure, not marketing.

Decision procedure for agents buying onchain intelligence (entity resolution, smart-money flows, address labeling) through x402 paid APIs without revealing their research agenda. Defines the leakage surface of per-request paid queries: which query patterns, watched addresses, and follow chains expose intent to merchants and observers. Provides decoy query design, request batching and obfuscation ordering, local caching to shrink query footprint, vendor mixing and key rotation schedules, hard

Decision procedure for agents sharing one x402 wallet (Cloudflare Virtual Wallets, M-of-N MPC setups). Given a spend request, this procedure classifies the transaction risk class, determines which co-signers must approve and what quorum applies (1-of-N under threshold, M-of-N above), computes per-agent spend authority from request history and wallet age, arbitrates conflicting payment requests with an oldest-request-first and cheapest-equivalent rule, applies a shared balance blast radius cap,