v2.0.0

Breaking

• PaymentAccept.amount is now required — v2 spec field. maxAmountRequired is deprecated (optional alias for v1 compat).
• PaymentAccept.extra is now optional — per v2 spec.
• TokenPricing methods are async — calculate(), validateQuote(), countTokens() return Promises. tiktoken is now an optional peer dependency (lazy-loaded on first call).

Added

• Budget Accounts — createBudgetAccount() wraps fetch with spending controls: total budget, per-request cap, hourly rate limit, and domain allowlist. Tracks cumulative spend with a full payment ledger. Give your agent $50 and let it spend autonomously.
• API Discovery — searchAPIs() searches the Dexter marketplace for x402 paid APIs by query, category, network, price range, and quality score. Returns typed DiscoveredAPI[] that can be called directly with wrapFetch.
• Retry with exponential backoff — maxRetries and retryDelayMs in client config. Retries on network errors and 502/503/504. Safe for payments — EIP-3009 nonces prevent double-spend.
• First-class Sponsored Access (Ads for Agents) — getSponsoredRecommendations(), getSponsoredAccessInfo(), fireImpressionBeacon() client helpers. React hook sponsoredRecommendations. Server onMatch callback. @dexterai/x402-ads-types promoted to direct dependency.
• Pre-payment inspection — onPaymentRequired callback on client and wrapFetch. Return false to reject a payment before signing.
• Settlement webhooks — onSettlement and onVerifyFailed callbacks in middleware config.
• CSP headers on browser paywall page.
• KEYPAIR_SYMBOL for safe access to the Solana Keypair (Symbol-keyed, hidden from serialization).
• escapeHtml() exported from server for safe HTML rendering of payment data.
• isSolanaNetwork() / isEvmNetwork() utility functions.
• New error codes — wallet_disconnected, user_rejected_signature, rpc_timeout, facilitator_timeout.
• Typed WalletSet — solana and evm fields are now typed as SolanaWallet and EvmWallet instead of unknown.
• 52 unit tests covering dynamic pricing, XSS escaping, USDC detection, type compliance, amount conversion, sponsored access.
• CI/CD — GitHub Actions: typecheck + build + test on Node 18/20/22. Publish workflow gated on tests, auto-creates GitHub releases.
• extensions field on PaymentRequired and PaymentSignature per v2 spec.
• Auto GitHub releases from tag pushes with changelog extraction.

Fixed

• EVM nonce security — Math.random() replaced with crypto.getRandomValues().
• Dynamic pricing security — FNV-1a replaced with HMAC-SHA256 with timestamp-bounded quotes (5-min TTL).
• Balance checks throw on RPC errors instead of silently returning 0.
• Resource URL validation — blocks javascript:, data:, file: schemes.
• Internal errors no longer leaked to clients.
• Stripe guard uses WeakMap instead of fragile as any property.
• Source maps removed from production build (62% smaller package).
• Client JWT cache capped to 24h regardless of decoded exp.