v2.0.0

What's Changed

• feat: add hash_operator_token helper by @vvillait88 in #22
• feat: add usd_to_atomic helper by @vvillait88 in #23
• feat: add detect_rail_from_headers helper by @vvillait88 in #24
• feat: extend extract_payment_signer to MPP credentials by @vvillait88 in #25
• feat: add zero_amount_carve_out helper by @vvillait88 in #26
• feat: add classify_orchestration_error helper by @vvillait88 in #27
• feat: add load_ucp_signing_key_from_env helper by @vvillait88 in #28
• refactor(examples): use load_ucp_signing_key_from_env in signed_ucp_merchant by @vvillait88 in #29
• test: lock public-surface barrel exports by @vvillait88 in #30
• docs: list TEC-302 helpers in the README inventory by @vvillait88 in #31
• feat: flatten challenge builders to kwargs; delete *Input + *Config wrappers by @vvillait88 in #32
• feat: flatten x402 verify+settle+validate builders to kwargs by @vvillait88 in #33
• feat: flatten payment directive + headers + override builders to kwargs by @vvillait88 in #34
• chore: remove dead _RequestLike Protocol in discovery/probe.py by @vvillait88 in #35
• feat: flatten payment_required_header to kwargs; delete PaymentRequiredHeaderInput by @vvillait88 in #36
• feat: flatten stripe_multichain helpers to kwargs; delete 4 wrappers by @vvillait88 in #37
• feat: flatten 7 discovery builders to kwargs; delete 10 *Input wrappers + convert 6 nested types to TypedDicts by @vvillait88 in #38
• refactor(identity, payment): flatten LoadUCPSigningKeyOptions + drop dead CreateX402ServerOptions by @vvillait88 in #39
• feat(payment): add canonical *RailSpec types for cross-helper rail config by @vvillait88 in #40
• refactor(challenge): build_accepted_methods + build_how_to_pay consume *RailSpec; async by @vvillait88 in #41
• refactor(identity/ucp): payment handlers consume *RailSpec by @vvillait88 in #42
• feat(payment)!: create_mppx_server consumes dict[str, *RailSpec] by @vvillait88 in #43
• feat(identity)!: rename GateClient -> AgentScoreCore by @vvillait88 in #44
• feat(checkout): add Checkout orchestrator for one-call agent-commerce flow by @vvillait88 in #45
• feat(checkout): seamless merchant helpers (adapters, hooks, discovery) by @vvillait88 in #46
• chore: bump transitive deps (requests, ty, uvicorn) by @vvillait88 in #47
• docs(examples): migrate 6 examples to Checkout + canonical 2.0 surface by @vvillait88 in #48
• feat: commerce 2.0.0 — Checkout orchestrator + per-framework adapters + signed UCP routes by @vvillait88 in #49

Full Changelog: v1.8.1...v2.0.0