Universal-Commerce-Protocol/ucp v2026-08-25

Release v2026-08-25

on GitHub

This release introduces major protocol enhancements, key structural refactorings to support multi-vertical expansion, payments security improvements (3DS2) and structured request constraints, independent capability versioning, and grocery vertical readiness.

📊 Executive Summary

• 📂 Multi-Vertical Refactoring: Foundation laid for supporting Food and Lodging verticals alongside Shopping, with polymorphic token binding and vertical-agnostic payment constructs.
• 🛒 Grocery Vertical Readiness: Introduction of Location Search & Lookup capabilities, deterministic operating hours, fulfillment location context, and fractional quantities with sale-basis pricing steps.
• 🔑 Payments Security & Structured Constraints: Implementation of vendor-agnostic 3D Secure (3DS2) authentication flows via Actions, response-carried $requestConstraints (with path targeting & anyOf), and split PAN / Network Token credentials.
• 📅 Payment Terms & Schedules: Deferred payments, deposits, and installment schedules, along with multi-instrument Split Payments.
• 📦 Capability Versioning & Architecture: Tightened the core version release contract for UCP and version negotiation strategy while also introducing support for namespace ordering (map_order).
• 🤝 Identity & Consent Overhaul: Modernized UCP’s identity and consent architecture—introducing reverse-DNS consent, delegated IdPs, and canonical profile keys—while launching the loyalty extension for interoperable reward ecosystems.

✨ New Capabilities & Detailed Changes

1. Core Protocol & Infrastructure

• ⚡ Actions Primitive (#582): Introduces a horizontal, extension-defined actions[] array to Cart, Checkout, and Catalog. Allows businesses to request out-of-band actions (like authentication or form-filling) from the platform.
• 🏷️ Namespace Reservation & Ordering (#657): Reserves the ucp protocol namespace and adds map_order to enforce registry ordering.
• 🔒 Namespace Authority Binding (#530, #627): Defines how platforms verify that a business has authority over a reverse-DNS namespace via DNS/host matching.
• 📦 Capability Versioning (#614): Clarified and tightened the core version release contract, establishing formal guidelines for date-based capability versioning and forward compatibility across protocol updates.
• 📂 Vertical Refactoring (#723, #736, #741, #761): Restructured the repository layout into domain verticals (Shopping, Payment, Common) and centralized common primitives in common/types/ and refactors payment extensions into dev.ucp.common.payment.*.
• 🌐 Polymorphic Token Binding (#746): Refactors token binding to be vertical-agnostic and polymorphic across multiple verticals.

2. Grocery & Location Capabilities

• 🔍 Location Search + Lookup (#589, #642, #753, #765, #766): Adds capability to search for physical store locations and lookup details (address, hours, geocoding) with location context hints and correlation.
• 🕒 Deterministic Operating Hours (#687): Standardizes how businesses publish regular and exception hours with timezone handling for pickup locations.
• 🏷️ Explicit Destination Types (#688): Requires explicit tagged destination types (shipping vs pickup) in fulfillment methods to prevent ambiguous union matches.
• ⚖️ Fractional Quantities & Sale-Basis (#597, #653): Allows purchasing products in non-integer quantities (e.g., weighted items by kg, lb), defines price/quantity steps, and enforces an integer bound cap.
• 🗺️ Fulfillment Location Context (#671): Connects negotiated fulfillment methods directly to specific location contexts across Catalog, Cart, and Checkout.

3. Payments & Security

• 🔑 3DS2 Authentication (#458): Implements vendor-agnostic 3D Secure (3DS2) support (Device Data Collection and Challenge flows) using the Actions primitive.
• ⚠️ Response-Carried Request Constraints (#655, #744, #757): Introduces $requestConstraints allowing businesses to return transaction-specific schema validation rules for subsequent requests, including path targeting and anyOf constraint evaluation.
• 💳 Instrument Requirements & Credential Splitting (#424): Expresses instrument requirements via constraints and splits PAN and Network Token into explicit, distinct credential types.
• 📅 Payment Terms & Schedules (#602, #603): Introduces payment schedules (simple and well-defined terms) supporting deferred payments, deposits, and installments at checkout.
• 🥞 Split Payments (#409): Adds support for split payments across multiple instruments.

4. Identity, Consent & Loyalty

• 🌐 Delegated Identity Providers (#423): Standardizes accelerated IdP sign-in flows and delegation mechanisms.
• 🎁 Loyalty Extension (#340): Formalizes the Loyalty capability across Catalog, Cart, and Checkout, transitioning from legacy discount-based workarounds.
• 🤖 Web Bot Auth (WBA) Interop (#483): Introduces WBA interop to allow automated agentic auth negotiation.
• 🔐 Canonical Profile Keys (#566): Promotes keys[] (JWK Set) as the sole canonical signing key field.
• 🛡️ Extensible Buyer Consent (#451): Restructures buyer consent from fixed booleans into a dynamic, reverse-DNS keyed map supporting granular, per-segment opt-in purposes.

5. Shopping Enhancements & Fixes

• 📣 Attribution (#391): Adds support for platform-driven referral and ad attribution context.
• 📄 Policies (#572): Adds a policies[] snapshot to Cart, Checkout, Catalog, and Order to carry return, refund, and warranty terms.
• 🔗 Shopping Permalink (#523): Adds permalink capabilities to recreate cart states via URL (useful for email/QR codes).
• 🛠️ Cart ID Fix (#633, #646): Standardizes cart.id as omitted in update requests to simplify client implementations.
• 🏷️ Discount Allocation Totals Path Fix (#558): Corrects totals path in discount allocation documentation examples.

🚨 Breaking Changes

The following changes are backward-incompatible and require schema updates:

• Fulfillment Schema Restructure (#507, #581, #763)
  • Configuration Flags: Renamed flags to drop the allows_ prefix (multi_destination, method_combinations).
  • Fulfillment Option: Upgraded fulfillment_option.description from a flat string to a structured description object.
  • Multi-Destination: Remodeled multi_destination configuration from a map to an array of objects.
  • Method Types: Opened fulfillment_available_method.type enum to string.
  • Merchant Consolidation: Consolidated merchant configurations into business_fulfillment_config.json and deleted merchant_fulfillment_config.json.
• Buyer Consent Overhaul (#451)
  • Dynamic Map: Restructured consent in buyer_consent.json from fixed boolean fields to a dynamic map keyed by reverse-DNS identifiers (dev.ucp.consent.*), returning complex consent_purpose objects with granular segment-level opt-ins.
• Profile Keys Promotion (#566)
  • Canonical Signing Keys: Removed signing_keys[] from profile.json and promoted keys[] (JWK Set) as the sole canonical signing key field to eliminate sync drift.
• Common Types & Vertical Refactoring (#436, #723, #736)
  • Hierarchy Restructure: Reorganized specification hierarchy into domain verticals (shopping/, payment/, common/).
  • Primitive Schemas: Moved shared primitive schemas under common/types/ (amount.json, price.json, line_item.json), changing their $id URLs.
• Payment Constructs & Extension Namespace Migration (#741)
  • Extension Namespacing: Migrated payment extensions from dev.ucp.shopping.* to dev.ucp.common.payment.* (split_payments, payment_terms, ap2_mandates).
  • Schema Relocation: Relocated payment constructs to common/types/payment.json as a vertical-agnostic capability.
• Vertical Agnostic Token Binding (#746)
  • Refactored token binding to be vertical agnostic and reusable across Retail, Food, Lodging and future verticals.
• Structured Request Constraints & Instrument Credentials (#424, #655, #744, #757)
  • Dynamic Validation: Replaced static instrument requirement schemas with response-carried $requestConstraints supporting JSONPath targeting and anyOf constraints.
  • Credential Splitting: Split PAN and Network Token into explicit, distinct credential types.
• Location Search + Lookup & Operating Hours (#589, #687, #688, #753)
  • Standardized Location: Replaced retail_location.json with common/types/location.json.
  • Explicit Destination Types: Disambiguated fulfillment methods with explicit destination types (shipping vs pickup).
  • Operating Hours: Defined deterministic regular and exception operating hours with timezone precision.
• Fractional Quantities & Sale-Basis (#597, #653)
  • Quantity Type: Upgraded Cart/Checkout quantity from strict integer to anyOf integer or structured measure.json object.
  • Sale-Basis Pricing: Defined transactional sale-basis steps for fractional units.
  • Integer Range Bounds: Enforced integer range bounds capped at $\pm(2^{53} - 1)$ with maximum scale: 15.
• Cart ID Omission & Transition Cleanup (#633, #763, #639)
  • Cart ID Omission: Standardized cart.id as omitted in update requests instead of required.
  • Orphaned Schemas: Deleted orphaned account_info.json and cleaned up deprecated test scaffolds.
• Identity Linking OAuth 2.0 Foundation (#354)
  • Capability Scopes: Introduced capability-driven OAuth 2.0 scopes for account linking.

Full Changelog: release/2026-04-08...v2026-08-25