x402-foundation · CarsonRoscoe · Apr 2, 2026 · Apr 2, 2026 · Apr 2, 2026 · Apr 2, 2026
diff --git a/go/.changes/v2.5.0.md b/go/.changes/v2.5.0.md
@@ -0,0 +1,12 @@
+## v2.5.0 - 2026-03-06
+### Added
+- Add route configuration validation during Initialize() to catch scheme/facilitator mismatches at startup
+- Added assetTransferMethod and supportsEip2612 flag to defaultAssets
+- Added `onProtectedRequest` hook to HTTP resource server
+- Add WithBazaar facilitator client decorator for querying /discovery/resources endpoint from bazaar in go
+- Added dynamic function for servers to generate custom response for settlement failures defaulting to empty
+- Add in-memory SettlementCache to prevent duplicate SVM transaction settlement during on-chain confirmation window
+### Changed
+- Separated v1 legacy network name resolution from v2 CAIP-2 resolution; v1 code now uses evm/v1 package, shared utils only accept eip155:CHAIN_ID format
+- GetSupported retries up to 3 times with exponential backoff on 429 rate limit responses
+- Add pluggable PaywallProvider interface for custom paywall HTML generation with PaywallBuilder pattern
diff --git a/go/.changes/v2.6.0.md b/go/.changes/v2.6.0.md
@@ -0,0 +1,8 @@
+## v2.6.0 - 2026-03-17
+### Added
+- Added simulation to permit2 verify and (optional) settle
+### Changed
+- Replaced SendRawApprovalAndSettle with a generic SendTransactions signer method that accepts an array of transaction requests (pre-signed or unsigned intents). Closed fail-open verification paths, aligned Permit2 amount check to exact match, and improved client extension fallback error handling
+- Simulate transaction in verify and (optional) settle; Added multicall utility for efficient rpc calls; Fixed undeployed smart wallet handling
+### Fixed
+- Fixed paywall config injection targeting `</body>` causing SVG parse errors in the browser
diff --git a/go/.changes/v2.7.0.md b/go/.changes/v2.7.0.md
@@ -0,0 +1,8 @@
+## v2.7.0 - 2026-03-23
+### Changed
+- Changed Bazaar discovery extension to support dynamic route patterns. EnrichDeclaration now
+translates [param] route segments to :param-style routeTemplate and populates pathParams with
+concrete values from each request. The EnrichExtensions call in go/http/server.go, previously
+disabled (commented out) in all prior Go releases, is now active: ALL existing Go routes that
+declare extensions will have their extensions enriched at request time. Added RouteTemplate field
+to DiscoveryExtension so callers can read it without a type assertion.
diff --git a/go/.changes/v2.8.0.md b/go/.changes/v2.8.0.md
@@ -0,0 +1,15 @@
+## v2.8.0 - 2026-04-02
+### Added
+- Add Arbitrum One (chain ID 42161) and Arbitrum Sepolid (chain ID 421614) support with USDC as the default stablecoin
+- Add Mezo Testnet (chain ID 31611) support with mUSD as the default stablecoin
+- Add Polygon mainnet (chain ID 137) support with USDC as the default stablecoin
+- Add Stable mainnet (chain ID 988) support with USDT0 as the default stablecoin
+- Add Stable testnet (chain ID 2201) support with USDT0 as the default stablecoin
+- Add net/http standard library adapter for x402 payment middleware (http/nethttp package)
+- Add Echo framework middleware adapter for x402 payment handling in go/http/echo package
+- Add upto EVM payment scheme with client, facilitator, and server support for permit2-based partial settlement on EVM chains
+### Changed
+- Updated x402UptoPermit2Proxy canonical address to 0x4020A4f3b7b90ccA423B9fabCc0CE57C6C240002, deployed with deterministic bytecode for reproducible cross-chain CREATE2 addresses
+- Migrated project from coinbase/x402 to x402-foundation/x402 organization
+### Fixed
+- Fix gin streaming content leak and echo panic on flush 
diff --git a/go/CHANGELOG.md b/go/CHANGELOG.md
@@ -1,3 +1,19 @@
+## v2.8.0 - 2026-04-02
+### Added
+- Add Arbitrum One (chain ID 42161) and Arbitrum Sepolid (chain ID 421614) support with USDC as the default stablecoin
+- Add Mezo Testnet (chain ID 31611) support with mUSD as the default stablecoin
+- Add Polygon mainnet (chain ID 137) support with USDC as the default stablecoin
+- Add Stable mainnet (chain ID 988) support with USDT0 as the default stablecoin
+- Add Stable testnet (chain ID 2201) support with USDT0 as the default stablecoin
+- Add net/http standard library adapter for x402 payment middleware (http/nethttp package)
+- Add Echo framework middleware adapter for x402 payment handling in go/http/echo package
+- Add upto EVM payment scheme with client, facilitator, and server support for permit2-based partial settlement on EVM chains
+### Changed
+- Updated x402UptoPermit2Proxy canonical address to 0x4020A4f3b7b90ccA423B9fabCc0CE57C6C240002, deployed with deterministic bytecode for reproducible cross-chain CREATE2 addresses
+- Migrated project from coinbase/x402 to x402-foundation/x402 organization
+### Fixed
+- Fix gin streaming content leak and echo panic on flush 
+
 ## v2.7.0 - 2026-03-23
 ### Changed
 - Changed Bazaar discovery extension to support dynamic route patterns. EnrichDeclaration now

diff --git a/go/constants.go b/go/constants.go
@@ -3,7 +3,7 @@ package x402
 // Version constants
 const (
 	// Version is the SDK version
-	Version = "2.7.0"
+	Version = "2.8.0"
 
 	// ProtocolVersion is the current x402 protocol version
 	ProtocolVersion = 2

diff --git a/python/x402/CHANGELOG.md b/python/x402/CHANGELOG.md
@@ -2,6 +2,23 @@
 
 <!-- towncrier release notes start -->
 
+## [2.6.0] - 2026-04-02
+
+### Fixed
+
+- Fixed author attribution to reference x402 Foundation instead of Coinbase ([#123](https://github.com/x402-foundation/x402/pull/123))
+- Fixed race condition in lazy facilitator initialization for FastAPI and Flask middleware under concurrent requests. ([#1584](https://github.com/x402-foundation/x402/pull/1584))
+- Fix extra: null incompatibility between python facilitator and TS zod schema ([#1762](https://github.com/x402-foundation/x402/pull/1762))
+
+### Added
+
+- Add Mezo Testnet (chain ID 31611) support with mUSD as the default stablecoin ([#mezo-testnet-default-asset](https://github.com/x402-foundation/x402/pull/mezo-testnet-default-asset))
+- Add Polygon mainnet (chain ID 137) support with USDC as the default stablecoin ([#polygon-support](https://github.com/x402-foundation/x402/pull/polygon-support))
+- Add Stable mainnet (chain ID 988) support with USDT0 as the default stablecoin ([#stable-support](https://github.com/x402-foundation/x402/pull/stable-support))
+- Add Stable testnet (chain ID 2201) support with USDT0 as the default stablecoin ([#stable-testnet-support](https://github.com/x402-foundation/x402/pull/stable-testnet-support))
+- Added dynamic route support to the Bazaar discovery extension — servers can now declare ``[param]`` route segments that consolidate to a single catalog entry per route template, with automatic ``pathParams`` enrichment and ``:param``-style ``routeTemplate`` in discovery output. ([#424](https://github.com/x402-foundation/x402/pull/424))
+
+
 ## [2.5.0] - 2026-03-19
 
 ### Fixed

diff --git a/python/x402/changelog.d/123.bugfix.md b/python/x402/changelog.d/123.bugfix.md
diff --git a/python/x402/changelog.d/1584.bugfix.md b/python/x402/changelog.d/1584.bugfix.md
diff --git a/python/x402/changelog.d/1762.bugfix.md b/python/x402/changelog.d/1762.bugfix.md
diff --git a/python/x402/changelog.d/424.feature.md b/python/x402/changelog.d/424.feature.md
diff --git a/python/x402/changelog.d/mezo-testnet-default-asset.feature.md b/python/x402/changelog.d/mezo-testnet-default-asset.feature.md
diff --git a/python/x402/changelog.d/polygon-support.feature.md b/python/x402/changelog.d/polygon-support.feature.md
diff --git a/python/x402/changelog.d/stable-support.feature.md b/python/x402/changelog.d/stable-support.feature.md
diff --git a/python/x402/changelog.d/stable-testnet-support.feature.md b/python/x402/changelog.d/stable-testnet-support.feature.md
diff --git a/python/x402/pyproject.toml b/python/x402/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "x402"
-version = "2.5.0"
+version = "2.6.0"
 description = "x402 Payment Protocol SDK for Python"
 readme = "README.md"
 license = { text = "MIT" }

diff --git a/typescript/.changeset/add-arbitrum-one-and-arbitrum-sepolia-default-stablecoin.md b/typescript/.changeset/add-arbitrum-one-and-arbitrum-sepolia-default-stablecoin.md
diff --git a/typescript/.changeset/add-fastify-adapter.md b/typescript/.changeset/add-fastify-adapter.md
diff --git a/typescript/.changeset/add-mezo-testnet-default-asset.md b/typescript/.changeset/add-mezo-testnet-default-asset.md
diff --git a/typescript/.changeset/add-polygon-support.md b/typescript/.changeset/add-polygon-support.md
diff --git a/typescript/.changeset/add-stable-support.md b/typescript/.changeset/add-stable-support.md
diff --git a/typescript/.changeset/add-stable-testnet-support.md b/typescript/.changeset/add-stable-testnet-support.md
diff --git a/typescript/.changeset/export-hook-types.md b/typescript/.changeset/export-hook-types.md
diff --git a/typescript/.changeset/fix-facilitator-redirect.md b/typescript/.changeset/fix-facilitator-redirect.md
diff --git a/typescript/.changeset/migrate-to-x402-foundation.md b/typescript/.changeset/migrate-to-x402-foundation.md
diff --git a/typescript/.changeset/settlement-overrides.md b/typescript/.changeset/settlement-overrides.md
diff --git a/typescript/.changeset/tall-windows-rescue.md b/typescript/.changeset/tall-windows-rescue.md
diff --git a/typescript/.changeset/upto-client-sdk.md b/typescript/.changeset/upto-client-sdk.md
diff --git a/typescript/.changeset/yummy-readers-cut.md b/typescript/.changeset/yummy-readers-cut.md
diff --git a/typescript/packages/core/CHANGELOG.md b/typescript/packages/core/CHANGELOG.md
@@ -1,5 +1,17 @@
 # @x402/core Changelog
 
+## 2.9.0
+
+### Minor Changes
+
+- 2250cae: Migrated project from coinbase/x402 to x402-foundation/x402 organization
+- d352574: Add SettlementOverrides support for partial settlement (upto scheme). Route handlers can call setSettlementOverrides() to settle less than the authorized maximum, enabling usage-based billing.
+
+### Patch Changes
+
+- 8cf3fca: Export all hook types and hook context interfaces from the server entry point
+- c0e3969: Fixed HTTPFacilitatorClient not following 308 redirects from facilitator endpoints. Normalized base URL to strip trailing slashes and explicitly set `redirect: "follow"` on all fetch calls for cross-runtime compatibility.
+
 ## 2.8.0
 
 ### Minor Changes

diff --git a/typescript/packages/core/package.json b/typescript/packages/core/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@x402/core",
-  "version": "2.8.0",
+  "version": "2.9.0",
   "main": "./dist/cjs/index.js",
   "module": "./dist/esm/index.js",
   "types": "./dist/cjs/index.d.ts",

diff --git a/typescript/packages/extensions/CHANGELOG.md b/typescript/packages/extensions/CHANGELOG.md
@@ -1,5 +1,19 @@
 # @x402/extensions Changelog
 
+## 2.9.0
+
+### Minor Changes
+
+- 2250cae: Migrated project from coinbase/x402 to x402-foundation/x402 organization
+
+### Patch Changes
+
+- Updated dependencies [8cf3fca]
+- Updated dependencies [c0e3969]
+- Updated dependencies [2250cae]
+- Updated dependencies [d352574]
+  - @x402/core@2.9.0
+
 ## 2.8.0
 
 ### Minor Changes

diff --git a/typescript/packages/extensions/package.json b/typescript/packages/extensions/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@x402/extensions",
-  "version": "2.8.0",
+  "version": "2.9.0",
   "main": "./dist/cjs/index.js",
   "module": "./dist/esm/index.js",
   "types": "./dist/cjs/index.d.ts",

diff --git a/typescript/packages/http/axios/CHANGELOG.md b/typescript/packages/http/axios/CHANGELOG.md
@@ -1,5 +1,19 @@
 # @x402/axios Changelog
 
+## 2.9.0
+
+### Minor Changes
+
+- 2250cae: Migrated project from coinbase/x402 to x402-foundation/x402 organization
+
+### Patch Changes
+
+- Updated dependencies [8cf3fca]
+- Updated dependencies [c0e3969]
+- Updated dependencies [2250cae]
+- Updated dependencies [d352574]
+  - @x402/core@2.9.0
+
 ## 2.8.0
 
 ### Minor Changes

diff --git a/typescript/packages/http/axios/package.json b/typescript/packages/http/axios/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@x402/axios",
-  "version": "2.8.0",
+  "version": "2.9.0",
   "main": "./dist/cjs/index.js",
   "module": "./dist/esm/index.js",
   "types": "./dist/index.d.ts",

diff --git a/typescript/packages/http/express/CHANGELOG.md b/typescript/packages/http/express/CHANGELOG.md
@@ -1,5 +1,22 @@
 # @x402/express Changelog
 
+## 2.9.0
+
+### Minor Changes
+
+- 2250cae: Migrated project from coinbase/x402 to x402-foundation/x402 organization
+- d352574: Add SettlementOverrides support for partial settlement (upto scheme). Route handlers can call setSettlementOverrides() to settle less than the authorized maximum, enabling usage-based billing.
+
+### Patch Changes
+
+- Updated dependencies [8cf3fca]
+- Updated dependencies [c0e3969]
+- Updated dependencies [2250cae]
+- Updated dependencies [d352574]
+  - @x402/core@2.9.0
+  - @x402/paywall@2.9.0
+  - @x402/extensions@2.9.0
+
 ## 2.8.0
 
 ### Minor Changes

diff --git a/typescript/packages/http/express/package.json b/typescript/packages/http/express/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@x402/express",
-  "version": "2.8.0",
+  "version": "2.9.0",
   "main": "./dist/cjs/index.js",
   "module": "./dist/esm/index.js",
   "types": "./dist/index.d.ts",

diff --git a/typescript/packages/http/fastify/CHANGELOG.md b/typescript/packages/http/fastify/CHANGELOG.md
@@ -0,0 +1,19 @@
+# @x402/fastify
+
+## 2.9.0
+
+### Minor Changes
+
+- bd42498: Added Fastify framework adapter for x402 payment middleware
+- 2250cae: Migrated project from coinbase/x402 to x402-foundation/x402 organization
+
+### Patch Changes
+
+- a0ec8e6: Applied monkey-patch on reply.raw write operations and buffered response to prevent content leak from direct raw writes bypassing Fastify's onSend lifecycle
+- Updated dependencies [8cf3fca]
+- Updated dependencies [c0e3969]
+- Updated dependencies [2250cae]
+- Updated dependencies [d352574]
+  - @x402/core@2.9.0
+  - @x402/paywall@2.9.0
+  - @x402/extensions@2.9.0
diff --git a/typescript/packages/http/fastify/package.json b/typescript/packages/http/fastify/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@x402/fastify",
-  "version": "0.1.0",
+  "version": "2.9.0",
   "main": "./dist/cjs/index.js",
   "module": "./dist/esm/index.js",
   "types": "./dist/index.d.ts",

diff --git a/typescript/packages/http/fetch/CHANGELOG.md b/typescript/packages/http/fetch/CHANGELOG.md
@@ -1,5 +1,19 @@
 # @x402/fetch Changelog
 
+## 2.9.0
+
+### Minor Changes
+
+- 2250cae: Migrated project from coinbase/x402 to x402-foundation/x402 organization
+
+### Patch Changes
+
+- Updated dependencies [8cf3fca]
+- Updated dependencies [c0e3969]
+- Updated dependencies [2250cae]
+- Updated dependencies [d352574]
+  - @x402/core@2.9.0
+
 ## 2.8.0
 
 ### Minor Changes

diff --git a/typescript/packages/http/fetch/package.json b/typescript/packages/http/fetch/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@x402/fetch",
-  "version": "2.8.0",
+  "version": "2.9.0",
   "main": "./dist/cjs/index.js",
   "module": "./dist/esm/index.js",
   "types": "./dist/index.d.ts",