feat: upto evm python (x402-foundation#2023)

* feat: add upto to python SDK

* feat: add unit & integration tests

* feat: add upto python clients/servers/facilitator to e2e suite

* initial cleanup

* implement partial settlement

* improve parity with ts/go

* better parity and fix tests

* fix(python): sort imports and format test file to pass ruff lint

New error constants were appended after ERR_UNSUPPORTED_SCHEME instead
of in alphabetical order, causing I001 (import block un-sorted).

Made-with: Cursor

* add comment to e2e tests

* fix failing integration test

* changelog

* fix changelog name

---------

Co-authored-by: Ethan Oroshiba <[email protected]>

Author: CarsonRoscoe

e2e/clients/go-http/go.mod

@@ -5,8 +5,8 @@ go 1.24.0
 toolchain go1.24.1
 
 require (
-	github.com/x402-foundation/x402/go v0.0.0
 	github.com/ethereum/go-ethereum v1.16.7
+	github.com/x402-foundation/x402/go v0.0.0
 )
 
 require (

e2e/clients/httpx/main.py

@@ -16,6 +16,7 @@
 from x402.http.clients import x402_httpx_transport
 from x402.mechanisms.evm import EthAccountSignerWithRPC
 from x402.mechanisms.evm.exact import register_exact_evm_client
+from x402.mechanisms.evm.upto import UptoEvmClientScheme
 from x402.mechanisms.svm import KeypairSigner
 from x402.mechanisms.svm.exact import register_exact_svm_client
 import httpx
@@ -53,6 +54,7 @@ async def main():
         evm_account = Account.from_key(evm_private_key)
         evm_signer = EthAccountSignerWithRPC(evm_account, rpc_url=evm_rpc_url)
         register_exact_evm_client(client, evm_signer)
+        client.register("eip155:*", UptoEvmClientScheme(evm_signer))
 
     # Register SVM exact scheme if private key is available
     if svm_private_key:

e2e/clients/httpx/test.config.json

@@ -10,8 +10,9 @@
     1,
     2
   ],
+  "schemes": ["exact", "upto"],
   "evm": {
-    "transferMethods": ["eip3009", "permit2"]
+    "transferMethods": ["eip3009", "permit2", "upto"]
   },
   "extensions": [
     "eip2612GasSponsoring",

e2e/clients/httpx/uv.lock

@@ -5,8 +5,8 @@ go 1.24.0
 toolchain go1.24.1
 
 require (
-	github.com/x402-foundation/x402/go v0.0.0
 	github.com/modelcontextprotocol/go-sdk v1.3.0
+	github.com/x402-foundation/x402/go v0.0.0
 )
 
 require (

e2e/clients/mcp-go/go.mod

@@ -10,6 +10,7 @@
 from x402.http.clients import x402_requests
 from x402.mechanisms.evm import EthAccountSignerWithRPC
 from x402.mechanisms.evm.exact import register_exact_evm_client
+from x402.mechanisms.evm.upto import UptoEvmClientScheme
 from x402.mechanisms.svm import KeypairSigner
 from x402.mechanisms.svm.exact import register_exact_svm_client
 
@@ -46,6 +47,7 @@ def main():
         evm_account = Account.from_key(evm_private_key)
         evm_signer = EthAccountSignerWithRPC(evm_account, rpc_url=evm_rpc_url)
         register_exact_evm_client(client, evm_signer)
+        client.register("eip155:*", UptoEvmClientScheme(evm_signer))
 
     # Register SVM exact scheme if private key is available
     if svm_private_key:

e2e/clients/mcp-python/uv.lock

@@ -10,8 +10,9 @@
     1,
     2
   ],
+  "schemes": ["exact", "upto"],
   "evm": {
-    "transferMethods": ["eip3009", "permit2"]
+    "transferMethods": ["eip3009", "permit2", "upto"]
   },
   "extensions": [
     "eip2612GasSponsoring",

e2e/clients/requests/main.py

@@ -5,10 +5,10 @@ go 1.24.0
 toolchain go1.24.1
 
 require (
-	github.com/x402-foundation/x402/go v0.0.0
 	github.com/ethereum/go-ethereum v1.16.7
 	github.com/gagliardetto/solana-go v1.14.0
 	github.com/gin-gonic/gin v1.11.0
+	github.com/x402-foundation/x402/go v0.0.0
 )
 
 require (