x402 payments on base sepolia (#158)

* v2 updates

* v2 updates

* updates

* updates

* updates

* updates

* Delete uv.lock

---------

Co-authored-by: Aniket Dixit <dixitaniket199@gmail.com>

Author: adambalogh

Makefile

@@ -68,11 +68,17 @@ completion:
 		--prompt "Hello, how are you?" \
 		--max-tokens 50
 
-chat:
+chat-og-evm:
 	python -m opengradient.cli chat \
-		--model $(MODEL) --mode TEE \
+		--model $(MODEL) \
+		--messages '[{"role":"user","content":"Tell me a fun fact"}]' \
+		--max-tokens 150 --network og-evm
+
+chat-base-testnet:
+	python -m opengradient.cli chat \
+		--model $(MODEL) \
 		--messages '[{"role":"user","content":"Tell me a fun fact"}]' \
-		--max-tokens 150
+		--max-tokens 150 --network base-testnet
 
 chat-stream:
 	python -m opengradient.cli chat \

examples/README.md

@@ -48,6 +48,18 @@ python examples/upload_model.py
 
 ## x402 LLM Examples
 
+#### `x402_permit2.py`
+Grants Permit2 approval so x402 payments can spend OPG on Base Sepolia.
+
+```bash
+python examples/x402_permit2.py
+```
+
+**What it does:**
+- Sends an `approve(PERMIT2, amount)` transaction for OPG
+- Uses `OG_PRIVATE_KEY` to sign and submit the transaction
+- Prints allowance before and after approval
+
 #### `run_x402_llm.py`
 Runs LLM inference with x402 transaction processing.
 
@@ -187,4 +199,3 @@ Browse available models on the [OpenGradient Model Hub](https://hub.opengradient
 - Run `opengradient --help` for CLI command reference
 - Visit our [documentation](https://docs.opengradient.ai/) for detailed guides
 - Check the main [README](../README.md) for SDK overview
-

examples/run_x402_llm.py

@@ -12,11 +12,16 @@
 import os
 
 import opengradient as og
+from x402_permit2 import check_permit2_approval
+
+network = "base-testnet"
 
 client = og.Client(
     private_key=os.environ.get("OG_PRIVATE_KEY"),
 )
 
+check_permit2_approval(client.wallet_address, network)
+
 messages = [
     {"role": "user", "content": "What is Python?"},
     {"role": "assistant", "content": "Python is a high-level programming language."},
@@ -27,6 +32,6 @@
     model=og.TEE_LLM.GPT_4_1_2025_04_14,
     messages=messages,
     x402_settlement_mode=og.x402SettlementMode.SETTLE_METADATA,
+    network=network
 )
-print(f"Response: {result.chat_output['content']}")
-print(f"Payment hash: {result.payment_hash}")
+print(f"Response: {result.chat_output['content']}")

examples/run_x402_llm_stream.py

@@ -1,21 +1,29 @@
 import os
 
 import opengradient as og
+from x402_permit2 import check_permit2_approval
+
+network = "base-testnet"
 
 client = og.Client(
     private_key=os.environ.get("OG_PRIVATE_KEY"),
 )
 
+check_permit2_approval(client.wallet_address, network)
+
 messages = [
-    {"role": "user", "content": "Describe to me the 7 network layers?"},
+    {"role": "user", "content": "What is Python?"},
+    {"role": "assistant", "content": "Python is a high-level programming language."},
+    {"role": "user", "content": "What makes it good for beginners?"},
 ]
 
 stream = client.llm.chat(
     model=og.TEE_LLM.GPT_4_1_2025_04_14,
     messages=messages,
     x402_settlement_mode=og.x402SettlementMode.SETTLE_METADATA,
     stream=True,
-    max_tokens=1000,
+    max_tokens=300,
+    network=network,
 )
 
 for chunk in stream:

examples/x402_permit2.py

@@ -0,0 +1,141 @@
+import argparse
+import os
+from typing import Optional
+
+import opengradient as og
+from x402v2.mechanisms.evm.constants import PERMIT2_ADDRESS
+from web3 import Web3
+
+BASE_OPG_ADDRESS = "0x240b09731D96979f50B2C649C9CE10FcF9C7987F"
+BASE_SEPOLIA_RPC = "https://sepolia.base.org"
+BASE_TESTNET = "base-testnet"
+MAX_UINT256 = (1 << 256) - 1
+
+ERC20_ABI = [
+    {
+        "inputs": [
+            {"name": "owner", "type": "address"},
+            {"name": "spender", "type": "address"},
+        ],
+        "name": "allowance",
+        "outputs": [{"name": "", "type": "uint256"}],
+        "stateMutability": "view",
+        "type": "function",
+    },
+    {
+        "inputs": [
+            {"name": "spender", "type": "address"},
+            {"name": "amount", "type": "uint256"},
+        ],
+        "name": "approve",
+        "outputs": [{"name": "", "type": "bool"}],
+        "stateMutability": "nonpayable",
+        "type": "function",
+    },
+]
+
+
+def _get_base_sepolia_web3() -> Web3:
+    return Web3(Web3.HTTPProvider(BASE_SEPOLIA_RPC))
+
+
+def get_permit2_allowance(client_address: str) -> int:
+    w3 = _get_base_sepolia_web3()
+    token = w3.eth.contract(address=Web3.to_checksum_address(BASE_OPG_ADDRESS), abi=ERC20_ABI)
+    return token.functions.allowance(
+        Web3.to_checksum_address(client_address),
+        Web3.to_checksum_address(PERMIT2_ADDRESS),
+    ).call()
+
+
+def check_permit2_approval(client_address: str, network: str) -> None:
+    """Raise an error if Permit2 approval is missing for base-testnet."""
+    if network != BASE_TESTNET:
+        return
+
+    allowance = get_permit2_allowance(client_address)
+    print(f"Current OPG Permit2 allowance: {allowance}")
+
+    if allowance == 0:
+        raise RuntimeError(
+            f"ERROR: No Permit2 approval found for address {client_address}. "
+            f"Approve Permit2 ({PERMIT2_ADDRESS}) to spend OPG ({BASE_OPG_ADDRESS}) "
+            "on Base Sepolia before using x402 payments."
+        )
+
+
+def grant_permit2_approval(
+    private_key: str,
+    amount: int = MAX_UINT256,
+    gas_multiplier: float = 1.2,
+    nonce: Optional[int] = None,
+) -> str:
+    """Send ERC-20 approve(spender=Permit2, amount=amount) for OPG on Base Sepolia."""
+    w3 = _get_base_sepolia_web3()
+
+    account = w3.eth.account.from_key(private_key)
+    token = w3.eth.contract(address=Web3.to_checksum_address(BASE_OPG_ADDRESS), abi=ERC20_ABI)
+
+    tx_nonce = nonce
+    if tx_nonce is None:
+        tx_nonce = w3.eth.get_transaction_count(account.address, "pending")
+
+    approve_fn = token.functions.approve(Web3.to_checksum_address(PERMIT2_ADDRESS), amount)
+    estimated_gas = approve_fn.estimate_gas({"from": account.address})
+
+    tx = approve_fn.build_transaction(
+        {
+            "from": account.address,
+            "nonce": tx_nonce,
+            "gas": int(estimated_gas * gas_multiplier),
+            "gasPrice": w3.eth.gas_price,
+            "chainId": w3.eth.chain_id,
+        }
+    )
+
+    signed = account.sign_transaction(tx)
+    tx_hash = w3.eth.send_raw_transaction(signed.raw_transaction)
+    receipt = w3.eth.wait_for_transaction_receipt(tx_hash)
+
+    if receipt.status != 1:
+        raise RuntimeError(f"Permit2 approval transaction failed: {tx_hash.hex()}")
+
+    return tx_hash.hex()
+
+
+def _parse_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser(description="Grant Permit2 approval to spend OPG on Base Sepolia.")
+    parser.add_argument(
+        "--amount",
+        type=int,
+        default=MAX_UINT256,
+        help="Approval amount in base units (default: max uint256).",
+    )
+    return parser.parse_args()
+
+
+def main() -> None:
+    args = _parse_args()
+
+    private_key = os.environ.get("OG_PRIVATE_KEY")
+    if not private_key:
+        raise RuntimeError("OG_PRIVATE_KEY is not set.")
+
+    client = og.Client(private_key=private_key)
+    wallet_address = client.wallet_address
+
+    before = get_permit2_allowance(wallet_address)
+    print(f"Wallet: {wallet_address}")
+    print(f"Permit2: {PERMIT2_ADDRESS}")
+    print(f"OPG Token: {BASE_OPG_ADDRESS}")
+    print(f"Allowance before: {before}")
+
+    tx_hash = grant_permit2_approval(private_key=private_key, amount=args.amount)
+    after = get_permit2_allowance(wallet_address)
+
+    print(f"Approval transaction hash: {tx_hash}")
+    print(f"Allowance after: {after}")
+
+
+if __name__ == "__main__":
+    main()

pyproject.toml

@@ -28,6 +28,7 @@ dependencies = [
     "openai>=1.58.1",
     "pydantic>=2.9.2",
     "og-test-x402==0.0.9",
+    "og-test-v2-x402==0.0.6"
 ]
 
 [project.scripts]

requirements.txt

@@ -7,4 +7,5 @@ requests>=2.32.3
 langchain>=0.3.7
 openai>=1.58.1
 pydantic>=2.9.2
-og-test-x402==0.0.9
+og-test-x402==0.0.9
+og-test-v2-x402==0.0.6

src/opengradient/cli.py

@@ -20,7 +20,7 @@
     DEFAULT_OG_FAUCET_URL,
     DEFAULT_RPC_URL,
 )
-from .types import InferenceMode, x402SettlementMode
+from .types import InferenceMode, x402Network, x402SettlementMode
 
 OG_CONFIG_FILE = Path.home() / ".opengradient_config.json"
 
@@ -74,6 +74,11 @@ def convert(self, value, param, ctx):
     "settle-metadata": x402SettlementMode.SETTLE_METADATA,
 }
 
+x402Networks = {
+    "og-evm": x402Network.OG_EVM,
+    "base-testnet": x402Network.BASE_TESTNET,
+}
+
 
 def initialize_config(ctx):
     """Interactively initialize OpenGradient config"""
@@ -461,6 +466,12 @@ def print_llm_completion_result(model_cid, tx_hash, llm_output, is_vanilla=True)
     default="settle-batch",
     help="Settlement mode for x402 payments: settle (hashes only), settle-batch (batched, default), settle-metadata (full data)",
 )
+@click.option(
+    "--network",
+    type=click.Choice(x402Networks.keys()),
+    default="og-evm",
+    help="x402 network to use for TEE chat payments: og-evm (default) or base-testnet",
+)
 @click.option("--stream", is_flag=True, default=False, help="Stream the output from the LLM")
 @click.pass_context
 def chat(
@@ -475,6 +486,7 @@ def chat(
     tools_file: Optional[Path],
     tool_choice: Optional[str],
     x402_settlement_mode: Optional[str],
+    network: str,
     stream: bool,
 ):
     """
@@ -561,6 +573,7 @@ def chat(
             tools=parsed_tools,
             tool_choice=tool_choice,
             x402_settlement_mode=x402SettlementModes[x402_settlement_mode],
+            network=x402Networks[network],
             stream=stream,
         )
 

src/opengradient/client/client.py

@@ -50,6 +50,7 @@ def __init__(
         email: Optional[str] = None,
         password: Optional[str] = None,
         twins_api_key: Optional[str] = None,
+        wallet_address: str = None,
         rpc_url: str = DEFAULT_RPC_URL,
         api_url: str = DEFAULT_API_URL,
         contract_address: str = DEFAULT_INFERENCE_CONTRACT_ADDRESS,
@@ -79,6 +80,7 @@ def __init__(
 
         # Create namespaces
         self.model_hub = ModelHub(hub_user=hub_user)
+        self.wallet_address = wallet_account.address
 
         self.llm = LLM(
             wallet_account=wallet_account,