x402-openai 0.2.0

Drop-in OpenAI Python client with transparent x402 payment support.

x402-openai

Drop-in OpenAI Python client with transparent x402 payment support — EVM, Solana, and beyond.

Install

# EVM only
pip install x402-openai[evm]

# Solana (SVM) only
pip install x402-openai[svm]

# Both chains
pip install x402-openai[all]

Quick Start

EVM (Ethereum / Base / …)

from x402_openai import X402OpenAI
from x402_openai.wallets import EvmWallet

client = X402OpenAI(wallet=EvmWallet(private_key="0x…"))

# Use exactly like openai.OpenAI — everything just works!
completion = client.chat.completions.create(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "Hello!"}],
)
print(completion.choices[0].message.content)

SVM (Solana)

from x402_openai import X402OpenAI
from x402_openai.wallets import SvmWallet

client = X402OpenAI(wallet=SvmWallet(private_key="base58…"))

Multi-chain

Register multiple wallets — the x402 protocol automatically selects the right chain based on the server's payment requirements.

from x402_openai import X402OpenAI
from x402_openai.wallets import EvmWallet, SvmWallet

client = X402OpenAI(wallets=[
    EvmWallet(private_key="0x…"),
    SvmWallet(private_key="base58…"),
])

EVM mnemonic phrase

from x402_openai.wallets import EvmWallet

wallet = EvmWallet(mnemonic="word1 word2 … word12")

# BIP-44 account #2: m/44'/60'/0'/0/2
wallet = EvmWallet(mnemonic="word1 word2 …", account_index=2)

# Ledger Live derivation path
wallet = EvmWallet(mnemonic="word1 word2 …", derivation_path="m/44'/60'/2'/0/0")

Legacy EVM shortcut (backward compatible)

Existing code using private_key= / mnemonic= directly continues to work:

client = X402OpenAI(private_key="0x…")
client = X402OpenAI(mnemonic="word1 word2 … word12")

Async

from x402_openai import AsyncX402OpenAI
from x402_openai.wallets import SvmWallet

client = AsyncX402OpenAI(wallet=SvmWallet(private_key="base58…"))

completion = await client.chat.completions.create(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "Hello!"}],
)

Streaming

stream = await client.chat.completions.create(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "Explain x402"}],
    stream=True,
)
async for chunk in stream:
    if chunk.choices[0].delta.content:
        print(chunk.choices[0].delta.content, end="")

Advanced: pre-built x402 client

from x402 import x402ClientSync
from x402_openai import X402OpenAI

x402 = x402ClientSync()
# ... register custom payment schemes ...

client = X402OpenAI(x402_client=x402)

Advanced: manual transport injection

import httpx
from openai import AsyncOpenAI
from x402_openai import AsyncX402Transport

transport = AsyncX402Transport(x402_client=x402_http)
client = AsyncOpenAI(
    api_key="x402",
    http_client=httpx.AsyncClient(transport=transport),
)

API

X402OpenAI(*, wallet=None, wallets=None, x402_client=None, **kwargs)

Drop-in replacement for openai.OpenAI. Provide exactly one credential source:

Parameter	Description
wallet	A single Wallet adapter (e.g. EvmWallet, SvmWallet)
wallets	List of Wallet adapters for multi-chain support
private_key	(legacy) EVM hex key ("0x…")
mnemonic	(legacy) BIP-39 phrase (12/24 words)
x402_client	Pre-configured x402HTTPClientSync

Legacy mnemonic companions: account_index (default 0), derivation_path, passphrase.

Default base_url is https://llm.qntx.fun/v1. All kwargs (base_url, timeout, max_retries, …) forward to openai.OpenAI.

AsyncX402OpenAI(*, ...)

Async version — identical parameters.

Wallet adapters

Class	Chain	Install extra
EvmWallet(private_key=…)	EVM (Ethereum, Base, …)	x402-openai[evm]
EvmWallet(mnemonic=…)	EVM (BIP-39)	x402-openai[evm]
SvmWallet(private_key=…)	Solana	x402-openai[svm]

All wallets implement the Wallet protocol. See wallets/_base.py to add support for a new chain.

X402Transport(x402_client, *, inner=None) / AsyncX402Transport(x402_client, *, inner=None)

Low-level httpx transports for manual wiring.

Examples

# EVM chat completion
EVM_PRIVATE_KEY="0x..." python examples/chat.py

# SVM (Solana) chat completion
SOLANA_PRIVATE_KEY="base58..." python examples/chat_svm.py

# Multi-chain (EVM + SVM)
EVM_PRIVATE_KEY="0x..." SOLANA_PRIVATE_KEY="base58..." python examples/chat_multichain.py

# Streaming
EVM_PRIVATE_KEY="0x..." python examples/streaming.py

# List models
MNEMONIC="word1 word2 ..." python examples/models.py

License

This project is licensed under either of the following licenses, at your option:

• Apache License, Version 2.0, (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this project by you, as defined in the Apache-2.0 license, shall be dually licensed as above, without any additional terms or conditions.