LangChain

Use 1ly directly inside LangChain agents to buy and sell APIs with USDC on Base or Solana.

This integration is production ready and published on PyPI as langchain-onely.

Install

pip install langchain-onely

Requirements: Python 3.10+

Wallet Setup

You need a wallet only for paid calls.

Base wallet: EVM private key (hex string)
Solana wallet: Base58 private key string

Endpoint format: always username/slug (example: 1ly/paid-api-vwo6oh).

Quick Start (Buyer)

LangChain tools return JSON strings. Parse them with json.loads.

import json
import os
from langchain_onely import OneLyToolkit
 
toolkit = OneLyToolkit(
    base_private_key=os.getenv("BASE_PRIVATE_KEY"),  # or solana_private_key
)
tools = toolkit.get_tools()
 
search = next(t for t in tools if t.name == "onely_search")
details = next(t for t in tools if t.name == "onely_get_details")
call = next(t for t in tools if t.name == "onely_call")
 
results = json.loads(search.invoke({"query": "emoji api"}))
info = json.loads(details.invoke({"endpoint": "1ly/paid-api-vwo6oh"}))
 
# Pay and call (x402 handled automatically)
response = json.loads(call.invoke({
    "endpoint": "1ly/paid-api-vwo6oh",
    "method": "GET",
    "preferredNetwork": "base",
    "preferredAsset": "USDC",
    "allowFallback": False
}))

Quick Start (Seller)

import json
import os
from langchain_onely import OneLyToolkit
 
# First: create your store and get an API key
toolkit = OneLyToolkit(base_private_key=os.getenv("BASE_PRIVATE_KEY"))
tools = toolkit.get_tools()
create_store = next(t for t in tools if t.name == "onely_create_store")
 
store = json.loads(create_store.invoke({
    "username": "my-store",
    "displayName": "My API Store"
}))
 
# Then: re-initialize with the API key for seller tools
toolkit = OneLyToolkit(
    base_private_key=os.getenv("BASE_PRIVATE_KEY"),
    api_key=store["data"]["apiKey"]
)
tools = toolkit.get_tools()
 
create_link = next(t for t in tools if t.name == "onely_create_link")
link = json.loads(create_link.invoke({
    "title": "My Paid API",
    "description": "Fast JSON data",
    "url": "https://api.example.com/endpoint",
    "price": 0.01
}))

Payment Selection

onely_call supports multiple payment options in the 402 response. You can control selection:

preferredNetwork: "base" or "solana"
preferredAsset: "USDC" or "1LY" (1LY is Solana only)
allowFallback: If True, tries other compatible options if the preferred choice fails

Solana + 1LY Example

import json
import os
from langchain_onely import OneLyToolkit
 
toolkit = OneLyToolkit(
    solana_private_key=os.getenv("SOLANA_PRIVATE_KEY"),
)
tools = toolkit.get_tools()
call = next(t for t in tools if t.name == "onely_call")
 
response = json.loads(call.invoke({
    "endpoint": "1ly/paid-api-vwo6oh",
    "method": "GET",
    "preferredNetwork": "solana",
    "preferredAsset": "1LY",
    "allowFallback": False
}))

Optional Configuration

You can pass RPC URLs directly:

toolkit = OneLyToolkit(
    base_private_key=os.getenv("BASE_PRIVATE_KEY"),
    solana_private_key=os.getenv("SOLANA_PRIVATE_KEY"),
    base_rpc_url="https://base.publicnode.com",
    solana_rpc_url="https://api.mainnet-beta.solana.com",
)

Tools

Buyer Tools

Tool	Required Inputs	Wallet Required	Notes
`onely_search`	`query`	No	Search marketplace
`onely_get_details`	`endpoint`	No	Get listing details
`onely_call`	`endpoint`	Yes (paid APIs)	Supports `preferredNetwork`, `preferredAsset`, `allowFallback`
`onely_review`	`purchaseId`, `reviewToken`	Yes	Must use the same wallet that paid

Seller Tools

Tool	Required Inputs	API Key Required	Notes
`onely_create_store`	`username`, `displayName`	No	Returns `apiKey` for seller tools
`onely_create_link`	`title`, `description`, `url`, `price`	Yes	List paid API
`onely_list_links`	none	Yes	List your links
`onely_get_stats`	none	Yes	Sales stats
`onely_withdraw`	`amount`	Yes	Solana only

Troubleshooting

Wallet not configured: Pass base_private_key or solana_private_key to OneLyToolkit
Payment failed: Ensure the wallet has enough USDC on the selected network
Review failed: Use the purchaseId and reviewToken returned by onely_call

API Reference MCP Server