txn.dev

Payment rails built for the multi-agent era. Create wallets, transfer funds between AI agents, and settle in milliseconds. SDK, MCP server, and LangChain integration out of the box.

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What's inside

Instant settlement

Transfers settle in ~4ms. No banking delays, no batch processing. Agents pay each other and keep working.

Sub-cent precision

8 decimal places using BigInt arithmetic. Pay $0.001 per word translated with zero floating-point drift.

Agent wallets

Each agent gets its own wallet with name, metadata, and real-time balance tracking. Multi-currency support.

TypeScript SDK

Three lines from install to production. Create wallets, transfer funds, check balances. Full TypeScript types.

MCP server

Drop into Claude Desktop, Cursor, or Windsurf. Five payment tools available through natural conversation.

LangChain toolkit

TxnToolkit class that slots into any LangChain or LangGraph agent. Five tools, drop-in integration.

Three ways to integrate

TypeScript SDK

@txn/sdk

import { Txn } from '@txn/sdk'

const txn = new Txn({ apiKey: 'txn_...' })

const wallet = await txn.wallets.create({
  name: 'research-agent',
  currency: 'USD'
})

await txn.pay({
  from: wallet.id,
  to: 'translator-wallet-id',
  amount: 0.003,
  memo: '1500 words translated'
})

MCP Server

@txn/mcp-server, added to claude_desktop_config.json

{
  "mcpServers": {
    "txn": {
      "command": "npx",
      "args": ["-y", "@txn/mcp-server"],
      "env": {
        "TXN_API_KEY": "txn_..."
      }
    }
  }
}

LangChain

@txn/langchain

import { TxnToolkit } from '@txn/langchain'

const toolkit = new TxnToolkit({
  apiKey: 'txn_...'
})

const tools = toolkit.getTools()

const agent = createReactAgent({
  llm,
  tools
})

Simple REST API

Five endpoints. Create wallets, move money, check balances. Bearer token auth, JSON in and out.

POST /wallets: Create a new agent wallet
GET /wallets: List all wallets
GET /wallets/:id: Get wallet details and balance
POST /pay: Transfer funds between wallets
POST /fund: Add funds via Stripe

Built for

Multi-agent workflows

Coordinator hires a translator at $0.001/word and a summarizer at $0.25 flat. Each agent gets paid the moment their work completes.

Agent marketplaces

Agents offer services, other agents consume them, payment happens inline. Build ecosystems where agents discover and pay each other.

Cross-Organization

Agent A from Company X needs Agent B from Company Y. Transfer funds between organizations instantly, no contracts.

Metered AI services

Charge per token, per word, per action. Sub-cent precision means granular pricing with instant settlement.

Simple pricing

No monthly fees. No setup costs. No minimums.

2.5%

per transfer

Unlimited wallets
Unlimited API calls
All integrations included

Agents need money too

If your agents hire other agents, they need a way to pay them. That's what txn.dev does.

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