Skip to main content
Session payments use an escrow-backed channel on Abstract so the client can pay repeatedly with off-chain vouchers after one initial on-chain open.

​
Session lifecycle

The client-side session flow has four main actions:
  • open to create the channel and sign the first voucher
  • voucher to increase the cumulative paid amount
  • topUp to add more deposit
  • close to finalize with a last voucher

​
1. Install the package

npm install @abstract-foundation/mpp mppx viem zod

​
2. Create the client session method

import { abstractSession } from "@abstract-foundation/mpp/client";
import { privateKeyToAccount } from "viem/accounts";

const session = abstractSession({
  account: privateKeyToAccount(process.env.PRIVATE_KEY as `0x${string}`),
  deposit: "10",
});
deposit is the default human-readable token amount to escrow unless the server challenge provides suggestedDeposit.

​
3. Register the server session method

import { Mppx } from "mppx/server";
import { abstract } from "@abstract-foundation/mpp/server";
import { privateKeyToAccount } from "viem/accounts";

const serverAccount = privateKeyToAccount(
  process.env.SERVER_PRIVATE_KEY as `0x${string}`
);

const mpp = Mppx.create({
  methods: [
    abstract.session({
      account: serverAccount,
      recipient: "0xYourWalletAddress",
      amount: "0.001",
      suggestedDeposit: "1",
      unitType: "request",
      testnet: true,
    }),
  ],
  secretKey: process.env.MPP_SECRET_KEY!,
});

​
4. Request shape

Session requests can include:
  • amount
  • currency
  • decimals
  • unitType
  • optional recipient
  • optional channelId
  • optional escrowContract
  • optional suggestedDeposit
  • optional minVoucherDelta

​
5. Operational guidance

  • pick a suggestedDeposit that supports several expected requests
  • settle when the open channel has accumulated enough value or when you need finality
  • use topUp instead of reopening when the remaining deposit is too low
  • expect cumulative amounts, not independent per-request signatures

​
When to use session mode

Use session payments when:
  • your agent will call the same paid API repeatedly
  • per-request on-chain overhead is too high
  • you want the HTTP flow to stay fast after the initial channel open