Documentation

LangChain plugin

npm: @upoch/langchain@langchain/core 1.x

One callback for a LangChain or LangGraph agent: every swap, transfer or trade tool call is checkpointed before and after it runs, and the agent can roll back to the last good state.

What it does

Automatic checkpoints. Before and after every consequential tool call (swaps, transfers, bridges, staking, lending, trades, mints, launches and approvals), UpochCallbackHandler saves a verified checkpoint on Robinhood Chain, with the transaction hash when the tool returns one. LangChain waits for the pre-tool checkpoint to commit before the tool runs.
Rollback. With upochTools(), the model can restore its last checkpoint at the start of a task and roll back to the checkpoint right before the last swap or transfer, or to one you name, and continue from there.
Works with LangChain and LangGraph (JavaScript and TypeScript). Every checkpoint opens in the Time-Travel Debugger.

Setup

Once, in your own terminal (Node.js 24 or later):

terminal

npm install -g @upoch/guard
upoch setup                      # keys, funding, registration

upoch setup creates two keys on your machine: the owner, which registers the agent, and the executor, the agent's key, which can only submit checkpoints. It waits while you send the owner a little ETH on Robinhood Chain (0.001 ETH is plenty), then registers the agent and gives the executor gas for checkpoints. Then add the callback to your agent:

agent.ts

// npm install @upoch/langchain
import { UpochCallbackHandler, upochTools } from "@upoch/langchain";

const upoch = new UpochCallbackHandler();

// Automatic checkpoints around consequential tool calls:
await agent.invoke(input, { callbacks: [upoch] });

// Optional: let the model restore, checkpoint and roll back itself.
const tools = [...yourTools, ...upochTools({ handler: upoch })];

Tools for the model

Tool
upoch_restore	Latest checkpoint, verified against the chain, and which actions completed
upoch_checkpoint	Save the current state
upoch_rollback	Go back to an earlier checkpoint and continue; by default the one right before the last swap or transfer
upoch_history	Recent checkpoints
upoch_complete	Mark the task finished

A rollback restores the agent's state; it cannot reverse transactions that already happened on-chain. The tools list the actions that ran after the restored checkpoint so the agent can account for them.

Options

agent.ts

new UpochCallbackHandler({
  watch: ["swap_tokens", "send_eth"],   // exact tool names, or a RegExp (default: value-moving names)
  state: () => myAgentState,            // what each checkpoint holds (default: the log of watched tool calls)
  strict: true,                         // stop the tool when its pre-tool checkpoint fails (default false)
});

Safety

Each checkpoint is one transaction from the executor key, with a daily limit (100 by default, maxCheckpointsPerDay in ~/.upoch/config.json).
State that looks like private keys, seed phrases or API tokens is refused before anything is stored: checkpoints are permanent.
Keys stay on your machine in ~/.upoch/secrets.json, unencrypted (owner-only permissions on macOS and Linux). Back it up, and keep only small amounts on these keys.
The Upoch contracts have not been audited.