Add force inclusion example

README.md

@@ -70,6 +70,7 @@ Using public testnet RPCs can be slow because many tutorials wait for transactio
 - 🌉 [Bridging a custom token through the generic-custom gateway](./packages/custom-token-bridging/)
 - 🌉 [Bridging a custom token through a custom gateway](./packages/custom-gateway-bridging/)
 - ✈️ [Send a signed transaction from the parent chain](./packages/delayedInbox-l2msg/)
+- 🛡️ [Force inclusion end-to-end test](./packages/force-inclusion/)
 - 🎁 [Redeem pending retryable ticket](./packages/redeem-pending-retryable/)
 - 🧮 [Gas estimation](./packages/gas-estimation/)
 - 🌀 [Deposit Ether or Tokens from L1 to L3](./packages/l1-l3-teleport/)

packages/force-inclusion/.env-sample

@@ -0,0 +1,18 @@
+# This is a sample .env file for use in local development.
+# Duplicate this file as .env here
+
+# Private key of the deployer (must have ETH on the parent chain)
+DEPLOYER_PRIVATE_KEY="0x your key here"
+
+# The parent chain's RPC
+# (default: Arbitrum Sepolia)
+PARENT_CHAIN_RPC="https://sepolia-rollup.arbitrum.io/rpc"
+
+# (Optional) Parent chain ID
+# Defaults to Arbitrum Sepolia (421614) if not set
+# PARENT_CHAIN_ID=421614
+
+# (Optional) Batch poster and validator keys
+# Auto-generated if not set (only needed for --with-node)
+# BATCH_POSTER_PRIVATE_KEY="0x..."
+# VALIDATOR_PRIVATE_KEY="0x..."

packages/force-inclusion/README.md

@@ -0,0 +1,92 @@
+# Tutorial: Force Inclusion End-to-End Test
+
+`force-inclusion` demonstrates Arbitrum's **censorship resistance** mechanism end-to-end. It deploys a fresh Orbit rollup with a short force inclusion delay (90 seconds), deposits ETH via the delayed inbox, waits for the delay window to pass, and then force includes the deposit — all without a running sequencer.
+
+## What is force inclusion?
+
+Arbitrum's [Sequencer](https://docs.arbitrum.io/how-arbitrum-works/sequencer) normally orders transactions. But what if the sequencer goes offline or starts censoring? Arbitrum guarantees that any message sent to the **delayed inbox** on the parent chain can be **force included** into the chain's inbox after a time delay, bypassing the sequencer entirely.
+
+This tutorial runs the full cycle in a single command:
+
+1. **Deploy** a new Orbit rollup with `maxTimeVariation.delaySeconds = 90` (instead of the default 24 hours)
+2. **Deposit** ETH via `Inbox.depositEth()` on the parent chain (goes into the delayed inbox)
+3. **Force include** the deposit by calling `SequencerInbox.forceInclusion()` after the delay window passes
+4. *(Optional)* **Start a fullnode** (no sequencer) to verify the deposit appears on the child chain
+
+## Prerequisites
+
+- Node.js 18+
+- A deployer account with ETH on the parent chain (Arbitrum Sepolia or a custom parent chain)
+- Docker (only needed for the `--with-node` option)
+
+## Set environment variables
+
+Copy the sample env file and fill in your values:
+
+```bash
+cp .env-sample .env
+```
+
+Required variables:
+
+| Variable | Description |
+|---|---|
+| `DEPLOYER_PRIVATE_KEY` | Private key of the deployer (must have ETH on the parent chain) |
+| `PARENT_CHAIN_RPC` | RPC URL of the parent chain |
+
+Optional variables:
+
+| Variable | Description |
+|---|---|
+| `PARENT_CHAIN_ID` | Parent chain ID (defaults to Arbitrum Sepolia 421614) |
+| `BATCH_POSTER_PRIVATE_KEY` | Batch poster key (auto-generated if not set) |
+| `VALIDATOR_PRIVATE_KEY` | Validator key (auto-generated if not set) |
+
+## Run
+
+Run steps 1–3 (deploy, deposit, force include):
+
+```bash
+yarn test
+```
+
+Run all 4 steps including fullnode verification (requires Docker):
+
+```bash
+yarn test:withNode
+```
+
+## How it works
+
+### Rollup deployment
+
+The script uses `@arbitrum/chain-sdk` (Orbit SDK) to deploy a new rollup. The key configuration is `sequencerInboxMaxTimeVariation`, which controls how long a delayed message must wait before it can be force included:
+
+```js
+sequencerInboxMaxTimeVariation: {
+  delayBlocks: 6n,
+  futureBlocks: 12n,
+  delaySeconds: 90n,
+  futureSeconds: 3600n,
+}
+```
+
+### Delayed inbox deposit
+
+ETH is deposited using `@arbitrum/sdk`'s `EthBridger.deposit()`. Under the hood, this calls `Inbox.depositEth()` on the parent chain, which routes through `bridge.enqueueDelayedMessage()`. Without a running sequencer, this message stays in the delayed inbox.
+
+### Force inclusion
+
+After the delay window passes (90 seconds + 6 blocks), `InboxTools.forceInclude()` calls `SequencerInbox.forceInclusion()` on the parent chain. This emits the same `SequencerBatchDelivered` event as a normal sequencer batch, making the deposit part of the canonical chain.
+
+### Fullnode verification (--with-node)
+
+When `--with-node` is passed, the script starts a Nitro fullnode via Docker with the sequencer disabled (`node.sequencer = false`, `execution.forwarding-target = "null"`). The fullnode reads from the parent chain and processes the force-included batch, allowing you to verify that the deposited ETH appears on the child chain.
+
+## Related tutorials
+
+- [Send a signed transaction from the parent chain](../delayedInbox-l2msg/) — demonstrates sending transactions via the delayed inbox with a running sequencer
+
+<p align="left">
+  <img width="350" height="150" src= "../../assets/logo.svg" />
+</p>

packages/force-inclusion/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "force-inclusion",
+  "version": "1.0.0",
+  "description": "End-to-end force inclusion test: deploy a rollup with a short delay, deposit ETH via delayed inbox, and force include — all without a sequencer.",
+  "scripts": {
+    "test": "node scripts/force-inclusion-test.js",
+    "test:withNode": "node scripts/force-inclusion-test.js --with-node"
+  },
+  "author": "Offchain Labs, Inc.",
+  "license": "Apache-2.0",
+  "dependencies": {
+    "@arbitrum/sdk": "^4.0.5",
+    "@arbitrum/chain-sdk": "^0.25.0",
+    "viem": "^1.20.0"
+  }
+}