New Template: Vault Harvester

starter-templates/README.md

@@ -43,9 +43,12 @@ They are more comprehensive than **building-blocks**, and can be adapted into yo
 2. **Bring Your Own Data (BYOD)** — NAV & PoR — [`./bring-your-own-data`](./bring-your-own-data)  
    End-to-end examples for publishing **Net Asset Value** and **Proof of Reserve** data on-chain using CRE workflows and demo contracts.
 
-3. **Multi-Chain Token Manager** — [`./multi-chain-token-manager`](./multi-chain-token-manager)  
+3. **Multi-Chain Token Manager** — [`./multi-chain-token-manager`](./multi-chain-token-manager)
    Orchestrate token operations and state across multiple chains, showing RPC configuration, bindings, and cross-chain patterns.
 
+4. **Vault Harvester** — [`./vault-harvester`](./vault-harvester)
+   Automated DeFi vault harvesting — check if yield is profitable, then harvest and compound. Same cron → read → check → write pattern as the Keeper Bot, with a DeFi-specific profitability check.
+
 > Each subdirectory includes its own README with template-specific steps and example logs.
 
 ## License

starter-templates/vault-harvester/vault-harvester-ts/.cre/template.yaml

@@ -0,0 +1,20 @@
+kind: starter-template
+id: vault-harvester-ts
+projectDir: .
+title: "Vault Harvester (TypeScript)"
+description: "Automated DeFi vault harvesting — check if yield is profitable, then harvest and compound."
+language: typescript
+category: workflow
+tags:
+  - vault
+  - harvester
+  - yield
+  - compounder
+  - defi
+  - cron
+  - on-chain-read
+  - on-chain-write
+workflows:
+  - dir: my-workflow
+postInit: |
+  A demo VaultHarvester contract is pre-deployed on Sepolia. See README.md for details.

starter-templates/vault-harvester/vault-harvester-ts/.gitignore

@@ -0,0 +1 @@
+*.env

starter-templates/vault-harvester/vault-harvester-ts/README.md

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+# Vault Harvester — CRE Starter Template (TypeScript)
+
+Automated DeFi vault harvesting — check if yield is profitable, then harvest and compound.
+
+**⚠️ DISCLAIMER**
+
+This template is an educational example to demonstrate how to interact with Chainlink systems, products, and services. It is provided **"AS IS"** and **"AS AVAILABLE"** without warranties of any kind, has **not** been audited, and may omit checks or error handling for clarity. **Do not use this code in production** without performing your own audits and applying best practices. Neither Chainlink Labs, the Chainlink Foundation, nor Chainlink node operators are responsible for unintended outputs generated due to errors in code.
+
+---
+
+## Overview
+
+This template demonstrates the **cron -> read -> check profitability -> harvest** pattern using Chainlink CRE (Compute Runtime Environment). Same cron -> read -> check -> write pattern as the Keeper Bot, but with a DeFi-specific vault contract.
+
+### Use Cases
+
+- **Vault harvesting** (primary): Check if `timeSinceLastHarvest > threshold` AND `yield > minThreshold`, then harvest
+- **Yield compounding**: Harvest + swap + redeposit accumulated rewards
+- **Protocol revenue collection**: Claim and redistribute protocol fees on schedule
+- **Target protocols**: Beefy, Yearn, Alchemix, and any vault with a `harvest()` function
+
+## Architecture
+
+```
+┌─────────────────────────────────────────────────────────────┐
+│                      CRE DON                                │
+│                                                             │
+│  ┌──────────┐    ┌───────────────┐    ┌──────────────────┐  │
+│  │   CRON   │───>│  Read Vault   │───>│  Profitable to   │  │
+│  │ Trigger  │    │  State        │    │  harvest?        │  │
+│  │ (5 min)  │    │  (EVMClient)  │    │  (time + yield)  │  │
+│  └──────────┘    └───────────────┘    └────────┬─────────┘  │
+│                                                │            │
+│                                     ┌──────────v──────────┐ │
+│                                     │  Profitable?        │ │
+│                                     │  YES -> Write report│ │
+│                                     │  NO  -> Log & skip  │ │
+│                                     └──────────┬──────────┘ │
+│                                                │            │
+└────────────────────────────────────────────────┼────────────┘
+                                                 │
+                                      ┌──────────v──────────────┐
+                                      │  KeystoneForwarder      │
+                                      │  -> Vault._processReport│
+                                      │    (harvest + compound) │
+                                      └─────────────────────────┘
+```
+
+## Components
+
+### CRE Workflow (`my-workflow/`)
+
+The TypeScript workflow runs off-chain inside CRE DON:
+
+1. **Cron trigger** fires every 5 minutes (configurable)
+2. **Reads** `shouldHarvest()`, `pendingYield()`, `totalHarvested()`, `harvestCount()` from the on-chain `VaultHarvester` contract
+3. **If profitable**: sends a signed report to trigger harvest on-chain
+4. **If not profitable**: logs and skips
+
+### Consumer Contract (`contracts/evm/src/VaultHarvester.sol`)
+
+A DeFi vault contract extending `ReceiverTemplate`:
+
+- `shouldHarvest()` — view function that checks if `harvestInterval` has elapsed AND `pendingYield >= minYieldThreshold`
+- `_processReport(bytes)` — called by CRE Forwarder, harvests pending yield, resets state, emits event
+- `accrueYield(uint256)` — simulates yield accrual (in production, yield comes from the underlying strategy)
+- `pendingYield`, `totalHarvested`, `harvestCount`, `lastHarvest` — public state variables
+
+## Getting Started
+
+A demo `VaultHarvester` contract is pre-deployed on Sepolia with simulated yield — this template works out of the box.
+
+### Prerequisites
+
+- [Bun](https://bun.sh/) runtime installed
+- [CRE CLI](https://docs.chain.link/cre) installed
+
+### 1. Install Dependencies
+
+```bash
+cd my-workflow && bun install && cd ..
+cd contracts && bun install && cd ..
+```
+
+### 2. Run Tests
+
+```bash
+cd my-workflow && bun test
+```
+
+### 3. Simulate
+
+```bash
+# Dry run (no broadcast)
+cre workflow simulate my-workflow --target staging-settings
+
+# With actual on-chain transaction
+cre workflow simulate my-workflow --target staging-settings --broadcast
+```
+
+### 4. Deploy Your Own Contract (Optional)
+
+To use your own contract, deploy `contracts/evm/src/VaultHarvester.sol` to Sepolia using [Remix](https://remix.ethereum.org/) or Foundry. Constructor arguments:
+
+- `forwarder`: CRE KeystoneForwarder address on Sepolia (`0x15fc6ae953e024d975e77382eeec56a9101f9f88`)
+- `_harvestInterval`: Seconds between allowed harvests (e.g., `300` for 5 minutes)
+- `_minYieldThreshold`: Minimum yield in wei to justify harvest (e.g., `1000000000000000000` for 1 token)
+
+Then update the `contractAddress` in `my-workflow/config.staging.json` with your deployed address.
+
+To simulate yield accrual on your contract:
+```bash
+cast send <YOUR_CONTRACT> "accrueYield(uint256)" 2000000000000000000 \
+  --private-key <YOUR_KEY> --rpc-url https://ethereum-sepolia-rpc.publicnode.com
+```
+
+## Customization
+
+- **Change the schedule**: Edit `schedule` in `config.staging.json` (cron syntax)
+- **Change the profitability check**: Modify `shouldHarvest()` in `VaultHarvester.sol`
+- **Change the harvest logic**: Modify `_processReport()` to implement your vault's harvest + compound strategy
+
+## Migration Guides
+
+### Coming from Gelato?
+
+This template replaces Gelato's vault harvesting Web3 Functions with CRE cron triggers. Gelato shut down Web3 Functions in March 2026.
+
+| Gelato | CRE |
+|--------|-----|
+| `Web3Function.onRun()` | CRE cron callback (`onCronTrigger`) |
+| `multiChainProvider` | `EVMClient` |
+| `userArgs` | `config.json` |
+
+### Coming from Chainlink Automation?
+
+This replaces the Beefy/Yearn `checkUpkeep + performUpkeep` pattern. Off-chain profitability check means no wasted gas.
+
+| Chainlink Automation | CRE |
+|---------------------|-----|
+| `checkUpkeep()` on-chain | `shouldHarvest()` read via `EVMClient` (off-chain) |
+| `performUpkeep()` | `_processReport()` via KeystoneForwarder |
+| LINK funding | No per-call LINK costs |
+
+## Security
+
+- The `VaultHarvester.sol` contract is a **demo** — audit and customize before production use
+- The `ReceiverTemplate` base contract validates that only CRE Forwarder can call `onReport()`
+- Never commit `.env` files or secrets
+
+## License
+
+MIT

starter-templates/vault-harvester/vault-harvester-ts/contracts/abi/VaultHarvester.ts

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+import { parseAbi } from "viem"
+
+export const VaultHarvesterAbi = parseAbi([
+  "function shouldHarvest() view returns (bool harvestNeeded)",
+  "function totalHarvested() view returns (uint256)",
+  "function lastHarvest() view returns (uint256)",
+  "function harvestCount() view returns (uint256)",
+  "function pendingYield() view returns (uint256)",
+  "function harvestInterval() view returns (uint256)",
+  "function minYieldThreshold() view returns (uint256)",
+])

starter-templates/vault-harvester/vault-harvester-ts/contracts/abi/index.ts

@@ -0,0 +1 @@
+export * from './VaultHarvester'

starter-templates/vault-harvester/vault-harvester-ts/contracts/evm/src/IERC165.sol

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts (last updated v5.4.0) (utils/introspection/IERC165.sol)
+
+pragma solidity >=0.4.16;
+
+/**
+ * @dev Interface of the ERC-165 standard, as defined in the
+ * https://eips.ethereum.org/EIPS/eip-165[ERC].
+ *
+ * Implementers can declare support of contract interfaces, which can then be
+ * queried by others ({ERC165Checker}).
+ *
+ * For an implementation, see {ERC165}.
+ */
+interface IERC165 {
+  /**
+   * @dev Returns true if this contract implements the interface defined by
+   * `interfaceId`. See the corresponding
+   * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[ERC section]
+   * to learn more about how these ids are created.
+   *
+   * This function call must use less than 30 000 gas.
+   */
+  function supportsInterface(
+    bytes4 interfaceId
+  ) external view returns (bool);
+}

starter-templates/vault-harvester/vault-harvester-ts/contracts/evm/src/IReceiver.sol

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+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import {IERC165} from "./IERC165.sol";
+
+/// @title IReceiver - receives keystone reports
+/// @notice Implementations must support the IReceiver interface through ERC165.
+interface IReceiver is IERC165 {
+  /// @notice Handles incoming keystone reports.
+  /// @dev If this function call reverts, it can be retried with a higher gas
+  /// limit. The receiver is responsible for discarding stale reports.
+  /// @param metadata Report's metadata.
+  /// @param report Workflow report.
+  function onReport(
+    bytes calldata metadata,
+    bytes calldata report
+  ) external;
+}