feat: Add account-modules Solidity package

.github/workflows/account-modules-ci.yml

@@ -0,0 +1,49 @@
+name: Account Modules CI
+
+on:
+  pull_request:
+    paths:
+      - 'solidity/account-modules/**'
+      - '.github/workflows/account-modules-ci.yml'
+  workflow_dispatch:
+
+env:
+  FOUNDRY_PROFILE: ci
+
+jobs:
+  check:
+    name: Account Modules Foundry project
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: solidity/account-modules
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Install Foundry
+        uses: foundry-rs/foundry-toolchain@v1
+
+      - name: Show Forge version
+        run: |
+          forge --version
+
+      - name: Install Node dependencies
+        run: |
+          cd lib/modulekit && npm install
+
+      - name: Run Forge fmt
+        run: |
+          forge fmt --check
+        id: fmt
+
+      - name: Run Forge build
+        run: |
+          forge build --sizes src/
+        id: build
+
+      - name: Run Forge tests
+        run: |
+          ACCOUNT_TYPE=SAFE forge test -vvv
+        id: test

.gitmodules

@@ -0,0 +1,15 @@
+[submodule "solidity/account-modules/lib/forge-std"]
+	path = solidity/account-modules/lib/forge-std
+	url = https://github.com/foundry-rs/forge-std
+[submodule "solidity/account-modules/lib/modulekit"]
+	path = solidity/account-modules/lib/modulekit
+	url = https://github.com/pcarranzav/modulekit
+[submodule "solidity/account-modules/lib/openzeppelin-contracts"]
+	path = solidity/account-modules/lib/openzeppelin-contracts
+	url = https://github.com/OpenZeppelin/openzeppelin-contracts
+[submodule "solidity/account-modules/lib/BokkyPooBahsDateTimeLibrary"]
+	path = solidity/account-modules/lib/BokkyPooBahsDateTimeLibrary
+	url = https://github.com/bokkypoobah/BokkyPooBahsDateTimeLibrary
+[submodule "solidity/account-modules/lib/safe-singleton-deployer-sol"]
+	path = solidity/account-modules/lib/safe-singleton-deployer-sol
+	url = https://github.com/wilsoncusack/safe-singleton-deployer-sol

.prettierignore

@@ -18,3 +18,6 @@ tmp/
 # Lock files
 pnpm-lock.yaml
 uv.lock
+
+# Solidity submodules (have their own prettier configs)
+solidity/**/lib/

solidity/account-modules/.gitignore

@@ -0,0 +1,11 @@
+# Compiler files
+cache/
+out/
+
+# Ignores development broadcast logs
+!/broadcast
+/broadcast/*/31337/
+/broadcast/**/dry-run/
+
+# Dotenv file
+.env

solidity/account-modules/README.md

@@ -0,0 +1,74 @@
+# Account Modules
+
+ERC-7579 compliant executor modules for smart account automation in the x402 payments system.
+
+## Modules
+
+### AutoTopUpModule
+
+- Automatically tops up agent accounts when balance falls below threshold
+- Configurable per-agent limits (daily, monthly)
+- Permissionless triggering with proper checks
+- Used by: Main accounts to fund agent accounts
+
+### AutoCollectModule
+
+- Automatically collects payments from service accounts
+- Configurable collection thresholds (amount and time)
+- Batch collection optimization
+- Used by: Service accounts to collect to main accounts
+
+## Architecture
+
+All modules implement the ERC-7579 executor module interface:
+
+- `onInstall(bytes calldata data)` - Module installation
+- `onUninstall(bytes calldata data)` - Module removal
+- `isModuleType(uint256 typeID)` - Returns true for executor type (0x01)
+- `isInitialized(address account)` - Check if module is initialized for account
+
+## Deployment
+
+The modules are deployed as immutable singletons using Safe's Singleton Factory, ensuring the same addresses across all
+chains:
+
+- **AutoTopUpExecutor**: `0x16f13052FbFFfcE34E5752b7F4CFF881a030F40B`
+- **AutoCollectExecutor**: `0x29864bd91370886c38dE9Fe95F5589E7EbE15130`
+
+These addresses are deterministic and will remain consistent on all supported chains (Base, Base Sepolia, etc.).
+
+## Development
+
+### Prerequisites
+
+- [Foundry](https://book.getfoundry.sh/getting-started/installation)
+- [pnpm](https://pnpm.io/installation) (for ModuleKit dependencies)
+
+### Setup
+
+```bash
+# Install Forge dependencies
+forge install
+
+# Install ModuleKit node dependencies (required for compilation)
+cd lib/modulekit && npm install && cd ../..
+
+# Build contracts
+forge build
+
+# Run tests
+forge test
+
+# Deploy
+forge script script/Deploy.s.sol --rpc-url $RPC_URL --broadcast
+```
+
+**Important**: ModuleKit requires its node modules to be installed for proper compilation. This step (`pnpm install` in
+the modulekit directory) must be performed after cloning the repository and before building.
+
+## Security
+
+- Non-custodial design - modules only execute based on user-defined rules
+- Access control via ERC-7579 standards
+- Immutable singleton contracts - no upgradeability, no owner
+- Comprehensive event logging