feat(pyth-evm-js): add transaction filler for automatic Pyth price data bundling

- Add TransactionFiller class and fillTransactionWithPythData function
- Support automatic detection of Pyth getPrice* method calls via transaction tracing
- Extract price feed IDs from trace results and fetch updates from Hermes
- Bundle price updates with original transaction using multicall
- Iterative approach to handle nested price feed dependencies
- Include comprehensive example and documentation
- Bump package version to 1.84.0

Co-Authored-By: Ali <[email protected]>

Author: devin-ai-integration[bot]

target_chains/ethereum/sdk/js/README_TRANSACTION_FILLER.md

@@ -0,0 +1,56 @@
+# Transaction Filler
+
+The Transaction Filler is a utility that automatically detects Pyth price feed usage in Ethereum transactions and bundles them with the necessary price updates.
+
+## Features
+
+- Automatically detects Pyth `getPrice*` method calls using transaction tracing
+- Fetches latest price updates from Hermes price service
+- Bundles price updates with original transaction using multicall
+- Iterative approach to handle nested price feed dependencies
+- Supports both `trace_call` and `debug_traceCall` methods
+
+## Usage
+
+```typescript
+import { createPublicClient, http } from "viem";
+import { mainnet } from "viem/chains";
+import { fillTransactionWithPythData } from "@pythnetwork/pyth-evm-js";
+
+const client = createPublicClient({
+  chain: mainnet,
+  transport: http("https://eth.drpc.org"),
+});
+
+const config = {
+  pythContractAddress: "0x4305FB66699C3B2702D4d05CF36551390A4c69C6",
+  priceServiceEndpoint: "https://hermes.pyth.network",
+  viemClient: client,
+};
+
+const transaction = {
+  to: "0xe0a80d35bB6618CBA260120b279d357978c42BCE",
+  data: "0xa824bf67000000000000000000000000c1d023141ad6935f81e5286e577768b75c9ff8e90000000000000000000000000000000000000000000000000000000000000001",
+};
+
+const result = await fillTransactionWithPythData(config, transaction);
+console.log("Detected price feeds:", result.detectedPriceFeeds);
+console.log("Final transaction:", result.transaction);
+```
+
+## Detected Methods
+
+The following Pyth methods are automatically detected:
+- `getPrice(bytes32 id)`
+- `getPriceUnsafe(bytes32 id)`
+- `getPriceNoOlderThan(bytes32 id, uint256 age)`
+- `getEmaPrice(bytes32 id)`
+- `getEmaPriceUnsafe(bytes32 id)`
+- `getEmaPriceNoOlderThan(bytes32 id, uint256 age)`
+
+## Configuration
+
+- `pythContractAddress`: Address of the Pyth contract on the target chain
+- `priceServiceEndpoint`: URL of the Hermes price service
+- `viemClient`: Viem public client for blockchain interactions
+- `maxIterations`: Maximum number of iterations for detecting nested dependencies (default: 5)

target_chains/ethereum/sdk/js/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@pythnetwork/pyth-evm-js",
-  "version": "1.83.0",
+  "version": "1.84.0",
   "description": "Pyth Network EVM Utils in JS",
   "homepage": "https://pyth.network",
   "author": {
@@ -24,6 +24,7 @@
     "example-client": "pnpm run build && node lib/examples/EvmPriceServiceClient.js",
     "example-relay": "pnpm run build && node lib/examples/EvmRelay.js",
     "example-benchmark": "pnpm run build && node lib/examples/EvmBenchmark.js",
+    "example-transaction-filler": "pnpm run build && node -e \"require('./lib/examples/TransactionFillerExample.js').main()\"",
     "test:format": "prettier --check \"src/**/*.ts\"",
     "test:lint": "eslint src/ --max-warnings 0",
     "fix:format": "prettier --write \"src/**/*.ts\"",
@@ -57,6 +58,7 @@
   },
   "dependencies": {
     "@pythnetwork/price-service-client": "workspace:*",
-    "buffer": "^6.0.3"
+    "buffer": "^6.0.3",
+    "viem": "^2.21.0"
   }
 }