Add data feeds starter kit example

chainlink-data-feeds-skill/SKILL.md

@@ -6,7 +6,7 @@ compatibility: Designed for AI agents that implement https://agentskills.io/spec
 allowed-tools: Read WebFetch Write Edit Bash
 metadata:
   purpose: Chainlink Data Feeds developer assistance and reference
-  version: "0.0.3"
+  version: "0.0.4"
 ---
 
 # Chainlink Data Feeds Skill
@@ -19,24 +19,26 @@ Route Data Feed requests to the simplest valid path. Generate working code on fi
 
 1. Keep this file as the default guide.
 2. Read [references/reading-price-feeds.md](references/reading-price-feeds.md) only when the user wants to read a price feed on EVM, write a consumer contract, read off-chain, look up AggregatorV3Interface, or debug a price feed integration.
-3. Read [references/mvr-feeds.md](references/mvr-feeds.md) only when the user asks about Multiple-Variable Response feeds, bundle feeds, or BundleAggregatorProxy.
-4. Read [references/svr-feeds.md](references/svr-feeds.md) only when the user asks about Smart Value Recapture, OEV recapture, or searcher onboarding.
-5. Read [references/feed-types.md](references/feed-types.md) only when the user asks about feed categories, SmartData/RWA, rates/volatility, tokenized equity feeds, or needs help choosing a feed type.
-6. Read [references/multi-chain.md](references/multi-chain.md) only when the user targets Solana, StarkNet, Aptos, or Tron.
-7. Read [references/feed-operations.md](references/feed-operations.md) only when the user asks about L2 sequencer uptime checks, feed deprecation, contract registry, developer responsibilities, or data sources.
-8. Read [references/official-sources.md](references/official-sources.md) only when the answer depends on live data that the reference files do not contain — feed addresses for a specific chain, current deprecation schedules, specific network parameters.
-9. Read [references/source-code.md](references/source-code.md) only when debugging interface mismatches or the user needs to inspect contract source code on GitHub.
-10. Do not load reference files speculatively.
+3. Read [templates/starter-kit/README.md](templates/starter-kit/README.md) and the files in [templates/starter-kit](templates/starter-kit) when the user asks for a working example project, Foundry starter kit, runnable Data Feeds example, or says something like "give me a working example of a data feeds project." Use this starter-kit template instead of inventing project scaffolding.
+4. Read [references/mvr-feeds.md](references/mvr-feeds.md) only when the user asks about Multiple-Variable Response feeds, bundle feeds, or BundleAggregatorProxy.
+5. Read [references/svr-feeds.md](references/svr-feeds.md) only when the user asks about Smart Value Recapture, OEV recapture, or searcher onboarding.
+6. Read [references/feed-types.md](references/feed-types.md) only when the user asks about feed categories, SmartData/RWA, rates/volatility, tokenized equity feeds, or needs help choosing a feed type.
+7. Read [references/multi-chain.md](references/multi-chain.md) only when the user targets Solana, StarkNet, Aptos, or Tron.
+8. Read [references/feed-operations.md](references/feed-operations.md) only when the user asks about L2 sequencer uptime checks, feed deprecation, contract registry, developer responsibilities, or data sources.
+9. Read [references/official-sources.md](references/official-sources.md) only when the answer depends on live data that the reference files do not contain -- feed addresses for a specific chain, current deprecation schedules, specific network parameters.
+10. Read [references/source-code.md](references/source-code.md) only when debugging interface mismatches or the user needs to inspect contract source code on GitHub.
+11. Do not load reference files speculatively.
 
 ## Routing
 
 1. Use reading-price-feeds.md as the default for any EVM price feed request — this covers the vast majority of Data Feeds use cases.
-2. Route to the chain-specific section of multi-chain.md for non-EVM chains (Solana, Aptos, StarkNet, Tron).
-3. Route to mvr-feeds.md for bundle or multi-variable feed requests.
-4. Route to svr-feeds.md for OEV or MEV recapture requests.
-5. Route to feed-operations.md for operational concerns (L2 sequencer checks, deprecation, monitoring).
-6. Ask one focused question if the chain, feed type, or integration method is unclear.
-7. Proceed without asking for read-only work: explanations, code generation, debugging.
+2. Use templates/starter-kit for project-level example requests, especially Foundry starter requests. Return a concise file tree, the relevant template files, install/test commands, and the Sepolia ETH/USD feed configuration unless the user asks for another chain.
+3. Route to the chain-specific section of multi-chain.md for non-EVM chains (Solana, Aptos, StarkNet, Tron).
+4. Route to mvr-feeds.md for bundle or multi-variable feed requests.
+5. Route to svr-feeds.md for OEV or MEV recapture requests.
+6. Route to feed-operations.md for operational concerns (L2 sequencer checks, deprecation, monitoring).
+7. Ask one focused question if the chain, feed type, or integration method is unclear.
+8. Proceed without asking for read-only work: explanations, code generation, debugging.
 
 ## Safety Defaults
 
@@ -68,3 +70,4 @@ This skill references official Data Feeds documentation URLs throughout its refe
 4. Keep answers proportional — a simple "read a price feed" question gets a code block and brief explanation, not a full tutorial.
 5. Generate code only when code is actually needed.
 6. Keep unsupported or out-of-scope features out of the answer rather than speculating.
+7. When using the starter-kit template, preserve its Foundry layout and contract names unless the user asks for a different framework. The template is based on the Chainlink Foundry Starter Kit `PriceFeedConsumer.sol` example, with the required Data Feeds validation added for safer generated code.

chainlink-data-feeds-skill/templates/starter-kit/README.md

@@ -0,0 +1,44 @@
+# Chainlink Data Feeds Foundry Starter Kit Template
+
+Use this template when a user asks for a working Data Feeds project, a Foundry starter kit, or a runnable example. It is based on the Chainlink Foundry Starter Kit `PriceFeedConsumer.sol` pattern and adds the skill's required validation: round completion, staleness, positive answer checks, and runtime decimals access.
+
+## Files
+
+```text
+foundry.toml
+remappings.txt
+src/PriceFeedConsumer.sol
+script/PriceFeedConsumer.s.sol
+test/PriceFeedConsumer.t.sol
+test/mocks/MockV3Aggregator.sol
+```
+
+## Dependencies
+
+For a fresh Foundry project, install these dependencies before running the template:
+
+```sh
+forge install foundry-rs/forge-std
+forge install smartcontractkit/chainlink-evm@contracts-v1.5.0
+```
+
+The included `remappings.txt` expects Chainlink contracts under `lib/chainlink-evm/` and forge-std under `lib/forge-std/`.
+
+## Default Network
+
+The deploy script defaults to Sepolia ETH/USD:
+
+```text
+0x694AA1769357215DE4FAC081bf1f309aDC325306
+```
+
+Tell users to verify feed addresses against the official Chainlink docs before deploying. For L2 networks, add a Sequencer Uptime Feed check before production use.
+
+## Commands
+
+```sh
+forge test
+forge script script/PriceFeedConsumer.s.sol:DeployPriceFeedConsumer --rpc-url $SEPOLIA_RPC_URL --private-key $PRIVATE_KEY --broadcast
+```
+
+Example code is unaudited and should be reviewed before production use.

chainlink-data-feeds-skill/templates/starter-kit/foundry.toml

@@ -0,0 +1,6 @@
+[profile.default]
+src = "src"
+out = "out"
+libs = ["lib"]
+optimizer = true
+optimizer_runs = 20000

chainlink-data-feeds-skill/templates/starter-kit/remappings.txt

@@ -0,0 +1,2 @@
+@chainlink/=lib/chainlink-evm/
+forge-std/=lib/forge-std/src/

chainlink-data-feeds-skill/templates/starter-kit/script/PriceFeedConsumer.s.sol

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.7;
+
+import {Script} from "forge-std/Script.sol";
+import {PriceFeedConsumer} from "../src/PriceFeedConsumer.sol";
+import {MockV3Aggregator} from "../test/mocks/MockV3Aggregator.sol";
+
+contract DeployPriceFeedConsumer is Script {
+    uint8 internal constant DECIMALS = 8;
+    int256 internal constant INITIAL_ANSWER = 2000e8;
+    uint256 internal constant STALENESS_THRESHOLD = 3600;
+
+    address internal constant SEPOLIA_ETH_USD_FEED = 0x694AA1769357215DE4FAC081bf1f309aDC325306;
+
+    function run() external returns (PriceFeedConsumer) {
+        vm.startBroadcast();
+        address priceFeed =
+            block.chainid == 11155111 ? SEPOLIA_ETH_USD_FEED : address(new MockV3Aggregator(DECIMALS, INITIAL_ANSWER));
+        PriceFeedConsumer consumer = new PriceFeedConsumer(priceFeed, STALENESS_THRESHOLD);
+        vm.stopBroadcast();
+
+        return consumer;
+    }
+}

chainlink-data-feeds-skill/templates/starter-kit/src/PriceFeedConsumer.sol

@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.7;
+
+import {AggregatorV3Interface} from "@chainlink/contracts/src/v0.8/shared/interfaces/AggregatorV3Interface.sol";
+
+/**
+ * @title PriceFeedConsumer
+ * @notice Reads the latest answer from a Chainlink Data Feed with basic safety checks.
+ */
+contract PriceFeedConsumer {
+    AggregatorV3Interface internal immutable priceFeed;
+    uint256 public immutable stalenessThreshold;
+
+    error IncompleteRound();
+    error StalePrice(uint256 updatedAt);
+    error InvalidPrice(int256 price);
+
+    constructor(address _priceFeed, uint256 _stalenessThreshold) {
+        priceFeed = AggregatorV3Interface(_priceFeed);
+        stalenessThreshold = _stalenessThreshold;
+    }
+
+    /**
+     * @notice Returns the latest validated price.
+     * @return latest price using the feed's decimals.
+     */
+    function getLatestPrice() public view returns (int256) {
+        (, int256 price,, uint256 updatedAt,) = priceFeed.latestRoundData();
+
+        if (updatedAt == 0) {
+            revert IncompleteRound();
+        }
+        if (block.timestamp - updatedAt > stalenessThreshold) {
+            revert StalePrice(updatedAt);
+        }
+        if (price <= 0) {
+            revert InvalidPrice(price);
+        }
+
+        return price;
+    }
+
+    /**
+     * @notice Returns the number of decimals used by the feed answer.
+     * @return feed decimals.
+     */
+    function getDecimals() public view returns (uint8) {
+        return priceFeed.decimals();
+    }
+
+    /**
+     * @notice Returns the Price Feed address.
+     * @return Price Feed contract.
+     */
+    function getPriceFeed() public view returns (AggregatorV3Interface) {
+        return priceFeed;
+    }
+}

chainlink-data-feeds-skill/templates/starter-kit/test/PriceFeedConsumer.t.sol

@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.7;
+
+import {Test} from "forge-std/Test.sol";
+import {PriceFeedConsumer} from "../src/PriceFeedConsumer.sol";
+import {MockV3Aggregator} from "./mocks/MockV3Aggregator.sol";
+
+contract PriceFeedConsumerTest is Test {
+    uint8 public constant DECIMALS = 8;
+    int256 public constant INITIAL_ANSWER = 2000e8;
+    uint256 public constant STALENESS_THRESHOLD = 3600;
+
+    PriceFeedConsumer public priceFeedConsumer;
+    MockV3Aggregator public mockV3Aggregator;
+
+    function setUp() public {
+        mockV3Aggregator = new MockV3Aggregator(DECIMALS, INITIAL_ANSWER);
+        priceFeedConsumer = new PriceFeedConsumer(address(mockV3Aggregator), STALENESS_THRESHOLD);
+    }
+
+    function testConsumerReturnsStartingValue() public view {
+        int256 price = priceFeedConsumer.getLatestPrice();
+
+        assertEq(price, INITIAL_ANSWER);
+    }
+
+    function testConsumerReturnsFeedDecimals() public view {
+        assertEq(priceFeedConsumer.getDecimals(), DECIMALS);
+    }
+
+    function testConsumerRevertsOnStalePrice() public {
+        vm.warp(block.timestamp + STALENESS_THRESHOLD + 1);
+
+        vm.expectRevert();
+        priceFeedConsumer.getLatestPrice();
+    }
+
+    function testConsumerRevertsOnInvalidPrice() public {
+        mockV3Aggregator.updateAnswer(0);
+
+        vm.expectRevert();
+        priceFeedConsumer.getLatestPrice();
+    }
+}

chainlink-data-feeds-skill/templates/starter-kit/test/mocks/MockV3Aggregator.sol

@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.7;
+
+contract MockV3Aggregator {
+    uint256 public constant version = 0;
+
+    uint8 public decimals;
+    int256 public latestAnswer;
+    uint256 public latestTimestamp;
+    uint256 public latestRound;
+
+    mapping(uint256 => int256) public getAnswer;
+    mapping(uint256 => uint256) public getTimestamp;
+    mapping(uint256 => uint256) private getStartedAt;
+
+    constructor(uint8 _decimals, int256 _initialAnswer) {
+        decimals = _decimals;
+        updateAnswer(_initialAnswer);
+    }
+
+    function updateAnswer(int256 _answer) public {
+        latestAnswer = _answer;
+        latestTimestamp = block.timestamp;
+        latestRound++;
+        getAnswer[latestRound] = _answer;
+        getTimestamp[latestRound] = block.timestamp;
+        getStartedAt[latestRound] = block.timestamp;
+    }
+
+    function updateRoundData(uint80 _roundId, int256 _answer, uint256 _timestamp, uint256 _startedAt) public {
+        latestRound = _roundId;
+        latestAnswer = _answer;
+        latestTimestamp = _timestamp;
+        getAnswer[latestRound] = _answer;
+        getTimestamp[latestRound] = _timestamp;
+        getStartedAt[latestRound] = _startedAt;
+    }
+
+    function getRoundData(uint80 _roundId)
+        external
+        view
+        returns (uint80 roundId, int256 answer, uint256 startedAt, uint256 updatedAt, uint80 answeredInRound)
+    {
+        return (_roundId, getAnswer[_roundId], getStartedAt[_roundId], getTimestamp[_roundId], _roundId);
+    }
+
+    function latestRoundData()
+        external
+        view
+        returns (uint80 roundId, int256 answer, uint256 startedAt, uint256 updatedAt, uint80 answeredInRound)
+    {
+        return (
+            uint80(latestRound),
+            getAnswer[latestRound],
+            getStartedAt[latestRound],
+            getTimestamp[latestRound],
+            uint80(latestRound)
+        );
+    }
+
+    function description() external pure returns (string memory) {
+        return "MockV3Aggregator";
+    }
+}

evals/chainlink-data-feeds-skill/README.md

@@ -28,8 +28,8 @@ npx promptfoo eval --filter-pattern "reading-price-feeds-01"
 
 ## Test Categories
 
-- **Functional** (12 cases): End-to-end workflow tests covering reading-price-feeds, mvr-feeds, svr-feeds, feed-types, multi-chain, and feed-operations
-- **Trigger Positive** (8 cases): Verify the skill activates for data-feeds-specific prompts
+- **Functional** (14 cases): End-to-end workflow tests covering reading-price-feeds, mvr-feeds, svr-feeds, feed-types, multi-chain, feed-operations, and starter-kit scaffolding
+- **Trigger Positive** (9 cases): Verify the skill activates for data-feeds-specific prompts
 - **Trigger Negative** (6 cases): Verify the skill does not over-trigger for CCIP, VRF, Automation, Data Streams, Functions, or generic Solidity requests
 
 ## Rubrics

evals/chainlink-data-feeds-skill/cases/functional/starter-kit-01.txt

@@ -0,0 +1 @@
+Give me a working example of a data feeds project that I can build and test locally.

evals/chainlink-data-feeds-skill/cases/functional/starter-kit-02.txt

@@ -0,0 +1 @@
+Scaffold a Foundry starter kit for reading the ETH/USD price feed on Sepolia, including a deploy script and tests I can run with `forge test`.

evals/chainlink-data-feeds-skill/cases/trigger-positive/starter-kit-01.txt

@@ -0,0 +1 @@
+Can you set me up with a runnable Foundry project for reading Chainlink price feeds?

evals/chainlink-data-feeds-skill/promptfooconfig.yaml

@@ -47,6 +47,20 @@ functional_asserts: &functional_asserts
   - type: llm-rubric
     value: file://rubrics/clarification.txt
 
+starter_kit_asserts: &starter_kit_asserts
+  - type: llm-rubric
+    value: file://rubrics/correctness.txt
+  - type: llm-rubric
+    value: file://rubrics/completeness.txt
+  - type: llm-rubric
+    value: file://rubrics/safety.txt
+  - type: llm-rubric
+    value: file://rubrics/freshness.txt
+  - type: llm-rubric
+    value: file://rubrics/clarification.txt
+  - type: llm-rubric
+    value: file://rubrics/starter-kit.txt
+
 tests:
   # ── Functional: Reading Price Feeds ──────────────────────────────────
   - vars:
@@ -142,6 +156,23 @@ tests:
       requires_live_source: "yes"
     assert: *functional_asserts
 
+  # ── Functional: Starter Kit ──────────────────────────────────────────
+  - vars:
+      case_file: cases/functional/starter-kit-01.txt
+      workflow: starter-kit
+      requires_live_source: "no"
+    metadata:
+      workflow: starter-kit
+      category: functional
+      smoke: true
+    assert: *starter_kit_asserts
+
+  - vars:
+      case_file: cases/functional/starter-kit-02.txt
+      workflow: starter-kit
+      requires_live_source: "no"
+    assert: *starter_kit_asserts
+
   # ── Trigger Positive ─────────────────────────────────────────────────
   - vars:
       case_file: cases/trigger-positive/reading-price-feeds-01.txt
@@ -199,6 +230,16 @@ tests:
       expected_trigger: "yes"
     assert: *trigger_positive_asserts
 
+  - vars:
+      case_file: cases/trigger-positive/starter-kit-01.txt
+      workflow: starter-kit
+      expected_trigger: "yes"
+    metadata:
+      workflow: starter-kit
+      category: trigger-positive
+      smoke: true
+    assert: *trigger_positive_asserts
+
   # ── Trigger Negative ─────────────────────────────────────────────────
   - vars:
       case_file: cases/trigger-negative/ccip-01.txt

evals/chainlink-data-feeds-skill/rubrics/correctness.txt

@@ -7,6 +7,7 @@ Workflow definitions:
 - feed-types: choosing a feed type, understanding SmartData/RWA, rates/volatility, or tokenized equity feeds
 - multi-chain: reading data feeds on Solana, Aptos, StarkNet, or Tron
 - feed-operations: L2 sequencer checks, feed deprecation, contract registry, developer responsibilities, data sources
+- starter-kit: scaffolding a complete, runnable Foundry project (PriceFeedConsumer contract, mock aggregator, deploy script, tests, and project config) from the starter-kit template when the user asks for a working example or Foundry starter kit
 
 The expected workflow is: {{workflow}}