Hashnote EA (#3913)

* Result of yarn new

* implementation

* changeset

Author: dskloetc

.changeset/early-gifts-appear.md

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+---
+'@chainlink/hashnote-adapter': major
+---
+
+Hashnote EA initial release

.pnp.cjs

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+# Chainlink External Adapter for hashnote
+
+This README will be generated automatically when code is merged to `main`. If you would like to generate a preview of the README, please run `yarn generate:readme hashnote`.

packages/sources/hashnote/CHANGELOG.md

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+{
+  "name": "@chainlink/hashnote-adapter",
+  "version": "0.0.0",
+  "description": "Chainlink hashnote adapter.",
+  "keywords": [
+    "Chainlink",
+    "LINK",
+    "blockchain",
+    "oracle",
+    "hashnote"
+  ],
+  "main": "dist/index.js",
+  "types": "dist/index.d.ts",
+  "files": [
+    "dist"
+  ],
+  "repository": {
+    "url": "https://github.com/smartcontractkit/external-adapters-js",
+    "type": "git"
+  },
+  "license": "MIT",
+  "scripts": {
+    "clean": "rm -rf dist && rm -f tsconfig.tsbuildinfo",
+    "prepack": "yarn build",
+    "build": "tsc -b",
+    "server": "node -e 'require(\"./index.js\").server()'",
+    "server:dist": "node -e 'require(\"./dist/index.js\").server()'",
+    "start": "yarn server:dist"
+  },
+  "devDependencies": {
+    "@types/jest": "^29.5.14",
+    "@types/node": "22.14.1",
+    "nock": "13.5.6",
+    "typescript": "5.8.3"
+  },
+  "dependencies": {
+    "@chainlink/external-adapter-framework": "2.6.0",
+    "axios": "1.9.0",
+    "tslib": "2.4.1"
+  }
+}

packages/sources/hashnote/README.md

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+import { AdapterConfig } from '@chainlink/external-adapter-framework/config'
+
+export const config = new AdapterConfig({
+  USYC_API_ENDPOINT: {
+    description: 'URL for the USYC price report API',
+    type: 'string',
+    default: 'https://usyc.hashnote.com/api/price-reports',
+  },
+})

packages/sources/hashnote/package.json

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+export { endpoint as price } from './price'

packages/sources/hashnote/src/config/index.ts

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+import { AdapterEndpoint } from '@chainlink/external-adapter-framework/adapter'
+import { InputParameters } from '@chainlink/external-adapter-framework/validation'
+import { config } from '../config'
+import { httpTransport } from '../transport/price'
+
+export const inputParameters = new InputParameters(
+  {
+    token: {
+      type: 'string',
+      default: 'USYC',
+      description: 'The token to get the price report for. Currently only USYC is supported.',
+    },
+  },
+  [
+    {
+      token: 'USYC',
+    },
+  ],
+)
+
+export type BaseEndpointTypes = {
+  Parameters: typeof inputParameters.definition
+  Response: {
+    Result: string
+    Data: {
+      result: string
+    }
+  }
+  Settings: typeof config.settings
+}
+
+export const endpoint = new AdapterEndpoint({
+  name: 'price',
+  aliases: [],
+  transport: httpTransport,
+  inputParameters,
+})

packages/sources/hashnote/src/endpoint/index.ts

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+import { expose, ServerInstance } from '@chainlink/external-adapter-framework'
+import { Adapter } from '@chainlink/external-adapter-framework/adapter'
+import { config } from './config'
+import { price } from './endpoint'
+
+export const adapter = new Adapter({
+  defaultEndpoint: price.name,
+  name: 'HASHNOTE',
+  config,
+  endpoints: [price],
+  rateLimiting: {
+    tiers: {
+      default: {
+        rateLimit1m: 1,
+        note: 'API only updates once per day',
+      },
+    },
+  },
+})
+
+export const server = (): Promise<ServerInstance | undefined> => expose(adapter)

packages/sources/hashnote/src/endpoint/price.ts

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+import { HttpTransport } from '@chainlink/external-adapter-framework/transports'
+import { AxiosResponse } from 'axios'
+import { BaseEndpointTypes, inputParameters } from '../endpoint/price'
+
+export interface PriceReport {
+  roundId: string
+  principal: string
+  interest: string
+  balance: string
+  price: string
+  nextPrice: string
+  totalSupply: string
+  decimals: number
+  fee: string
+  timestamp: string
+  txhash: string
+}
+
+export interface ResponseSchema {
+  entity: string
+  data: PriceReport[]
+}
+
+export type HttpTransportTypes = BaseEndpointTypes & {
+  Provider: {
+    RequestBody: never
+    ResponseBody: ResponseSchema
+  }
+}
+
+export type RequestParams = typeof inputParameters.validated
+
+export type Config = BaseEndpointTypes['Settings']
+
+const getApiUrl = (param: RequestParams, config: Config) => {
+  const token = param.token.toLowerCase()
+  switch (token) {
+    case 'usyc':
+      return config.USYC_API_ENDPOINT
+    default:
+      throw new Error(`Unsupported token: ${token}`)
+  }
+}
+
+const getNewestPriceReport = (reports: PriceReport[]): PriceReport => {
+  if (reports.length === 0) {
+    throw new Error('No price reports available')
+  }
+  let newestReport = reports[0]
+  let newestTimestamp = Number(newestReport.timestamp)
+  for (const report of reports) {
+    const timestamp = Number(report.timestamp)
+    if (timestamp > newestTimestamp) {
+      newestReport = report
+      newestTimestamp = timestamp
+    }
+  }
+  return newestReport
+}
+
+// Exported for testing
+export const prepareRequests = (params: RequestParams[], config: Config) => {
+  return params.map((param) => {
+    const baseURL = getApiUrl(param, config)
+    return {
+      params: [param],
+      request: {
+        baseURL,
+      },
+    }
+  })
+}
+
+// Exported for testing
+export const parseResponse = (params: RequestParams[], response: AxiosResponse<ResponseSchema>) => {
+  if (!response.data) {
+    return params.map((param) => {
+      return {
+        params: param,
+        response: {
+          errorMessage: `The data provider didn't return any value for ${param.token}`,
+          statusCode: 502,
+        },
+      }
+    })
+  }
+
+  return params.map((param) => {
+    const result = getNewestPriceReport(response.data.data).price
+    return {
+      params: param,
+      response: {
+        result,
+        data: {
+          result,
+        },
+      },
+    }
+  })
+}
+
+export const httpTransport = new HttpTransport<HttpTransportTypes>({
+  prepareRequests,
+  parseResponse,
+})