Creating a Balancer API provider to fetch pool state for join txs;

.gitignore

@@ -80,3 +80,5 @@ typechain-types
 cache
 artifacts
 
+#IDE
+.idea

README.md

@@ -21,3 +21,85 @@ If your platform does not support one of the required features, it is also possi
 Testing requires access to an archive node for onchain quote comparisons. This can be done using Infura.
 
 `pnpm test`
+
+## Balancer Api Provider
+
+The Balancer API Provider is a provider that facilitates 
+data fetching from the Balancer API,
+it can be used for:
+- Fetch Pool State for Joins;
+- Fetch Pool State for Exits.
+
+### Usage for Joining Pool
+
+```ts
+  import { BalancerApi, PoolJoin } from "@balancer/sdk";
+    ...
+    const joinInput: ProportionalJoinInput = {
+      bptOut,
+      chainId,
+      rpcUrl,
+      kind: JoinKind.Proportional,
+    };
+
+    const balancerApi = new BalancerApi('https://backend-v3-canary.beets-ftm-node.com/graphql', 1);
+    const poolState = await balancerApi.pools.fetchPoolState('0x5f1d6874cb1e7156e79a7563d2b61c6cbce03150000200000000000000000586');
+    const poolJoin = new PoolJoin();
+    const queryResult = await poolJoin.query(joinInput, poolState);
+    const { call, to, value, maxAmountsIn, minBptOut } =
+        poolJoin.buildCall({
+            ...queryResult,
+            slippage,
+            sender: signerAddress,
+            recipient: signerAddress,
+        });
+    const client = createClient({
+      ...
+    })
+
+    await client.sendTransaction({
+      account: signerAddress,
+      chain: client.chain,
+      data: call,
+      to,
+      value,
+    });
+```
+Full working join example: [examples/join/weighted.ts](./examples/join/weighted.ts)
+
+### Usage for Exiting Pool
+```ts
+import { BalancerApi, PoolExit } from "@balancer/sdk";
+...
+const exitInput: SingleAssetExitInput = {
+  chainId,
+  rpcUrl,
+  bptIn,
+  tokenOut,
+  kind: ExitKind.SINGLE_ASSET,
+};
+
+const balancerApi = new BalancerApi('https://backend-v3-canary.beets-ftm-node.com/graphql', 1);
+const poolState = await balancerApi.pools.fetchPoolState('0x5f1d6874cb1e7156e79a7563d2b61c6cbce03150000200000000000000000586');
+const poolExit = new PoolExit();
+const queryResult = await poolExit.query(exitInput, poolState);
+const { call, to, value, maxAmountsIn, minBptOut } =
+  poolExit.buildCall({
+    ...queryResult,
+    slippage,
+    sender: signerAddress,
+    recipient: signerAddress,
+  });
+const client = createClient({
+  ...
+})
+
+await client.sendTransaction({
+  account: signerAddress,
+  chain: client.chain,
+  data: call,
+  to,
+  value,
+});
+```
+Full working exit example: [examples/exit/weighted.ts](./examples/exit/weighted.ts)

examples/exit/weighted.ts

@@ -0,0 +1,92 @@
+import dotenv from 'dotenv';
+dotenv.config();
+
+import { BalancerApi } from "../../src/data/providers/balancer-api";
+import {
+  ChainId,
+  CHAINS, ExitKind, PoolExit, PoolStateInput,
+  SingleAssetExitInput,
+  Slippage,
+  Token,
+  TokenAmount,
+} from "../../src";
+import {
+  Client,
+  createTestClient,
+  http,
+  parseUnits,
+  PublicActions,
+  publicActions,
+  TestActions, WalletActions,
+  walletActions
+} from "viem";
+import { forkSetup, sendTransactionGetBalances } from "../../test/lib/utils/helper";
+
+const balancerApiUrl = 'https://backend-v3-canary.beets-ftm-node.com/graphql';
+const poolId = '0x5c6ee304399dbdb9c8ef030ab642b10820db8f56000200000000000000000014'; // 80BAL-20WETH
+const chainId = ChainId.MAINNET;
+const rpcUrl = 'http://127.0.0.1:8545/';
+const blockNumber = BigInt(18043296);
+const testAddress = '0x10A19e7eE7d7F8a52822f6817de8ea18204F2e4f'; // Balancer DAO Multisig
+const slippage = Slippage.fromPercentage('1'); // 1%
+
+const exit = async () => {
+  const balancerApi = new BalancerApi(balancerApiUrl, 1);
+  const poolState: PoolStateInput = await balancerApi.pools.fetchPoolState(poolId);
+  const client: Client & PublicActions & TestActions & WalletActions = createTestClient({
+    mode: 'hardhat',
+    chain: CHAINS[chainId],
+    transport: http(rpcUrl),
+  })
+    .extend(publicActions)
+    .extend(walletActions);
+  const bpt = new Token(chainId, poolState.address, 18, 'BPT');
+
+  await forkSetup(
+    client,
+    testAddress,
+    [poolState.address],
+    [0], 
+    [
+      parseUnits('100', 18),
+    ],
+    process.env.ETHEREUM_RPC_URL as string,
+    blockNumber,
+  );
+
+  const bptIn = TokenAmount.fromHumanAmount(bpt, '1');
+  const tokenOut = '0xba100000625a3754423978a60c9317c58a424e3D'; // BAL
+
+  const poolExit = new PoolExit();
+
+  const exitInput: SingleAssetExitInput = {
+    chainId,
+    rpcUrl,
+    bptIn,
+    tokenOut,
+    kind: ExitKind.SINGLE_ASSET,
+  };
+
+  const queryResult = await poolExit.query(exitInput, poolState);
+
+  const { call, to, value } =
+    poolExit.buildCall({
+      ...queryResult,
+      slippage,
+      sender: testAddress,
+      recipient: testAddress,
+    });
+  const { transactionReceipt, balanceDeltas } =
+    await sendTransactionGetBalances(
+      [...poolState.tokens.map(({address})=>address), bpt.address],
+      client,
+      testAddress,
+      to,
+      call,
+      value,
+    );
+  console.log(`transaction status: ${transactionReceipt.status}`);
+  console.log(`token amounts deltas per token: ${balanceDeltas}`);
+}
+
+exit();

examples/join/weighted.ts

@@ -0,0 +1,98 @@
+import dotenv from 'dotenv';
+dotenv.config();
+
+import {
+  BalancerApi,
+  ChainId,
+  CHAINS,
+  JoinKind,
+  PoolJoin, PoolStateInput,
+  Slippage,
+  Token,
+  TokenAmount,
+  UnbalancedJoinInput
+} from "../../src";
+import {
+  Client,
+  createTestClient,
+  http,
+  parseUnits,
+  PublicActions,
+  publicActions,
+  TestActions, WalletActions,
+  walletActions
+} from "viem";
+import { forkSetup, sendTransactionGetBalances } from "../../test/lib/utils/helper";
+
+const balancerApiUrl = 'https://backend-v3-canary.beets-ftm-node.com/graphql';
+const poolId = '0x5c6ee304399dbdb9c8ef030ab642b10820db8f56000200000000000000000014'; // 80BAL-20WETH
+const chainId = ChainId.MAINNET;
+const rpcUrl = 'http://127.0.0.1:8545/';
+const blockNumber = BigInt(18043296);
+const testAddress = '0x10A19e7eE7d7F8a52822f6817de8ea18204F2e4f'; // Balancer DAO Multisig
+const slippage = Slippage.fromPercentage('1'); // 1%
+
+const join = async () => {
+  const balancerApi = new BalancerApi(balancerApiUrl, 1);
+  const poolState: PoolStateInput = await balancerApi.pools.fetchPoolState(poolId);
+  const client: Client & PublicActions & TestActions & WalletActions = createTestClient({
+    mode: 'hardhat',
+    chain: CHAINS[chainId],
+    transport: http(rpcUrl),
+  })
+    .extend(publicActions)
+    .extend(walletActions);
+
+  await forkSetup(
+    client,
+    testAddress,
+    [...poolState.tokens.map((t) => t.address), poolState.address],
+    [1,3,0],
+    [
+      ...poolState.tokens.map((t) => parseUnits('100', t.decimals)),
+      parseUnits('100', 18),
+    ],
+    process.env.ETHEREUM_RPC_URL as string,
+    blockNumber,
+  );
+
+
+  const poolJoin = new PoolJoin();
+  const poolTokens = poolState.tokens.map(
+    (t) => new Token(chainId, t.address, t.decimals),
+  );
+  const amountsIn = poolTokens.map((t) =>
+    TokenAmount.fromHumanAmount(t, '1'),
+  );
+
+  // perform join query to get expected bpt out
+  const joinInput: UnbalancedJoinInput = {
+    amountsIn,
+    chainId,
+    rpcUrl,
+    kind: JoinKind.Unbalanced,
+  };
+
+  const queryResult = await poolJoin.query(joinInput, poolState);
+
+  const { call, to, value } =
+    poolJoin.buildCall({
+      ...queryResult,
+      slippage,
+      sender: testAddress,
+      recipient: testAddress,
+    });
+  const { transactionReceipt, balanceDeltas } =
+    await sendTransactionGetBalances(
+      [...poolState.tokens.map(({address})=>address), poolState.address /*BPT*/],
+      client,
+      testAddress,
+      to,
+      call,
+      value,
+    );
+  console.log(`transaction status: ${transactionReceipt.status}`);
+  console.log(`token amounts deltas per token: ${balanceDeltas}`);
+}
+
+join();

package.json

@@ -25,7 +25,8 @@
         "test:ci": "vitest run",
         "changeset": "changeset",
         "changeset:release": "pnpm build && changeset publish",
-        "node": "npx hardhat node --tsconfig tsconfig.testing.json --fork $(. ./.env && echo $ETHEREUM_RPC_URL)"
+        "node": "npx hardhat node --tsconfig tsconfig.testing.json --fork $(. ./.env && echo $ETHEREUM_RPC_URL)",
+        "example": "npx ts-node -P tsconfig.testing.json -r tsconfig-paths/register"
     },
     "dependencies": {
         "async-retry": "^1.3.3",
@@ -43,6 +44,7 @@
         "pino-pretty": "^10.0.0",
         "rome": "12.1.3",
         "ts-node": "^10.9.1",
+        "tsconfig-paths": "^4.2.0",
         "tsup": "^6.6.0",
         "typescript": "^5.0.4",
         "vite": "^4.4.2",

src/data/index.ts

@@ -1,3 +1,4 @@
 export * from './enrichers/onChainPoolDataEnricher';
 export * from './providers/subgraphPoolProvider';
+export * from './providers/balancer-api';
 export * from './types';

src/data/providers/balancer-api/client/index.ts

@@ -0,0 +1,22 @@
+export class BalancerApiClient {
+  apiUrl: string;
+  chainId: number;
+  constructor(apiUrl: string, chainId: number) {
+    this.apiUrl = apiUrl;
+    this.chainId = chainId;
+  }
+
+  async fetch(operationName: string, query: any, variables: any) {
+    const requestQuery = {
+      operationName,
+      query,
+      variables,
+    };
+    const response = await fetch(this.apiUrl, {
+      method: 'post',
+      body: JSON.stringify(requestQuery),
+      headers: { 'Content-Type': 'application/json', ChainId: this.chainId.toString() },
+    });
+    return response.json();
+  }
+}

src/data/providers/balancer-api/index.ts

@@ -0,0 +1,16 @@
+import { Pools } from "./modules/pool-state";
+import { BalancerApiClient } from "./client";
+
+export class BalancerApi {
+
+  balancerApiClient: BalancerApiClient;
+  pools: Pools;
+
+
+  constructor(balancerApiUrl: string, chainId: number){
+    this.balancerApiClient = new BalancerApiClient(balancerApiUrl, chainId);
+    this.pools = new Pools(this.balancerApiClient);
+  }
+
+
+}