Dynamic Airdop fees (#308)

* Airdrop Dynamic Fees

* Lint fixes

* Bump

* Minor fixes

* Alpha release

* chore: prepare publish (built & versioned)

* Proper version bump

* Remove pnpm scrap

* Removed unused stuff

* Cleanup

* PR fixes

* API failsafe

Author: LukaStreamflow

.vscode/settings.json

@@ -8,7 +8,15 @@
       "pattern": "./packages/*/"
     }
   ],
-  "cSpell.words": ["Blockhash", "merkle", "permissionless", "Solana", "Streamflow", "Unstake"],
+  "cSpell.words": [
+    "Blockhash",
+    "lamports",
+    "merkle",
+    "permissionless",
+    "Solana",
+    "Streamflow",
+    "Unstake"
+  ],
   "typescript.tsdk": "node_modules/typescript/lib",
   "javascript.preferences.importModuleSpecifierEnding": "js",
   "typescript.preferences.importModuleSpecifierEnding": "js",

lerna.json

@@ -2,7 +2,7 @@
   "packages": [
     "packages/*"
   ],
-  "version": "8.9.0",
+  "version": "9.0.0",
   "$schema": "node_modules/lerna/schemas/lerna-schema.json",
   "command": {
     "run": {

packages/common/index.ts

@@ -1,3 +1,4 @@
 export * from "./types.js";
 export * from "./lib/assertions.js";
 export * from "./lib/utils.js";
+export * from "./lib/fetch-token-price.js";

packages/common/lib/fetch-token-price.ts

@@ -0,0 +1,41 @@
+import { ICluster } from "../types.js";
+
+export type TokensPricesResponse = {
+  data: Record<string, TokenPriceResult>;
+};
+
+export type TokenPriceResult = { id: string; value: number | undefined };
+
+export interface FetchTokenPriceOptions {
+  fetchImpl?: typeof fetch;
+  timeoutMs?: number;
+}
+
+export const fetchTokenPrice = async (
+  mintId: string,
+  cluster: ICluster = ICluster.Mainnet,
+  options?: FetchTokenPriceOptions,
+): Promise<TokenPriceResult> => {
+  const url = `https://token-api.streamflow.finance/price?ids=${encodeURIComponent(mintId)}&cluster=${encodeURIComponent(cluster)}`;
+
+  const impl = options?.fetchImpl ?? fetch;
+  const controller = new AbortController();
+  const timeout = options?.timeoutMs
+    ? setTimeout(() => controller.abort(), options.timeoutMs)
+    : undefined;
+
+  try {
+    const res = await impl(url, {
+      headers: { "Content-Type": "application/json" },
+      signal: controller.signal,
+    });
+    if (!res.ok) {
+      throw new Error(`Price API error: ${res.status} ${res.statusText}`);
+    }
+    const json = (await res.json()) as TokensPricesResponse;
+    const entry = json?.data?.[mintId];
+    return { id: mintId, value: typeof entry?.value === "number" ? entry.value : undefined };
+  } finally {
+    if (timeout) clearTimeout(timeout);
+  }
+};

packages/common/lib/utils.ts

@@ -61,3 +61,22 @@ export function sleep(ms: number): Promise<void> {
 }
 
 export const divCeilN = (n: bigint, d: bigint): bigint => n / d + (n % d ? BigInt(1) : BigInt(0));
+
+/**
+ * Multiply a bigint by a JS number using string-based fixed-point to avoid overflow/precision issues.
+ * Returns floor(x * y).
+ */
+export function multiplyBigIntByNumber(x: bigint, y: number, scaleDigits = 9): bigint {
+  if (!Number.isFinite(y) || y === 0) return 0n;
+  const isNegative = (x < 0n) !== (y < 0);
+  const absX = x < 0n ? -x : x;
+  const absY = Math.abs(y);
+
+  const s = absY.toFixed(scaleDigits);
+  const [intPart, fracPartRaw = ""] = s.split(".");
+  const fracPart = fracPartRaw.padEnd(scaleDigits, "0").slice(0, scaleDigits);
+  const yScaled = BigInt(intPart + fracPart); // absY * 10^scaleDigits
+  const scale = 10n ** BigInt(scaleDigits);
+  const product = (absX * yScaled) / scale;
+  return isNegative ? -product : product;
+}

packages/common/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@streamflow/common",
-  "version": "8.9.0",
+  "version": "9.0.0",
   "description": "Common utilities and types used by streamflow packages.",
   "homepage": "https://github.com/streamflow-finance/js-sdk/",
   "type": "module",

packages/distributor/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@streamflow/distributor",
-  "version": "8.9.0",
+  "version": "9.0.0",
   "description": "JavaScript SDK to interact with Streamflow Airdrop protocol.",
   "homepage": "https://github.com/streamflow-finance/js-sdk/",
   "main": "./dist/cjs/index.cjs",

packages/distributor/solana/clients/BaseDistributorClient.ts

@@ -34,6 +34,7 @@ import {
   DISTRIBUTOR_PROGRAM_ID,
   STREAMFLOW_TREASURY_PUBLIC_KEY,
 } from "../constants.js";
+import { MINIMUM_FEE_FALLBACK, resolveAirdropFeeLamportsUsingApi } from "../fees.js";
 import MerkleDistributorIDL from "../descriptor/idl/merkle_distributor.json";
 import type { MerkleDistributor as MerkleDistributorProgramType } from "../descriptor/merkle_distributor.js";
 import { MerkleDistributor } from "../generated/accounts/index.js";
@@ -90,6 +91,8 @@ export default abstract class BaseDistributorClient {
 
   public merkleDistributorProgram: Program<MerkleDistributorProgramType>;
 
+  protected cluster: ICluster;
+
   public constructor({
     clusterUrl,
     cluster = ICluster.Mainnet,
@@ -99,6 +102,7 @@ export default abstract class BaseDistributorClient {
     sendThrottler,
   }: IInitOptions) {
     this.commitment = commitment;
+    this.cluster = cluster;
     this.connection = new Connection(clusterUrl, this.commitment);
     this.programId = programId !== "" ? new PublicKey(programId) : new PublicKey(DISTRIBUTOR_PROGRAM_ID[cluster]);
     this.sendThrottler = sendThrottler ?? buildSendThrottler(sendRate);
@@ -360,12 +364,40 @@ export default abstract class BaseDistributorClient {
       ixs.push(claimLocked(accounts, this.programId));
     }
 
-    ixs.push(
-      this.prepareClaimFeeInstruction(
-        extParams.feePayer ?? extParams.invoker.publicKey,
-        typeof _serviceTransfer === "bigint" ? _serviceTransfer : undefined,
-      ),
-    );
+    // Determine fee: prefer service internal (if provided by service), else fetch params from API
+    // and compute dynamically through resolver, else default minimum
+    let feeLamports = typeof _serviceTransfer === "bigint" ? _serviceTransfer : undefined;
+    if (!feeLamports) {
+      try {
+        const { mint: mintAccount } = await getMintAndProgram(this.connection, distributor.mint);
+        // Backward-compatible: compute claimable amount if not provided by the caller
+        // Prefer explicit field if present; otherwise default to unlocked + locked inputs
+        const claimableAmountRaw = (data as unknown as {
+          // optional for legacy callers
+          claimableAmount?: BN | bigint | number | string;
+        })?.claimableAmount;
+        // Default legacy fields to 0 when missing
+        const unlockedRaw = (data as unknown as { amountUnlocked?: BN | number | string })?.amountUnlocked;
+        const lockedRaw = (data as unknown as { amountLocked?: BN | number | string })?.amountLocked;
+        const unlocked = unlockedRaw != null ? new BN(unlockedRaw) : new BN(0);
+        const locked = lockedRaw != null ? new BN(lockedRaw) : new BN(0);
+        const computedFallback = unlocked.add(locked);
+        const claimableAmount =
+          claimableAmountRaw != null
+            ? BigInt(claimableAmountRaw.toString())
+            : BigInt(computedFallback.toString());
+
+        feeLamports = await resolveAirdropFeeLamportsUsingApi({
+          distributorAddress: distributorPublicKey.toBase58(),
+          mintAccount,
+          claimableAmount,
+          cluster: this.cluster,
+        });
+      } catch (_) {
+        feeLamports = MINIMUM_FEE_FALLBACK;
+      }
+    }
+    ixs.push(this.prepareClaimFeeInstruction(extParams.feePayer ?? extParams.invoker.publicKey, feeLamports));
 
     return ixs;
   }