feat: add /extended/v2/mempool/fees endpoint (#1795)

* docs: endpoints

* feat: fees endpoint

* test: strict eq

docs/api/mempool/get-fee-priorities.example.json

@@ -0,0 +1,26 @@
+{
+  "all": {
+    "no_priority": 3000,
+    "low_priority": 3000,
+    "medium_priority": 6000,
+    "high_priority": 401199
+  },
+  "token_transfer": {
+    "no_priority": 3000,
+    "low_priority": 3000,
+    "medium_priority": 6000,
+    "high_priority": 401199
+  },
+  "smart_contract": {
+    "no_priority": 837500,
+    "low_priority": 925000,
+    "medium_priority": 1012500,
+    "high_priority": 1082500
+  },
+  "contract_call": {
+    "no_priority": 3000,
+    "low_priority": 10368,
+    "medium_priority": 100000,
+    "high_priority": 1000000
+  }
+}

docs/api/mempool/get-fee-priorities.schema.json

@@ -0,0 +1,107 @@
+{
+  "description": "GET request that returns fee priorities from mempool transactions",
+  "title": "MempoolFeePriorities",
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "all"
+  ],
+  "properties": {
+    "all": {
+      "type": "object",
+      "additionalProperties": false,
+      "required": [
+        "no_priority",
+        "low_priority",
+        "medium_priority",
+        "high_priority"
+      ],
+      "properties": {
+        "no_priority": {
+          "type": "integer"
+        },
+        "low_priority": {
+          "type": "integer"
+        },
+        "medium_priority": {
+          "type": "integer"
+        },
+        "high_priority": {
+          "type": "integer"
+        }
+      }
+    },
+    "token_transfer": {
+      "type": "object",
+      "additionalProperties": false,
+      "required": [
+        "no_priority",
+        "low_priority",
+        "medium_priority",
+        "high_priority"
+      ],
+      "properties": {
+        "no_priority": {
+          "type": "integer"
+        },
+        "low_priority": {
+          "type": "integer"
+        },
+        "medium_priority": {
+          "type": "integer"
+        },
+        "high_priority": {
+          "type": "integer"
+        }
+      }
+    },
+    "smart_contract": {
+      "type": "object",
+      "additionalProperties": false,
+      "required": [
+        "no_priority",
+        "low_priority",
+        "medium_priority",
+        "high_priority"
+      ],
+      "properties": {
+        "no_priority": {
+          "type": "integer"
+        },
+        "low_priority": {
+          "type": "integer"
+        },
+        "medium_priority": {
+          "type": "integer"
+        },
+        "high_priority": {
+          "type": "integer"
+        }
+      }
+    },
+    "contract_call": {
+      "type": "object",
+      "additionalProperties": false,
+      "required": [
+        "no_priority",
+        "low_priority",
+        "medium_priority",
+        "high_priority"
+      ],
+      "properties": {
+        "no_priority": {
+          "type": "integer"
+        },
+        "low_priority": {
+          "type": "integer"
+        },
+        "medium_priority": {
+          "type": "integer"
+        },
+        "high_priority": {
+          "type": "integer"
+        }
+      }
+    }
+  }
+}

docs/generated.d.ts

@@ -49,6 +49,7 @@ export type SchemaMergeRootStub =
   | GetStxSupplyLegacyFormatResponse
   | GetStxTotalSupplyPlainResponse
   | GetStxSupplyResponse
+  | MempoolFeePriorities
   | MicroblockListResponse
   | UnanchoredTransactionListResponse
   | RosettaAccountBalanceRequest
@@ -1694,6 +1695,35 @@ export interface GetStxSupplyResponse {
    */
   block_height: number;
 }
+/**
+ * GET request that returns fee priorities from mempool transactions
+ */
+export interface MempoolFeePriorities {
+  all: {
+    no_priority: number;
+    low_priority: number;
+    medium_priority: number;
+    high_priority: number;
+  };
+  token_transfer?: {
+    no_priority: number;
+    low_priority: number;
+    medium_priority: number;
+    high_priority: number;
+  };
+  smart_contract?: {
+    no_priority: number;
+    low_priority: number;
+    medium_priority: number;
+    high_priority: number;
+  };
+  contract_call?: {
+    no_priority: number;
+    low_priority: number;
+    medium_priority: number;
+    high_priority: number;
+  };
+}
 /**
  * GET request that returns microblocks
  */

docs/openapi.yaml

@@ -69,6 +69,8 @@ tags:
     externalDocs:
       description: Hiro Documentation - Transactions
       url: https://docs.hiro.so/get-started/transactions
+  - name: Mempool
+    description: Endpoints to obtain Mempool information
 
 paths:
   /extended/v1/faucets/stx:
@@ -296,6 +298,24 @@ paths:
               example:
                 $ref: ./api/transaction/get-mempool-transactions.example.json
 
+  /extended/v2/mempool/fees:
+    get:
+      summary: Get mempool transaction fee priorities
+      tags:
+        - Mempool
+      operationId: get_mempool_fee_priorities
+      description: |
+          Returns estimated fee priorities (in micro-STX) for all transactions that are currently in the mempool. Also returns priorities separated by transaction type.
+      responses:
+        200:
+          description: Mempool fee priorities
+          content:
+            application/json:
+              schema:
+                $ref: ./api/transaction/get-mempool-transactions.schema.json
+              example:
+                $ref: ./api/transaction/get-mempool-transactions.example.json
+
   /extended/v1/tx/mempool/dropped:
     get:
       summary: Get dropped mempool transactions

src/api/init.ts

@@ -45,6 +45,7 @@ import { createPox3EventsRouter } from './routes/pox3';
 import { isPgConnectionError } from '../datastore/helpers';
 import { createStackingRouter } from './routes/stacking';
 import { logger, loggerMiddleware } from '../logger';
+import { createMempoolRouter } from './v2/mempool';
 
 export interface ApiServer {
   expressApp: express.Express;
@@ -220,6 +221,21 @@ export async function startApiServer(opts: {
     })()
   );
 
+  app.use(
+    '/extended/v2',
+    (() => {
+      const router = express.Router();
+      router.use(cors());
+      router.use((req, res, next) => {
+        // Set caching on all routes to be disabled by default, individual routes can override
+        res.set('Cache-Control', 'no-store');
+        next();
+      });
+      router.use('/mempool', createMempoolRouter(datastore));
+      return router;
+    })()
+  );
+
   app.use(
     '/extended/beta',
     (() => {

src/api/v2/mempool.ts

@@ -0,0 +1,55 @@
+import * as express from 'express';
+import { asyncHandler } from '../async-handler';
+import {
+  ETagType,
+  getETagCacheHandler,
+  setETagCacheHeaders,
+} from '../controllers/cache-controller';
+import { PgStore } from '../../datastore/pg-store';
+import { DbMempoolFeePriority, DbTxTypeId } from '../../datastore/common';
+import { MempoolFeePriorities } from '../../../docs/generated';
+
+function parseMempoolFeePriority(fees: DbMempoolFeePriority[]): MempoolFeePriorities {
+  const out: MempoolFeePriorities = {
+    all: { no_priority: 0, low_priority: 0, medium_priority: 0, high_priority: 0 },
+  };
+  for (const fee of fees) {
+    const value = {
+      no_priority: fee.no_priority,
+      low_priority: fee.low_priority,
+      medium_priority: fee.medium_priority,
+      high_priority: fee.high_priority,
+    };
+    if (fee.type_id == null) out.all = value;
+    else
+      switch (fee.type_id) {
+        case DbTxTypeId.TokenTransfer:
+          out.token_transfer = value;
+          break;
+        case DbTxTypeId.ContractCall:
+          out.contract_call = value;
+          break;
+        case DbTxTypeId.SmartContract:
+        case DbTxTypeId.VersionedSmartContract:
+          out.smart_contract = value;
+          break;
+      }
+  }
+  return out;
+}
+
+export function createMempoolRouter(db: PgStore): express.Router {
+  const router = express.Router();
+  const mempoolCacheHandler = getETagCacheHandler(db, ETagType.mempool);
+
+  router.get(
+    '/fees',
+    mempoolCacheHandler,
+    asyncHandler(async (req, res, next) => {
+      setETagCacheHeaders(res);
+      res.status(200).json(parseMempoolFeePriority(await db.getMempoolFeePriority()));
+    })
+  );
+
+  return router;
+}

src/datastore/common.ts

@@ -235,6 +235,14 @@ export interface DbMempoolStats {
   >;
 }
 
+export interface DbMempoolFeePriority {
+  type_id: DbTxTypeId | null;
+  high_priority: number;
+  medium_priority: number;
+  low_priority: number;
+  no_priority: number;
+}
+
 export interface DbMempoolTx extends BaseTx {
   pruned: boolean;
 

src/datastore/pg-store.ts

@@ -38,6 +38,7 @@ import {
   DbGetBlockWithMetadataOpts,
   DbGetBlockWithMetadataResponse,
   DbInboundStxTransfer,
+  DbMempoolFeePriority,
   DbMempoolStats,
   DbMempoolTx,
   DbMicroblock,
@@ -1286,6 +1287,44 @@ export class PgStore {
     };
   }
 
+  async getMempoolFeePriority(): Promise<DbMempoolFeePriority[]> {
+    const txFeesQuery = await this.sql<DbMempoolFeePriority[]>`
+      WITH fees AS (
+        (
+          SELECT
+          NULL AS type_id,
+          ROUND(PERCENTILE_CONT(0.95) WITHIN GROUP (ORDER BY fee_rate ASC)) AS high_priority,
+          ROUND(PERCENTILE_CONT(0.75) WITHIN GROUP (ORDER BY fee_rate ASC)) AS medium_priority,
+          ROUND(PERCENTILE_CONT(0.50) WITHIN GROUP (ORDER BY fee_rate ASC)) AS low_priority,
+          ROUND(PERCENTILE_CONT(0.25) WITHIN GROUP (ORDER BY fee_rate ASC)) AS no_priority
+          FROM mempool_txs
+          WHERE pruned = FALSE
+        )
+        UNION
+        (
+          WITH txs_grouped AS (
+            SELECT
+              (CASE type_id WHEN 6 THEN 1 ELSE type_id END) AS type_id,
+              fee_rate
+            FROM mempool_txs
+            WHERE pruned = FALSE
+            AND type_id NOT IN (4, 5)
+          )
+          SELECT
+            type_id,
+            ROUND(PERCENTILE_CONT(0.95) WITHIN GROUP (ORDER BY fee_rate ASC)) AS high_priority,
+            ROUND(PERCENTILE_CONT(0.75) WITHIN GROUP (ORDER BY fee_rate ASC)) AS medium_priority,
+            ROUND(PERCENTILE_CONT(0.50) WITHIN GROUP (ORDER BY fee_rate ASC)) AS low_priority,
+            ROUND(PERCENTILE_CONT(0.25) WITHIN GROUP (ORDER BY fee_rate ASC)) AS no_priority
+          FROM txs_grouped
+          GROUP BY type_id
+        )
+      )
+      SELECT * FROM fees ORDER BY type_id ASC NULLS FIRST
+    `;
+    return txFeesQuery;
+  }
+
   async getMempoolTxList({
     limit,
     offset,

src/test-utils/test-builders.ts

@@ -16,7 +16,6 @@ import {
   DbBnsNamespace,
   DbEventTypeId,
   DbFtEvent,
-  DbMempoolTx,
   DbMempoolTxRaw,
   DbMicroblockPartial,
   DbMinerReward,
@@ -259,6 +258,8 @@ interface TestMempoolTxArgs {
   smart_contract_contract_id?: string;
   status?: DbTxStatus;
   token_transfer_recipient_address?: string;
+  token_transfer_amount?: bigint;
+  token_transfer_memo?: string;
   tx_id?: string;
   type_id?: DbTxTypeId;
   nonce?: number;
@@ -287,8 +288,8 @@ export function testMempoolTx(args?: TestMempoolTxArgs): DbMempoolTxRaw {
     sponsor_address: undefined,
     origin_hash_mode: 1,
     sender_address: args?.sender_address ?? SENDER_ADDRESS,
-    token_transfer_amount: 1234n,
-    token_transfer_memo: '',
+    token_transfer_amount: args?.token_transfer_amount ?? 1234n,
+    token_transfer_memo: args?.token_transfer_memo ?? '',
     token_transfer_recipient_address: args?.token_transfer_recipient_address ?? RECIPIENT_ADDRESS,
     smart_contract_clarity_version: args?.smart_contract_clarity_version,
     smart_contract_contract_id: args?.smart_contract_contract_id ?? CONTRACT_ID,