diff --git a/services/ingest-equities/package.json b/services/ingest-equities/package.json
index 5452f2f..bf85916 100644
--- a/services/ingest-equities/package.json
+++ b/services/ingest-equities/package.json
@@ -11,6 +11,7 @@
     "@islandflow/observability": "workspace:*",
     "@islandflow/storage": "workspace:*",
     "@islandflow/types": "workspace:*",
+    "ws": "^8.18.3",
     "zod": "^3.23.8"
   }
 }
diff --git a/services/ingest-equities/src/adapters/alpaca.ts b/services/ingest-equities/src/adapters/alpaca.ts
new file mode 100644
index 0000000..97b7205
--- /dev/null
+++ b/services/ingest-equities/src/adapters/alpaca.ts
@@ -0,0 +1,335 @@
+import { createLogger } from "@islandflow/observability";
+import type { EquityPrint, EquityQuote } from "@islandflow/types";
+import type { EquityIngestAdapter, EquityIngestHandlers } from "./types";
+import WebSocket from "ws";
+
+export type AlpacaEquitiesFeed = "iex" | "sip";
+
+export type AlpacaEquitiesAdapterConfig = {
+  keyId: string;
+  secretKey: string;
+  restUrl: string;
+  wsBaseUrl: string;
+  feed: AlpacaEquitiesFeed;
+  symbols: string[];
+};
+
+type AlpacaExchangeMetaEntry = {
+  code: string;
+  name: string;
+};
+
+type AlpacaTradeMessage = {
+  T: "t";
+  S: string;
+  t: string;
+  p: number;
+  s: number;
+  x?: string;
+  c?: string[];
+  z?: string;
+};
+
+type AlpacaQuoteMessage = {
+  T: "q";
+  S: string;
+  t: string;
+  bp: number;
+  ap: number;
+  bs?: number;
+  as?: number;
+  bx?: string;
+  ax?: string;
+  c?: string[];
+  z?: string;
+};
+
+const logger = createLogger({ service: "ingest-equities" });
+
+const normalizeSymbols = (symbols: string[]): string[] => {
+  const seen = new Set<string>();
+  const result: string[] = [];
+
+  for (const entry of symbols) {
+    const symbol = entry.trim().toUpperCase();
+    if (!symbol || seen.has(symbol)) {
+      continue;
+    }
+
+    seen.add(symbol);
+    result.push(symbol);
+  }
+
+  return result;
+};
+
+const buildHeaders = (config: AlpacaEquitiesAdapterConfig): Record<string, string> => ({
+  "APCA-API-KEY-ID": config.keyId,
+  "APCA-API-SECRET-KEY": config.secretKey
+});
+
+const parseTimestamp = (value: string): number => {
+  const parsed = Date.parse(value);
+  if (Number.isFinite(parsed)) {
+    return parsed;
+  }
+  return Date.now();
+};
+
+const decodePayload = (data: WebSocket.RawData): unknown => {
+  if (typeof data === "string") {
+    return JSON.parse(data) as unknown;
+  }
+
+  if (data instanceof ArrayBuffer) {
+    return JSON.parse(new TextDecoder().decode(new Uint8Array(data))) as unknown;
+  }
+
+  if (ArrayBuffer.isView(data)) {
+    return JSON.parse(new TextDecoder().decode(new Uint8Array(data.buffer, data.byteOffset, data.byteLength))) as unknown;
+  }
+
+  return JSON.parse(new TextDecoder().decode(new Uint8Array(data as ArrayBuffer))) as unknown;
+};
+
+const extractExchangeMeta = (payload: unknown): AlpacaExchangeMetaEntry[] => {
+  if (!Array.isArray(payload)) {
+    return [];
+  }
+
+  const result: AlpacaExchangeMetaEntry[] = [];
+
+  for (const entry of payload) {
+    if (!entry || typeof entry !== "object") {
+      continue;
+    }
+    const candidate = entry as Record<string, unknown>;
+    const code = typeof candidate.code === "string" ? candidate.code : typeof candidate.exchange === "string" ? candidate.exchange : null;
+    const name = typeof candidate.name === "string" ? candidate.name : typeof candidate.description === "string" ? candidate.description : null;
+    if (!code || !name) {
+      continue;
+    }
+
+    result.push({ code, name });
+  }
+
+  return result;
+};
+
+const buildExchangeNameMap = (entries: AlpacaExchangeMetaEntry[]): Map<string, string> => {
+  const map = new Map<string, string>();
+  for (const entry of entries) {
+    const code = entry.code.trim();
+    const name = entry.name.trim();
+    if (!code || !name) {
+      continue;
+    }
+    map.set(code, name);
+  }
+  return map;
+};
+
+const OFF_EXCHANGE_HINTS = ["FINRA", "TRF", "ADF", "OTC", "Trade Reporting Facility", "Alternative Display Facility"];
+
+export const inferOffExchangeFlag = (exchangeCode: string | undefined, exchangeNameMap: Map<string, string>): boolean => {
+  if (!exchangeCode) {
+    return false;
+  }
+
+  const name = exchangeNameMap.get(exchangeCode) ?? "";
+  const normalized = name.toUpperCase();
+
+  if (normalized) {
+    return OFF_EXCHANGE_HINTS.some((hint) => normalized.includes(hint.toUpperCase()));
+  }
+
+  // Conservative fallback: only tag the most common FINRA code when no mapping is available.
+  return exchangeCode.toUpperCase() === "D";
+};
+
+const buildWsUrl = (wsBaseUrl: string, feed: AlpacaEquitiesFeed): string => {
+  const parsed = new URL(wsBaseUrl);
+  return `${parsed.origin}/v2/${feed}`;
+};
+
+const fetchExchangeMeta = async (config: AlpacaEquitiesAdapterConfig): Promise<Map<string, string>> => {
+  const url = new URL("/v2/stocks/meta/exchanges", config.restUrl);
+
+  try {
+    const response = await fetch(url.toString(), {
+      headers: buildHeaders(config)
+    });
+
+    if (!response.ok) {
+      logger.warn("alpaca exchange meta request failed", {
+        status: response.status
+      });
+      return new Map();
+    }
+
+    const payload = (await response.json()) as unknown;
+    const entries = extractExchangeMeta(payload);
+    return buildExchangeNameMap(entries);
+  } catch (error) {
+    logger.warn("alpaca exchange meta request error", {
+      error: error instanceof Error ? error.message : String(error)
+    });
+    return new Map();
+  }
+};
+
+export const createAlpacaEquitiesAdapter = (
+  config: AlpacaEquitiesAdapterConfig
+): EquityIngestAdapter => {
+  return {
+    name: "alpaca",
+    start: async (handlers: EquityIngestHandlers) => {
+      if (!config.keyId || !config.secretKey) {
+        throw new Error("Alpaca equities adapter requires ALPACA_KEY_ID and ALPACA_SECRET_KEY.");
+      }
+
+      const symbols = normalizeSymbols(config.symbols);
+      if (symbols.length === 0) {
+        throw new Error("Alpaca equities adapter requires at least one symbol.");
+      }
+
+      const exchangeNameMap = await fetchExchangeMeta(config);
+      const wsUrl = buildWsUrl(config.wsBaseUrl, config.feed);
+      const ws = new WebSocket(wsUrl);
+
+      let seq = 0;
+      let stopped = false;
+      let authenticated = false;
+
+      ws.on("open", () => {
+        ws.send(
+          JSON.stringify({
+            action: "auth",
+            key: config.keyId,
+            secret: config.secretKey
+          })
+        );
+      });
+
+      const subscribe = () => {
+        const message: Record<string, unknown> = {
+          action: "subscribe",
+          trades: symbols
+        };
+
+        if (handlers.onQuote) {
+          message.quotes = symbols;
+        }
+
+        ws.send(JSON.stringify(message));
+      };
+
+      ws.on("message", (data) => {
+        if (stopped) {
+          return;
+        }
+
+        let payload: unknown;
+        try {
+          payload = decodePayload(data);
+        } catch (error) {
+          logger.warn("alpaca equities message decode failed", {
+            error: error instanceof Error ? error.message : String(error)
+          });
+          return;
+        }
+
+        if (!Array.isArray(payload)) {
+          return;
+        }
+
+        for (const entry of payload) {
+          if (!entry || typeof entry !== "object") {
+            continue;
+          }
+
+          const message = entry as (AlpacaTradeMessage | AlpacaQuoteMessage | { T?: string; msg?: string });
+          const type = message.T;
+
+          if (type === "success") {
+            const msg = (message as { msg?: string }).msg ?? "";
+            if (msg === "authenticated") {
+              authenticated = true;
+              subscribe();
+            }
+            continue;
+          }
+
+          if (type === "subscription") {
+            continue;
+          }
+
+          if (type === "error") {
+            logger.error("alpaca equities stream error", { message });
+            continue;
+          }
+
+          if (type === "t") {
+            const trade = message as AlpacaTradeMessage;
+            const sourceTs = parseTimestamp(trade.t);
+            seq += 1;
+            const exchangeCode = trade.x ?? "";
+
+            void handlers.onTrade({
+              source_ts: sourceTs,
+              ingest_ts: Date.now(),
+              seq,
+              trace_id: `alpaca-equities-${seq}`,
+              ts: sourceTs,
+              underlying_id: trade.S,
+              price: trade.p,
+              size: trade.s,
+              exchange: exchangeCode || "ALPACA",
+              offExchangeFlag: inferOffExchangeFlag(exchangeCode, exchangeNameMap)
+            } satisfies EquityPrint);
+
+            continue;
+          }
+
+          if (type === "q" && handlers.onQuote) {
+            const quote = message as AlpacaQuoteMessage;
+            const sourceTs = parseTimestamp(quote.t);
+            seq += 1;
+
+            void handlers.onQuote({
+              source_ts: sourceTs,
+              ingest_ts: Date.now(),
+              seq,
+              trace_id: `alpaca-equity-quote-${seq}`,
+              ts: sourceTs,
+              underlying_id: quote.S,
+              bid: quote.bp,
+              ask: quote.ap
+            } satisfies EquityQuote);
+
+            continue;
+          }
+        }
+      });
+
+      ws.on("error", (error) => {
+        logger.error("alpaca equities websocket error", {
+          error: error instanceof Error ? error.message : String(error)
+        });
+      });
+
+      ws.on("close", (code, reason) => {
+        logger.warn("alpaca equities websocket closed", {
+          code,
+          reason: reason.toString(),
+          authenticated
+        });
+      });
+
+      return () => {
+        stopped = true;
+        ws.close();
+      };
+    }
+  };
+};
diff --git a/services/ingest-equities/src/index.ts b/services/ingest-equities/src/index.ts
index 1572aa2..3644e7a 100644
--- a/services/ingest-equities/src/index.ts
+++ b/services/ingest-equities/src/index.ts
@@ -22,6 +22,7 @@ import {
   type EquityPrint,
   type EquityQuote
 } from "@islandflow/types";
+import { createAlpacaEquitiesAdapter } from "./adapters/alpaca";
 import { createSyntheticEquitiesAdapter } from "./adapters/synthetic";
 import type { EquityIngestAdapter, StopHandler } from "./adapters/types";
 import { z } from "zod";
@@ -35,6 +36,15 @@ const envSchema = z.object({
   CLICKHOUSE_DATABASE: z.string().default("default"),
   EQUITIES_INGEST_ADAPTER: z.string().min(1).default("synthetic"),
   EMIT_INTERVAL_MS: z.coerce.number().int().positive().default(1000),
+
+  // Alpaca (equities)
+  ALPACA_KEY_ID: z.string().default(""),
+  ALPACA_SECRET_KEY: z.string().default(""),
+  ALPACA_REST_URL: z.string().default("https://data.alpaca.markets"),
+  ALPACA_WS_BASE_URL: z.string().default("wss://stream.data.alpaca.markets"),
+  ALPACA_UNDERLYINGS: z.string().default("SPY,NVDA,AAPL"),
+  ALPACA_EQUITIES_FEED: z.enum(["iex", "sip"]).default("iex"),
+
   TESTING_MODE: z
     .preprocess((value) => {
       if (typeof value === "string") {
@@ -113,11 +123,29 @@ const retry = async <T>(
   throw lastError ?? new Error(`${label} failed after retries`);
 };
 
+const parseSymbolList = (value: string): string[] => {
+  return value
+    .split(",")
+    .map((entry) => entry.trim())
+    .filter(Boolean);
+};
+
 const selectAdapter = (name: string): EquityIngestAdapter => {
   if (name === "synthetic") {
     return createSyntheticEquitiesAdapter({ emitIntervalMs: env.EMIT_INTERVAL_MS });
   }
 
+  if (name === "alpaca") {
+    return createAlpacaEquitiesAdapter({
+      keyId: env.ALPACA_KEY_ID,
+      secretKey: env.ALPACA_SECRET_KEY,
+      restUrl: env.ALPACA_REST_URL,
+      wsBaseUrl: env.ALPACA_WS_BASE_URL,
+      feed: env.ALPACA_EQUITIES_FEED,
+      symbols: parseSymbolList(env.ALPACA_UNDERLYINGS)
+    });
+  }
+
   throw new Error(`Unknown ingest adapter: ${name}`);
 };
 
diff --git a/services/ingest-equities/tests/alpaca.test.ts b/services/ingest-equities/tests/alpaca.test.ts
new file mode 100644
index 0000000..c7422b0
--- /dev/null
+++ b/services/ingest-equities/tests/alpaca.test.ts
@@ -0,0 +1,29 @@
+import { describe, expect, test } from "bun:test";
+import { inferOffExchangeFlag } from "../src/adapters/alpaca";
+
+describe("alpaca equities adapter helpers", () => {
+  test("inferOffExchangeFlag tags FINRA/TRF venues as off-exchange", () => {
+    const map = new Map<string, string>([
+      ["D", "FINRA / Nasdaq TRF"],
+      ["N", "FINRA / NYSE TRF"],
+      ["Q", "NASDAQ"],
+      ["P", "NYSE ARCA"],
+      ["O", "OTC Markets"]
+    ]);
+
+    expect(inferOffExchangeFlag("D", map)).toBe(true);
+    expect(inferOffExchangeFlag("N", map)).toBe(true);
+    expect(inferOffExchangeFlag("O", map)).toBe(true);
+    expect(inferOffExchangeFlag("Q", map)).toBe(false);
+    expect(inferOffExchangeFlag("P", map)).toBe(false);
+  });
+
+  test("inferOffExchangeFlag falls back conservatively when no mapping", () => {
+    const empty = new Map<string, string>();
+
+    expect(inferOffExchangeFlag(undefined, empty)).toBe(false);
+    expect(inferOffExchangeFlag("", empty)).toBe(false);
+    expect(inferOffExchangeFlag("D", empty)).toBe(true);
+    expect(inferOffExchangeFlag("N", empty)).toBe(false);
+  });
+});