diff --git a/src/adapters/chains/solana/adapter.ts b/src/adapters/chains/solana/adapter.ts
index f777b4a..18e8729 100644
--- a/src/adapters/chains/solana/adapter.ts
+++ b/src/adapters/chains/solana/adapter.ts
@@ -8,7 +8,7 @@ import {
   fetchOutgoingMessage,
   type OutgoingMessage,
 } from "../../../clients/ts/src/bridge";
-import { validateRpcUrl } from "../../../core/validation";
+import { validateRpcUrl, validateWssUrl } from "../../../core/validation";
 import type { SolanaAdapterConfig, SolanaChainAdapter } from "./types";
 
 /**
@@ -30,6 +30,9 @@ export function makeSolanaAdapter(
   config: SolanaAdapterConfig,
 ): SolanaChainAdapter {
   validateRpcUrl(config.rpcUrl);
+  if (config.wssUrl !== undefined) {
+    validateWssUrl(config.wssUrl);
+  }
 
   const payer = config.payer;
   const chain = config.chain ?? solanaMainnet;
@@ -39,6 +42,7 @@ export function makeSolanaAdapter(
     kind: "solana",
     chain,
     rpcUrl: config.rpcUrl,
+    wssUrl: config.wssUrl,
     payer,
     async ping() {
       await rpc.getLatestBlockhash().send();
diff --git a/src/adapters/chains/solana/types.ts b/src/adapters/chains/solana/types.ts
index 1c7f4b7..3d8e25a 100644
--- a/src/adapters/chains/solana/types.ts
+++ b/src/adapters/chains/solana/types.ts
@@ -8,6 +8,8 @@ import type { ChainAdapter, ChainRef } from "../../../core/types";
 
 export interface SolanaAdapterConfig {
   rpcUrl: string;
+  /** Optional WebSocket URL for RPC subscriptions. If not provided, derived from `rpcUrl`. */
+  wssUrl?: string;
   payer: KeyPairSigner;
   /** Optional label for chain ref. */
   chain?: ChainRef;
@@ -17,6 +19,7 @@ export interface SolanaChainAdapter extends ChainAdapter {
   readonly chain: ChainRef;
   readonly kind: "solana";
   readonly rpcUrl: string;
+  readonly wssUrl?: string;
   readonly payer: KeyPairSigner;
 
   fetchOutgoingMessage(
diff --git a/src/core/protocol/engines/solana-engine.ts b/src/core/protocol/engines/solana-engine.ts
index 2618a8e..0ad8ee8 100644
--- a/src/core/protocol/engines/solana-engine.ts
+++ b/src/core/protocol/engines/solana-engine.ts
@@ -102,6 +102,8 @@ const DEFAULT_RELAY_GAS_LIMIT = 200_000n;
 
 interface SolanaEngineConfig {
   rpcUrl: string;
+  /** Optional WebSocket URL for RPC subscriptions. If not provided, derived from `rpcUrl`. */
+  wssUrl?: string;
   payer: KeyPairSigner;
   bridgeProgram: SolAddress;
   relayerProgram: SolAddress;
@@ -276,9 +278,14 @@ export class SolanaEngine {
     this.logger = opts.logger ?? NOOP_LOGGER;
     this.rpc = createSolanaRpc(this.config.rpcUrl);
 
-    const url = new URL(this.config.rpcUrl);
-    const wsScheme = url.protocol === "http:" ? "ws" : "wss";
-    const wssUrl = `${wsScheme}://${url.host}${url.pathname}${url.search}`;
+    let wssUrl: string;
+    if (this.config.wssUrl !== undefined) {
+      wssUrl = this.config.wssUrl;
+    } else {
+      const url = new URL(this.config.rpcUrl);
+      const wsScheme = url.protocol === "http:" ? "ws" : "wss";
+      wssUrl = `${wsScheme}://${url.host}${url.pathname}${url.search}`;
+    }
     const rpcSubscriptions = createSolanaRpcSubscriptions(wssUrl);
     this.sendAndConfirmTx = sendAndConfirmTransactionFactory({
       rpc: this.rpc,
diff --git a/src/core/protocol/routes/base-to-svm.ts b/src/core/protocol/routes/base-to-svm.ts
index 5cd660d..5892cb5 100644
--- a/src/core/protocol/routes/base-to-svm.ts
+++ b/src/core/protocol/routes/base-to-svm.ts
@@ -125,6 +125,7 @@ export class BaseToSvmRouteAdapter implements RouteAdapter {
     this.solanaEngine = new SolanaEngine({
       config: {
         rpcUrl: this.solana.rpcUrl,
+        wssUrl: this.solana.wssUrl,
         payer: this.solana.payer,
         bridgeProgram: this.solanaDeployment.bridgeProgram,
         relayerProgram: this.solanaDeployment.relayerProgram,
diff --git a/src/core/protocol/routes/svm-to-base.ts b/src/core/protocol/routes/svm-to-base.ts
index df6060f..3f851b6 100644
--- a/src/core/protocol/routes/svm-to-base.ts
+++ b/src/core/protocol/routes/svm-to-base.ts
@@ -141,6 +141,7 @@ export class SvmToBaseRouteAdapter implements RouteAdapter {
     this.solanaEngine = new SolanaEngine({
       config: {
         rpcUrl: this.solana.rpcUrl,
+        wssUrl: this.solana.wssUrl,
         payer: this.solana.payer,
         bridgeProgram: this.solanaDeployment.bridgeProgram,
         relayerProgram: this.solanaDeployment.relayerProgram,
diff --git a/src/core/validation.ts b/src/core/validation.ts
index 299443f..f58e6dd 100644
--- a/src/core/validation.ts
+++ b/src/core/validation.ts
@@ -16,29 +16,41 @@ import {
 
 const MAX_TRANSFER_AMOUNT = 2n ** 64n - 1n;
 
-export function validateRpcUrl(rpcUrl: string): void {
-  if (rpcUrl.trim() === "") {
+function validateUrlScheme(
+  url: string,
+  allowedProtocols: string[],
+  label: string,
+): void {
+  if (url.trim() === "") {
     throw new BridgeValidationError(
-      `Invalid RPC URL: expected a non-empty HTTP(S) URL, got "${truncate(String(rpcUrl))}"`,
+      `Invalid ${label}: expected a non-empty URL, got "${truncate(String(url))}"`,
     );
   }
 
   let parsed: URL;
   try {
-    parsed = new URL(rpcUrl);
+    parsed = new URL(url);
   } catch {
     throw new BridgeValidationError(
-      `Invalid RPC URL: not a valid URL, got "${truncate(rpcUrl)}"`,
+      `Invalid ${label}: not a valid URL, got "${truncate(url)}"`,
     );
   }
 
-  if (parsed.protocol !== "http:" && parsed.protocol !== "https:") {
+  if (!allowedProtocols.includes(parsed.protocol)) {
     throw new BridgeValidationError(
-      `Invalid RPC URL: expected http: or https: scheme, got "${parsed.protocol}" in "${truncate(rpcUrl)}"`,
+      `Invalid ${label}: expected ${allowedProtocols.join(" or ")} scheme, got "${parsed.protocol}" in "${truncate(url)}"`,
     );
   }
 }
 
+export function validateRpcUrl(rpcUrl: string): void {
+  validateUrlScheme(rpcUrl, ["http:", "https:"], "RPC URL");
+}
+
+export function validateWssUrl(wssUrl: string): void {
+  validateUrlScheme(wssUrl, ["ws:", "wss:"], "WebSocket URL");
+}
+
 export function validateAction(action: BridgeAction, route: BridgeRoute): void {
   if (action.kind === "transfer") {
     validateAmount(action.amount);
diff --git a/tests/adapter-config.test.ts b/tests/adapter-config.test.ts
index 3684268..3c92131 100644
--- a/tests/adapter-config.test.ts
+++ b/tests/adapter-config.test.ts
@@ -4,7 +4,7 @@ import { makeEvmAdapter } from "../src/adapters/chains/evm/adapter";
 import type { EvmAdapterConfig } from "../src/adapters/chains/evm/types";
 import { makeSolanaAdapter } from "../src/adapters/chains/solana/adapter";
 import { BridgeValidationError } from "../src/core/errors";
-import { validateRpcUrl } from "../src/core/validation";
+import { validateRpcUrl, validateWssUrl } from "../src/core/validation";
 
 /** Minimal mock that satisfies the KeyPairSigner interface shape at runtime. */
 const mockPayer = {
@@ -85,6 +85,69 @@ describe("validateRpcUrl", () => {
   });
 });
 
+describe("validateWssUrl", () => {
+  describe("rejects invalid URLs", () => {
+    test("throws for empty string", () => {
+      expect(() => validateWssUrl("")).toThrow("Invalid WebSocket URL");
+    });
+
+    test("throws for whitespace-only string", () => {
+      expect(() => validateWssUrl("   ")).toThrow("Invalid WebSocket URL");
+    });
+
+    test("throws for non-URL string", () => {
+      expect(() => validateWssUrl("not-a-url")).toThrow(
+        "Invalid WebSocket URL",
+      );
+    });
+
+    test("throws for http:// scheme", () => {
+      expect(() => validateWssUrl("http://localhost:8899")).toThrow(
+        "expected ws: or wss: scheme",
+      );
+    });
+
+    test("throws for https:// scheme", () => {
+      expect(() => validateWssUrl("https://api.example.com")).toThrow(
+        "expected ws: or wss: scheme",
+      );
+    });
+  });
+
+  describe("accepts valid URLs", () => {
+    test("accepts wss:// URL", () => {
+      expect(() =>
+        validateWssUrl("wss://api.mainnet-beta.solana.com"),
+      ).not.toThrow();
+    });
+
+    test("accepts ws:// URL (localhost dev)", () => {
+      expect(() => validateWssUrl("ws://localhost:8900")).not.toThrow();
+    });
+
+    test("accepts wss:// URL with path", () => {
+      expect(() =>
+        validateWssUrl("wss://rpc.example.com/v1/mainnet"),
+      ).not.toThrow();
+    });
+  });
+
+  describe("error properties", () => {
+    test("thrown error is a BridgeValidationError", () => {
+      let error: BridgeValidationError | undefined;
+      try {
+        validateWssUrl("");
+      } catch (e) {
+        error = e as BridgeValidationError;
+      }
+      expect(error).toBeInstanceOf(BridgeValidationError);
+      expect(error?.code).toBe("VALIDATION");
+      expect(error?.outcome).toBe("user_fix");
+      expect(error?.stage).toBe("initiate");
+    });
+  });
+});
+
 describe("makeSolanaAdapter config validation", () => {
   test("throws for empty rpcUrl", () => {
     expect(() => makeSolanaAdapter({ rpcUrl: "", payer: mockPayer })).toThrow(
@@ -121,6 +184,81 @@ describe("makeSolanaAdapter config validation", () => {
       makeSolanaAdapter({ rpcUrl: VALID_RPC, payer: mockPayer }),
     ).not.toThrow();
   });
+
+  describe("wssUrl validation", () => {
+    test("accepts config without wssUrl (optional)", () => {
+      expect(() =>
+        makeSolanaAdapter({ rpcUrl: VALID_RPC, payer: mockPayer }),
+      ).not.toThrow();
+    });
+
+    test("accepts valid wss:// URL", () => {
+      expect(() =>
+        makeSolanaAdapter({
+          rpcUrl: VALID_RPC,
+          wssUrl: "wss://api.mainnet-beta.solana.com",
+          payer: mockPayer,
+        }),
+      ).not.toThrow();
+    });
+
+    test("accepts valid ws:// URL", () => {
+      expect(() =>
+        makeSolanaAdapter({
+          rpcUrl: "http://localhost:8899",
+          wssUrl: "ws://localhost:8900",
+          payer: mockPayer,
+        }),
+      ).not.toThrow();
+    });
+
+    test("throws for http:// wssUrl", () => {
+      expect(() =>
+        makeSolanaAdapter({
+          rpcUrl: VALID_RPC,
+          wssUrl: "http://localhost:8899",
+          payer: mockPayer,
+        }),
+      ).toThrow("expected ws: or wss: scheme");
+    });
+
+    test("throws for empty wssUrl", () => {
+      expect(() =>
+        makeSolanaAdapter({
+          rpcUrl: VALID_RPC,
+          wssUrl: "",
+          payer: mockPayer,
+        }),
+      ).toThrow("Invalid WebSocket URL");
+    });
+
+    test("throws for invalid wssUrl", () => {
+      expect(() =>
+        makeSolanaAdapter({
+          rpcUrl: VALID_RPC,
+          wssUrl: "not-a-url",
+          payer: mockPayer,
+        }),
+      ).toThrow("Invalid WebSocket URL");
+    });
+
+    test("wssUrl is available on the returned adapter", () => {
+      const adapter = makeSolanaAdapter({
+        rpcUrl: VALID_RPC,
+        wssUrl: "wss://custom.rpc.example.com",
+        payer: mockPayer,
+      });
+      expect(adapter.wssUrl).toBe("wss://custom.rpc.example.com");
+    });
+
+    test("wssUrl is undefined when not provided", () => {
+      const adapter = makeSolanaAdapter({
+        rpcUrl: VALID_RPC,
+        payer: mockPayer,
+      });
+      expect(adapter.wssUrl).toBeUndefined();
+    });
+  });
 });
 
 describe("makeEvmAdapter config validation", () => {