diff --git a/apps/swift-ios/Core/HTTP.swift b/apps/swift-ios/Core/HTTP.swift
index 08b714f4298fc..04335640f6a24 100644
--- a/apps/swift-ios/Core/HTTP.swift
+++ b/apps/swift-ios/Core/HTTP.swift
@@ -368,6 +368,8 @@ public actor EnvironmentAPI {
         )
     }
 
+    /// `path` is percent-encoded: callers escape dynamic segments themselves so
+    /// an ID containing `%` or `/` stays one literal segment.
     func authorized<Result: Decodable & Sendable>(
         environment: Environment,
         path: String,
@@ -504,7 +506,7 @@ public actor EnvironmentAPI {
         headers: [String: String] = [:]
     ) -> URLRequest {
         var request = URLRequest(
-            url: endpoint(environment.httpBaseURL, path: path, queryItems: queryItems)
+            url: endpoint(environment.httpBaseURL, percentEncodedPath: path, queryItems: queryItems)
         )
         request.httpMethod = method
         request.httpBody = body
@@ -723,3 +725,11 @@ func endpoint(_ baseURL: URL, path: String, queryItems: [URLQueryItem] = []) ->
     components.fragment = nil
     return components.url!
 }
+
+func endpoint(_ baseURL: URL, percentEncodedPath: String, queryItems: [URLQueryItem] = []) -> URL {
+    var components = URLComponents(url: baseURL, resolvingAgainstBaseURL: false)!
+    components.percentEncodedPath = percentEncodedPath
+    components.queryItems = queryItems.isEmpty ? nil : queryItems
+    components.fragment = nil
+    return components.url!
+}
diff --git a/apps/swift-ios/Tests/CoreTests/DualOrchestrationClientTests.swift b/apps/swift-ios/Tests/CoreTests/DualOrchestrationClientTests.swift
index 7e3ae42b18f7c..949c1f9eac2ec 100644
--- a/apps/swift-ios/Tests/CoreTests/DualOrchestrationClientTests.swift
+++ b/apps/swift-ios/Tests/CoreTests/DualOrchestrationClientTests.swift
@@ -94,6 +94,18 @@ final class V2OrchestrationClientTests: XCTestCase {
         XCTAssertEqual(history.value(forHTTPHeaderField: "x-t3-orchestration-protocol"), "2")
     }
 
+    func testThreadReadEncodesLiteralPercentInThreadIDOnce() async throws {
+        let transport = try V2ClientHTTPTransport()
+        let client = makeClient(transport: transport)
+        _ = try? await client.threadSnapshot(id: "thread:delegated-task:command%3Amcp%3Aissue-17643")
+        let requests = await transport.requests
+        let read = try XCTUnwrap(requests.last { $0.url?.path.hasSuffix("/bounded") == true })
+        XCTAssertEqual(
+            URLComponents(url: try XCTUnwrap(read.url), resolvingAgainstBaseURL: false)?.percentEncodedPath,
+            "/api/orchestration/threads/thread:delegated-task:command%253Amcp%253Aissue-17643/bounded"
+        )
+    }
+
     func testV2ConnectionSendsCanonicalLaunchCommand() async throws {
         let transport = try V2ClientHTTPTransport()
         let socket = V2ClientCommandSocket()