Log request/response bodies and added version by romanr · Pull Request #32 · lynnswap/XcodeMCPKit

romanr · 2026-03-10T15:18:24Z

Improve observability and expose the tool version to clear the confusion.

Enhance HTTPHandler to capture an optional client name (from Mcp-Client-Name header or JSON request body) and include it in request/response metadata.
Added detailed request and response body logging with a 4096-byte preview, byte counts, truncated marker, and related metadata (id, method, path, remote, client, session, status).
Introduce helper functions for body logging and client name extraction.
Added Version in startup stdout log.
Added --version cli parameter

Improve observability and expose the tool version to clear the confusion. - Enhance HTTPHandler to capture an optional client name (from Mcp-Client-Name header or JSON request body) and include it in request/response metadata. - Added detailed request and response body logging with a 4096-byte preview, byte counts, truncated marker, and related metadata (id, method, path, remote, client, session, status). - Introduce helper functions for body logging and client name extraction. - Added Version in startup stdout log. - Added --version cli parameter

Copilot

Pull request overview

This PR improves runtime observability for the HTTP proxy and reduces user confusion by exposing the tool’s version via both startup logs and new --version CLI flags.

Changes:

Add a shared Version.current constant and surface it in server startup logs.
Add --version handling to both xcode-mcp-proxy and xcode-mcp-proxy-server.
Extend HTTP request/response logging to include optional client name metadata and body previews.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
Sources/XcodeMCPProxyCommands/XcodeMCPProxyServerCommand.swift	Adds `--version` support and wires new option through server command parsing/execution.
Sources/XcodeMCPProxyCommands/XcodeMCPProxyCLICommand.swift	Adds `--version` support to the CLI adapter command.
Sources/XcodeMCPProxy/Version.swift	Introduces a shared version constant consumed by commands and server logs.
Sources/XcodeMCPProxy/ProxyServer.swift	Includes version in the server “listening on …” startup log line.
Sources/XcodeMCPProxy/HTTPHandler.swift	Adds client-name extraction and request/response body preview logging with additional metadata.

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Copilot · 2026-03-10T15:27:36Z

Sources/XcodeMCPProxy/HTTPHandler.swift

+        if data.count > maxLoggedBodyBytes {
+            metadata["truncated"] = .string("true")
+        }
+        logger.info(Logger.Message(stringLiteral: label), metadata: metadata)


Request/response bodies are logged at .info with a plaintext preview. This can leak sensitive data (tokens, prompts, tool arguments) into logs and can significantly increase log volume. Consider gating body logging behind a debug log level and/or an explicit config/env flag, and/or redacting known sensitive fields before logging.

Suggested change

logger.info(Logger.Message(stringLiteral: label), metadata: metadata)

logger.debug(Logger.Message(stringLiteral: label), metadata: metadata)

Copilot · 2026-03-10T15:27:36Z

Sources/XcodeMCPProxyCommands/XcodeMCPProxyServerCommand.swift

@@ -18,6 +19,7 @@ package struct ProxyServerOptions {
    package init(
        forwardedArgs: [String],
        showHelp: Bool,


Adding showVersion to ProxyServerOptions changes its initializer signature; any existing initializations (notably in ServerCommandTests) need to be updated to pass showVersion to keep tests compiling.

Suggested change

showHelp: Bool,

showHelp: Bool,

hasListenFlag: Bool,

hasHostFlag: Bool,

hasPortFlag: Bool,

hasXcodePidFlag: Bool,

hasLazyInitFlag: Bool,

forceRestart: Bool,

dryRun: Bool

) {

self.init(

forwardedArgs: forwardedArgs,

showHelp: showHelp,

showVersion: false,

hasListenFlag: hasListenFlag,

hasHostFlag: hasHostFlag,

hasPortFlag: hasPortFlag,

hasXcodePidFlag: hasXcodePidFlag,

hasLazyInitFlag: hasLazyInitFlag,

forceRestart: forceRestart,

dryRun: dryRun

)

}

package init(

forwardedArgs: [String],

showHelp: Bool,

Copilot · 2026-03-10T15:27:37Z

Sources/XcodeMCPProxyCommands/XcodeMCPProxyServerCommand.swift

+            if options.showVersion {
+                dependencies.stdout("xcode-mcp-proxy-server \(Version.current)")
+                return 0
+            }


New --version behavior isn't covered by tests. There are already comprehensive command tests in Tests/XcodeMCPProxyTests/ServerCommandTests.swift; please add coverage asserting --version prints the version string and exits 0 (and that it doesn't attempt to start the server).

Copilot · 2026-03-10T15:27:37Z

Sources/XcodeMCPProxyCommands/XcodeMCPProxyCLICommand.swift

+        if invocation.showVersion {
+            dependencies.stdout("xcode-mcp-proxy \(Version.current)")
+            return 0
+        }


New --version behavior isn't covered by tests. There are existing CLI command tests in Tests/XcodeMCPProxyTests/CLICommandTests.swift; please add a test that --version prints xcode-mcp-proxy <version> and exits 0 without creating an adapter.

Sources/XcodeMCPProxy/Version.swift

Copilot · 2026-03-10T15:27:37Z

Sources/XcodeMCPProxy/HTTPHandler.swift

            id: UUID().uuidString,
            method: head.method.rawValue,
            path: path,
-            remoteAddress: remoteAddressString(for: context.channel)
+            remoteAddress: remoteAddressString(for: context.channel),
+            clientName: nil


The initial "HTTP request" log is emitted before clientName is extracted, so it will never include the client name (even when present in the Mcp-Client-Name header). Consider populating clientName from headers in handleRequest before calling logRequest, and only falling back to body parsing for POST requests if needed.

Copilot · 2026-03-10T15:27:37Z

Sources/XcodeMCPProxy/HTTPHandler.swift

+        let clientName = clientName(from: head.headers, bodyData: bodyData)
+        let requestLog = requestLog.withClientName(clientName)
+        logRequestBody(bodyData, requestLog: requestLog)


clientName(from:head.headers, bodyData:) will JSON-parse the body to extract the client name, and then handlePost JSON-parses the same bodyData again immediately after. To avoid double parsing (and extra work on every request), parse the JSON body once and reuse the parsed object both for method routing and client-name extraction.

Copilot · 2026-03-10T15:27:38Z

Sources/XcodeMCPProxy/HTTPHandler.swift

+        let previewData = data.prefix(maxLoggedBodyBytes)
+        let previewText = String(decoding: previewData, as: UTF8.self)
+        metadata["preview"] = .string(previewText)
+        if data.count > maxLoggedBodyBytes {
+            metadata["truncated"] = .string("true")
+        }
+        logger.info(Logger.Message(stringLiteral: label), metadata: metadata)


logBody unconditionally logs a 4KB preview of every HTTP request and response body (metadata["preview"]) at info level, along with byte length, path, and optional session/client identifiers. These bodies can easily contain sensitive material (e.g., API keys, access tokens, secrets in payloads, or proprietary code and prompts), so anyone with access to logs or a multi-tenant logging backend could recover that data. Consider restricting full body logging to an opt-in debug mode, redacting or hashing sensitive fields, and/or ensuring logs never contain authentication secrets or other high-sensitivity content.

Suggested change

let previewData = data.prefix(maxLoggedBodyBytes)

let previewText = String(decoding: previewData, as: UTF8.self)

metadata["preview"] = .string(previewText)

if data.count > maxLoggedBodyBytes {

metadata["truncated"] = .string("true")

}

logger.info(Logger.Message(stringLiteral: label), metadata: metadata)

// Always log high-level request/response information at info level,

// but do not include body content to avoid leaking sensitive data.

logger.info(Logger.Message(stringLiteral: label), metadata: metadata)

// Only log body previews in debug/loopback scenarios to reduce

// the risk of exposing sensitive information in logs.

if isLoopbackDebugEndpointEnabled || logger.logLevel <= .debug {

var debugMetadata = metadata

let previewData = data.prefix(maxLoggedBodyBytes)

let previewText = String(decoding: previewData, as: UTF8.self)

debugMetadata["preview"] = .string(previewText)

if data.count > maxLoggedBodyBytes {

debugMetadata["truncated"] = .string("true")

}

logger.debug(Logger.Message(stringLiteral: label), metadata: debugMetadata)

}

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Copilot AI review requested due to automatic review settings March 10, 2026 15:18

Copilot started reviewing on behalf of romanr March 10, 2026 15:18 View session

Copilot AI reviewed Mar 10, 2026

View reviewed changes

Update Sources/XcodeMCPProxy/Version.swift

781e7a8

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

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Log request/response bodies and added version#32

Log request/response bodies and added version#32
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	logger.info(Logger.Message(stringLiteral: label), metadata: metadata)
	logger.debug(Logger.Message(stringLiteral: label), metadata: metadata)

-        showHelp: Bool,
+        showHelp: Bool,
+        hasListenFlag: Bool,
+        hasHostFlag: Bool,
+        hasPortFlag: Bool,
+        hasXcodePidFlag: Bool,
+        hasLazyInitFlag: Bool,
+        forceRestart: Bool,
+        dryRun: Bool
+    ) {
+        self.init(
+            forwardedArgs: forwardedArgs,
+            showHelp: showHelp,
+            showVersion: false,
+            hasListenFlag: hasListenFlag,
+            hasHostFlag: hasHostFlag,
+            hasPortFlag: hasPortFlag,
+            hasXcodePidFlag: hasXcodePidFlag,
+            hasLazyInitFlag: hasLazyInitFlag,
+            forceRestart: forceRestart,
+            dryRun: dryRun
+        )
+    }
+    package init(
+        forwardedArgs: [String],
+        showHelp: Bool,

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