MCP User Guide

01 What Is MCP?

MCP (Model Context Protocol) is a standard protocol that connects AI clients to local applications.

When the Packet Capture Pro MCP service is enabled, an authorized MCP-compatible AI client can read and work with data in Packet Capture Pro. You can use natural-language instructions to ask the AI client to:

• View and filter live capture data.
• View and filter capture history.
• Generate cURL commands or HAR data from capture records.
• Create, edit, enable, disable, or delete rewrite rules.
• Run standard and advanced replays.
• Create and run debugging tasks.
• Import and analyze HAR files.

The AI client selects and calls the appropriate MCP tools provided by Packet Capture Pro based on your request.

02 Desktop and Mobile Differences

03 Desktop Requirements

Before using MCP on desktop, make sure that:

1. Packet Capture Pro has been updated to a version that supports MCP (version 3.0.0 or later).
2. Your AI client supports local stdio MCP servers.
3. MCP Service is enabled in Packet Capture Pro.
4. The Packet Capture Pro MCP server has been added to your AI client.
5. You approved the AI client in Packet Capture Pro when it connected for the first time.

04 Opening the Desktop MCP Service

1. Open Packet Capture Pro.
2. Select MCP in the left sidebar.
3. Open the MCP Service page.
4. Turn on MCP Service.
5. Select Configure AI Client and follow the on-screen instructions.

When MCP Service is turned on, Packet Capture Pro begins accepting connection requests from AI clients running on the same computer. Turning on the service does not immediately send any data to an AI client. You must configure the client and approve it the first time it connects.

05 Desktop Connection Status

The MCP Service page shows the current connection status and any connected AI clients.

06 First-Time Connection Approval on Desktop

When a new AI client requests access to Packet Capture Pro for the first time, you must choose whether to allow the connection.

• If you allow the connection, the client can discover and call the MCP tools currently exposed by Packet Capture Pro.
• If you deny the connection, the client cannot read or work with Packet Capture Pro data.
• The AI client may have its own tool-confirmation, security-approval, or automatic-execution settings. These settings are controlled by the AI client, not by Packet Capture Pro.

07 Configuring a Desktop AI Client

On the Configure AI Client page, select the client you want to use. Follow the command or configuration-file instructions shown on the page to add the Packet Capture Pro MCP server to that client.

Configuration normally requires the MCP server executable path shown in Packet Capture Pro. Setup locations and formats vary by AI client, so always follow the latest instructions displayed in Packet Capture Pro.

Supported clients include:

• Claude Code
• Cursor
• Codex
• TRAE
• Other AI clients that support local stdio MCP servers

08 Sensitive Data Protection on Desktop

Sensitive Data Protection reduces the risk of authentication information in captured traffic being sent directly to an AI client.

When enabled, Packet Capture Pro automatically processes the following fields before returning data through MCP:

Sensitive Data Protection affects only the data returned to AI clients through MCP. It does not modify the original capture data stored in Packet Capture Pro, which remains available in the application.

When Sensitive Data Protection is disabled, Packet Capture Pro no longer masks these fields automatically in MCP responses. Before turning it off, make sure the connected AI client is trusted and the data is permitted to be shared.

09 Turning Off the Desktop MCP Service

When MCP Service is turned off:

• All connected AI clients are disconnected.
• AI clients can no longer read Packet Capture Pro data.
• AI clients can no longer call MCP tools provided by Packet Capture Pro.
• MCP calls that are waiting for results may be cancelled or return a connection error.
• Completed delete, clear, rewrite, and replay operations are not automatically undone.

10 Mobile Requirements

Before using MCP on mobile, make sure that:

1. Packet Capture Pro Mobile has been updated to a version that supports MCP (version 5.6.0 or later).
2. Your account has access to the MCP feature.
3. The phone and the computer running the AI client are connected to the same local network.
4. The AI client supports remote MCP servers over HTTP.
5. MCP Service is enabled in Packet Capture Pro Mobile.
6. The service address and access token shown on the mobile device have been added to the AI client.

11 Opening the Mobile MCP Service

1. Open Packet Capture Pro Mobile.
2. Open the sidebar and select MCP.
3. Turn on MCP Service.
4. View the current MCP service address and access token.
5. Select Configure AI Client.
6. Choose an AI client, then copy and apply the configuration shown.

Once enabled, the mobile app starts an HTTP MCP server on the current local network. An AI client must provide the correct access token before it can discover or call any tools.

12 Mobile MCP Service Address and Port

Port Rules

• Default port: 19027.
• Allowed range: 1024–65535.
• The port must be an integer.
• Changing the port changes the service address. The AI client must then be configured again with the new address.

Network Changes

The previous MCP service address may stop working when the phone switches Wi-Fi networks, reconnects to the network, or receives a new local IP address. Packet Capture Pro generates a new address for the current network; copy that address and update the AI client configuration.

13 Mobile Access Token

The access token authenticates AI clients that connect to the mobile MCP service.

Token Rules

• Packet Capture Pro generates the token using a cryptographically secure random process.
• The token does not contain predictable account, device, or IP address information.
• A token is generated automatically the first time MCP Service is enabled.
• Use the copy button to copy the complete token.
• Do not share the token in public screenshots, chats, or email.
• The access token is used only for authentication.

Refreshing the Access Token

When you select refresh and confirm, Packet Capture Pro generates a new access token:

• The current token becomes invalid immediately.
• Connections established with the old token are closed.
• AI clients that used the old token must be configured again with the new token.

14 Sensitive Data Protection on Mobile

Sensitive Data Protection reduces the risk of authentication information in captured traffic being sent directly to an AI client.

When enabled, Packet Capture Pro automatically processes the following fields before returning data to the AI client:

Sensitive Data Protection affects only data returned through MCP. It does not modify the original capture data stored in Packet Capture Pro.

15 Configuring a Mobile AI Client

On the Configure AI Client page, select the client you want to use.

Available clients:

• Claude Code
• Cursor
• Codex
• TRAE
• Other AI clients

16 Limitations in Collaboration Mode

Collaboration Mode and MCP Service can be enabled at the same time. However, while Collaboration Mode is active, capture data is stored on the computer and cannot currently be queried or modified through Mobile MCP.

17 Turning Off the Mobile MCP Service

When Mobile MCP Service is turned off:

• The service stops accepting new MCP connections.
• Connected AI clients are disconnected.
• MCP calls that are running or waiting may be cancelled.
• Other Packet Capture Pro capture features and non-MCP operations are not affected.

If the service address or access token changes after MCP Service is turned on again, update the AI client configuration.

18 MCP Tool Reference

The desktop and mobile apps each register the tools supported by their current version. Shared capabilities use consistent tool names, parameters, and response structures, but the number and scope of available tools differ between platforms. The tools discovered by the AI client are the tools available for the current platform.

18.1 MCP Tools Available on Desktop

After the desktop connection is established, the AI client can discover and call the following tools:

18.2 MCP Tools Available on Mobile

The current version of Mobile MCP supports only Live Capture and Capture History. After the connection is established, the AI client can discover and call the following tools:

19 Tool Execution Rules

Packet Capture Pro follows a “tool availability defines access” model:

• An AI client can call only the tools registered for the current connection.
• Before a tool runs, Packet Capture Pro validates required parameters, target objects, file-access scope, and concurrency limits.
• If parameters are invalid, the target does not exist, or execution fails, the AI client receives a clear error.
• The AI client may still require its own approval before calling a tool.
• Completed delete, clear, replay, and rewrite operations are not automatically undone when a rule is disabled, MCP is turned off, or the connection ends.
• Waiting tasks are cancelled when MCP Service is turned off, authorization expires, or the connection ends.

20 Security and Privacy Notes

• Only allow trusted AI clients to connect to Packet Capture Pro.
• The AI client may require confirmation before calling a tool.
• MCP setup, tool-confirmation behavior, and timeout limits vary by AI client.
• An AI client's ability to complete multi-step tasks also depends on its model capabilities, context window, and execution limits.
• The mobile service address and access token are sensitive connection details. Do not share them publicly.
• Do not enable Mobile MCP on public Wi-Fi or an untrusted local network.

Desktop Troubleshooting

21 The AI Client Cannot Connect to Desktop MCP

Check the following:

1. Packet Capture Pro is running on the desktop.
2. MCP Service is enabled in Packet Capture Pro.
3. The AI client supports local stdio MCP servers.
4. The configuration does not contain extra quotation marks, spaces, line breaks, or escape characters.

22 No Approval Prompt Appears on First Connection

Make sure the AI client has actually started a connection. Packet Capture Pro does not display an approval prompt until the AI client successfully starts the MCP server.

Try the following:

1. Keep Packet Capture Pro running and MCP Service enabled.
2. Make sure the MCP configuration is enabled in the AI client.
3. Reload or restart the AI client so that it attempts to connect again.
4. If the prompt still does not appear, remove the old configuration and add it again using the latest instructions shown in Packet Capture Pro.

23 The Desktop Connection Drops Unexpectedly

The connection is interrupted when:

• Packet Capture Pro quits or closes unexpectedly.
• MCP Service is turned off in Packet Capture Pro.
• The AI client quits, restarts, or reloads its configuration.
• The computer goes to sleep, the user signs out, or the relevant process is terminated by the operating system.

24 Desktop MCP Connects, but Data Cannot Be Queried or Modified

Make sure there is data available in Packet Capture Pro on the desktop.

A tool call may also fail because:

• Required tool parameters are missing or invalid.
• The specified capture record, history record, or rule no longer exists.
• The operation is not allowed in the current application state.
• The file path is outside the permitted access scope.
• The operation times out or exceeds a concurrency limit.
• The AI client did not approve the tool call.

25 Can Multiple AI Clients Connect at the Same Time?

Multiple clients can connect at the same time. If several clients modify or delete data, clear records, update rewrite rules, or run replays concurrently, their operations may conflict or the target state may change.

For write operations, use one trusted client at a time. Other clients can remain connected for queries and analysis.

Mobile Troubleshooting

26 The AI Client Cannot Connect to Mobile MCP

Check the following:

1. MCP Service is enabled on the mobile device.
2. The phone and the computer are connected to the same local network.
3. The AI client supports MCP servers over HTTP.
4. The configured MCP service address matches the address currently shown on the mobile device.
5. The access token is complete and is prefixed with Bearer .
6. The configured port is within 1024–65535 and is not already in use.
7. The router has not enabled AP isolation, guest-network isolation, or client isolation.
8. The mobile app is still running.

27 The Previous Mobile Service Address No Longer Works

The service address may change when the phone switches networks, reconnects to Wi-Fi, or receives a new IP address. Open the MCP page on the mobile device, copy the current service address, and update the AI client configuration.

28 Mobile MCP Connects, but Capture Data Cannot Be Queried

Check whether Collaboration Mode is enabled. While Collaboration Mode is active, capture data is stored on the computer and cannot currently be queried or modified through Mobile MCP.

29 The Connection Drops When the App Is Closed or Sent to the Background

Mobile MCP is unavailable while Packet Capture Pro is not running. Reopen Packet Capture Pro, then verify the MCP service status and service address.