generated: '2026-08-29'
method: searched
source: https://www.telerik.com/fiddler/fiddler-everywhere/documentation/agent-tools/fiddler-mcp-server
provider: Fiddler
providerId: fiddler
name: Fiddler Everywhere MCP Server
description: >-
  Fiddler Everywhere ships a first-party Model Context Protocol server that lets
  a coding agent drive the locally installed proxy: start browser/terminal/
  network captures, read captured sessions and full request/response details,
  apply filters, create traffic-rewriting rules, manage a reverse proxy, and
  cache LLM agent calls. The server is hosted BY the desktop application on the
  loopback interface — it is not a hosted, internet-reachable endpoint.
docs:
  - https://www.telerik.com/fiddler/fiddler-everywhere/documentation/agent-tools/fiddler-mcp-server
  - https://www.telerik.com/fiddler/fiddler-everywhere/documentation/agent-tools/agent-skills
  - https://www.telerik.com/fiddler/fiddler-everywhere/documentation/agent-tools/prompt-library
  - https://www.telerik.com/fiddler/fiddler-everywhere/mcp
status: published
deployment:
  mode: local-stdio
  endpoint: ''
  install: >-
    Install Fiddler Everywhere (Pro or higher), then enable Settings > MCP Server
    and generate an API key. Automated client configuration is offered from
    inside the app; manual clients point at http://localhost:8868/mcp.
  package: https://www.telerik.com/download/fiddler-everywhere
  auth: api-key
  verified: searched
  note: >-
    RECORDED AS local-stdio BECAUSE IT IS NOT AGENT-REACHABLE WITHOUT A HUMAN.
    The transport is streamable HTTP rather than stdio — the documented server
    URL is http://localhost:8868/mcp — but that is a LOOPBACK address served by
    the Fiddler Everywhere desktop app on the developer's own machine. There is
    no hosted endpoint an agent can POST to; a person must install the app, sign
    in, hold a Pro-or-higher subscription and generate an API key first. Port and
    server handle (#fiddler) are configurable in Settings > MCP Server.
transport: streamable-http (loopback)
default_url: http://localhost:8868/mcp
default_handle: '#fiddler'
authentication:
  type: api-key
  header: Authorization
  scheme: ApiKey
  example: 'Authorization: ApiKey <key generated in Settings > MCP Server>'
  requires_subscription: Fiddler Everywhere Pro or higher
prerequisites:
  - Latest version of Fiddler Everywhere installed and running
  - Fiddler Everywhere Pro or higher subscription
  - Active internet connection
  - API key generated in Settings > MCP Server
  - Administrator privileges for the network-capture extension (capture_application)
clients_documented:
  - name: GitHub Copilot in Visual Studio Code
    config_file: .vscode/mcp.json
  - name: Cursor
    config_file: .cursor/mcp.json
  - name: Claude Code
    config_file: .mcp.json
    cli: 'claude mcp add --transport http fiddler http://localhost:8868/mcp -H "Authorization: ApiKey KEY_HERE"' 
  - name: Claude Desktop
    config_file: claude_desktop_config.json
    note: Bridged with npx mcp-remote per the fiddler-mcp-setup skill.
  - name: GitHub Copilot CLI
    config_file: ~/.copilot/mcp-config.json
tools:
  - name: get_status
    category: authentication-and-status
    description: >-
      Gets the current status of Fiddler, including IsUserLoggedIn,
      IsRootCertificateTrusted, number of Browser and Terminal instances running,
      reverse proxy status and configured ports, IsSystemProxyEnabled,
      IsNetworkCaptureEnabled, and the number of captured and visible sessions.
  - name: is_user_logged_in
    category: authentication-and-status
    description: Indicates whether Fiddler is currently authenticated.
  - name: initiate_login
    category: authentication-and-status
    description: Performs login to Fiddler. Opens a new Chrome window for authentication.
  - name: open_trust_root_certificate_dialog
    category: authentication-and-status
    description: Opens the system trust root certificate dialog. Required for HTTPS traffic interception.
  - name: start_capture_with_browser
    category: traffic-capture
    description: Opens a fresh Chrome-based browser instance with Fiddler proxy settings applied.
  - name: start_capture_with_terminal
    category: traffic-capture
    description: Starts a new terminal with Fiddler proxy settings applied.
  - name: capture_application
    category: traffic-capture
    description: >-
      Starts network-level traffic capture scoped to a specific application.
      Accepts an optional process name or PID; auto-detects the target from the
      active IDE or CLI context when omitted.
    parameters:
      - name: process name or PID
        required: false
  - name: get_sessions
    category: session-management
    description: >-
      Gets the sessions from the specified Fiddler sessions source with active
      filters applied. LiveTraffic for captured HTTP/HTTPS traffic, AgentCalls
      for LLM agent API calls.
    parameters:
      - name: sessionsSource
        required: true
  - name: get_sessions_count
    category: session-management
    description: Gets the number of sessions in the specified Fiddler sessions source.
    parameters:
      - name: sessionsSource
        required: true
  - name: get_session_details
    category: session-management
    description: >-
      Gets detailed information about a specific session, including request and
      response headers, bodies, HTTP method, URL, status code, protocol, start
      time, duration, client and remote HTTP versions, TLS versions and IPs.
    parameters:
      - name: sessionId
        required: true
        type: integer
      - name: sessionsSource
        required: true
  - name: apply_filters
    category: session-management
    description: >-
      Applies filters to the specified sessions source. Applying filters wipes
      all existing filters; call with an empty filter collection to clear.
    parameters:
      - name: filters
        required: true
        type: object
      - name: sessionsSource
        required: true
  - name: clear_sessions
    category: session-management
    description: Clears all sessions in the specified Fiddler sessions source.
    parameters:
      - name: sessionsSource
        required: true
  - name: cache_agent_calls
    category: agent-cache
    description: >-
      Enables or disables caching for a specific session in the Agent Calls
      section.
    parameters:
      - name: sessionId
        required: true
        type: integer
      - name: enableCache
        required: true
        type: boolean
  - name: check_cache_status
    category: agent-cache
    description: Checks whether a specific session in the Agent Calls section is currently cached.
    parameters:
      - name: sessionId
        required: true
        type: integer
  - name: create_rule
    category: rules
    description: >-
      Creates a rule to modify sessions in Fiddler, applied to all sessions
      matching the specified criteria. At least one condition must be specified.
  - name: clear_rules
    category: rules
    description: Clears all rules created from the MCP server.
  - name: add_reverse_proxy_port
    category: reverse-proxy
    description: >-
      Adds a reverse proxy configuration forwarding requests from a local port to
      a remote host and intercepting the traffic in between.
    parameters:
      - name: clientPort
        required: true
        type: integer
      - name: remoteHost
        required: true
        type: string
  - name: remove_reverse_proxy_port
    category: reverse-proxy
    description: Removes a reverse proxy configuration for a specific port.
    parameters:
      - name: clientPort
        required: true
        type: integer
  - name: enable_reverse_proxy
    category: reverse-proxy
    description: Enables the reverse proxy.
  - name: disable_reverse_proxy
    category: reverse-proxy
    description: Disables the reverse proxy.
tool_count: 20
governance:
  output_sanitization: >-
    Fiddler Everywhere can sanitize captured traffic before it is handed to the
    MCP client, removing sensitive values from what the model sees.
  access_policy:
    - platform: Windows
      key: DisableMCP
      type: DWORD-32
      example: '1'
    - platform: macOS
      key: DisableMCP
      type: integer
      example: '1'
  note: >-
    Administrators can disable the MCP server entirely through managed
    application configuration on both Windows and macOS.
introspection:
  attempted: false
  reason: >-
    tools/list could not be probed. The server binds to loopback on the end
    user's machine and requires an installed, licensed, signed-in Fiddler
    Everywhere plus a generated API key. The tool list above is transcribed from
    the provider's own published reference, not from a live handshake.
skills: skills/_index.yml