#Breakpoint

#Overview

Breakpoint pauses HTTP requests or responses at specific phases, allowing you to inspect and optionally modify them before forwarding. Similar to a debugger breakpoint, it provides interactive control over traffic flow in real-time.

Unlike intercept rules that automatically modify traffic based on predefined rules, Breakpoint lets you inspect each request/response and decide on a case-by-case basis — ideal for interactive debugging.

flowchart TD
    A[HTTP Request] --> B{Breakpoint Rule Match?}
    B -->|No Match| C[Forward to Server]
    B -->|Request Phase| D[⏸ Pause Request]
    D --> E{User Decision}
    E -->|Forward| F[Forward Original]
    E -->|Modify| G[Forward Modified]
    E -->|Block| H[Return Block Response]
    F --> I[Server Response]
    G --> I
    I --> J{Response Breakpoint?}
    J -->|No| K[Forward to Client]
    J -->|Yes| L[⏸ Pause Response]
    L --> M{User Decision}
    M -->|Forward| K
    M -->|Modify| N[Forward Modified Response]

    style D fill:#fff3e0
    style L fill:#fff3e0

#Rule Configuration

#Breakpoint Rules

Use wildcard patterns to specify which requests to pause.

Setting both request and response breakpoints will pause twice for a single request.

#Timeout

Paused requests are automatically forwarded after 60 seconds by default, preventing applications from hanging indefinitely if a breakpoint is left unresolved.

#Actions

#Forward

Pass the request/response through without modification.

#Modify

Edit the request or response before forwarding.

Request modifications:

• URL
• HTTP method
• Headers
• Body

Response modifications:

• Status code
• Headers
• Body

#Block

Immediately return a block response without forwarding to the server. Available only for request-phase breakpoints.

#Use Cases

#API Debugging

Modify request parameters in real-time to test various scenarios — change authentication tokens, edit request body fields, and observe server behavior.

#Error Simulation

Change server response status codes to 500 or inject error messages to verify client-side error handling logic.

#Timing Control

Pause specific requests to test async processing, loading states, and timeout handling in time-sensitive logic.

#Usage

#Desktop

1. Select Breakpoint from the sidebar
2. Add rules with patterns and break phases
3. When a rule matches, you'll be notified and the request/response pauses
4. Inspect the content and choose Forward, Modify, or Block

#TUI

1. Navigate to the Breakpoint tab
2. Add/edit rules
3. Review and resolve paused requests

#MCP

"Add a breakpoint rule for api.example.com"
"Show me the list of pending breakpoints"