Vakthund is an HTTP inspection proxy. Drop it in front of any service, send traffic through it, and see exactly what is going on in a live Blazor UI.

It captures headers, bodies, tokens, timing, and auth failures without touching the target application. Useful for local development, but also runs well on servers and staging environments where you want a persistent inspection layer that survives restarts.

What It Does

• Proxies HTTP traffic with YARP.
• Captures live request and response details.
• Streams captured requests from the proxy to the UI over SignalR.
• Decodes bearer JWTs and basic auth headers in the request detail view.
• Explains common auth failures with route-level issuer, audience, scope, role, and signature checks.
• Can reject unauthenticated or unauthorized requests at the proxy before forwarding them.
• Can decrypt JWE tokens when a key is configured.
• Shows dashboard metrics, request history, route configuration, and per-request details.

By default, captured traffic is kept in memory for the current run. Switch to disk storage to persist requests across restarts, set a retention window, and keep the dashboard graphs loaded between sessions.

Documentation

• Getting Started
• How Vakthund Works
• Configuration
• Using the UI
• Development

Quick Start

The recommended setup is Docker Compose with two services:

• proxy, which accepts client traffic and forwards it to your target service.
• ui, which connects to the proxy management hub and displays captured requests.

For a single upstream service, set TARGET on the proxy:

services:
  proxy:
    image: ghcr.io/albinalm/vakthund-proxy:latest
    ports:
      - "8080:8080"
      - "8081:8081"
    environment:
      TARGET: "http://host.docker.internal:5000"

  ui:
    image: ghcr.io/albinalm/vakthund-ui:latest
    ports:
      - "8082:8080"
    environment:
      HUB: "http://proxy:8081/connect/audit"
    depends_on:
      - proxy

Then send client traffic to http://localhost:8080 and open the UI at http://localhost:8082.

You can also open http://localhost:8081 in a browser to confirm the proxy management port is running.

For multiple upstreams or path-based routing, mount a routes file instead. See Getting Started for the full Compose example and the routes.yaml format.

Projects

• Vakthund.Proxy: reverse proxy, request capture middleware, management endpoints, and SignalR audit hub.
• Vakthund.UI: Blazor Server frontend for dashboard, request list, request details, and configuration.
• Vakthund.Shared: shared models used by both services.
• Vakthund.Tests: unit tests plus the Docker/k6 smoke and load-test suite.

License

Vakthund is completely FOSS and licensed under the terms in LICENSE.