Can databases and raw TCP connections work?

can databases / raw TCP connections work with this?

Now I have a comprehensive understanding. Here's the answer:

No — Agent Vault does not support databases or raw TCP connections. It is exclusively an HTTP/HTTPS credential proxy.

Here's why, grounded in the source code:

###1. The proxy only speaks HTTP

The core proxy (internal/mitm/proxy.go) is explicitly scoped to HTTP:

// Package mitm implements a transparent TLS-intercepting HTTP proxy.
// ...
// v1 scope: HTTP/1.1 only (ALPN pinned).

The dispatch method only accepts CONNECT (the standard HTTP method for establishing a tunnel through a proxy) and rejects everything else:

func (p *Proxy) dispatch(w http.ResponseWriter, r *http.Request) {
    if r.Method == http.MethodConnect {
        p.handleConnect(w, r)
        return
    }
    http.Error(w, fmt.Sprintf("method %s not supported on transparent proxy", r.Method),
        http.StatusMethodNotAllowed)
}

###2. CONNECT tunnels are terminated as HTTP, not passed through as raw TCP

In internal/mitm/connect.go, after the CONNECT handshake, the proxy terminates TLS and serves HTTP/1.1 on the inner connection — it does not relay raw bytes:

tlsConf := &tls.Config{
    MinVersion: tls.VersionTLS12,
    NextProtos: []string{"http/1.1"},  // ALPN pinned to HTTP/1.1
    ...
}
tlsConn := tls.Server(clientConn, tlsConf)
// ...
srv := &http.Server{
    Handler: p.forwardHandler(target, host, scope),
    ...
}
_ = srv.Serve(listener)

The tunnel is an http.Server that parses each inner request, injects credentials at the HTTP header level, and forwards via http.Transport.RoundTrip. There is no raw byte relay.

###3. Credential injection is HTTP-header based

The broker config (internal/broker/broker.go) supports these auth types:

// "bearer", "basic", "api-key", "custom", "passthrough"

All of these inject into HTTP headers (e.g., Authorization: Bearer ..., Authorization: Basic ..., custom header templates). There's no mechanism to inject credentials into a TCP stream, connection string, or wire protocol.

###4. Host matching, not port/protocol matching

Services are matched by HTTP host (Host header / SNI), not by port or protocol. The forwarding in internal/mitm/forward.go constructs an https:// URL and makes a standard HTTP round-trip.

###What this means for databases

Protocols like PostgreSQL, MySQL, MongoDB, Redis, etc. use their own binary wire protocols over TCP — not HTTP. Agent Vault cannot:

• Intercept and inject credentials into a Postgres StartupMessage or MySQL handshake
• Relay raw TCP connections with credential injection
• Act as a SOCKS proxy or generic TCP tunnel

###Workaround

If your agent needs database access, the skill markdown files (cmd/skill_http.md, cmd/skill_cli.md) do mention storing DB_HOST and DB_PASSWORD as credential keys, but these would only be useful if you have an HTTP-based API layer in front of your database (e.g., a REST API, Hasura, PostgREST, Supabase, etc.) that the agent calls over HTTPS. The proxy could then inject the API token for that HTTP gateway.