VoxNode-ux/nullwire-mcp

### Your AI agent can debug live HTTP traffic. It never sees a single secret.
Every token, cookie and IP is swapped for a stable, salted tag, so the agent can still tell
"same token reused" from "token rotated": the question behind most auth bugs.
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Quick start ·
How it works ·
Install ·
Tools ·
Security ·
[Limitations]#-honest-scope-&-known-limitations) ·
FAQ
## 👀 See the difference
text
You send Authorization: Bearer sk-live-51Hk3...
Your AI sees Authorization: Bearer [REDACTEDTOKEN#a1b2c3]
Request #1 Bearer [REDACTEDTOKEN#a1b2c3]
Request #2 Bearer [REDACTEDTOKEN#a1b2c3] ◄── same token, reused ✔
Request #3 Bearer [REDACTEDTOKEN#7f09de] ◄── different token, it rotated ✔
Blind [REDACTED] protects you but makes the AI useless for auth bugs. NullWire keeps the identity of each secret and throws away the value.
| 📦 0 dependencies | 💾 0 bytes written to disk | 🔍 1 source file to audit | 🖥️ 9 release targets |
| pure Go stdlib | RAM-only 50-flow ring | main.go | Linux · macOS · Windows · FreeBSD |
## ⚡ Quick start in 60 seconds
bash
# 1. install (Go 1.23+), or grab a prebuilt binary from Releases
go install github.com/VoxNode-ux/nullwire-mcp@latest
# 2. register it with your AI client (Claude Code shown; Cursor/Windsurf/Desktop configs below)
claude mcp add nullwire -- nullwire-mcp -port 8080 -target https://api.example.com
# 3. point your app at the proxy instead of the real API
curl http://127.0.0.1:8080/v1/orders -H "Authorization: Bearer $MYTOKEN"
Then just ask your agent:
> "Why is /v1/orders returning 401? Compare the auth headers of the last 5 requests."
> "Did request 3 and 4 use the same token, or did it rotate?"
> "Give me a curl to replay the failing call."
Your app always gets the real, untouched response. Only the agent's view is scrubbed.
## 🔥 Why this exists
Point an AI agent at your network traffic and a typical capture proxy hands it everything: live bearer tokens, session cookies, internal IPs. All of it lands in a cloud LLM context window, and often in a capture file left on disk.
Blind [REDACTED] stops the leak but kills the debugging. NullWire-MCP redacts every secret in RAM and swaps it for a deterministic, per-process salted tag: the agent keeps the identity of each secret and never sees the value.
> The tag is SHA-256(nonce ‖ secret)[:6]. The nonce is 32 random bytes drawn from crypto/rand at startup, kept only in RAM, and gone when the process exits. See the security deep-dive for why that matters.
## 🧭 How it works
mermaid
flowchart LR
APP["Your app / curl / SDK"] -->|"plain HTTP to 127.0.0.1"| PROXY["NullWire proxy loopback only"]
PROXY -->|"original request, untouched"| UP["Upstream API http or https"]
UP -->|"original response"| PROXY
PROXY -->|"original response, untouched"| APP
PROXY -.->|"async copy"| DLP["DLP scrubber regex, then SHA-256 tag"]
DLP --> RING[("RAM ring 50 flows")]
RING -->|"MCP over stdio scrubbed data only"| AGENT["AI agent Claude · Cursor · Windsurf"]
Two paths, one rule: the real bytes go to your app, only a scrubbed copy goes to the AI. Nothing touches the disk.
Diagram not rendering (mobile, Mermaid disabled)? Open the ASCII version
text
╔══ [1] LOCAL APP / CLI ══════════════════════════════════════╗