Claude Code sends every request through the BlindHush proxy on your computer. The proxy masks your messages, the files Claude Code reads, command output and tool results, then forwards the request to Anthropic with your own Anthropic key. Answers come back with the real values put in again.
Set up
The installer does this for you. To do it by hand, add the proxy to ~/.claude/settings.json:
{
"env": {
"ANTHROPIC_BASE_URL": "http://127.0.0.1:8788"
}
}
Or for one session only:
ANTHROPIC_BASE_URL=http://127.0.0.1:8788 claude
The Code tab in Claude Desktop reads the same settings file. The Claude Desktop chat window has no proxy setting; use the browser extension for chat.
Real values in answers and tools
Two switches on the local dashboard (http://127.0.0.1:8787/dashboard):
| Setting | On | Off |
|---|---|---|
| Show real values in answers | you read real names | you read [PERSON_1] |
| Give tools the real values | a tool such as send-email gets the real address | tools get placeholders; safer, some actions fail |
Anthropic never receives real values either way.
If BlindHush is not running
The proxy fails closed: if masking is not possible, nothing is sent to Anthropic and Claude Code shows an error. Start the client with blindhush serve, or check with blindhush status.