TokenPak Security Notes

Header Security

Server Version Disclosure (Fixed 2026-03-26)

Issue: Default BaseHTTPServer emitted Server: BaseHTTP/0.6 Python/3.12.3 in all responses, leaking runtime version.

Fix: ForwardProxyHandler.server_version = "TokenPak" and sys_version = "" — response header is now Server: TokenPak.

Verification:

HTTP/1.0 200 OK
Server: TokenPak

Upstream Authorization Headers

Status: ✅ Not forwarded to clients

The proxy strips the following headers from upstream responses before relaying to the client: - Authorization - X-Api-Key - Anthropic-Api-Key - Server - X-Powered-By

Outgoing requests to upstream also strip: host, proxy-authorization, proxy-connection, connection, keep-alive, transfer-encoding, accept-encoding.

Security Headers

X-Content-Type-Options: nosniff is added to all proxied responses.

Internal Path Exposure

The /health and /stats endpoints expose operational data (token counts, cost, circuit breaker state). These endpoints are localhost-only by design — the proxy binds to 127.0.0.1:8766 and is not externally accessible.

Auth Key Handling

API keys are passed to upstream providers in outbound requests. They are: - Never logged - Never echoed in responses - Read from your local environment (for example, a local .env file) and never written to configuration files committed to version control

Known Limitations

• No HTTPS on the proxy listener (localhost-only, low risk)
• /stats exposes cost and token data (localhost-only, acceptable)

Reporting a Vulnerability

If you discover a security issue in TokenPak, please report it privately by email to security@tokenpak.ai. Include a description of the issue, steps to reproduce, and the affected version.

Please do not open a public issue for security reports.

We aim to acknowledge reports within a few business days and to share a remediation timeline after triage. These are response targets, not guarantees — TokenPak is an open-source beta maintained on a best-effort basis.

Supported Versions

Security fixes are applied to the current OSS beta release line (the 1.7.x series, currently 1.7.1, installed via pip install tokenpak). Older pre-beta versions are not maintained.