Features overview

A one-page tour of every capability. Grouped by layer; each section links to deeper docs when relevant.

Traffic layer

• HTTP/HTTPS forward proxy on a random loopback port, bound to 127.0.0.1 only
• SOCKS5 listener (RFC 1928) on a separate port for apps that prefer SOCKS
• CONNECT tunnels for TLS, with optional MITM interception per-host
• Chunked Transfer-Encoding, keep-alive, pipelining
• IPv6 end-to-end (address literals, CIDR in allowlist, NWConnection IPv6)

Filtering layer

• Block Domain rules with O(1) Set lookup — ~90 K built-in entries
• Block IP rules with CIDR range matching
• Block Content rules using Aho-Corasick multi-pattern search (URL + headers + body)
• Mock action — stealth 200 OK so trackers don't retry
• Shadow mode — log-only evaluation, useful for rule authoring without breaking traffic
• Allowlist with domain + CIDR entries, evaluated first

Blacklist feeds

19 built-in feeds, 8 categories, refreshable in background:

Source	Category
Steven Black Hosts (Ads/Tracking)	Ads
NoCoin Filter	Crypto mining
URLhaus Malware Domains	Malware
Malware Domain List	Malware
Coinblocker	Crypto
Phishing Army	Phishing
OISD	Mixed (trackers, malware, phishing)
TOR Exit Nodes	Network

Privacy layer

Per-host policy. Every option is a checkbox.

• Strip User-Agent (rewrite to a configurable stock value)
• Strip Referer (fully, origin-only, or keep)
• Inject DNT: 1 and Sec-GPC: 1
• Filter tracking cookies by prefix (_ga, _fbp, utma, fbm_, …)
• Rewrite ETag (cache-busting tracker)
• Strip Accept-Language minor variants that enable fingerprinting

TLS interception (MITM)

• Per-installation root CA, generated on first enable
• AES-256 encrypted at rest; passphrase in Keychain
• Leaf certs forged on demand per hostname, with SAN
• Bundled mitmproxy sidecar (88 MB, Python 3.14, OpenSSL 3.5) handles the TLS dance
• Auto-exclude for pinned apps, *.apple.com, banking, *.signal.org, etc.
• Curated streaming-media exclude list (RAI, Mediaset, La7, Netflix, Spotify, Twitch, YouTube media CDN, Disney+, DAZN, Brightcove, Akamai media subdomains)
• Runtime auto-exclude after 3 consecutive pinning failures per host
• Browser compatibility hardening (0.9.54 – 0.9.56): Alt-Svc stripped to keep browsers on HTTP/2 inside the tunnel, HTTP/2 disabled on the downstream leg to prevent connection coalescing across hosts, one-click Export Root CA for Firefox import
• Export button in Preferences → TLS Interception writes ~/Downloads/proxymate-ca.pem and reveals it in Finder — ready to drag-drop into Firefox's Certificate Authorities

See security model for the full CA lifecycle and MITM & browser trust for the Firefox / HSTS / HTTP/3 / coalescing writeup.

AI / agent controls

• Detects Claude Code, Cursor, Codex, Continue.dev, Aider, MCP clients
• Tracks OpenAI, Anthropic, Google, Mistral, Groq, Together, Deepseek, …
• Per-token + per-request cost estimation (configurable per-provider pricing)
• Agent loop breaker — identical-request rapid-fire threshold
• Budget caps with block action when exceeded
• Model allowlist/blocklist per provider

Observability

• Persistent logger (JSONL + OSLog), rotates at 2 MB, keeps 5 files
• Prometheus metrics server on a configurable local port
• Webhook events for allow / block / AI detection / C2 hit
• macOS notifications for high-severity events
• Stats tab with real-time counters, per-host memory, latency histograms

Threat detection

• Beaconing detector — periodic callback patterns (interval + jitter)
• C2 framework fingerprints — Cobalt Strike, Sliver, Mythic, Havoc, Empire
• Exfiltration scanner — 7 pattern packs, 28 patterns (AWS keys, JWT, card numbers, PII)
• HSTS preload enforcement — 65 high-value domains

Caching

• L1 RAM cache with TTL
• L2 SQLite disk cache, configurable size
• Respects Cache-Control, Vary, ETag, Last-Modified

Routing

Multi-upstream pools with 6 load-balancing strategies:

• Round-robin
• Least connections
• Weighted random
• Weighted round-robin
• Latency-based (health-probe driven)
• Sticky (session affinity by cookie or src-ip)

Per-pool health checks with circuit breaker — unhealthy members drop out, return after recovery.

Everything else

• PAC server (dynamic proxy.pac with smart bypass for LAN + VPN endpoints)
• DNS-over-HTTPS (RFC 8484 JSON API, configurable resolver)
• HSTS preload list (65 domains)
• iCloud sync of rule sets and allowlist (NSUbiquitousKeyValueStore)
• Process resolver — maps active port → app name in logs
• Request fingerprinting (SHA256 of header order) — detect suspicious clients
• Rule importer — hosts files, ABP, plain text