Prefex runs entirely on your machine. Your prompts go directly from Prefex to the upstream API (Anthropic or OpenAI) — nobody else sees them.
Every request writes one row to a local SQLite database at
~/.prefex/data/prefex.db. The row contains:
| Field | Logged | Example |
|---|---|---|
| Timestamp | Yes | 2026-03-27T14:23:01Z |
| Channel | Yes | claude_code |
| Mode | Yes | live |
| Model used | Yes | claude-haiku-4-5-20251001 |
| Input tokens | Yes | 1024 |
| Output tokens | Yes | 312 |
| Cost (USD) | Yes | 0.0003 |
| Router decision | Yes | weak |
| Cache hit | Yes | true |
| Latency (ms) | Yes | 72 |
| Prompt text | Opt-in | Off by default. Stored locally if store_system_prompt_text: true. |
| Response text | Never | — |
| System prompt text | Opt-in | Off by default. Local only, for cache analysis. |
| API keys | Never | — |
Prefex has no telemetry, no analytics endpoint, no phone-home. The SQLite database is local. The dashboard reads from that database.
The only outbound connections Prefex makes are the ones your application
already makes — to api.anthropic.com or api.openai.com.
One opt-in exception: the leaderboard. If you choose to submit to the public savings leaderboard, Prefex sends aggregate numbers only — your chosen username, total dollars saved, and days running. No prompts, no request content, no identifiers. The submission is a deliberate action you take in the dashboard; nothing is sent automatically.
Run this while Prefex is active (without a leaderboard submission):
# Capture all TCP traffic from the Prefex process sudo tcpdump -i any -n "port 8019 or host api.anthropic.com" 2>/dev/null # You should see connections to api.anthropic.com only. # Leaderboard submissions additionally reach prefex.vercel.app — opt-in only.
Prefex is a single ~20MB standalone binary with zero external dependencies.
# Check the binary ls -lh $(which prefex) # Output: ~20MB binary
Prefex includes a 30-day free license, renewable at prefex.dev/renew. No credit card. No call-home. We don't run servers — renewal is a manual step you do in your browser.
Prefex ships as a pre-compiled Go binary. The proxy is proprietary. The embedded rules-based router runs entirely in-process — no external ML services needed.
Open an issue or discussion at github.com/PromptForcePrime/prefex for anything privacy, data, or security related.