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 promptforce.ai, 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.