Privacy Architecture
Zero-knowledge proxy design, GDPR, and data minimization
Privacy Architecture
VoidLLM is a zero-knowledge proxy. It never stores, logs, or persists any prompt or response content. This is not a configurable option - it is an architecture decision.
What VoidLLM stores
| Data | Stored | Purpose |
|---|---|---|
| API key hash | Yes | Authentication (HMAC-SHA256, not reversible) |
| Upstream API keys | Yes | Encrypted at rest (AES-256-GCM) |
| User accounts | Yes | Email, display name, password hash |
| Usage events | Yes | Who, when, which model, token counts, cost, duration |
| MCP tool call logs | Yes | Server, tool name, duration, status |
| Audit logs | Yes (Enterprise) | Admin action metadata |
What VoidLLM never stores
| Data | Stored | Why |
|---|---|---|
| Prompt content | Never | Not even temporarily - streams through memory |
| Response content | Never | Same - passes through and is forgotten |
| System prompts | Never | Not inspected |
| Function call content | Never | Proxied as opaque bytes |
| Images / files | Never | Proxied without inspection |
How it works
The proxy reads exactly one field from the request body: model. This is used for routing. Everything else passes through as an opaque byte stream:
- Request arrives with
Authorization: Bearer vl_uk_... - VoidLLM validates the key (HMAC-SHA256 hash lookup in memory)
- Reads the
modelfield for routing - Rewrites the model name if using aliases
- Forwards the request body to the upstream provider
- Streams the response back to the client
- Extracts token counts from the response header/body (metadata only)
- Emits a usage event asynchronously (fire-and-forget, never blocks the response)
Content passes through process memory during streaming but is never written to disk, database, or log files.
GDPR
The zero-knowledge architecture significantly reduces the GDPR compliance surface area:
- No personal data from prompts is processed or stored by VoidLLM
- Usage metadata (API key ID, org, team, model, tokens) may qualify as personal data if linkable to an individual
- VoidLLM acts as a data processor for usage metadata; you (the deployer) are the data controller
- Data processing agreements with upstream LLM providers (for prompt/response content) are between you and the provider - VoidLLM is not a party
Data Minimization
VoidLLM implements data minimization (GDPR Article 5(1)(c)) and Privacy by Design (Article 25) by architecture:
- Only the minimum data needed for routing and usage tracking is collected
- Content data is never collected because there is no code path to collect it
- Usage events are the smallest possible record: a few integers and strings per request
Comparison
| VoidLLM | Typical proxy | |
|---|---|---|
| Prompt logging | Never (no code path) | Usually default, opt-out |
| GDPR scope at proxy | Metadata only | Metadata + content |
| DPA complexity | Minimal | Significant |
| Data breach impact at proxy | Usage metadata | Potentially all prompts |
| Right to deletion scope | API key + usage records | All of the above + prompt content |