Privacy Policy

PCBWay Studio MCP ("the service") is operated by Manuel Pérez
(@mperez90). This document explains what personal data the service
collects, how it is used, where it is stored, and how to exercise your
rights under the GDPR and similar regimes.

If you have any question about this policy, write to <[email protected]>.

_Last updated: 2026-04-10_

1. What data the service handles

The service is a Model Context Protocol (MCP) server for AI-assisted PCB
design. It is invoked by an upstream LLM client (Claude, ChatGPT, an IDE
plugin, etc.) on behalf of an end user. We collect the minimum data
necessary to provide the requested functionality.

1.1 Data you actively send

Category	Examples	Why we receive it
Design files you upload	`.kicad_sch`, `.kicad_pcb`, `.zip`, BOM CSVs	Required to render previews, run validators, generate quotes, place orders.
Natural-language prompts	"Design a 5 V LED blinker with an STM32"	Forwarded to the upstream LLM client; the server only sees the parameters the client extracts.
API keys you supply	PCBWay, Mouser, DigiKey	Stored encrypted at rest in our database, never logged in plaintext. Used to make calls on your behalf.
Email address (optional)	If you sign up for order notifications	Sent only to Resend, our transactional email provider, when you ask for a notification.

1.2 Data automatically logged

Category	Retained	How
HTTP request metadata (path, method, status, latency)	30 days	Local journald + offsite Hetzner Storage Box copy
MCP session record (session id, tool count, timestamps)	Indefinite (session) / 30 days (PII)	SQLite via `better-sqlite3`
Client name + version (`clientInfo`)	Indefinite	SQLite
User agent	30 days	SQLite — older entries are pruned automatically
IP address	Hashed after 30 days (sha256, irreversible)	SQLite, see storage/access-log.ts
API key hash	Indefinite	sha256 fingerprint only — the raw key is never persisted in the access log

We honor the DNT: 1 browser header and the x-mcp-dnt: 1 MCP header.
When DNT is set the IP address is hashed immediately instead of stored
raw, and the session is marked as do-not-track. Operators may also set
MCP_DEFAULT_DNT=1 to make this the default for all sessions.

1.3 Data we do not collect

We do not run third-party analytics, advertising trackers, or fingerprinting.
We do not sell or rent any data to third parties.
We do not log the contents of design files beyond what is required to

generate the requested output (e.g. component count for a summary).

We do not store the raw bytes of your prompts.

2. Where your data is processed

Component	Provider	Region	Subprocessor data
Compute, database, file storage	Hetzner Cloud	Germany (Falkenstein / Nürnberg)	DPA
Reverse proxy / TLS	Self-hosted Caddy on the same Hetzner box	Germany	n/a
DNS / DDoS edge (optional)	Cloudflare	Global anycast	DPA
Transactional email (only when you opt in)	Resend	US (with EU option)	DPA
Component data lookups	Mouser API, DigiKey API, JLCPCB search	US / global	Only the part numbers you query
Quote and order forwarding	PCBWay API	China	The design files and BOM you submit for the quote
Optional GitHub App reviews	GitHub	US	Repository metadata, commit SHA, file diff
Optional crash tracking	Sentry (free tier)	EU	Stack traces, error types — no PII

When you call place_order, get_quote, or any other tool that contacts
a third party, the relevant payload (your design files, BOM, contact
details) is transmitted to that third party. Their privacy policies
govern what they do with it.

3. Legal basis for processing (GDPR Art. 6)

Activity	Legal basis
Running the design tools you invoke	Art. 6(1)(b) — performance of the contract you initiated
Storing your account and PCBWay key	Art. 6(1)(b) — performance of the contract
Access logging for security and abuse prevention	Art. 6(1)(f) — legitimate interest in maintaining the service
Transactional email (opt-in only)	Art. 6(1)(a) — your consent
Sending commission attribution to PCBWay (operator-side)	Art. 6(1)(f) — legitimate interest, no personal data shared

4. Retention

Account, PCBWay key, project store: kept for as long as your account

is active. When you delete your account (see §6), all rows are removed within 30 days.

Access log: 30 days for raw IP addresses, indefinite for hashed

identifiers and aggregate counters.

Render artifacts (/renders/<id>/...): 7 days, then automatically

deleted by cleanup_old_renders.

PDF reports (/reports/<id>.pdf): 30 days.
Order history records: 7 years (required for tax and warranty

reasons).

GitHub webhook delivery cache: 1 hour (deduplication only).

You can shorten any of these by self-hosting and adjusting the relevant
environment variables. Operators self-hosting the code can tune retention
via the env vars described in the repository README.

5. Security measures

The full security posture is documented in the v0.17.1 CHANGELOG.md
and summarized below:

Transport: HTTPS only, terminated by Caddy with Let's Encrypt

certificates. The MCP server itself binds on 127.0.0.1 and is not reachable from the internet directly.

Authentication: OAuth 2.1 with PKCE for marketplace clients;

per-user PCBWay API key kept encrypted at rest.

Authorization: admin tools gated by a constant-time-compared admin

key (MCP_ADMIN_KEY), with non-admin callers receiving a generic "tool not found" response so the existence of admin endpoints is not leaked.

Input validation: Zod schemas on every tool, file extension and

magic-byte allowlist on uploads, path containment + symlink rejection on every filesystem read.

Rate limiting: bounded LRU rate limiter applied globally.
SSRF protection: every outbound HTTP fetch from a user-supplied URL

runs through ssrfGuard(), which DNS-resolves the host and refuses any IP in private, link-local, or loopback ranges.

Secrets at rest: SQLite database files are owned by the pcbmcp

systemd user and not world-readable. API keys are stored encrypted with a key kept in MCP_DATA_ENCRYPTION_KEY (32-byte random).

Subprocess isolation: ngspice runs inside systemd-run --scope

with MemoryMax, CPUQuota, PrivateNetwork=yes, and NoNewPrivileges=yes.

Logs: every log line passes through redactSecrets() to strip

known secret prefixes (Resend re_, GitHub PAT ghp_, OpenAI sk-, AWS AKIA, Slack xox*, BEGIN PRIVATE KEY blocks).

We follow the principle of least privilege and patch dependencies on a
weekly Dependabot schedule.

6. Your rights

Under the GDPR you have the right to:

Access — request a copy of the personal data we hold about you.
Rectification — correct inaccurate data.
Erasure ("right to be forgotten") — delete your account and all

associated rows. The MCP exposes forget_order and forget_observed_components for self-service deletion of those specific stores. For full account deletion, use the Delete account button on the /account page or email the support address.

Data portability — receive a machine-readable export of your data.

The MCP exposes list_my_orders and list_observed_components which return JSON dumps you can copy.

Objection — object to processing based on legitimate interest.
Withdraw consent — for opt-in email notifications, use

unsubscribe or the unsubscribe link in any email.

Lodge a complaint with your local supervisory authority. The lead

authority for Hetzner-hosted services in Germany is the Bundesbeauftragte für den Datenschutz und die Informationsfreiheit (BfDI).

To exercise any of these rights, email <[email protected]> with
a brief description and the email or hashed identifier you used. We
respond within 30 days.

7. Children

The service is not directed at children under 16 and we do not knowingly
collect data from them. If you believe we have collected data from a
child, please contact us so we can delete it.

8. Changes to this policy

When we update this policy we bump the date at the top and record the
change in CHANGELOG.md. Material changes (new subprocessors, new data
categories, expanded retention) are announced via the release notes for
the version that introduces them.

9. Contact

Operator: Manuel Pérez (@mperez90)
Email: <[email protected]>
Repository: <https://github.com/mperez90/pcb-mcp-server>
Address: _to be filled in once the operator entity is finalised_