Pseudonymizes PII before your LLM and returns a cryptographically signed receipt per response.
Official client libraries for Lucairn — an EU-based privacy-preserving AI gateway. Lucairn sits between your application (or AI agent) and the upstream LLM provider you choose, removes personal data from prompts before the model ever sees them, and returns a signed Lucairn Certificate proving what was redacted, when, and by which sanitizer layer.
This monorepo hosts four packages at parity:
@lucairn/mcp-server — Model Context Protocol server (one-line npx install for Claude Desktop, Cursor, Cline, Continue, …)@lucairn/sdk — TypeScript / Node SDKlucairn — Python SDKgithub.com/declade/lucairn-sdks/go — Go SDKFor most agent use cases, the fastest path is the MCP server. No build step, no install — npx runs it on demand:
npx -y @lucairn/mcp-server
Add it to your MCP client config (Claude Desktop's claude_desktop_config.json, Cursor's mcp.json, Cline's cline_mcp_settings.json, Continue, etc.):
{
"mcpServers": {
"lucairn": {
"command": "npx",
"args": ["-y", "@lucairn/mcp-server"],
"env": {
"LUCAIRN_API_KEY": "<your_lucairn_api_key>",
"ANTHROPIC_API_KEY": "<optional_byok_anthropic_key>",
"OPENAI_API_KEY": "<optional_byok_openai_key>"
}
}
}
}
Restart your client. The chat_via_lucairn tool becomes available immediately. See mcp-server/README.md for full details.
Each request through any Lucairn SDK follows the same pipeline:
[PERSON_1], [EMAIL_2], [IBAN_3], …) before the request reaches the upstream LLM.For Lucairn-hosted Developer-tier callers, on-gateway pseudonymization happens before your LLM sees the request. Enterprise self-host deployments can run the entire stack inside the customer environment, in which case no raw identity data leaves that environment at all.
The gateway picks the upstream provider from the model parameter you send:
| Model prefix | Upstream provider | BYOK env var |
|---|---|---|
claude-*, anthropic-* | Anthropic | ANTHROPIC_API_KEY |
gpt-*, openai-*, o1-*, o3-*, o4-* | OpenAI | OPENAI_API_KEY |
Cross-provider BYOK shipped in @lucairn/mcp-server@1.1.0 — set one or both keys in the same MCP config and the server forwards the matching one as X-Upstream-Key per request, so your provider account is billed directly.
| Language | Package | Version | README |
|---|---|---|---|
| MCP server | @lucairn/mcp-server | 1.2.7 | mcp-server/README.md |
| TypeScript | @lucairn/sdk | 1.1.1 | ts/README.md |
| Python | lucairn | 1.4.1 | python/README.md |
| Go | github.com/declade/lucairn-sdks/go | v1.3.1 | go/README.md |
All SDKs are at parity at the observable level. Cross-language byte-equivalence is locked via shared Go-assembler-generated fixtures, so a certificate signed via one SDK verifies identically via the other two.
Sign up at https://lucairn.eu/account/signup. Free Developer tier: 500 requests/month, no credit card required.
Pro adds response re-linking, programmatic certificate JSON access, audit-event export, and higher quota. Enterprise adds self-host, BYOK with provider-side billing isolation, and the optional custom-trained PII shield (priced per scope).
See https://lucairn.eu/pricing for the full tier comparison.
Every response through any SDK gets a signed Lucairn certificate. Two surfaces:
getCertificateSummary (TS) / get_certificate_summary (Python) / GetCertificateSummary (Go), or paste the certificate URL into https://lucairn.eu/verify.getCertificate + verifyCertificate (and language equivalents). The verifier is in-tree — see ts/src/verify-certificate/, python/src/lucairn/verify_certificate/, and the internal/verify package under go/.External RFC 3161 + Sigstore Rekor anchor verification is currently surfaced as pass-through metadata; full external anchor verification lands in a follow-up release.
Production packages are versioned independently and tagged per the table above. Cross-language byte-equivalence is locked via shared fixtures. Follow CHANGELOG.md for release notes.
@lucairn/mcp-server: https://www.npmjs.com/package/@lucairn/mcp-server@lucairn/sdk: https://www.npmjs.com/package/@lucairn/sdklucairn: https://pypi.org/project/lucairn/See CONTRIBUTING.md. Security reports: SECURITY.md.
MIT — see LICENSE.
Source-derived launch command. Check the maintainer’s required arguments and credentials before running:
npx -y @lucairn/mcp-serverMerge this template into ~/Library/Application Support/Claude/claude_desktop_config.json. Keep existing servers. Add any arguments, credentials, and permissions required by the maintainer; this template has not been install-tested.
{
"mcpServers": {
"io-github-declade-lucairn-mcp-server": {
"command": "npx",
"args": [
"-y",
"@lucairn/mcp-server"
]
}
}
}Restart Claude Desktop completely for changes to take effect. Confirm the server appears connected in the client’s tool list, then try a read-only example from its documentation.
Claude Desktop setup reference@lucairn/mcp-servernpmio.github.Declade/lucairn-mcp-server works with any MCP-compatible client. Copy the config snippet from the Configuration section above and add it to the file shown for your client, then restart the application.
~/Library/Application Support/Claude/claude_desktop_config.jsonRestart Claude Desktop completely for changes to take effect.~/.cursor/mcp.jsonRestart Cursor for changes to take effect..vscode/mcp.jsonReload VS Code window for changes to take effect.~/.codeium/windsurf/mcp_config.jsonRestart Windsurf for changes to take effect..mcp.jsonSave at the project root, then start Claude Code in that project and review the MCP server approval prompt. Keep real credentials out of shared files.