Klar Pro · white-label · on-prem

Spam detection you can ship under your own brand.

Klar Pro is the same XLM-RoBERTa engine that powers Klar, packaged for email providers, relays and platforms to embed in their own infrastructure. Your brand, your servers, our classifier.

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Two ways to integrate

  1. 01

    Drop-in Milter for SMTP

    Klar runs as a milter for Postfix and other SMTP servers and relays. Every inbound message is classified in-line and tagged with X-Klar headers your filtering rules can act on. No mail-flow rewrite required.

  2. 02

    C API for direct embedding

    For platforms with their own messaging stack, the engine ships a stable C ABI. Call the classifier directly from your service in any language with an FFI. No subprocess, no network hop.

  3. 03

    Your brand, your infrastructure

    Classification runs where your mail already lives. Nothing is sent to a third party, and the product surfaces under your name, not ours.

Why platforms pick Klar Pro

Multilingual
One XLM-RoBERTa model covers 100+ languages out of the box and detects the language automatically, with no per-language configuration or separate models.
Low latency
13–44 ms per message on a single Apple M1 Pro GPU (GGUF Q4_K_M, Metal), with a ~2 ms statistical pre-filter that skips the encoder on confident cases. Real-world median classification under 20 ms.
Footprint
A 382 MB quantized model runs on commodity hardware. No GPU cluster, no per-message API spend, no external dependency to scale.
Privacy by design
The engine runs entirely on your infrastructure. Mail content never leaves your servers. That is the data sovereignty cloud-based filters cannot offer.

Performance figures measured on Apple M1 Pro (GGUF Q4_K_M encoder on Metal); see the engine speed benchmarks. Numbers vary with hardware and message length.

Klar Pro · B2B

Let's scope your integration.

Tell us about your stack, whether it's a provider, relay or platform, and we'll work out the integration surface, deployment and licensing with you.

Contact Klar Pro

B2B enquiry, not a self-serve signup. We'll reply personally.