White Circle, a platform that helps companies monitor, secure and control AI models in production, has raised $11m in Seed funding, the company announced today. The capital will fund product development and hiring across the US, UK and Europe.
The round features personal investments from a notable list of AI-industry figures: Romain Huet (OpenAI); Dirk Kingma (formerly OpenAI, now at Anthropic); Guillaume Lample (Mistral); Thomas Wolf (Hugging Face); Olivier Pomel (Datadog); François Chollet (creator of Keras); Mehdi Ghissassi (formerly DeepMind); Paige Bailey (DeepMind); and David Cramer (Sentry).
The participation list reads as senior practitioners from the labs that build the models White Circle is designed to police.
White Circle was founded by engineer Denis Shilov, who went viral in 2024 after a single prompt bypassed the safety filters of every major AI model. The post reached 1.4 million views, prompted contact from Anthropic, OpenAI and Hugging Face, and led to Shilov joining Anthropic's bug-bounty programme.
The White Circle platform was built to address the gap his demonstration exposed.
The product is a single-API control layer that scans AI inputs and outputs in real time against customer-defined policies. It detects harmful content, catches hallucinations, blocks prompt-injection attacks, flags model drift and identifies abusive users.
Customers can set custom enforcement actions, including rate-limiting and bans, and feed labelled user feedback back into White Circle's models to improve accuracy over time.
The platform supports 150 languages and is SOC 2 Type I and Type II certified and HIPAA-compliant. Head of design is Elena Iumagulova.
Shilov said in the announcement that the platform addresses an accountability gap that has grown alongside the rapid expansion of AI deployments.
“AI is moving faster than our ability to guide it,” Shilov said.
“We already trust it with decisions that touch millions of people, from hiring to healthcare, finance and security. With White Circle, we're finally giving companies everything they need to hold their AI accountable and optimise their models in a single place, without sacrificing security, compliance or risk.”
The company has released two pieces of research alongside the platform. CircleGuardBench, published in May 2025, is a benchmark that tests how AI moderation models perform under real-world conditions.
KillBench ran more than one million experiments across 15 AI models from OpenAI, Google, Anthropic and xAI; the study found preferences linked to nationality, religion, body type and even phone brand when models were asked to make decisions about human lives.
KillBench also documented that structured-output integrations, the standard for production AI deployments, caused refusal rates to collapse and biases to amplify.
Ophelia Cai, partner at Tiny VC, said in the announcement that the team had built infrastructure the industry needs. “Denis and the White Circle team have an unusual combination of deep technical credibility and a clear commercial instinct,” Cai said.
The platform has served more than one billion API requests to date. Customers named in the announcement include Lovable and two of the world's largest digital banks (not specifically identified). White Circle did not disclose its post-money valuation or revenue.