Salus

Salus provides runtime control over the actions AI agents take. Rather than scoring outputs after the fact, the product sits at commit time: when an agent proposes an action, Salus checks it against policy and against the evidence gathered during the run before the customer's backend executes it. Decisions include allowing the action, asking for clarification, or blocking it, and each intervention produces a decision receipt that records the proposed action, the governing policy, the missing evidence and the recommended safe retry. When an action is blocked, the agent receives structured feedback intended to guide a corrected attempt.

The company describes the product as an API that wraps around an existing agent, installable via a pip install and a few lines of code. Validation rests on two mechanisms: an evidence cache per run, holding prior tool-call outputs and conversation history, against which proposed actions must be grounded; and policies authored in YAML, markdown or plain English that are compiled into runtime checks that can be version-controlled, diffed and shadow-tested. Additional features include PII detection, budget and loop protection, idempotency, human-in-the-loop escalation and content moderation. Salus also bundles eval generation and observability in the same product, generating adversarial and realistic evals with context of the customer's agent domain.

Salus is a Y Combinator Winter 2026 company based in San Francisco, categorized under artificial intelligence, developer tools, B2B, API and infrastructure. Team size is listed as two, with an open founding GTM/BDR role in San Francisco or remote.

Founding story

Salus was founded in 2026 and joined Y Combinator's Winter 2026 batch. Its launch post describes two founders, Kevin and Vedant, former roommates at Stanford who studied computer science and are now working on Salus full-time. Vedant Singh is listed as Founder/CTO and described as an AI researcher formerly at Stanford CS. The founding motivation described is the gap between reactive tooling — evals, output scoring and observability — and the absence of a mechanism that inspects an agent action at the moment it is about to execute, illustrated by examples such as an agent issuing a refund without looking up the order or emailing a lead with hallucinated data, with the error discovered only hours later.

Business model

Salus sells software infrastructure to companies deploying AI agents. Customers integrate the API into their agent stack, typically starting with a single protected action route, and Salus makes the runtime allow/clarify/block decision before the customer's backend executes the action. Onboarding is described as a pip install plus a few lines of code, and prospective customers are engaged through demos and a pilot application. Pricing terms are not stated.

Traction

Salus reports internal controlled benchmark results reproduced across three matched repetitions. On AgentDojo banking with gpt-4o-mini, mean prompt-injection attack success fell from 47.7% to 0.69%, a 98.6% reduction, with attack success held to 1.4% or less in every repetition and 0% in the best single run. On AgentDojo workspace with gpt-4o-mini, utility rose from 37.5% to 64.4% while attack success fell from 17.1% to 1.73%. The company also cites tests on tau-squared-bench, where agents with Salus are said to follow policies more reliably at up to 60% lower cost, and ODCV-Bench, where it reports a 52% average reduction in misalignment across 12 frontier models. In its own benchmarks, 58% of blocked actions are reported to recover and complete the task correctly. Customer counts and revenue are not disclosed; the company is soliciting pilots.

Latest developments

Salus participated in Y Combinator's Winter 2026 batch, with Ankit Gupta as primary partner, and published a launch post describing the runtime guardrails product, its benchmark results and immediate onboarding for teams deploying agents. The company is running a pilot program starting in shadow mode on a single protected action route and is recruiting its first go-to-market hire.