Prompt Security was acquired by SentinelOne in September 2025.
The company now operates as part of a larger organization. Contact the acquirer for current pricing and availability.
Prompt Security
Prompt Security, Inc.
SentinelOne's AI security product for employee AI use, homegrown AI apps, coding assistants and agents; acquired by SentinelOne in September 2025
Last checked October 15, 2026Quick facts: Prompt Security is an AI compliance vendor founded in 2023 and headquartered in Tel Aviv, Israel. Pricing is available on request. Profile last checked October 15, 2026; sources are cited at the bottom of this page.
About Prompt Security
Prompt Security is an AI security product that controls how employees use AI tools and protects the AI applications and agents companies build. Itamar Golan (CEO) and Lior Drihem (CTO), who had worked at Check Point and Orca Security, founded it in August 2023; it is based in Tel Aviv. It raised $23 million: a $5 million seed round led by Hetz Ventures (January 2024) and an $18 million Series A led by Jump Capital (November 2024), with Ridge Ventures, Okta and F5 joining. SentinelOne, the Mountain View, California security company, agreed to buy Prompt Security on August 5, 2025 and completed the deal on September 5, 2025. Its Form 8-K puts the consideration at approximately $180 million in cash and SentinelOne Class A stock. Prompt Security is still sold under its own name, as part of SentinelOne's Singularity Platform. The product page is on sentinelone.com; prompt.security now hosts research and free tools such as the open-source Prompt Fuzzer, and the old press release we checked there redirects to SentinelOne. **What it does** SentinelOne's Prompt Security page lists three areas. AI Usage Control inventories the AI tools and code assistants employees and developers use, including unsanctioned shadow AI, and redacts sensitive data and enforces policies across more than 15,000 AI services in real time. It also covers GitHub Copilot, Cursor and Claude Code, keeping secrets and intellectual property out of them. AI Application Security tests homegrown AI apps for prompt injection, jailbreaks and data poisoning before deployment, runs a real-time AI firewall, and turns red-team findings into guardrails. Agentic AI Security finds shadow MCP servers and unsanctioned agents, enforces least-privilege access for agents and keeps a searchable audit log. SentinelOne says Prompt's MCP gateway scores the risk of more than 13,000 known MCP servers and can allow, block, filter or redact their actions. Prompt deploys through a lightweight agent and browser extensions, and covers major LLM providers, including OpenAI, Anthropic and Google, and self-hosted models. **Product changes since the acquisition** At its OneCon conference in November 2025 SentinelOne launched Prompt Security for Employees, for AI Code Assistants and for AI Applications, plus Prompt Security for Agentic AI in beta. At RSAC in March 2026 it announced Prompt AI Agent Security, a discovery and governance control plane for agents and MCP servers (agent posture management was in preview), and Prompt AI Red Teaming for testing homegrown AI apps. **Frameworks** Neither SentinelOne's Prompt Security pages nor prompt.security name the EU AI Act, ISO 42001 or the NIST AI RMF; they refer only to meeting compliance requirements in general terms. This profile lists no frameworks. **Who it's for** Companies that want to let employees use generative AI and coding assistants while controlling data exposure, especially existing SentinelOne customers. Named customers include 10x Banking and Carnival Corporation.
Framework coverage
Prompt Security features
Capabilities Prompt Security markets publicly. Inclusion means the feature is documented on the vendor's site — not that it's best-in-class. Last checked October 15, 2026.
Shadow AI Detection
Discovery of unsanctioned AI tools and model usage across an organization.
AI Discovery
Inventory of AI assets, models, prompts, and datasets across an enterprise environment.
Data Leakage Prevention
Inspection of LLM outputs to block PII, secrets, and regulated data from leaving the boundary.
Prompt Injection Defense
Detection and mitigation of malicious prompts intended to bypass system instructions or exfiltrate data.
AI Guardrails
Runtime controls that constrain LLM input and output to enforce safety, compliance, and brand policies.
LLM Guardrails & Content Filtering
Runtime guardrails that block or redact unsafe prompts and responses in production LLM applications.
Policy Enforcement
Mechanism for applying organizational and regulatory policies to AI usage at runtime.
Runtime Enforcement
Inline policy enforcement on AI inputs and outputs at request time.
LLM Red Teaming
Automated adversarial testing of LLMs for jailbreaks, prompt injection, and unsafe outputs.
Risk Scoring
Quantitative risk assessment for AI use cases, vendors, or model deployments.
Audit Logging
Tamper-evident logging of governance events (approvals, model changes, policy decisions) required by EU AI Act Article 12 and similar regulations.
Integrations
Documented by Prompt Security in public product materials.
- OpenAI API
- Anthropic API
Prompt Security pricing
No public price. SentinelOne's Prompt Security page offers a demo, and its Pricing & Packages page links to Prompt Security without a price; the packages it does price (Singularity Complete and Commercial, per endpoint per year) don't list Prompt Security. We found no AWS Marketplace listing for Prompt Security.
Third-party reviews
Publicly cited ratings from independent review platforms. We don't collect reviews ourselves and we don't weight these in our rankings. Low review counts (≤2) are noted so you can decide how much signal to take from them.
G2
2 reviews · thin sample
We publish the cited numbers as-is and do not combine them into an aggregate rating, on this page or in search-result markup.
Vendor changelog
Durable events we've independently sourced — acquisitions, certification milestones, product launches. Each entry cites a primary or trusted secondary source.
- product launch
Announced Prompt AI Agent Security and Prompt AI Red Teaming
A discovery and governance control plane for AI agents and MCP servers, and red teaming for homegrown AI apps.
Security Boulevard - product launch
SentinelOne launched the Prompt Security suite at OneCon
Prompt Security for Employees, for AI Code Assistants and for AI Applications, plus Prompt Security for Agentic AI in beta.
Business Wire - acquisition
SentinelOne completed its acquisition of Prompt Security
SentinelOne's Form 8-K puts the consideration at approximately $180 million in cash and Class A stock.
SentinelOne Form 8-K - acquisition
SentinelOne agreed to acquire Prompt Security
SentinelOne said it would pay in cash and stock and fold Prompt into its Singularity Platform.
SentinelOne - funding
Raised an $18M Series A led by Jump Capital
Hetz Ventures, Ridge Ventures, Okta and F5 also took part; total funding reached $23M.
Calcalist - funding
Raised a $5M seed round led by Hetz Ventures
Prompt Security came out of stealth with browser extensions and a developer SDK.
SecurityWeek
Pros and cons of Prompt Security
Pros
- Covers employee AI use, coding assistants, homegrown AI apps and agents in one product, with real-time redaction of sensitive data.
- Agent and MCP controls: discovery of shadow MCP servers and unsanctioned agents, least-privilege policies, a searchable audit log and an MCP gateway that risk-scores more than 13,000 known MCP servers.
- Backed by a public security company: SentinelOne completed the acquisition in September 2025 and keeps selling and extending it under the Prompt Security name.
- Free open-source tooling, including Prompt Fuzzer for testing system prompts against LLM-based attacks.
Cons
- No public pricing: Prompt Security is quoted by SentinelOne and isn't priced on its packages page.
- No documented framework mapping: we found no reference to the EU AI Act, ISO 42001 or the NIST AI RMF on its current pages.
- Naming and packaging are in flux: SentinelOne has used 'Prompt Security for Employees', 'Prompt AI Agent Security' and 'Prompt AI Red Teaming', and some agent features were in beta or preview, so confirm what a quote includes.
- Most product detail now sits on SentinelOne's site, and its public pages name few integrations: the coding assistants it covers and major LLM providers such as OpenAI, Anthropic and Google.
Alternatives to Prompt Security
Lasso Security
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WitnessAI
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Lakera
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Harmonic Security
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Pillar Security
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Noma Security
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Frequently asked
What is Prompt Security?+
Prompt Security is SentinelOne's AI security product. It discovers and controls employee use of AI tools, protects coding assistants, secures homegrown AI applications against prompt injection and data leakage, and governs AI agents and MCP servers.
Did SentinelOne acquire Prompt Security?+
Yes. SentinelOne agreed to acquire Prompt Security on August 5, 2025 and completed the deal on September 5, 2025, paying approximately $180 million in cash and stock according to its Form 8-K. Prompt Security is still sold under its own name as part of SentinelOne's Singularity Platform.
How much does Prompt Security cost?+
SentinelOne doesn't publish a price. Its Prompt Security page offers a demo, and its Pricing & Packages page links to Prompt Security without listing a price.
Does Prompt Security support the EU AI Act or ISO 42001?+
We found no documented support. Neither SentinelOne's Prompt Security pages nor prompt.security mention the EU AI Act, ISO 42001 or the NIST AI RMF, so ask SentinelOne what compliance reporting it provides.
What are the alternatives to Prompt Security?+
The closest alternatives in this directory are Lasso Security, WitnessAI, Lakera, Harmonic Security, Pillar Security and Noma Security.
Sources
- SentinelOne: Prompt Security product page (AI Usage Control, AI Application Security, Agentic AI Security; customers)
- SentinelOne: Securing AI (Prompt Security, a SentinelOne company; Pricing & Packages link)
- SentinelOne: Pricing & Packages (no Prompt Security price)
- SentinelOne: SentinelOne to acquire Prompt Security (August 5, 2025)
- SentinelOne blog: A new chapter for AI and cybersecurity (August 5, 2025; agent, browser extensions, MCP gateway, LLM providers)
- SentinelOne Form 8-K (September 8, 2025): Prompt Security acquisition completed September 5, 2025, approximately $180 million
- SentinelOne Form 10-Q, quarter ended October 31, 2025 (Prompt Security, Inc. acquired September 5, 2025)
- Business Wire: SentinelOne at OneCon 2025 (Prompt Security for Employees, AI Code Assistants, AI Applications, Agentic AI beta)
- Business Wire: SentinelOne at RSAC 2026 (Prompt AI Agent Security, Prompt AI Red Teaming)
- Security Boulevard: SentinelOne announces AI agent security and red teaming at RSAC 2026 (March 23, 2026)
- prompt.security: Prompt Security from SentinelOne (research, ClawSec, OneClaw, Prompt Fuzzer)
- SentinelOne Prompt Security datasheet, 2025 (hosted by reseller ePlus; GitHub Copilot and Cursor)
- SecurityWeek: Israeli startup gets $5M seed capital to tackle AI security (January 24, 2024; Tel Aviv)
- Calcalist: Prompt Security raises $18M Series A (November 20, 2024; founded August 2023; founders)
- SecurityBrief UK: Prompt Security raises $18M (November 2024; founders' backgrounds, investors)
- G2: Prompt Security reviews
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