AgentShield vs Prompt Security - Independent Control Plane or SentinelOne Suite
Prompt Security built a strong GenAI security product covering prompt injection and data protection across enterprise AI usage. In September 2025 it was acquired by SentinelOne for roughly 250 million dollars and is being integrated into the Singularity platform. AgentShield is an independent, self-serve control plane for agents that take actions. Which fits depends on whether you are securing an organization or shipping an agent.
| Capability | AgentShield | Prompt Security |
|---|---|---|
| Agent action enforcement (block/deny/hold) | Partial Prompt/data centric | |
| Employee GenAI usage governance | × | Core strength |
| Tool and data permissions per agent | Partial Platform policies | |
| Human-approval gates | × | |
| Immutable action audit trail | Partial Platform logging | |
| Vendor-neutral / standalone | × Part of SentinelOne | |
| Self-serve with pricing on the page | × Enterprise sales |
The verdict
Choose Prompt Security if you are a SentinelOne shop or a security org governing GenAI usage across the whole company, including employee AI use. Choose AgentShield if you are the team shipping an agent and want an independent, vendor-neutral action-path firewall with permissions, approval gates, and audit you can deploy yourself today.
This comparison is meant to be fair and reflects publicly available information. Both products evolve; verify the latest before deciding.
What the SentinelOne acquisition changes for buyers
SentinelOne completed its acquisition of Prompt Security in September 2025 and is integrating it into the Singularity platform as its GenAI and agent security layer. For SentinelOne customers this is good news: AI security lands inside a platform they already run, with endpoint and cloud telemetry next to it.
For everyone else it changes the calculus. Roadmap priorities now follow the platform, buying it means engaging SentinelOne enterprise sales, and the natural pull is toward consolidation on Singularity. None of that is a criticism; it is what platform acquisitions are for. But if you wanted an independent, stack-neutral control you can drop in front of any agent without adopting a security platform, that is now a different product category, and it is the one AgentShield occupies. We stay deliberately narrow: the agent action path, self-serve, priced on the page. If the question you are really weighing is whether to govern employee AI usage or to govern the agents your own team ships, the enforcement side of that is set out on per-agent tool permissions, and the longer commercial read on Prompt Security alternatives.
FAQ
Common questions about this comparison.
Was Prompt Security acquired by SentinelOne?
Yes. SentinelOne announced the acquisition in August 2025 and completed it in September 2025, in a deal reported at roughly 250 million dollars. Prompt Security is being integrated into the SentinelOne Singularity platform as its generative AI and agent security capability.
What is the difference between AgentShield and Prompt Security?
Scope and ownership. Prompt Security covers broad GenAI security, including employee AI usage, inside the SentinelOne platform. AgentShield is an independent runtime control plane for agents that take actions: injection firewall, per-agent tool and data permissions, human-approval gates, and an immutable audit trail, self-serve and vendor-neutral.
Do I need SentinelOne to use Prompt Security?
Not strictly today, but the direction of travel is platform integration, and evaluation and purchase run through SentinelOne. If you are already a Singularity customer that is a plus. If you are not, weigh whether you want your AI security tied to an endpoint-platform vendor. Verify current packaging with them before deciding.
Which should a team shipping its first production agent pick?
Usually the tool it can deploy and afford this week. AgentShield is self-serve with transparent pricing and drops in front of any framework, which fits a product team shipping now. Prompt Security inside SentinelOne fits a security organization standardizing AI controls across a large company on an existing platform.