Frequently asked questions

PexLens is a security platform for how organizations build and use software in the AI era. It protects the open-source packages and the browser and IDE extensions your teams install, and controls how employees use AI tools such as ChatGPT, Claude and Gemini.

Security, AppSec and platform teams, and developers who want to stop malicious packages, risky extensions and AI data leaks without slowing engineering down. Plans range from a free plan for individual developers to enterprise deployments.

PexLens offers supply chain and extension security (package intelligence, real-time protection with PexLens Sentinel and the PexLens Proxy, and policy enforcement), AI Guard for inspecting prompts and responses, and the PexLens AI Browser, which is coming soon.

Vulnerability scanners and SCA tools mainly match your dependencies against known CVEs. PexLens also looks for malicious intent and risky change in packages and extensions, such as credential theft, suspicious updates or publisher changes, and can block them at install time, before the code runs.

Yes. The PexLens Research Team publishes malicious package research, security advisories and analysis on the PexLens blog.

Yes. Instead of a time-limited trial, PexLens offers a Free plan for npm and PyPI projects with up to 1,500 unique package versions. Upgrade when you need every ecosystem, browser and IDE extensions or team features.

Start on the Free plan from the pricing page. For a guided setup or a pilot across your organization, request a demo and the team will walk you through integration.

Sentinel is the PexLens component that runs on devices. It identifies installed packages, dependencies and extensions using package manifests and related technical signals, and keeps monitoring for changes in the background.

The PexLens Proxy sits in the package installation path. Each package request is checked against PexLens intelligence and your policies, and packages that fail are blocked before they are installed.

No. Sentinel identifies packages from package manifests and related technical signals and is not designed to collect the broader contents of your projects. For private packages, PexLens uses hashes so raw proprietary source code is not sent to external servers.

Yes. We offer dedicated private cloud, hybrid, and isolated physical server architectures for complex corporate topologies.

AI Guard is priced at $5 per device, per month, covering all monitored prompts and responses on that device.

No. AI Guard is a separate per-device subscription, so you can buy it on its own or alongside any package plan.

No. Supply chain plans are priced per organization by the number of unique package versions you protect, never per developer or device. AI Guard is the only product priced per protected device.

A package is any third-party code module, dependency, or version tracked across your repositories or containers (e.g. lodash v4.17.21).

Only one package is counted. The volume of devices using the package version does not multiply your monitored footprint.

Capacity is determined strictly by the number of unique package versions actively monitored and enforced across your entire organization.

Yes. Add +1,000 package versions for $6/mo, +5,000 for $28/mo or +10,000 for $54/mo to any plan. Add-ons always cost less per package version than the plans, so topping up is the cheapest way to grow.

PexLens activates a grace period automatically. Pipelines and protections will continue to run normally while notifying administrators.

The Free plan covers npm and PyPI packages. Developer, Team, Business and Enterprise cover all supported ecosystems, including npm, PyPI, Maven and RubyGems, plus browser and IDE extensions.

Browser and IDE extensions, such as VS Code extensions, are protected on the Developer plan and above. Each unique extension version counts toward your package capacity, just like an npm or PyPI package version. There is no separate extension charge.

Yes. Pay yearly for any paid plan or add-on and get 2 months free, about 17% off the monthly price.

Enterprise pricing is tailored to your package capacity, deployment model and policy requirements. Request a demo to get a quote.

Yes. You can move to a larger plan or add package capacity as your software estate grows, and scale AI Guard devices up or down at any time.

Yes. Sentinel runs background passive monitoring looking for dependency tree modifications without consuming local CPU performance.

Yes. Using advanced hashes, PexLens maps internal binaries without leaking proprietary raw source code to external servers.

Pricing will be announced at launch. You can join the waitlist from the pricing page.

AI security protects how an organization builds and uses AI: the data employees share with AI tools, the AI-related components and extensions developers install, and the agents that act on their behalf.

PexLens is being built to detect AI-related signals in packages, dependencies and extensions so teams can evaluate risk before it reaches production.

PexLens will evaluate AI-related requests in real time against your organization’s policies and return a clear decision (allow, alert or block) before software is installed.

Yes. AI guardrails are designed around organization-defined rules, so your team decides which AI-related signals are approved, need review or should be blocked.

Yes. Browser and developer extensions are part of the AI-related risk PexLens is being built to evaluate, alongside packages and dependencies.

AI Guard inspects prompts on the employee device and detects source code, secrets, API keys and personal information before they reach an AI service. Depending on your policy it allows, redacts or blocks the content and logs the decision.

AI Guard is a PexLens product that inspects prompts and responses on employee devices, detects sensitive data such as source code, secrets and personal information, and allows, redacts or blocks it according to your organisation’s policy.

AI Guard works across ChatGPT, Claude, Gemini, AI search engines and local developer tools.

Source code, secrets and API keys, personal information (PII) and other sensitive content defined in your organization policies, across more than 30 security categories.

AI Guard can allow, redact, block or log a prompt or response based on your policy. Every decision is recorded, so security teams can review AI usage and tune policies.

Yes. AI Guard inspects both prompts and responses, so you can monitor and control what flows to and from AI services.

No. AI Guard is designed to let teams keep using AI. It removes or blocks only the sensitive data your policy covers and logs every decision.

Traditional DLP watches email, files and network traffic. AI Guard works at the prompt itself, on the device, before the text reaches an AI service.

An enterprise AI browser is a managed web browser that lets employees use AI assistants while giving the organisation control over which AI services are allowed, what data can flow into them and how usage is audited.

Not yet. It is coming soon, and you can join the waitlist from the PexLens pricing page. For protection today, AI Guard works with the browsers your teams already use.

Yes. PexLens AI Browser is Chromium-based, so existing web applications work as they do in Chrome.

Allow-listing of approved AI models and instances, clipboard isolation that stops sensitive content moving to unapproved destinations, AI usage dashboards with audited prompt history, browser group policies for extensions, certificates and DNS filters, and zero-touch deployment across distributed machines.

AI Guard protects prompts and responses on existing browsers and devices. The AI Browser adds session, clipboard and browser-policy controls. Both use the same PexLens policy engine.

Prompt injection is an attack in which text written by an attacker is interpreted by a large language model as instructions, causing it to ignore its intended behaviour, leak data or take unintended actions.

Indirect prompt injection hides malicious instructions in content the model reads by itself, such as a web page, document, email, code file or tool response, rather than in the user’s own prompt.

Common examples include hidden instructions in a web page that an AI assistant summarizes, a comment in a code file read by a coding agent, a poisoned tool description in an MCP server, and an email that tells an AI assistant to forward data.

Yes. Prompt injection is ranked first (LLM01) in the OWASP Top 10 for Large Language Model Applications.

Not with any single control today. Effective protection combines input and output inspection, strict limits on what AI tools can access and do, vetting of the components that feed them, and monitoring.

PexLens AI Guard inspects prompts and responses and enforces data policy, and PexLens analyses extensions, packages and AI-related components before and after they are installed, reducing both the paths for injected instructions and the damage they can do.

Agentic AI security protects autonomous AI agents that act on their own, such as coding agents and tool-using assistants, by controlling what they are built from, what they can access and what actions they can take.

The Model Context Protocol (MCP) connects AI agents to tools and data sources. Each MCP server extends what an agent can do, so a malicious or compromised server, or a poisoned tool description, can expose data or trigger unintended actions.

The main risks are compromised extensions or MCP servers, malicious or non-existent packages suggested by the model and then installed, over-broad credentials and tokens, and actions taken without human review.

PexLens inventories AI assistants and agent components on developer machines, analyses them for malicious behaviour and risky changes before and after install, and enforces policy to block, quarantine, monitor or require approval.

Yes. When package installs are routed through the PexLens Proxy, requests made by an AI agent are checked against the same intelligence and policies as a developer’s, and malicious packages are blocked before installation.

Prompt injection is one attack against agents. Agentic AI security also covers compromised components, excessive permissions, persistence and the reach of the credentials an agent can use.

At minimum: which AI tools are approved, what data may and may not be shared with them, rules for AI coding assistants, extensions and agents, how usage is monitored, how to report incidents, training requirements and how often the policy is reviewed.

An acceptable use policy tells employees how they may use AI. An AI security policy adds the technical controls, ownership and incident handling that protect data and systems. This template combines both.

Outright bans tend to push usage to personal accounts and devices. Most organisations get better results by approving specific tools, setting data rules and enforcing them with inspection and logging.

Usually the security team or CISO, working with legal, privacy, IT and engineering. Review it at least once a year and whenever you adopt a significant new AI tool.

Combine an approved-tools list and training with technical controls: AI Guard to inspect, redact or block sensitive data in prompts, PexLens policies for AI-related extensions and packages, and logging so you can audit usage.

Yes. Copy the AI security policy template, adapt it to your organisation and share it with your teams.

A supply chain attack compromises something you trust instead of attacking you directly, for example a malicious package published to npm or PyPI, a hijacked maintainer account or a poisoned update. The malicious code then reaches every team that installs it.

PexLens scans software packages installed on endpoints as well as packages present within project folders. It also identifies browser and developer extensions, giving organizations visibility into the software components running across their environment.

PexLens analyzes major open-source package ecosystems, including npm, PyPI, Maven and RubyGems, along with browser and IDE extensions. Support for additional ecosystems is expanding as the platform grows.

Package installation requests can be routed through the PexLens Proxy, where the package is evaluated against PexLens intelligence and your organization’s security policies. Packages that fail the defined security criteria can be blocked before installation.

Yes. Organizations can define their own security requirements, including risk and CVE thresholds, and PexLens applies those policies when evaluating package requests.

Yes. PexLens can identify and assess browser extensions and developer-environment extensions, including VS Code extensions, helping organizations detect malicious, suspicious, or risky extensions.

PexLens continuously discovers and analyzes new packages and package versions, updating its intelligence as the software ecosystem evolves. This helps organizations make decisions using current risk information rather than relying only on historical scans.

A package firewall sits between developers and public registries such as npm and PyPI, and checks each package request against threat intelligence and policy before the package is installed.

Checks run at install time and return an allow, alert or block decision, so safe packages install as normal and only risky ones are stopped.

PexLens returns a block or alert decision with the reason, and records it for audit.

Extension security is the practice of checking browser and IDE extensions, such as Chrome and VS Code extensions, for malicious code, excessive permissions and risky behaviour before and after they are installed.

Browser extensions can read pages, sessions and clipboard content, and IDE extensions run with access to source code and credentials. A malicious or hijacked extension, often delivered through a routine update, can steal data without the user noticing.

Yes. PexLens analyses VS Code and browser extensions for suspicious code, network activity, permission changes and publisher changes, and flags or blocks risky ones based on your policy.

Extension drift is when a trusted extension changes after approval, for example through a malicious update or a new maintainer. PexLens re-checks new versions so a safe extension does not silently become a risky one.

You decide. Policies can allow, alert on or block an extension, and security teams see the reason for every decision.

Open source security means making sure the open-source packages your software depends on are not malicious, compromised or dangerously vulnerable.

A vulnerable package has an accidental flaw, usually tracked as a CVE. A malicious package was built or modified to cause harm, for example to steal credentials. PexLens detects both.

Yes. Vulnerability intelligence is included on every plan, and policies can set CVE and risk thresholds alongside malicious-package detection.

Developer machines hold source code, credentials and access to CI and cloud systems, so a malicious package, extension or AI tool installed there can reach far beyond one laptop.

Yes. PexLens treats AI coding assistants and their extensions like any other component that enters the developer environment, and checks them for risky behaviour and changes.

An inventory of the packages, extensions and tools on developer machines, the risk of each, and every allow, alert or block decision.

Yes, with AI Guard. It detects source code, secrets and API keys in prompts on the device and redacts or blocks them according to your policy.

It tracks malicious and suspicious packages and extensions across more than 80 million entries, updated as new versions are published.

Security teams use it to block known-bad packages, enrich alerts and hunt for compromised components already in their environment.

Advisories are formal write-ups by the PexLens Research Team covering affected packages and versions, key dates, severity and recommended action. Severity uses CVSS-based scoring, and any analyst override is shown with its reason.

Developer API access is included on the Business and Enterprise plans.

It means applying your organisation’s rules, such as blocked licences, maximum risk scores or banned publishers, automatically when a package or extension is requested.

Yes. The same policy engine can allow, warn on or block AI tools and AI-related components, and AI Guard applies policy to prompts and responses.

Yes. The Team plan and above include package allow and block overrides, so you can approve a package your policy would block, or block one it would allow.

Yes. Centralized organization policies are included from the Team plan, and the Business plan adds advanced global enforcement.

Sentinel identifies installed packages, dependencies and extensions using package manifests and related technical signals. It is not designed to collect the broader contents of your projects. See the privacy policy for details.

AI Guard inspects prompts on the device and can redact or block sensitive data before it leaves for an AI service. Decisions are logged according to your policy so you can audit them.

PexLens maintains administrative, technical and physical safeguards, including access controls, encryption in transit, logging and security review. Data is kept only as long as needed to provide the service and meet legal obligations.

Where GDPR, UK GDPR or similar laws apply, you can request access, correction, deletion, restriction or portability of your personal information. Contact us and see the privacy policy.

Send the details through the contact page and mark the message as a security report. Please do not include sensitive personal data in the first message.

Use the contact page for questions, partnerships and support. Business plan customers get priority 24/7 technical support.

Yes. Request a demo for a one-to-one guided integration and pilot covering supply chain security and AI security.