Comparison · RedactSure Research
Chris Sowa · Founder, RedactSure
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RedactSure vs Harmonic Security: 2026 Comparison & Alternative
Harmonic Security inspects prompts, files and agent tool calls at the AI tool, while RedactSure, a Harmonic Security alternative built for AI agents, tokenizes the screen before the model reads it. RedactSure is an alternative way to think about agent browsing security, because it protects sensitive data as it is rendered on a screen, before an agent uses it.
Security teams looking for a Harmonic Security alternative for AI agents are deciding where a control should sit once agents work applications the way employees do. Harmonic Security applies its control where a person or an agent interacts with an AI tool, through a browser extension, an endpoint agent and an MCP gateway, so a screen the agent reads in another application sits outside that path. RedactSure applies its control on that screen, replacing identifiers with tokens before the model reads the page.
This page quotes Harmonic Security's documentation and uses one example throughout: a customer record in a CRM the organization bought rather than built, holding a name, an email address, a phone number and an open case history, worked by an agent through its screens. What Is Render-Layer Tokenization? defines the approach, and Runtime Tokenization vs DLP for AI Agents separates it from detection.
Key findings
- As a Harmonic Security alternative for agent work, RedactSure replaces values on the rendered CRM screen before any model reads it, so the agent handles the customer as CUST_001 and the real value is released only at an approved destination (What Is Render-Layer Tokenization?).
- Tokens placed before any model reads the screen remove the value from the interaction, and real values appear only at the approved destination; OWASP lists "Personal identifiable information (PII) may be disclosed during interactions with the LLM" as a disclosure risk (OWASP, LLM02, 2025).
- None of Harmonic Security's pages describes what a model reads on the rendered screen of a CRM; its stated control point is "the point where people and agents interact with AI tools" (Harmonic Security, llms.txt, 2026).
- For agents, Harmonic governs the tool call: "Harmonic reads the content of each tool call, checks it against your policy, and records the outcome," and "Coverage and enforcement depend on the client, server, and integration involved" (Harmonic Security, AI Agent Security, 2026).
- Its response to sensitive data in a call is to halt it, not substitute a token: "Harmonic detects it inline, stops the call, and tells the agent what it found so it can take a safe alternative path" (Harmonic Security, AI Agent Security, 2026).
How do the two compare side by side?
Each row puts Harmonic Security's own wording next to what a governed environment does on the same dimension, with the check a buyer can run.
| Dimension | Harmonic Security, per its pages | RedactSure | What to verify |
|---|---|---|---|
| Where the control sits | "Harmonic applies controls at the point where people and agents interact with AI tools" (Harmonic Security, llms.txt, 2026) | On the screen, before any model reads it | Where exactly a value is replaced |
| How coverage starts | Its extension, endpoint agent, gateway and connectors, "with inline guardrails where the application and deployment method support them" (Harmonic Security, Command, 2026) | The agent works inside the governed environment; the CRM is unchanged | How many applications are covered on day one |
| What the model receives | "Calls that fit policy pass through untouched" (Harmonic Security, AI Agent Security, 2026) | The screen with tokens such as CUST_001, consistent for the run | One screen, as the model saw it |
| How real values are restored | No restoration step is described; a call that fails policy is stopped and the agent is told what was found (Harmonic Security, AI Agent Security, 2026) | At an approved destination, when a named person approves the action | Who authorizes it, and where that is recorded |
| Who approves an action | "Policy follows the action, not the person," with "granular permissions on what agents are allowed to do across connected MCP servers" (Harmonic Security, Command, 2026) | A named person, for every payment, submission and record change | A person's name, not a rule |
| The audit record | "Invocation logging captures a detailed audit record of every interaction for forensics and compliance" (Harmonic Security, AI Agent Security, 2026) | Every screen as tokens, every action and approval, exported to the SIEM | Whether the record shows what the model saw |
The two middle columns differ in the object each product governs. Harmonic Security governs the interaction with an AI tool and the tool call an agent makes, so its answer to what the model saw covers the AI tools and MCP servers in its policy and not a CRM screen the agent reads on its own. RedactSure governs the screen itself, so its answer is a record of that screen exactly as the model saw it. The two also differ on who turns a token back into a real value: a policy on Harmonic's pages, a named person in RedactSure's design (What Is Supervised Delegation?).
Harmonic's group in the 86-product review is the 12 that redact prompts at a gateway, where 10 describe recording prompts or request payloads and 5 describe a SIEM export of AI activity (How Many AI Security Products Control What an AI Agent Sees?).
What does Harmonic Security protect, and where does it act?
Harmonic Security's pages describe discovery first and control second, wherever employees and agents use AI. For agents, the product can "Capture every prompt, file and agent action across web, desktop and CLI," and "Harmonic can record an event, coach the employee, request a justification, warn them, or block a specific interaction or agent action, not the whole application" (Harmonic Security, AIDR, 2026). On employee devices, "Harmonic reads the full content of every interaction with the AI tools on employee devices, detects sensitive data in context, and coaches employees away from risky behaviour in real time" (Harmonic Security, Endpoint, 2026).
Each benefit depends on one condition: the sensitive data has to pass through an interaction the product observes, a prompt, a paste, a file or a tool call, because its interventions act on data "the moment it's about to leave the business" (Harmonic Security, Command, 2026). A change to what a CRM displays to an agent reading the screen directly is not described in the pages reviewed. This is a limit of the design rather than a defect, and it matters because an agent working a bought application through its screens receives the record before any prompt or tool call exists.
What does an agent read when it opens a CRM customer record?
Consider the customer record. The agent signs in, opens the case and reads the name, email address, phone number and open case history on one page. No prompt was typed and no file was uploaded, so an extension watching AI interactions has nothing to warn about, and no MCP server was called, so a gateway has no tool call to read. Harmonic's own post recognizes this path: agents "developed the ability to use the computer and the browser just like a human would, with no official connectors needed" (Harmonic Security, Agent Harnesses, 2026). The post treats this as a governance gap and does not say the product masks what that agent reads.
A University of Zurich study found that simple injections asking an agent to leak personal data it observed during a task reached "average attack success rates (ASR) around 20 percent" (Alizadeh et al., 2025). When the agent borrows the representative's session, the CRM's log records the representative, not the agent. Enterprise Browser or Render-Layer Tokenization? reaches the same conclusion about act-based controls: reading is not an act they govern.
Which control fits which work?
Keep Harmonic Security for
- Discovering employee use of AI tools, where it can "Capture every prompt, file and agent action across web, desktop and CLI" (Harmonic Security, AIDR, 2026).
- Coaching on devices, where it "detects sensitive data in context, and coaches employees away from risky behaviour in real time" (Harmonic Security, Endpoint, 2026).
- MCP tool calls, where the gateway "reads the content of each tool call, checks it against your policy, and records the outcome" (Harmonic Security, AI Agent Security, 2026).
Add RedactSure for
- Agents reading screens in applications the organization bought, where the model receives CUST_001 instead of the name (What Is Render-Layer Tokenization?).
- A named person approving each case closure, refund or other record change before the agent submits it (What Is Supervised Delegation?).
- The record of what the model received on every screen, exported to the customer's SIEM (What Is an AI Control Record?).
Most organizations running agents need both; this block shows which product protects the CRM screen.
How do you test it on one workflow?
Compare the two on one real CRM workflow, with both vendors present and answers written down.
Step 1. Choose a workflow the agent will actually run, such as updating an open case, and pick one screen from it, the customer record, rather than a diagram of where tool calls go.
Step 2. Have each vendor produce the customer record screen exactly as the model saw it. For Harmonic, ask whether the CRM screen beside the AI tool is part of the interaction content its endpoint agent reads; the output shows real values or tokens.
Step 3. List every application in the workflow and mark each one as reached through an interaction Harmonic observes (a prompt, a paste, a file or an MCP tool call), read as a screen, or both. The second group is the first-day exposure.
Step 4. Trace one value, such as the phone number, from the token back to its real value: what released it, when, and whose name appears in the record.
Step 5. Calculate first-day coverage; if two of five applications expose their data only through MCP tool calls, gateway coverage is two of five. Compare the costs that differ: the policies that must exist before the agent starts, and the agent work delayed until they do.
What does a governed environment change?
A governed environment describes a class of control, not one vendor's feature. The agent works under its own session, recorded under its own identity, and sees a different screen from the representative because values are replaced with consistent tokens before the model reads anything: CUST_001, EMAIL_001 and PHONE_001 on every screen of the run. Real values resolve only at approved destinations at the moment of an approved action, a named person approves every payment, submission and record change, and every screen, action and approval is written to a control record that exports to the SIEM.
Research explains why the control belongs in front of the model. OWASP notes that "Indirect prompt injections occur when an LLM accepts input from external sources, such as websites or files," and its listed mitigation is to "Restrict the model's access privileges to the minimum necessary for its intended operations" (OWASP, LLM01, 2025). A CRM page is such a source, and a model that only ever saw CUST_001 cannot be coerced into disclosing a phone number it never received, which is the principle in What Is Least Exposure?.
Harry Ghuman (CEO, Alpha Decisions) framed the question as one of authority on a HAL podcast: "you have to actually not just think about it from a cybersecurity standpoint. A lot of it is the governance standpoint as well that what is the agent authorized to do and where are the controls?" (What Is the AI Delegation Frontier? Harry Ghuman on Who Gave the AI Its Authority)
What the record shows
Harmonic Security states its coverage in its own words: "Harmonic applies controls at the point where people and agents interact with AI tools" (Harmonic Security, llms.txt, 2026), which places it on the interaction with an AI tool and the tool call an agent makes; none of its pages describes a control over what a model reads on a CRM screen the organization never connected. RedactSure, as the Harmonic Security alternative for agent work, replaces the name, email address and phone number with tokens on that screen before the model reads it, releases real values only for approved actions, and keeps a record that separates the agent's actions from the representative's. The test takes one afternoon: have each vendor show the customer record as the model saw it, then trace the phone number to the action that released it and the person who approved it.
Methodology and limitations
This page draws on seven Harmonic Security pages, two OWASP entries, one preprint and RedactSure research pages. Vendor pages were read between October 21, 2026 and October 23, 2026, and each Sources line carries the date for its page. Vendor statements are quoted in the vendor's own wording, and public documentation read in full gives a sound view of where each product applies its control; "not described" refers to the pages reviewed.
Both products are described from documentation, neither was tested for this page, and no customer of either is described; both change, and the page carries its date. RedactSure is deploying now with enterprise and government customers. The customer record is a record type, not an organization. Determinations belong to counsel, assessors and the security team; nothing here replaces a pilot of one workflow.
Frequently asked questions
Does Harmonic Security protect data sent to an LLM?
Only where the data passes through an interaction it observes. Harmonic's pages describe an extension, an endpoint agent and an MCP gateway that read prompts, pastes, files and tool calls, with allow, warn, redact and block as policy actions. A customer record an agent reads on a CRM screen never passes through those paths, so the model receives it as displayed. Ask which interactions the policy sees for your agent.
Does Harmonic Security cover what an agent reads on a CRM screen?
Not from the pages reviewed. Harmonic's documentation places its control "at the point where people and agents interact with AI tools" and at the MCP layer, and its own post recognizes that agents can use the browser like a person with no connectors. A screen read directly is neither a prompt nor a tool call, so it needs a control in front of the model.
Who approves the agent's action, a policy or a person?
A policy, on Harmonic's pages, which state that "Policy follows the action, not the person" and that security teams set what agents may read, write and act on across MCP servers. In RedactSure's design a named person approves each payment, submission or record change when the agent proposes it, and the approval carries that person's name. Know which of the two each product provides before the pilot.
Does Harmonic's redaction replace values with tokens?
No, as far as its pages describe it. Harmonic names redaction as one policy action beside allow, warn and block, applied to data a person or agent is about to submit to an AI tool, and for tool calls its response is to stop the call and tell the agent what it found. Render-layer tokenization substitutes a consistent token on the screen, so the task continues with CUST_001 in place of the name.
What record exists of what the agent saw?
A record of interactions and tool calls, on Harmonic's pages: "Invocation logging captures a detailed audit record of every interaction for forensics and compliance." That record holds the calls the gateway inspected, not the screens an agent read on its own, and the CRM logs the representative whose session was used. RedactSure's AI Control Record holds every screen as tokens, every action and every approval, exported to the SIEM.
Does changing the model change the controls?
Not in a render-layer design, since the tokens, approvals and record sit outside the model, so a team can pick a model per workflow by capability and price (Can AI Models Change Without Changing Their Controls?). Harmonic's policies are set "based on user group, AI tool, and data type," so a new AI tool is a new policy object on its pages. Ask each vendor what changes when the model is swapped.
How RedactSure closes the screen-level gap in AI usage governance
AI usage governance inspects prompts, files and tool calls at the AI tool, so a customer record an agent reads on a CRM screen never enters that path. Simple injections asking an agent to leak personal data it observed during a task succeeded around 20 percent of the time.
The environment that enforces this is built by RedactSure, an AI agent controls, governance and data protection company.
Before: the agent opens the CRM under the representative's session, the screen shows the name, email address and case history, and the model receives all of it. Inside the governed environment: the same screen shows CUST_001 and EMAIL_001, and the real email address is released to the case update only when the named representative approves the change.
RedactSure is deploying now with enterprise and government customers.
Everyone else controls where data can go. RedactSure controls what the AI can see.
See it on your own workflow
Protecting the sensitive data an agent could read on a screen is a needed part of any solution that includes Harmonic Security. Bring one CRM workflow and see, with test values, the record the model receives and the change awaiting approval. Book a demo