Comparison · RedactSure Research
Chris Sowa · Founder, RedactSure
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RedactSure vs Modal: 2026 Comparison & Alternative
Modal delivers a credential into the sandbox as an environment variable, while RedactSure, a Modal alternative built for AI agents, replaces the value on 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.
The key management page sits open on a platform engineer's screen, a key in each row, and the coding agent waiting to read it is the case any Modal alternative has to answer. Modal injects a credential into the container that runs the agent, where the process holds the value, and RedactSure, a Modal alternative built for AI agents, replaces the value on the rendered page before any model reads it. The controls sit in different places: Modal governs the process and its egress, and RedactSure governs what a model receives from the page.
Modal's own documentation is quoted here, with one record type throughout: a key management page in a cloud console the organization bought, holding a key in each row. What Is Render-Layer Tokenization? defines the control, and What Is Least Exposure? sets out the principle behind it.
Key findings
- As a Modal alternative for agent work, RedactSure replaces the values on a rendered page with consistent tokens before any model reads it, so a key appears as KEY_001 in every row and the real value is released only at an approved destination (What Is Render-Layer Tokenization?).
- Web agents complete less than two-thirds of their tasks within policy, so a control on the rendered page, before any model reads it, does not depend on the agent staying inside the rules (Levy et al., 2026).
- The pages reviewed do not describe a control on a rendered screen, and Modal's audit page says "container runtime activity is not audited" (Modal, Audit logs, 2026).
- Modal's Secrets page offers to "Securely provide credentials and other sensitive information to your Modal Functions with Secrets," and its code reads a value by "accessing its contents as environment variables" (Modal, Secrets, 2026).
- A Sandbox can carry inline values, and including an identity token will "inject a MODAL_IDENTITY_TOKEN environment variable containing an OIDC token into the Sandbox" (Modal, Sandboxes, 2026).
- A default Sandbox has "no ability to accept incoming network connections or access your Modal resources," while its code can still reach any public address until an allowlist narrows it (Modal, Networking, 2026).
How do the two compare side by side?
The table sets Modal's own wording beside what a governed environment does on the same point, with the check a buyer can run.
| Dimension | Modal, per its pages | RedactSure | What to verify |
|---|---|---|---|
| Where the control sits | "To inject Secrets into the container running your Function, add the secrets=[...] argument" (Modal, Secrets, 2026) | On the rendered page, before any model reads it | The object the control covers |
| How coverage starts | "You can set environment variables using inline secrets:" (Modal, Sandboxes, 2026) | The agent works the application inside the governed environment, unchanged | First-day coverage of the agent's applications |
| What the model receives | Values are read "accessing its contents as environment variables", and the page describes no screen (Modal, Secrets, 2026) | The page with consistent tokens, KEY_001 in each row | One row, field by field |
| How real values are restored | Including an identity token will "inject a MODAL_IDENTITY_TOKEN environment variable containing an OIDC token into the Sandbox" (Modal, Sandboxes, 2026) | Released at the destination a named person approved | What releases the value, and whose name is on it |
| Who approves an action | No approver is named; a network rule limits egress to "Only allows TLS traffic (port 443) to the listed domain names" (Modal, Networking, 2026) | A named person approves every payment, submission and record change | A person's name, not a rule |
| The audit record | "Note: container runtime activity is not audited." (Modal, Audit logs, 2026) | Every screen as tokens, every action and approval, in the AI Control Record sent to the customer's SIEM | Whether the record shows what the model saw |
The two middle columns describe different objects, and that difference is the whole comparison. Modal governs the container and the destinations its code may reach, so its answer to what a model read covers the process and not the page. RedactSure governs what an agent reads on the page, and its answer is a record of that screen in tokens. They also differ on who turns a token back into a real value: an environment variable the process holds, or a named person, the distinction What Is Supervised Delegation? draws. In the ten-product review, all 6 coding agents place a credential in an environment variable the agent can read, and 2 of the 4 sandboxes keep it out by default (Can AI Coding Agents Read Your API Keys?).
What does Modal protect, and where does it act?
Modal runs code in containers and sandboxes, and its documentation describes the credential boundary around that code. A team can "Securely provide credentials and other sensitive information to your Modal Functions with Secrets," and the page explains the mechanism: "To inject Secrets into the container running your Function, add the secrets=[...] argument," with a value read by "accessing its contents as environment variables" (Modal, Secrets, 2026).
"Sandboxes are built to be secure-by-default, meaning that a default Sandbox has no ability to accept incoming network connections or access your Modal resources," while "By default, Sandboxes can make outbound connections to any public IP address," and a team can narrow that with "three levels of outbound network restriction," up to an allowlist that "Only allows TLS traffic (port 443) to the listed domain names" (Modal, Networking, 2026).
Each benefit depends on one condition: the code that needs the value runs inside the container, and the value is placed in its environment. That covers the process and its destinations, and the limit belongs to the layer, since "trustworthy agent automation cannot be solved at a single layer of the stack" (DAPLab, 2026). A value on a page the agent opens sits outside the boundary these pages draw, and the pages describe no approver for a sandbox action.
What does an agent read when it opens a key management page?
The record is a key management page in a cloud console the organization bought, with a key in each row beside the service it belongs to and its creation and last-used dates. The console renders the page from its own database, so the key is on the screen before any Modal Secret is involved, and Modal's boundary runs around the process: Modal injects a Secret into the container's environment, and any code in that container can print or send the value (Modal, Secrets, 2026). The page reaches the model as the console draws it, key included.
What the model receives is the full row: the key, the service and both dates. A page can carry an instruction as well as a record, the attack class AgentDojo measures in its environment for prompt injection attacks and defenses on agents (Debenedetti et al., 2024), and a key read on the first screen is still in the context on the tenth.
There is also an identity gap. An agent that works the console under the engineer's session is logged as the engineer, so the console's own log cannot separate the two, and the grant behind the work is what to review, as What Is a Permission Slip for an AI Agent? sets out. What Is a Tethered Agent? sets out the arrangement a governed run has instead, and What Happens to Credentials When an Agent Sandbox Is Destroyed? covers what teardown ends. Keeping a value outside a sandbox still leaves the page the agent read, as Can Credentials Stay Outside the Sandbox and Still Be Used Inside It? sets out.
Which control fits which work?
Keep Modal for
- Work that needs the value inside a container, where Modal's secrets=[...] argument places it in the environment (Modal, Secrets, 2026).
- Code whose egress must be bounded, with "three levels of outbound network restriction" and an allowlist that admits only TLS to named domains (Modal, Networking, 2026).
- Workspace actions that need a record, since the audit log covers deploying an App or creating a Volume and returns only an identifier and metadata (Modal, Audit logs, 2026).
Add RedactSure for
- Agents reading screens in applications the organization bought, where the model receives KEY_001 instead of the key (What Is Render-Layer Tokenization?).
- A named person's approval on every payment, submission and record change before the action leaves the governed environment (What Is Supervised Delegation?).
- The record of what the model received on every screen, separated from what the person did, in the customer's SIEM (What Is an AI Control Record?).
An organization running agents in sandboxes and on bought applications usually needs both, and the block above shows which one protects the screen.
How do you test it on one workflow?
Run the comparison on one real workflow, over an afternoon, with both vendors present and every answer written down.
Step 1. Choose a workflow the agent will run and pick one screen from it, the key management page rather than a diagram of the data flow, and write down which keys and records the screen shows.
Step 2. Ask each vendor to replay the model's input for that screen, field by field, and keep the output, which shows whether the key arrived as a live value or as a token and who could read it.
Step 3. List every application the workflow touches and mark each one as covered by this vendor's control or not. The uncovered group is the exposure a team starts with, so count it internally.
Step 4. Trace one key from the value the model held to the moment the real value appeared: what released it, when, and whose name the record carries. Ask what the record shows about the page itself as well as the process that read it.
Step 5. Calculate first-day coverage, then compare the costs that actually differ: policy tuning, agent work delayed, and the applications left uncovered. Ask each vendor to price this one workflow in writing, so the comparison stays on the costs a team can measure.
What does a governed environment change?
A governed environment is a control class rather than a product feature. The agent works in its own session under its own identity, reads a page whose values are replaced with consistent tokens before any model reads it, and acts only where a named person approved the action. Real values resolve at the approved destination at the moment of the action, and every screen, action and approval lands in a record that exports to the organization's SIEM.
Research explains why the control sits in front of the model. Web agents complete under two-thirds of their tasks within policy, so a run can succeed and still depart from the rules around it (Levy et al., 2026). Injected instructions can move a model off the task the user set, which one study's authors "define this deviation as task drift" (Abdelnabi et al., 2025). Data minimisation points the same way: personal data must be "adequate, relevant and limited to what is necessary in relation to the purposes for which they are processed" (GDPR, 2016). What Is Least Exposure? states the principle for the data an agent receives.
What the record shows
Each row of the key management page carries a key, a service name, a creation date and a last-used date, and on an ungoverned run the model receives all four. RedactSure, as the Modal alternative for agent work, puts KEY_001 in place of the key in every row, holds that token for the whole run, and releases the real value only at the destination a named person approved. Modal's real coverage is the container and its egress: a credential is injected into the environment for the process, and the audit record covers workspace actions such as deploying an App, not what a model read on a screen. Run the test on one row: replay it against each product, then trace the key to the action and the person that released it.
Methodology and limitations
This page draws on four Modal documentation pages, three research papers, one regulation and a university lab's analysis, with the RedactSure research pages linked above. Vendor pages were read between October 16, 2026 and October 24, 2026, and each Sources line carries the date for its page. Modal's statements are quoted in its own wording, and public documentation read in full gives a sound view of where each product applies its control.
The products on this page are described from documentation, and none was tested for this page. No customer of either product is described, both products change, and the page carries its date. RedactSure is deploying now with enterprise and government customers. The key management page is a record type, not an organization. Compliance determinations belong to the organization's counsel, assessors and security team, and nothing here replaces a pilot of one workflow on the organization's own screens.
Frequently asked questions
Does Modal protect the keys an agent reads on a screen?
No, not at the screen. Modal's Secrets page delivers values to the code in the container as environment variables, and it describes no substitution on a rendered page. An agent that opens a key management page reads it as the console draws it, key included. A screen-level control has to sit between that render and the model, and Modal's own pages describe no such layer.
Does a Modal Secret keep a key out of the model's context?
Only for the process environment. Modal injects the Secret into the container that runs the Function so the code can use it, and any code in that container can read the value and print it. The model receives whatever the process returns plus any page the agent reads, so a value kept out of the environment can still be on the screen.
Who approves an agent's action in Modal?
No approver is described in the pages reviewed. Modal's sandbox pages document network restrictions and credential injection, and the audit page says "container runtime activity is not audited" (Modal, Audit logs, 2026). A policy decides where a process may connect, and no page names a person who approves a payment or a record change. That decision needs an owner.
What record does Modal keep of an agent's work?
Workspace actions only. The audit log covers actions such as deploying an App or creating a Volume, and it states that container runtime activity is not audited and that the record does not reach "individual Function invocations or Sandbox exec calls" (Modal, Audit logs, 2026). It does not record what a model read on a screen. A record that separates the agent's work from the person's has to come from the environment the agent worked in.
Is a Modal Sandbox the same as a governed browser environment?
No. A sandbox bounds where code runs and what it may reach; a default Sandbox accepts no incoming connections and its egress rules can be narrowed to a TLS allowlist. A governed environment also decides what the model sees on a page, who approves an action and what the record shows. The two answer different questions, and a workflow can need both.
What should a buyer ask both vendors to show?
One screen, replayed field by field, which shows whether the model read the real key or a token. Then ask what releases a real value, whose name is on the approval and where the record exports. RedactSure answers those questions on the rendered page; Modal's pages answer them for the container and its egress. Write both answers down, because the comparison is only as useful as its record.
How RedactSure closes the screen-level gap in Modal's sandbox
Modal's control covers the container and its egress, and an agent reading a key management page inside it still receives the key the console draws. The audit page confirms that container runtime activity is not audited.
The environment that enforces this is built by RedactSure, an AI agent controls, governance and data protection company.
Before, the page rendered the full key in every row and the model read it, so the value stayed in context for the run. Inside the governed environment, each row renders KEY_001, the agent works the key by name, and the real value resolves only at the destination a named person approved.
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 Modal. Bring one key management page and see, with test values, what the model reads and who approves the release. Book a demo