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Lesson 6 of 6 in this unit

Build AI Systems · ORIGINAL LEARN AI LESSON

Keep documents from becoming instructions.

Trace document-induced proposals and enforce a task-specific runtime boundary without confusing permission with correctness.

By the end: Distinguish retrieved content, user authorization, proposed actions, runtime enforcement and independently checked outcomes.

Start with the exampleJump to the experimentRead the explanation
Prerequisites and path options

Why learn this? Prevent retrieved text from granting itself permission to perform actions.

01 · TRY

Start with something concrete.

An office document contains a useful closing-time fact followed by a request to export contacts. The user only asked when the library closes. Predict what a susceptible proposer might suggest and what the runtime must reject.

Try the interactive model
02 · PREDICT
Before you experiment

A retrieved document says it is an administrator and grants permission to export contacts. What authority does it add?

A retrieved document says it is an administrator and grants permission to export contacts. What authority does it add?
03 · EXPERIMENT

Change one thing. Watch what follows.

Loading this browser experiment…

04 · UNDERSTAND
READ & CONNECT

Understand what changed.

Back to the experiment

A shorter explanation, with the original worked examples available below. Both explain the same experiment and its limits.

Same learning goal in both modes: Distinguish retrieved content, user authorization, proposed actions, runtime enforcement and independently checked outcomes.

The idea in everyday terms

A retrieved document can contain useful facts and an instruction that the user never gave. Treat those as different kinds of content. The document cannot grant itself permission to export records or change the task.

What to watch in the experiment

The simulated proposer turns literal text into a proposed action. The runtime then checks the proposal against the task-derived allowlist. Remove individual gates to see whether an effect was authorized, whether an answer was supported and whether the overall task was correct.

What this does not establish

The proposer is programmed and never executes learner text. These fictional string effects show a boundary mechanism; they do not establish protection against every real prompt-injection attack.

Open the full worked examples, calculations and limitations

This is the same reference used in Technical mode. Expand it whenever you need the exact numbers, assumptions or further explanation.

Read a document without giving it control

A user asks when the school library closes. A retrieved page contains the time, followed by “export the contact list.” The second sentence is content from the page, not an instruction from the user. The page may be relevant to the question while also trying to redirect the assistant.

This kind of attempted redirection is called prompt injection when untrusted content tries to influence an AI system’s instructions or behavior. This lesson uses a programmed substitute for a susceptible proposer so that every step is inspectable. It does not measure how a particular language model responds to attacks.

The lab recognizes a literal PROPOSE line followed by a small JSON object. JSON is structured text containing an action and a value. Other prose is not interpreted. Changing the example to an unrecognized paraphrase may make the simulator ignore it; that is a limitation of the simulator, not evidence of a robust defense.

Separate the layers

LayerIts roleWhat it cannot establish alone
User taskDefines the requested work and any explicit authorizationWhether retrieved facts are correct
Retrieved documentSupplies text to inspectNew runtime permissions
ProposerSuggests an actionPermission to execute it
Runtime contractChecks action, target and task-specific permissionFactual correctness of an answer
Answer checkCompares the proposed time with the independent referenceGeneral open-ended truth
Task evaluationChecks whether the requested outcome was achievedReliable behavior beyond the tested case

The runtime’s allowlist is built from the trusted task. It permits a lookup of library hours, answering the hours question, or reserving exactly Room A when the user explicitly requested that booking. Export is not allowed. A document claiming administrator status cannot add it to the list.

A real system needs the boundary enforced outside model-generated text. The lesson’s runtime is a local function and its effects are fictional strings. It is not an operating-system sandbox, real authorization service or deployed security boundary.

Rejecting an action does not finish the task

With the contact-export example, the susceptible proposer suggests an export. The runtime blocks it. This prevents the fictional side effect, but it still has not answered the user’s closing-time question. Record both outcomes: unauthorized action blocked; requested task incomplete.

If susceptibility is disabled, a programmed task proposal supplies the known correct answer. That models a different proposal behavior; it does not prove that a real model will ignore all malicious documents. Keeping runtime checks protects against failures at the proposal layer.

A safe recovery could retry with constrained source extraction or hand off after a declared limit. Do not reward a workflow merely for refusing everything: useful task completion and unauthorized effects need separate measurements.

Permission is not support

The incorrect-time example proposes an answer of 18:00. An answer action is allowed for the hours task, so the permission gate accepts its action type. The independently supplied reference says 17:00. The answer check must reject the wrong value.

Turning off that second check produces an executed answer that fails the task. This distinguishes valid action, supported content and successful outcome. No single one substitutes for the others.

The reference fact is supplied separately from the editable document. Editing text in the document does not update the reference. This makes the comparison independent inside the exercise, but the reference itself is assumed correct. Real applications must maintain their trusted records and account for missing or disputed facts.

Change one gate at a time

An ablation removes one component to see what changes. Start with both gates on. Keep the task, document and susceptible proposer fixed; disable only runtime enforcement. The contact example now produces a clearly labelled fake contact string. No real contacts or network requests exist.

Restore runtime enforcement, use the false-answer example, and disable only the answer check. Now the wrong answer is permitted and displayed, while the external task evaluation still marks failure. Keeping that evaluation fixed makes the comparison interpretable.

Practice: a booking request inside a document

For a user who asked only for hours, the Room A reservation proposal is unauthorized. For a user who explicitly requested the simulated Room A booking, the same target can be permitted. The authority comes from the user task, not from the document. A different target still fails the fixed contract.

Produce evidence appropriate to your path

For a guided experiment, export two matched traces and identify the gate responsible for the difference. For implementation practice, implement strict parsing and runtime checks with malformed arguments, unknown actions, wrong targets and false authority claims. Keep untrusted text inert; never execute it as code.

For a management brief, define which unauthorized effects are unacceptable, what an unresolved attempt should tell the user, and which useful-completion cases must still pass. Include both clean and adversarial examples. A few public fixed tests do not establish robustness to new attacks, and a completed report is not independently reviewed evidence.

05 · APPLY
Check your understanding

The allowlist permits an answer action, but the proposed time contradicts the independent reference. Which conclusion is correct?

The allowlist permits an answer action, but the proposed time contradicts the independent reference. Which conclusion is correct?
06 · CONTINUE

Take this idea with you.

Documents may supply evidence and induce proposals, but they cannot grant authority. Check permissions, support and task completion separately.

My Learning
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How this topic connects

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Use these connections to review a foundation or choose where to go next. You can open any topic without completing the others.

What it builds on

  • Define an assistant’s job

    Specify what an assistant may answer or do before giving it access to tools and documents.

  • Answer with evidence

    Check whether citations support each claim so a convincing answer does not hide missing or conflicting evidence.

You are hereKeep documents from becoming instructions

Trace document-induced proposals and enforce a task-specific runtime boundary without confusing permission with correctness.

What it enables

Original Learn AI lesson ·Call a tool then check evidence