AI Agent Transactions: Test Identity, Tools and Authority

Sources checked: 29 October 2026. FailSafe Research.

An agent that can prepare or submit a business action crosses a security boundary long before a signature appears. Test who requested the action, what the tool can do and which approval covers the final transaction. Use a controlled environment and synthetic assets rather than real transactions for an initial assessment.

Map the authority before the tool call

List the user, agent, tool service and signing component involved in the workflow. Define which identity may propose, approve and execute an action. A model's instruction to stay within scope is not the same as enforcement by the application. Record the permitted systems, resources, recipients and action types. Separate a read-only analysis request from a request that can change state so the assessment has an observable expected result.

Bind approval to the action that executes

Use a mock transaction service to compare the approved recipient, network, amount and method with the final submitted operation. Test a changed argument, a cancelled approval and a bounded retry. The objective is to establish whether approval is checked at the point of execution. Preserve a legitimate control case as well as the denied case. Avoid publishing working attack payloads or using a real production credential to demonstrate a preventable boundary failure.

Keep retrieved content below user authority

An agent may read token metadata, documentation, messages or tool responses while deciding what to do. Treat that content as potentially untrusted. Use harmless conflicting instructions in a fixture and observe whether they can change a permitted mock action. Record the provenance of the content, the tool request and the application's authorization decision. An unsafe answer is useful evidence about behavior, but it does not alone establish that a transaction occurred.

Follow secrets and evidence separately

Signing credentials should remain in the approved signing or execution service rather than entering prompts, chat transcripts or ordinary diagnostics. Review how the agent refers to a credential and how the backend uses it. Keep synthetic markers in the initial test and inspect the channels where they appear. If source or investigation records have a restricted processing requirement, review the inference endpoint, support access and retained traces as part of the architecture.

Retest the same invariant after a change

A fix should preserve the intended business workflow while blocking the unauthorized action. Record the model, connector, application and policy versions, then repeat both the original controlled case and the permitted control. Include outstanding coverage gaps in the report. This establishes a concrete result for the assessed workflow rather than a general claim that every agent or transaction is secure.

OWASP transaction-authorization guidance provides background for action integrity. For a tool-enabled application, FailSafe AI security testing can connect prompts, tools, identities and APIs within an agreed scope. Review the agentic pentesting workflow and discuss the exact authority boundary before sharing access. This guide makes no real-time monitoring, guaranteed detection or automated transaction-safety promise.