A user code is the short code shown to a signed-in person so they can confirm an AI agent claim. It is not a password, but it functions as a proof step that the right user is present before the agent is trusted. The code must only be displayed inside an authenticated session.
Expanded Definition
User code is a verification token shown to an authenticated person so they can confirm that an AI agent is acting on their behalf. In NHI security, it is a proof step for presence, not a password, and it should only appear inside an active session where the user has already been authenticated. That distinction matters because the code validates the human at the point of delegated action, while the agent’s own identity, permissions, and trust boundaries remain separate.
Definitions vary across vendors on whether a user code is treated as a one-time challenge, a session binding signal, or a lightweight approval mechanism. NHI Management Group treats it as an explicit confirmation control for agent claims, especially where an AI agent requests access, executes a sensitive workflow, or escalates an action. This aligns conceptually with least-privilege thinking in NIST Cybersecurity Framework 2.0, even though the framework does not define user codes by name.
The most common misapplication is exposing the code before authentication or reusing it as a de facto login credential, which occurs when teams confuse proof of presence with access authorization.
Examples and Use Cases
Implementing user codes rigorously often adds a small interaction cost, requiring organisations to balance faster agent approvals against stronger confirmation that the right person is present.
- An AI support agent proposes a refund, then displays a code that the signed-in employee must re-enter before the action is committed.
- A finance workflow agent drafts a wire transfer and uses a user code to confirm the human approver is present during the session.
- A developer tooling agent requests permission to rotate a secret, and the code prevents silent approval from a background session.
- A regulated workflow links the code to a specific browser session so that replay from another device is rejected, reflecting guidance commonly discussed in the Ultimate Guide to NHIs.
- An agentic assistant surfaces a code after a sensitive data request, complementing session controls described in NIST Cybersecurity Framework 2.0.
Used well, the code is short, ephemeral, and tightly bound to the current authenticated session. Used poorly, it becomes just another prompt that users can copy, forward, or approve without understanding what the agent is about to do.
Why It Matters in NHI Security
User codes matter because they create a human confirmation point before an AI agent is trusted to act. That is especially important when the agent can access secrets, trigger privileged workflows, or make decisions that appear routine until something goes wrong. The control does not replace strong authentication, authorization, or step-up approval; it reinforces them by proving a signed-in user is still present at the moment of execution.
This is a practical response to the broader NHI exposure problem: NHI Management Group reports that Ultimate Guide to NHIs shows only 5.7% of organisations have full visibility into their service accounts, which is why identity controls around agents and delegated actions need explicit human confirmation. The same governance logic appears in NIST Cybersecurity Framework 2.0, where access decisions should be traceable and bounded by active context.
Organisations typically encounter the need for user codes only after an agent completes an unintended action, at which point the confirmation step becomes operationally unavoidable to address.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Agentic AI Top 10 and OWASP Non-Human Identity Top 10 address the attack and risk surface, while NIST CSF 2.0, NIST Zero Trust (SP 800-207) and NIST SP 800-63 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Agentic AI Top 10 | A1 | Agentic workflows need explicit human confirmation before sensitive tool use. |
| OWASP Non-Human Identity Top 10 | NHI-03 | User codes help control delegated agent actions and reduce unauthorized use. |
| NIST CSF 2.0 | PR.AC | Access control depends on confirming the right user is present at decision time. |
| NIST Zero Trust (SP 800-207) | IA-1 | Zero Trust requires continuous trust evaluation, not static approval from a prior session. |
| NIST SP 800-63 | AAL2 | Authenticated-session verification supports stronger assurance for delegated actions. |
Use authenticated-session proof steps to support the needed assurance level for sensitive actions.
Related resources from NHI Mgmt Group
- How should security teams harden user authentication without building custom auth code?
- What should teams do after a user completes device-code authentication?
- What breaks when a workflow platform can evaluate user code on the server?
- What breaks when AI-generated authentication code uses a fake user store?
