AI agent identity means treating each agent as a named, authenticated entity with its own credentials and limited permissions, not as an anonymous process running under a shared account. It matters because you can then authorize what the agent may do, record what it did, and revoke access without disturbing people or other agents.
Definitions
Identification. The agent has a unique, stable name in your systems.
Authentication. The agent proves that identity with a credential, preferably short-lived.
Authorization. The system decides what that identity may do, outside the model.
Auditing. Actions are logged against the identity, so you can answer who or what did this.
Non-repudiation. The record is trustworthy enough that the actor cannot plausibly deny the action.
NIST's National Cybersecurity Center of Excellence published a draft concept paper in February 2026 on applying existing identity standards and best practices to software and AI agents. Its feedback questions cover identification, authorization, auditing, non-repudiation and prompt injection controls. It is a concept paper and demonstration project, not a finished standard.
Shared account versus agent identity
| Aspect | Shared service account | Own identity per agent |
|---|---|---|
| Audit trail | Every action looks the same | Actions tie to one agent |
| Access | Broad, because many jobs share it | Scoped to the agent's task |
| Revocation | Breaks everything | Disable one agent |
| Compromise | Attacker inherits wide access | Attacker inherits narrow access |
| Accountability | Unclear owner | Named owner on record |
Steps to introduce agent identity
- Inventory your agents. List every agent, assistant, scheduled automation and MCP client, with an owner for each.
- Issue separate credentials. One per agent and per environment. Avoid reusing a human's login.
- Scope tightly. Give each identity the narrowest permissions for its task. OWASP lists excessive permissions as a root cause of excessive agency.
- Use short-lived tokens. The MCP authorization specification recommends short-lived access tokens and requires refresh token rotation for public clients.
- Bind tokens to the target service. Servers should accept only tokens issued for them, so one agent token cannot be replayed elsewhere.
- Log every action with the identity. Include tool, arguments summary and result.
- Decide when the agent acts as a user. Where the agent works on a person's behalf, run actions in that user's context with their authorization.
- Review and expire. Remove identities for retired agents on a schedule.
Why prompts cannot do this job
An agent can be manipulated through the content it reads. The NCSC suggests designing as if the model can be manipulated and using deterministic controls on what it can reach. Identity and authorization are those deterministic controls: the rule holds even when the model is tricked.
Quick check
Is agent identity the same as a service account?
A service account can be a building block. Agent identity adds a named owner, narrow scope, short-lived credentials and per-agent audit.
Do I need this for a single coding assistant?
At small scale, start with an inventory and separate keys per tool. The habits matter before the numbers grow.
Is there a finished standard?
Not that I could confirm. The NIST work is a draft concept paper. Check current status before citing it as guidance.
Where Safeguard fits
Safeguard offers agent identity, asset discovery and an MCP Guardrail, so you can see which agents exist and apply policies to what they do. You can start with a free scan at gold.safeguard.sh/scan.
Sources
- NIST news: concept paper on identity and authority of software agents
- OWASP LLM06 Excessive Agency
- MCP authorization specification
- NCSC on prompt injection
Last reviewed: 19 October 2026.
