What should organisations use instead of shared API secrets for AI agents?

Organisations should use federated identity, short-lived credentials, and credential binding so the API consumer can be verified at request time. That approach reduces token reuse, supports revocation, and makes delegated access easier to scope and audit.

Use federated identity instead of shared API secrets

Shared API secrets are a weak fit for AI agents because they blur who or what is acting, make revocation coarse, and encourage long-lived access that is easy to copy across tools, environments, or prompts. Federated identity gives each request a verifiable principal, while short-lived credentials and credential binding narrow replay risk and improve auditability.

For agent-facing access, the important shift is from “who knows the secret” to “can this request be proven at the moment it is made.” That lets organisations scope delegation to the task, environment, and tenant, rather than handing out one reusable token that any component can present.

A practical pattern is to issue an identity-backed assertion or exchange-based token for the agent, then bind it to the channel or presentation context so a stolen value is less useful outside the original session. This is why AI Agent Authorisation Guide and Agentic AI Identity Guide are more useful than a static secret model for delegated agent access.

What changes operationally when the credential is no longer shared

Once access is federated, every agent instance, workflow, or tool chain can have its own identity boundary and its own policy path. That makes it easier to separate development from production, to revoke one integration without breaking the rest, and to answer which agent or workflow used a given permission at a given time.

This also reduces the chance that a secret pasted into one agent context becomes a standing credential elsewhere. Guidance on Zero Trust for AI Agents is relevant here because the control objective is continuous verification, not trust in a previously issued token. For broader background on the identity model behind non-shared access, Ultimate Guide to NHIs, What are Non-Human Identities remains the clearest overview.

Credential binding matters because short-lived tokens alone still replay if an attacker can steal and present them quickly enough. Binding the credential to the client, key material, or request context closes that gap and makes the access path much harder to reuse outside the intended flow.

Why shared secrets fail faster for AI agents

Shared API secrets are attractive because they are simple to wire up, but that simplicity creates hidden blast radius. One exposed secret can support many agent actions, multiple services, and long time windows, so a single leak can become broad misuse rather than a contained event. The more autonomous the workflow, the more damaging that reuse becomes.

That is why Top 10 Agentic AI Identity Issues is a useful companion resource: it frames shared credentials, overprivilege, and unverified trust as design errors, not just operational mistakes. The same logic appears in Agentic AI Security Guide, which treats identity and access as part of the agent threat model rather than an afterthought.

Federation also improves lifecycle control. If an agent is retired, offboarded, or reassigned, its delegated access can be invalidated without waiting for every downstream system to rotate the same shared secret.

Risk and Threat Considerations

Shared API secrets are especially risky for AI agents because they are easy to exfiltrate from prompts, logs, configuration files, CI jobs, or copied tool definitions, then reused without an obvious ownership trail. In agentic systems, that creates a direct path from one leaked value to repeated unauthorized actions.

Failure mechanism: A reusable secret is presented as a legitimate credential across many requests, so theft, duplication, or accidental exposure can enable replay, impersonation, and privilege reuse until the secret is rotated everywhere.

Impact: Attackers or misconfigured agents can gain persistent access to APIs, lateral movement into adjacent systems, and higher investigation cost because the same token may be shared by multiple workflows.

Standards & Framework Alignment

This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.

OWASP Non-Human Identity Top 10, OWASP Agentic AI Top 10 and OWASP API Security Top 10 address the attack and risk surface, while NIST SP 800-63 and NIST Zero Trust (SP 800-207) set the governance and control requirements practitioners need to meet.

Framework	Control / Reference	Relevance
OWASP Non-Human Identity Top 10	NHI-07 — Long-Lived Secrets	Shared API secrets for agents create durable bearer risk that this control directly targets.
	NHI-05 — Overprivileged NHI	Agent secrets often grant broader access than the task requires, increasing blast radius.
	NHI-04 — Insecure Authentication	Federated identity and credential binding address weak request-time verification for agents.
Recommendation — Replace shared secrets with short-lived, revocable credentials. Scope each agent credential to the minimum required permissions. Use federated, bound authentication instead of reusable shared secrets.
OWASP Agentic AI Top 10	ASI03 — Identity & Privilege Abuse	AI agents using shared secrets can overstep delegated authority and hide misuse.
	ASI02 — Tool Misuse	Reusable secrets make it easier for agents or attackers to misuse downstream tools and APIs.
Recommendation — Bind agent identity to per-action authorization and review privilege scope. Gate tool access with request-time policy checks and task-scoped credentials.
NIST SP 800-63	Digital Identity Guidelines	Federated identity and proofed request-time verification follow digital identity principles for delegated access.
Recommendation — Apply authenticated federation and assurance appropriate to the delegated access path.
NIST Zero Trust (SP 800-207)	Zero Trust Architecture	Request-time verification and no standing trust align with zero trust principles for agents.
Recommendation — Verify each request continuously instead of relying on shared standing trust.
OWASP API Security Top 10	API2 — Broken Authentication	Shared API secrets create brittle authentication and replay risk for API consumers.
	API5 — Broken Function Level Authorization	Agent access must be scoped per action so credentials do not imply broad function access.
Recommendation — Replace static shared secrets with stronger API authentication patterns. Enforce function-level authorization for every agent action.

Practitioner Guidance

What to verify: Confirm that each agent or workflow authenticates with its own federated identity path and that every issued credential is short-lived, audience-bound, and revocable. If a system still depends on one static secret for multiple agents, treat that as a migration priority rather than an acceptable shortcut.

Decision rule: If the API consumer can act independently of a specific human session, do not use a shared secret as the primary control; use a delegated identity with scoped authorization and request-time verification instead.

Practitioner takeaway: The goal is not merely to hide the secret, but to remove the secret as the durable bearer of authority so each agent action can be bounded, attributed, and stopped cleanly when needed.