Delegated Access for Agents: What Comes After Tokens

Traditional tokens—like API keys, session tokens, or even JWTs—are the backbone of modern authentication. They work well for human users and traditional applications. But as AI agents become more autonomous and act with delegated authority, these tokens are breaking. They struggle with the nuances of dynamic delegation, fine-grained control, and the ephemeral nature of many agent workflows. This post explores the next evolution in delegated access for agents: identity chaining, intent-bound credentials, and what’s next in auth.

The Limitations of Traditional Tokens for Agents

Tokens are great for conveying a fixed set of permissions for a fixed identity. But agents are different:

• Context Sensitivity: Agent permissions often depend heavily on the context of the current task. A simple token can't easily capture this.

• Delegation Depth: A user delegates to an agent, which might then delegate to a sub-agent or another service. Standard tokens don't neatly represent this chain of delegation.

• Ephemeral Nature: Many agents are short-lived. Managing and revoking a proliferation of static tokens for these agents becomes an operational nightmare.

• Intent Mismatch: Tokens convey "what" an identity can do, not "why" (the user's intent).

What Comes Next: Evolving Beyond Simple Tokens

The future of delegated access for agents moves towards more intelligent, context-aware, and auditable credentialing.

1. Identity Chaining and Verifiable Delegation

Instead of a single token, imagine a chain of cryptographic proofs.

• User-to-Agent Delegation: The user initiates a delegation, cryptographically signing a statement granting the agent specific authority for a defined purpose (e.g., "Agent X is authorized by User Y to manage my calendar for the next 2 hours for meeting scheduling."). This creates the first link in the chain.

• Agent-to-Service/Sub-Agent Delegation: When the agent needs to interact with a service or delegate to a sub-agent, it presents its own identity and proof of its delegated authority from the user. This "sub-delegation" is also cryptographically signed, extending the chain.

• Verifiable Credentials: Leveraging standards like Decentralized Identifiers (DIDs) and Verifiable Credentials (VCs) can enable a system where each link in the delegation chain is cryptographically verifiable, creating an irrefutable audit trail. This means any service receiving an agent's request can verify the entire chain of delegation back to the original user.

2. Intent-Bound Credentials

This is perhaps the most significant shift. Instead of granting blanket permissions, credentials are tied directly to the specific intent of the delegated task.

• Dynamic Scoping: When a user asks an agent to "draft an email about X," the agent receives a credential for "drafting email" with a scope limited to content related to "X," and potentially for a very short duration. If the agent tries to access billing info, the credential is invalid.

• Policy Enforcement Points: Access decisions are made at runtime, not just at token issuance. Policies evaluate not only the agent's identity and its general permissions but also the context of the current request against the original user's intent.

• Domain-Specific Languages (DSLs) for Policy: As discussed in another post, a DSL allows you to precisely define these intent-based policies, linking user goals to permissible agent actions.

3. Time-Bound and Single-Use Credentials

Minimizing the lifespan and reusability of credentials dramatically reduces risk.

• Short-Lived Access Tokens: While traditional OAuth uses refresh tokens, for agents, access tokens should be extremely short-lived, perhaps valid for only minutes or even seconds for a specific API call.

• One-Time Use Tokens: For highly sensitive operations, a credential might be valid for only a single API call or a single transaction. Once used, it's immediately invalidated.

4. Behavior-Based Authorization

Beyond static policies, the future involves continuous evaluation of agent behavior.

• Anomaly Detection: Systems will monitor agent actions in real-time. If an agent with a "read-only" credential suddenly tries to "write" data, or accesses an unusual number of records, its current credentials could be automatically revoked.

• Adaptive Access Policies: Policies can adapt based on observed trust levels. An agent consistently adhering to its delegated intent might temporarily gain slightly broader (but still tightly controlled) permissions, while an agent exhibiting suspicious behavior has its access restricted.

The move beyond static tokens for AI agents isn't just an improvement; it's a necessity. Embracing identity chaining, intent-bound credentials, and dynamic, behavior-aware authorization is crucial for building secure, scalable, and auditable agent-powered systems.