Warrants

Warrants are the core primitive in Tenuo's authorization model. They are cryptographically signed tokens that grant specific capabilities to an agent.

What is a Warrant?

A warrant is like a permission slip that says:

"The holder of this warrant is allowed to perform these specific actions, until this expiration time"

Unlike traditional access control (roles, ACLs), warrants are:

• Bearer tokens: Whoever holds the warrant can use it
• Self-contained: All permission info is in the token itself
• Cryptographically signed: Cannot be forged or modified
• Time-limited: Automatically expire

Warrant Structure

┌─────────────────────────────────────────┐
│              Warrant                     │
├─────────────────────────────────────────┤
│ ID:        tnu_wrt_abc123               │
│ Holder:    agent-456                     │
│ Actions:   ["read:docs", "write:summary"]│
│ Issued At: 2024-01-15T10:00:00Z         │
│ Expires:   2024-01-15T11:00:00Z         │
│ Issuer:    (public key of issuer)        │
│ Signature: (Ed25519 signature)           │
└─────────────────────────────────────────┘

How Warrants Work

┌────────────┐     ┌────────────┐     ┌─────────────┐
│   Issuer   │     │   Agent    │     │ Authorizer  │
│ (your app) │     │            │     │  (sidecar)  │
└─────┬──────┘     └─────┬──────┘     └──────┬──────┘
      │                  │                   │
      │  Issue Warrant   │                   │
      │─────────────────>│                   │
      │                  │                   │
      │                  │  Present Warrant  │
      │                  │──────────────────>│
      │                  │                   │
      │                  │                   │ Verify:
      │                  │                   │ - Signature
      │                  │                   │ - Expiration
      │                  │                   │ - Not revoked
      │                  │                   │
      │                  │   Grant Access    │
      │                  │<──────────────────│

1. Issue: Your application creates a warrant for an agent
2. Present: The agent presents the warrant when requesting access
3. Verify: The authorizer checks the warrant is valid
4. Grant: If valid, the action is allowed

Warrant vs JWT

Key Concepts

Holder

The entity (usually an AI agent) that holds and presents the warrant. Identified by a public key or opaque ID.

Actions

The specific operations the warrant allows. Actions are strings that you define:

read:documents
write:summaries
execute:code
access:database:users

Constraints

Optional CEL expressions that further restrict when the warrant is valid:

resource.owner == holder.id
request.time.hour >= 9 && request.time.hour < 17
action.amount < 1000

Expiration

All warrants have an expiration time. Short-lived warrants (minutes to hours) are more secure than long-lived ones.

Creating Warrants

Warrants are created using the Tenuo SDK, not directly in the dashboard:

from tenuo import Tenuo
 
tenuo = Tenuo(issuer_key="your-issuer-key")
 
warrant = tenuo.issue(
    holder="agent-123",
    actions=["read:documents"],
    expires_in="1h",
    constraints=["resource.category == 'public'"]
)

Viewing Warrants

The Warrants page in the dashboard lets you:

• Decode and inspect warrant contents
• Verify warrant signatures
• Check revocation status
• View the delegation chain

Best Practices

Use short expiration times

Issue warrants for the minimum time needed. Hours, not days.

Scope actions narrowly

read:documents:project-123 is better than read:*

Add constraints for sensitive actions

Use CEL constraints to limit when and how warrants can be used.

Rotate issuer keys

Regularly rotate issuer keys and re-issue warrants.

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