Crate astrid_capabilities 

Astrid Capabilities - Cryptographically signed authorization tokens.

This crate provides:

• Capability tokens with ed25519 signatures
• Resource patterns with glob matching
• Session and persistent token storage
• Token validation and authorization checking

Security Model

Every capability token is:

• Signed by the runtime’s ed25519 key
• Linked to the approval audit entry that created it
• Time-bounded (optional expiration)
• Scoped (session or persistent)

Example

use astrid_capabilities::{
    CapabilityToken, CapabilityStore, ResourcePattern, TokenScope, AuditEntryId,
};
use astrid_core::Permission;
use astrid_crypto::KeyPair;

// Create a capability store
let store = CapabilityStore::in_memory();

// Runtime key for signing
let runtime_key = KeyPair::generate();

// Create a capability token
let token = CapabilityToken::create(
    ResourcePattern::new("mcp://filesystem:*").unwrap(),
    vec![Permission::Invoke],
    TokenScope::Session,
    runtime_key.key_id(),
    AuditEntryId::new(),
    &runtime_key,
    None,
);

// Add to store
store.add(token).unwrap();

// Check capability
assert!(store.has_capability("mcp://filesystem:read_file", Permission::Invoke));

Modules

prelude

Prelude module - commonly used types for convenient import.

Structs

AuditEntryId

Unique identifier for an audit entry (used for linking).

CapabilityStore

Capability store with both session and persistent storage.

CapabilityToken

A capability token granting permissions for a resource.

CapabilityValidator

Capability validator for checking authorization.

DirHandle

A cryptographic handle representing an open directory within the VFS. This acts as a capability token preventing the guest from forging arbitrary paths.

FileHandle

A cryptographic handle representing an open file within the VFS.

ResourcePattern

A pattern that matches resources.

Enums

AuthorizationResult

Authorization result after validation.

CapabilityError

Errors that can occur with capability tokens.

TokenScope

Token scope - how long it lasts.

Type Aliases

CapabilityResult

Result type for capability operations.