## MODIFIED Requirements

### Requirement: Host identity is authenticated and bound to one host id
Except for the bootstrap enrollment operation authenticated by a configured one-time enrollment credential, the internal Host Agent API SHALL require a host-scoped bearer principal and SHALL reject any request that attempts to act for a `host_id` different from the authenticated principal's bound host.

#### Scenario: Host authenticates as itself
- **WHEN** a Host Agent presents valid static or dynamically enrolled credentials bound to its requested `host_id`
- **THEN** the internal API authorizes permitted device enrollment, heartbeat, claim, renewal, and result operations

#### Scenario: Host attempts to impersonate another host
- **WHEN** valid credentials bound to host A are used on a request for host B
- **THEN** the internal API rejects the request without reading or modifying host B's state

#### Scenario: Unknown Host credential is presented
- **WHEN** a caller presents a bearer credential that is neither statically configured nor bound to a non-revoked enrolled Host
- **THEN** the internal API rejects the request without exposing whether a Host ID exists

### Requirement: Host Agent synchronizes heartbeat and complete device snapshots
The Host Agent SHALL periodically submit its complete local device snapshot to the control plane, and the control plane SHALL atomically refresh the host heartbeat and replace only that host's pooled-device records. Enrollment-managed Hosts SHALL report the cloud device IDs assigned through device enrollment.

#### Scenario: Managed Host reports enrolled devices
- **WHEN** an enrollment-managed Host Agent submits a valid heartbeat containing cloud device IDs enrolled to that Host
- **THEN** the control plane updates the host's last-seen time and exposes the submitted devices through the aggregated pool

#### Scenario: Managed Host reports an unknown device ID
- **WHEN** an enrollment-managed Host reports a device ID not enrolled to that Host or a driver type that conflicts with its enrollment
- **THEN** the control plane rejects the entire snapshot without changing the previous heartbeat or pooled-device state

#### Scenario: Legacy Host reports devices
- **WHEN** a statically configured legacy Host submits a valid device snapshot
- **THEN** the control plane retains the existing compatible snapshot and ownership-conflict behavior

#### Scenario: Host reports no devices
- **WHEN** a previously populated Host submits an empty device snapshot
- **THEN** only that Host's prior pooled-device records are removed while durable enrollment records and devices owned by other Hosts remain unchanged

## ADDED Requirements

### Requirement: Managed Host startup enrolls before normal protocol loops
The Host Agent SHALL resolve its Host identity and cloud device mappings before starting heartbeat synchronization or assignment long-polling.

#### Scenario: New managed Host starts
- **WHEN** the Host Agent has an enrollment token but no completed local Host identity
- **THEN** it performs idempotent Host enrollment, enrolls configured local devices, constructs its `DeviceManager` with cloud device IDs, and only then starts heartbeat and claim loops

#### Scenario: Explicit legacy credentials are configured
- **WHEN** both `HOST_AGENT_HOST_ID` and `HOST_AGENT_TOKEN` are explicitly supplied
- **THEN** the Host Agent skips bootstrap enrollment and preserves existing local device ID behavior