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The Control Center serves as the central process supervisor and lifecycle manager for the Palyra Desktop application. It is responsible for orchestrating the execution of the core daemon (palyrad), the browser automation daemon (palyra-browserd), and the local palyra node host. The supervisor ensures these sidecars remain healthy, handles log aggregation with sensitive data redaction, and implements an exponential backoff strategy for service recovery.

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ControlCenter Architecture

The ControlCenter struct is the primary state container for the supervisor, managed within a Tauri State and wrapped in a Mutex for thread-safe access from async commands apps/desktop/src-tauri/src/commands.rs#63-65. It maintains the runtime configuration, service handles, and log buffers.

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Key Components

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Service Entity Mapping

System NameCode Entity (ServiceKind)Binary NameRole
GatewayServiceKind::GatewaypalyradCentral control plane and API provider apps/desktop/src-tauri/src/supervisor.rs#54-54.
BrowserServiceKind::Browserdpalyra-browserdHeadless Chrome automation service apps/desktop/src-tauri/src/supervisor.rs#55-55.
Node HostServiceKind::NodeHostpalyra node hostLocal capability execution host apps/desktop/src-tauri/src/supervisor.rs#56-56.
Sources: apps/desktop/src-tauri/src/supervisor.rs#35-71, apps/desktop/src-tauri/src/lib.rs#1-10

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ManagedService Lifecycle

Each sidecar is modeled as a ManagedService. The supervisor transitions services between states based on the desired_running flag and the actual process status.

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Restart Strategy: Exponential Backoff

When a service fails, the supervisor increments restart_attempt and calculates a delay using compute_backoff_ms.

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Lifecycle State Machine

Sources: apps/desktop/src-tauri/src/supervisor.rs#120-148, apps/desktop/src-tauri/src/supervisor.rs#445-465, apps/desktop/src-tauri/src/lib.rs#1-1

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Log Management and Sanitization

The supervisor captures stdout and stderr from sidecars using Stdio::piped() apps/desktop/src-tauri/src/supervisor.rs#520-521.

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Data Flow

  1. Capture: tokio::io::BufReader reads lines from the process pipes apps/desktop/src-tauri/src/supervisor.rs#17-18.
  2. Sanitization: Every line is passed through sanitize_log_line, which redacts:
  3. Ingestion: Sanitized lines are sent via log_tx to the ControlCenter’s internal log_rx receiver apps/desktop/src-tauri/src/supervisor.rs#231-232.
  4. Storage: Lines are stored in a VecDeque<LogLine> per service, capped at MAX_LOG_LINES_PER_SERVICE (400 lines) to prevent memory exhaustion apps/desktop/src-tauri/src/lib.rs#2-2.
Sources: apps/desktop/src-tauri/src/supervisor.rs#530-550, apps/desktop/src-tauri/src/lib.rs#2-3, apps/desktop/src-tauri/src/snapshot.rs#11-16

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Sidecar Specifics

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palyrad (Gateway)

The primary sidecar. It is launched with essential environment variables including PALYRA_ADMIN_TOKEN and PALYRA_BROWSER_AUTH_TOKEN to secure the internal gRPC and HTTP surfaces apps/desktop/src-tauri/src/supervisor.rs#560-580. It binds to ports 7142 (Admin), 7443 (gRPC), and 7444 (QUIC) by default apps/desktop/src-tauri/src/lib.rs#16-18.

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palyra-browserd

Managed based on the browser_service_enabled preference in DesktopStateFile. If enabled, the supervisor ensures it is running and healthy, binding to ports 7143 (Health) and 7543 (gRPC) apps/desktop/src-tauri/src/lib.rs#19-20.

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palyra node host

The supervisor manages the local node host using the CLI binary.

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Implementation Reference

Sources: apps/desktop/src-tauri/src/supervisor.rs#108-118, apps/desktop/src-tauri/src/supervisor.rs#212-234, apps/desktop/src-tauri/src/supervisor.rs#35-41