relayrl_framework 0.5.0-beta

# RelayRL Framework Version Comparison

## v0.4.52 → v0.5.0-alpha

This document provides a comprehensive comparison between `relayrl_framework` v0.4.52 (prototype) and v0.5.0-alpha (rewrite), analyzing architecture changes, API differences, dependency updates, and breaking changes.

---

## Executive Summary

Version 0.5.0-alpha represents a **complete rewrite** of the RelayRL framework, transforming it from a Python-centric prototype into a Rust-first, multi-actor native reinforcement learning framework.

| Aspect | v0.4.52 | v0.5.0-alpha |
|--------|---------|--------------|
| **Design Philosophy** | Python-first with Rust backend | Rust-first, language-agnostic |
| **Agent Model** | Single-agent focused | Multi-actor native |
| **Tensor Backend** | TorchScript (`tch`) only | Backend-agnostic (`burn-tensor`) |
| **Transport** | gRPC + ZMQ | ZMQ only (gRPC removed) |
| **Python Bindings** | Embedded (PyO3) | Separated crate (`relayrl_python`) |
| **Type System** | Internal modules | External crate (`relayrl_types`) |
| **Configuration** | Single unified config | Separated client/server configs |
| **Error Handling** | Panics & unwraps | Proper error types with propagation |

---

## 1. Package Metadata Changes

### Cargo.toml Comparison

| Field | v0.4.52 | v0.5.0-alpha |
|-------|---------|--------------|
| **Version** | `0.4.52` | `0.5.0-alpha` |
| **Description** | "A system-oriented, distributed reinforcement learning framework using a Rust backend with Python interfaces" | "A distributed, system-oriented multi-agent reinforcement learning framework" |
| **Keywords** | `reinforcement`, `learning`, `rl`, `distributed`, `system-integration` | `machine-learning`, `multi-agent`, `framework`, `client-server`, `system-integration` |
| **Crate Type** | `["rlib", "cdylib"]` | `["rlib"]` |
| **Repository** | Included | Removed |
| **Documentation** | `docs.rs` link | Removed |

### Key Changes:
- Removed `cdylib` crate type (no longer building Python extension module)
- Updated description to emphasize "multi-agent" over "Python interfaces"
- Simplified metadata by removing repository and documentation links

---

## 2. Dependency Changes

### Removed Dependencies

| Dependency | Version | Purpose in v0.4.52 |
|------------|---------|-------------------|
| `tch` | 0.18.1 | PyTorch/TorchScript tensor operations |
| `tonic` | 0.12.3 | gRPC client/server |
| `tonic-build` | 0.12.3 | Protobuf compilation |
| `prost` | 0.13.5 | Protobuf serialization |
| `pyo3` | 0.24.2 | Python bindings |
| `pyo3-build-config` | 0.24.2 | Python build configuration |
| `safetensors` | 0.5.3 | Tensor serialization |

### Added Dependencies

| Dependency | Version | Purpose in v0.5.0-alpha |
|------------|---------|------------------------|
| `relayrl_types` | 0.3.21 | External type definitions |
| `active-uuid-registry` | 0.3.0 | UUID pool management |
| `burn-tensor` | 0.18.0 | Backend-agnostic tensor operations |
| `arrow` | 57.1.0 | Trajectory data serialization |
| `arrow-schema` | 57.1.0 | Arrow schema definitions |
| `arrow-array` | 57.1.0 | Arrow array types |
| `dashmap` | 6.1.0 | Concurrent hash maps |
| `thiserror` | 2.0.17 | Error derive macros |
| `async-trait` | 0.1.89 | Async trait support |
| `uuid` | 1.18.1 | UUID generation |
| `log` | 0.4.28 | Logging facade |
| `bincode` | 2.0.1 | Binary serialization |

### Updated Dependencies

| Dependency | v0.4.52 | v0.5.0-alpha |
|------------|---------|--------------|
| `tokio` | 1.44.2 | 1.48.0 |
| `serde` | 1.0.215 | 1.0.195 |
| `rand` | 0.8.5 | 0.9.2 |
| `once_cell` | 1.20.2 | 1.19.0 |
| `tempfile` | 3.17.1 | 3.9.0 |
| `serde_json` | 1.0.133 | 1.0.111 |
| `serde-pickle` | 1.2.0 | 1.1.1 |
| `bytemuck` | 1.20.0 | 1.14.1 |

### Optional Dependencies (New)

| Dependency | Feature Flag | Purpose |
|------------|--------------|---------|
| `postgres` | `postgres_db` | PostgreSQL database support |
| `sqlite` | `sqlite_db` | SQLite database support |
| `prometheus` | `metrics` | Prometheus metrics export |
| `opentelemetry` | `metrics` | OpenTelemetry integration |
| `opentelemetry_sdk` | `metrics` | OpenTelemetry SDK |
| `opentelemetry-otlp` | `metrics` | OTLP exporter |
| `log4rs` | `logging` | Logging implementation |

---

## 3. Feature Flag Reorganization

### v0.4.52 Feature Flags

```toml
[features]
default = ["full"]
full = ["networks", "data_types", "python_bindings"]
networks = ["grpc_network", "zmq_network"]
grpc_network = ["tonic", "prost", "tonic-build", "pyo3", "data_types"]
zmq_network = ["zmq", "pyo3", "data_types"]
data_types = []
python_ipc_channel = ["pyo3"]
python_bindings = ["networks"]
profile = ["flamegraph", "console-subscriber"]
```

### v0.5.0-alpha Feature Flags

```toml
[features]
default = ["client"]

network = ["client", "inference_server", "training_server"]
client = []
inference_server = ["transport_layer"]
training_server = ["transport_layer"]

transport_layer = ["async_transport", "sync_transport"]
async_transport = []
sync_transport = ["zmq_transport"]
zmq_transport = ["zmq"]

database_layer = ["postgres_db", "sqlite_db"]
postgres_db = ["postgres"]
sqlite_db = ["sqlite"]

logging = ["log4rs"]
metrics = ["prometheus", "opentelemetry", "opentelemetry_sdk", "opentelemetry-otlp"]
profile = ["flamegraph", "console-subscriber"]
```

### Key Feature Changes:
1. **Default changed**: `full` → `client`
2. **gRPC removed**: No more `grpc_network` feature
3. **Python removed**: No more `python_bindings`, `python_ipc_channel`
4. **New server features**: `inference_server`, `training_server`
5. **New data layers**: `database_layer` with PostgreSQL/SQLite
6. **New observability**: `logging`, `metrics` features

---

## 4. Architecture Changes

### v0.4.52 Architecture

```
┌─────────────────────────────────────────────────┐
│  Python Bindings (PyO3)                         │
│  - PyRelayRLAgent, PyTrainingServer             │
│  - PyConfigLoader, PyRelayRLAction              │
└─────────────────────────────────────────────────┘
                      │
┌─────────────────────────────────────────────────┐
│  Network Layer                                  │
│  - agent_wrapper.rs (unified agent interface)   │
│  - agent_grpc.rs / agent_zmq.rs                 │
│  - training_server_wrapper.rs                   │
│  - training_grpc.rs / training_zmq.rs           │
└─────────────────────────────────────────────────┘
                      │
┌─────────────────────────────────────────────────┐
│  Core Types & Utilities                         │
│  - types/action.rs, types/trajectory.rs         │
│  - sys_utils/config_loader.rs                   │
│  - Python subprocess management                 │
└─────────────────────────────────────────────────┘
```

### v0.5.0-alpha Architecture

```
┌─────────────────────────────────────────────────┐
│  Public API (RelayRLAgent, AgentBuilder)        │
│  - network/client/agent.rs                      │
└─────────────────────────────────────────────────┘
                      │
┌─────────────────────────────────────────────────┐
│  Runtime Coordination Layer                     │
│  - ClientCoordinator                            │
│  - ScaleManager (router scaling)                │
│  - StateManager (actor state)                   │
│  - LifecycleManager (shutdown coordination)     │
└─────────────────────────────────────────────────┘
                      │
┌─────────────────────────────────────────────────┐
│  Message Routing Layer                          │
│  - RouterDispatcher                             │
│  - Router instances (scalable workers)          │
│  - TrajectoryBuffer (priority scheduling)       │
└─────────────────────────────────────────────────┘
                      │
┌─────────────────────────────────────────────────┐
│  Actor Execution Layer                          │
│  - Concurrent Actor instances                   │
│  - Local model inference                        │
│  - Trajectory building                          │
└─────────────────────────────────────────────────┘
                      │
┌─────────────────────────────────────────────────┐
│  Data Collection Layer                          │
│  - Arrow File Sink (available)                  │
│  - Transport Sink (under development)           │
│  - Database Sink (under development)            │
└─────────────────────────────────────────────────┘
```

---

## 5. Module Structure Comparison

### v0.4.52 Directory Structure

```
src/
├── lib.rs                          # PyO3 module definition
├── default_config.json
├── bindings/
│   └── python/
│       ├── network/
│       │   ├── client/o3_agent.rs
│       │   └── server/o3_training_server.rs
│       ├── o3_action.rs
│       ├── o3_config_loader.rs
│       └── o3_trajectory.rs
├── native/
│   └── python/                     # Python algorithm implementations
│       ├── algorithms/
│       │   └── REINFORCE/
│       └── _common/_algorithms/
├── network/
│   ├── mod.rs
│   ├── client/
│   │   ├── agent_wrapper.rs
│   │   ├── agent_grpc.rs
│   │   └── agent_zmq.rs
│   └── server/
│       ├── training_server_wrapper.rs
│       ├── training_grpc.rs
│       ├── training_zmq.rs
│       └── python_subprocesses/
├── sys_utils/
│   ├── config_loader.rs
│   ├── grpc_utils.rs
│   ├── misc_utils.rs
│   ├── resolve_server_config.rs
│   └── tokio_utils.rs
└── types/
    ├── action.rs
    └── trajectory.rs
```

### v0.5.0-alpha Directory Structure

```
src/
├── lib.rs                          # Prelude and module exports
├── network/
│   ├── mod.rs                      # TransportType, HyperparameterArgs
│   ├── client/
│   │   ├── mod.rs
│   │   ├── agent.rs                # Public API: RelayRLAgent, AgentBuilder
│   │   └── runtime/
│   │       ├── actor.rs
│   │       ├── router_dispatcher.rs
│   │       ├── coordination/
│   │       │   ├── coordinator.rs
│   │       │   ├── lifecycle_manager.rs
│   │       │   ├── scale_manager.rs
│   │       │   └── state_manager.rs
│   │       ├── router/
│   │       │   ├── buffer.rs
│   │       │   ├── filter.rs
│   │       │   └── receiver.rs
│   │       └── data/
│   │           ├── database/
│   │           │   ├── postgres.rs
│   │           │   └── sqlite.rs
│   │           └── transport/
│   │               └── zmq.rs
│   └── server/
│       ├── mod.rs
│       ├── inference_server.rs     # Skeleton
│       ├── training_server.rs      # Skeleton
│       └── runtime/coordination/
├── templates/
│   └── mod.rs                      # Environment traits
└── utilities/
    ├── configuration.rs            # Client/Server config loaders
    ├── observability/
    │   ├── logging/
    │   │   ├── builder.rs
    │   │   ├── filters.rs
    │   │   └── sinks/
    │   └── metrics/
    │       ├── manager.rs
    │       └── export/
    │           ├── prometheus.rs
    │           └── open_telemetry.rs
    └── tokio/
```

---

## 6. API Changes

### Agent Construction

**v0.4.52:**
```rust
use relayrl_framework::network::client::agent_wrapper::RelayRLAgent;
use tch::CModule;

let agent = RelayRLAgent::new(
    model: Option<CModule>,
    config_path: Option<PathBuf>,
    server_type: Option<String>,      // "grpc" or "zmq"
    training_prefix: Option<String>,
    training_port: Option<String>,
    training_host: Option<String>,
).await;
```

**v0.5.0-alpha:**
```rust
use relayrl_framework::prelude::network::*;
use burn_ndarray::NdArray;
use burn_tensor::Float;

let (agent, params) = AgentBuilder::<NdArray, D_IN, D_OUT, Float, Float>::builder()
    .actor_count(4)
    .router_scale(2)
    .default_device(DeviceType::Cpu)
    .default_model(model)
    .config_path(PathBuf::from("client_config.json"))
    .trajectory_persistence_mode(TrajectoryPersistenceMode::Local(Some(params)))
    .build()
    .await?;

agent.start(
    params.actor_count,
    params.router_scale,
    params.default_device,
    params.default_model,
    params.config_path,
).await?;
```

### Agent Interaction

**v0.4.52:**
```rust
// Single action request via internal ZMQ/gRPC transport
let action = agent.request_for_action(obs_tensor, mask_tensor, reward).await;
```

**v0.5.0-alpha:**
```rust
// Multi-actor action request
let actor_ids = agent.get_actor_ids()?;
let actions: Vec<(Uuid, Arc<RelayRLAction>)> = agent
    .request_action(actor_ids, observation, mask, reward)
    .await?;

// Flag last action as terminal
agent.flag_last_action(actor_ids, Some(final_reward)).await?;

// Get model versions per actor
let versions = agent.get_model_version(actor_ids).await?;
```

### Actor Management (New in v0.5.0-alpha)

```rust
// Create new actors
agent.new_actor(DeviceType::Cpu, Some(model)).await?;
agent.new_actors(10, DeviceType::Mps, None).await?;

// Remove actors
agent.remove_actor(actor_id).await?;

// Modify actor IDs
agent.set_actor_id(current_id, new_id).await?;

// Scale throughput (router workers)
agent.scale_throughput(2).await?;   // Add 2 routers
agent.scale_throughput(-1).await?;  // Remove 1 router
```

### Lifecycle Management

**v0.4.52:**
```rust
agent.restart_agent(training_server_address).await;
agent.enable_agent(training_server_address).await;
agent.disable_agent().await;
```

**v0.5.0-alpha:**
```rust
agent.restart(/* params */).await?;
agent.shutdown().await?;
```

---

## 7. Configuration System Changes

### v0.4.52 Configuration

Single `ConfigLoader` class with unified `relayrl_config.json`:

```rust
pub struct ConfigLoader {
    pub algorithm_params: Option<LoadedAlgorithmParams>,
    pub train_server: ServerParams,
    pub traj_server: ServerParams,
    pub agent_listener: ServerParams,
    pub tb_params: TensorboardParams,
    pub client_model_path: PathBuf,
    pub server_model_path: PathBuf,
    pub max_traj_length: u32,
    pub grpc_idle_timeout: u32,
}
```

### v0.5.0-alpha Configuration

Separated configuration with builders:

```rust
// Client Configuration
pub struct ClientConfigLoader {
    pub client_config: ClientConfigParams,
    pub transport_config: TransportConfigParams,
}

pub struct ClientConfigParams {
    pub algorithm_name: String,
    pub config_path: PathBuf,
    pub config_update_polling_seconds: f32,
    pub init_hyperparameters: HyperparameterConfig,
    pub trajectory_file_output: TrajectoryFileParams,
}

// Server Configuration  
pub struct ServerConfigLoader {
    pub server_config: ServerConfigParams,
    pub transport_config: TransportConfigParams,
}

// Transport Configuration
pub struct TransportConfigParams {
    pub inference_server_address: NetworkParams,
    pub agent_listener_address: NetworkParams,
    pub model_server_address: NetworkParams,
    pub trajectory_server_address: NetworkParams,
    pub scaling_server_address: NetworkParams,
    pub max_traj_length: u128,
    pub local_model_module: LocalModelModuleParams,
}
```

### Configuration File Format

**v0.4.52 (`relayrl_config.json`):**
```json
{
    "algorithms": {
        "REINFORCE": { /* params */ }
    },
    "grpc_idle_timeout": 30,
    "max_traj_length": 1000,
    "model_paths": {
        "client_model": "client_model.pt",
        "server_model": "server_model.pt"
    },
    "server": {
        "training_server": { "prefix": "tcp://", "host": "127.0.0.1", "port": "50051" },
        "trajectory_server": { /* ... */ },
        "agent_listener": { /* ... */ }
    },
    "tensorboard": { /* ... */ }
}
```

**v0.5.0-alpha (`client_config.json`):**
```json
{
    "client_config": {
        "algorithm_name": "REINFORCE",
        "config_update_polling_seconds": 10.0,
        "init_hyperparameters": {
            "DDPG": { /* params */ },
            "PPO": { /* params */ },
            "REINFORCE": { /* params */ },
            "TD3": { /* params */ }
        },
        "trajectory_file_output": {
            "enabled": true,
            "encode": true,
            "output": { "directory": "data", "file_name": "action_data", "format": "json" }
        }
    },
    "transport_config": {
        "addresses": {
            "model_server": { /* ... */ },
            "trajectory_server": { /* ... */ },
            "agent_listener": { /* ... */ },
            "scaling_server": { /* ... */ },
            "inference_server": { /* ... */ }
        },
        "local_model_module": { /* ... */ },
        "max_traj_length": 1000
    }
}
```

### Algorithm Support Expansion

| Algorithm | v0.4.52 | v0.5.0-alpha |
|-----------|---------|--------------|
| REINFORCE | ✓ | ✓ |
| PPO | - | ✓ |
| DDPG | - | ✓ |
| TD3 | - | ✓ |
| CUSTOM | - | ✓ |

---

## 8. Type System Changes

### Relocation to External Crate

The following types moved from internal `types/` module to `relayrl_types` crate:

| Type | v0.4.52 Location | v0.5.0-alpha Location |
|------|-----------------|----------------------|
| `RelayRLAction` | `types/action.rs` | `relayrl_types::types::data::action` |
| `TensorData` | `types/action.rs` | `relayrl_types::types::data::tensor` |
| `RelayRLData` | `types/action.rs` | `relayrl_types::types::data::action` |
| `RelayRLTrajectory` | `types/trajectory.rs` | `relayrl_types::types::data::trajectory` |

### New Types in v0.5.0-alpha

```rust
// Backend-agnostic tensor types
pub enum AnyBurnTensor<B: Backend, const D: usize> {
    Float(FloatBurnTensor<B, D>),
    Int(IntBurnTensor<B, D>),
    Bool(BoolBurnTensor<B, D>),
}

// Model module wrapper
pub struct ModelModule<B: Backend> {
    pub model: /* backend-specific model */,
    pub metadata: ModelMetadata,
}

// Device type enum
pub enum DeviceType {
    Cpu,
    Cuda(usize),
    Mps,
}

// Codec configuration
pub struct CodecConfig {
    pub compression: CompressionType,
    pub format: SerializationFormat,
}
```

---

## 9. Error Handling Improvements

### v0.4.52 Error Handling

Heavy reliance on panics and unwraps:

```rust
// Example from agent_wrapper.rs
let input_dim: IValue = model
    .method_is::<IValue>("get_input_dim", &[])
    .expect("Failed to get input dimension");

// Example from config_loader.rs
config_path.expect("[ConfigLoader - new] Invalid config path")
```

### v0.5.0-alpha Error Handling

Comprehensive error types with `thiserror`:

```rust
#[derive(Debug, Error)]
pub enum ClientError {
    #[error(transparent)]
    UuidPoolError(#[from] UuidPoolError),
    #[error("Inference server mode disabled: {0}")]
    InferenceServerModeDisabled(String),
    #[error(transparent)]
    CoordinatorError(#[from] CoordinatorError),
    #[error("Backend mismatch: {0}")]
    BackendMismatchError(String),
    // ... more variants
}

#[derive(Debug, Error)]
pub enum CoordinatorError {
    #[error("Client modes are invalid: {0}")]
    InvalidClientModesError(String),
    #[error(transparent)]
    TransportError(#[from] TransportError),
    #[error(transparent)]
    ScaleManagerError(#[from] ScaleManagerError),
    #[error(transparent)]
    StateManagerError(#[from] StateManagerError),
    #[error(transparent)]
    LifeCycleManagerError(#[from] LifeCycleManagerError),
    // ... more variants
}
```

---

## 10. Observability (New in v0.5.0-alpha)

### Logging System

```rust
// New logging infrastructure
pub struct LoggingBuilder {
    // Configurable logging with multiple sinks
}

// Sinks available:
// - Console sink (utilities/observability/logging/sinks/console.rs)
// - File sink (utilities/observability/logging/sinks/file.rs)

// Filters available:
// - Level filters
// - Module filters
```

### Metrics System

```rust
// New metrics infrastructure
pub struct MetricsManager {
    // Unified metrics collection and export
}

// Export options:
// - Prometheus (utilities/observability/metrics/export/prometheus.rs)
// - OpenTelemetry (utilities/observability/metrics/export/open_telemetry.rs)

// Usage in coordinator:
#[cfg(feature = "metrics")]
params.metrics.record_counter("actors_created", 1, &[]);

#[cfg(feature = "metrics")]
params.metrics.record_histogram("action_request_latency", duration, &[]);
```

---

## 11. Breaking Changes Summary

### Removed Functionality

1. **Python Bindings**: All PyO3 code removed from core framework
   - `PyRelayRLAgent`, `PyTrainingServer`, `PyConfigLoader`, etc.
   - Moved to separate `relayrl_python` crate (not yet implemented)

2. **gRPC Transport**: All Tonic/Protobuf code removed
   - `agent_grpc.rs`, `training_grpc.rs`
   - `grpc_utils.rs`
   - `proto/relayrl_grpc.proto`

3. **Python Algorithm Runtime**: Python subprocess management removed
   - `python_subprocesses/` directory
   - `native/python/` algorithm implementations

4. **TorchScript Direct Support**: `tch` crate dependency removed
   - Direct `CModule` usage no longer supported
   - Replaced with `ModelModule<B>` abstraction

### API Breaking Changes

1. **Agent Construction**: `RelayRLAgent::new()` → `AgentBuilder::builder().build()`

2. **Type Parameters**: Agent now requires generic type parameters
   ```rust
   // Old
   RelayRLAgent
   // New  
   RelayRLAgent<B, D_IN, D_OUT, KindIn, KindOut>
   ```

3. **Action Request**: Returns `Vec<(Uuid, Arc<RelayRLAction>)>` instead of single action

4. **Configuration**: `ConfigLoader` → `ClientConfigLoader` / `ServerConfigLoader`

5. **Config File**: `relayrl_config.json` → `client_config.json` / `server_config.json`

### Migration Requirements

| Task | Description |
|------|-------------|
| Update imports | Change from `tch` to `burn_tensor` types |
| Rewrite agent init | Use `AgentBuilder` pattern |
| Update config files | Migrate to new JSON structure |
| Handle multi-actor | Update code to handle multiple actor IDs |
| Error handling | Handle `Result` returns instead of expecting success |

---

## 12. Files Comparison Table

| Component | v0.4.52 Path | v0.5.0-alpha Path | Status |
|-----------|--------------|-------------------|--------|
| **Package Config** | `Cargo.toml` | `Cargo.toml` | Restructured |
| **Library Root** | `src/lib.rs` | `src/lib.rs` | Completely rewritten |
| **Agent API** | `network/client/agent_wrapper.rs` | `network/client/agent.rs` | Completely rewritten |
| **gRPC Agent** | `network/client/agent_grpc.rs` | - | Removed |
| **ZMQ Agent** | `network/client/agent_zmq.rs` | `network/client/runtime/data/transport/zmq.rs` | Redesigned |
| **Training Server** | `network/server/training_server_wrapper.rs` | `network/server/training_server.rs` | Skeleton only |
| **gRPC Server** | `network/server/training_grpc.rs` | - | Removed |
| **ZMQ Server** | `network/server/training_zmq.rs` | `network/server/runtime/transport/zmq.rs` | Skeleton only |
| **Configuration** | `sys_utils/config_loader.rs` | `utilities/configuration.rs` | Expanded (3x larger) |
| **Action Types** | `types/action.rs` | `relayrl_types` crate | Moved externally |
| **Trajectory Types** | `types/trajectory.rs` | `relayrl_types` crate | Moved externally |
| **gRPC Utils** | `sys_utils/grpc_utils.rs` | - | Removed |
| **Protobuf** | `proto/relayrl_grpc.proto` | - | Removed |
| **Python Bindings** | `bindings/python/*` | `relayrl_python` crate | Moved externally |
| **Python Algorithms** | `native/python/*` | `relayrl_algorithms` crate | Moved externally |
| **Coordinator** | - | `network/client/runtime/coordination/coordinator.rs` | New |
| **Scale Manager** | - | `network/client/runtime/coordination/scale_manager.rs` | New |
| **State Manager** | - | `network/client/runtime/coordination/state_manager.rs` | New |
| **Lifecycle Manager** | - | `network/client/runtime/coordination/lifecycle_manager.rs` | New |
| **Router** | - | `network/client/runtime/router/*.rs` | New |
| **Actor** | - | `network/client/runtime/actor.rs` | New |
| **Logging** | - | `utilities/observability/logging/*` | New |
| **Metrics** | - | `utilities/observability/metrics/*` | New |
| **Templates** | - | `templates/mod.rs` | New |

---

## 13. Development Status

### v0.5.0-alpha Completion Status

| Component | Status | Notes |
|-----------|--------|-------|
| **Client Runtime** | ✓ Available | Multi-actor native, fully functional |
| **Agent API** | ✓ Available | Builder pattern, comprehensive |
| **Local File Sink** | ✓ Available | Arrow format trajectory storage |
| **Configuration** | ✓ Available | Separated client/server configs |
| **Observability** | ✓ Available | Logging + metrics infrastructure |
| **ZMQ Transport** | ⚠ Under Development | Client-side partially implemented |
| **Database Layer** | ⚠ Under Development | PostgreSQL/SQLite interfaces |
| **Training Server** | ⚠ Skeleton Only | Runtime not implemented |
| **Inference Server** | ⚠ Skeleton Only | Runtime not implemented |
| **Python Bindings** | ✗ Not Available | Moved to separate crate |
| **Algorithms** | ✗ Not Available | Moved to separate crate |

### Roadmap to v1.0.0

- **v0.5.0**: Complete ZMQ transport and database interfaces
- **v0.6.0**: Training server implementation
- **v0.7.0**: Inference server implementation  
- **v0.8.0**: Full integration and optimization
- **v0.9.0/v1.0.0**: API stabilization

---

## 14. Recommendations for Migration

### For Rust Users

1. **Update Dependencies**: Add `relayrl_types` to your `Cargo.toml`
2. **Choose Backend**: Select `NdArray` (CPU) or `Tch` (CPU/CUDA/MPS)
3. **Use Builder Pattern**: Migrate agent creation to `AgentBuilder`
4. **Handle Multi-Actor**: Update loops to iterate over actor IDs
5. **Migrate Config**: Create new `client_config.json` file

### For Python Users

The v0.5.0-alpha release does not include Python bindings. Options:

1. **Wait for `relayrl_python`**: Future crate will provide bindings
2. **Use v0.4.52**: Continue with prototype for Python workflows
3. **Use CLI (Future)**: `relayrl_cli` will enable language-agnostic usage

---

*Document generated for RelayRL Framework comparison between v0.4.52 and v0.5.0-alpha*