photoncloud-monorepo/specifications/TEMPLATE.md

[Component Name] Specification

Version: 1.0 | Status: Draft | Last Updated: YYYY-MM-DD

1. Overview

1.1 Purpose

Brief description of what this component does and why it exists.

1.2 Scope

• In scope: What this component handles
• Out of scope: What is explicitly NOT handled

1.3 Design Goals

• Goal 1
• Goal 2
• Goal 3

2. Architecture

2.1 Crate Structure

component/
├── crates/
│   ├── component-api/      # gRPC service definitions
│   ├── component-client/   # Client library
│   ├── component-core/     # Core business logic
│   ├── component-server/   # Server binary
│   ├── component-storage/  # Persistence layer
│   └── component-types/    # Shared types
└── proto/                  # Protocol definitions

2.2 Data Flow

[Client] → [API Layer] → [Core Logic] → [Storage]
                ↓
          [Consensus] (if distributed)

2.3 Dependencies

Crate	Purpose
tokio	Async runtime
tonic	gRPC framework
...	...

3. API

3.1 gRPC Services

service ServiceName {
  rpc Method(Request) returns (Response);
}

3.2 Public Traits

pub trait TraitName {
    async fn method(&self, input: Input) -> Result<Output>;
}

3.3 Client Library

let client = Client::connect("http://localhost:2379").await?;
let value = client.get("key").await?;

4. Data Models

4.1 Core Types

pub struct CoreType {
    field: Type,
}

4.2 Storage Format

• Engine: RocksDB / SQLite / Memory
• Serialization: Protocol Buffers / MessagePack
• Key format: Describe key structure

5. Configuration

5.1 Config File Format (TOML)

[section]
key = "value"

5.2 Environment Variables

Variable	Default	Description
VAR_NAME	value	What it does

5.3 CLI Arguments

component-server [OPTIONS]
  --config <PATH>    Config file path
  --data-dir <PATH>  Data directory

6. Security

6.1 Authentication

• Method (mTLS / tokens / etc.)

6.2 Authorization

• Access control model

6.3 Multi-tenancy

• Isolation mechanisms
• Namespace/org scoping

7. Operations

7.1 Deployment

• Single node
• Cluster mode

7.2 Monitoring

• Metrics exposed (Prometheus format)
• Health endpoints

7.3 Backup & Recovery

• Snapshot mechanism
• Point-in-time recovery

8. Compatibility

8.1 API Versioning

• Version scheme
• Deprecation policy

8.2 Wire Protocol

• Protocol buffer version
• Backward compatibility guarantees

Appendix

A. Error Codes

Code	Meaning
...	...

B. Glossary

• Term: Definition