# sneham18/fast_api-poc architecture

> Architecture diagram of the GitHub repository sneham18/fast_api-poc, generated by GitDiagram from its file tree, README and a sample of source files (last updated 2026-08-13). It is an AI-made overview: check details against the source.

- Interactive diagram: https://gitdiagram.com/sneham18/fast_api-poc
- Repository: https://github.com/sneham18/fast_api-poc

## Overview

#### Purpose and Entry Points
This is a small Python/FastAPI learning or demonstration repository focused on API behavior, typing, async execution, validation, configuration, and LLM integration. The primary server entry point is `main.py`, intended to run via Uvicorn as `main:app`. Container execution is defined by `Dockerfile`.

#### API Application Layer
`main.py` owns the FastAPI application object and likely exposes the HTTP routes exercised by the examples. It is the boundary between inbound HTTP requests and the repository’s Python demonstration modules.

Relevant paths:
- `main.py`
- `Dockerfile`
- `requirements.txt`

#### Data Validation and Response Contracts
Pydantic models and explicitly declared return types shape request/response payloads. This separates API contracts from route implementation and provides FastAPI-generated validation and serialization.

Relevant paths:
- `pydantic_basic.py`
- `return_data_type.py`
- `main.py`

#### Asynchronous Execution
Async/await behavior is isolated as a teaching or reusable execution component, likely called from routes or independently run examples. FastAPI can execute async endpoints directly under its ASGI runtime.

Relevant paths:
- `async_await.py`
- `main.py`

#### Configuration and Environment Boundary
Application configuration is centralized rather than embedded in route logic. Environment-variable handling appears to be demonstrated separately, creating a boundary between deployment-provided settings and application code.

Relevant paths:
- `config.py`
- `ind_std_env_file.py`
- `.python-version`

#### Cross-Cutting Route/Function Behavior
Decorators provide reusable wrapping behavior around functions or endpoints, such as logging, authorization, timing, or instrumentation. They should remain independent of API transport details where possible.

Relevant paths:
- `decorators.py`
- `main.py`

#### External AI Service Integration
Groq-backed functionality is isolated in a dedicated module, creating the principal external-service boundary. API handlers should call this module rather than coupling provider-specific client usage directly into routes.

Relevant paths:
- `with_groq.py`
- `config.py`
- `main.py`

#### Runtime and Deployment Flow
The service runs on Python with FastAPI/Uvicorn dependencies managed through `pyproject.toml`, `requirements.txt`, and a locked dependency graph in `uv.lock`. Docker packages the application and exposes it on port 8000. Primary control flow is: container or Uvicorn starts `main:app` → FastAPI dispatches request routes → routes validate models and invoke async/decorator/config/LLM modules → typed response is serialized to HTTP.

Relevant paths:
- `Dockerfile`
- `pyproject.toml`
- `uv.lock`

Main entry points: [`main.py`](https://github.com/sneham18/fast_api-poc/blob/main/main.py) (FastAPI app & routes), [`config.py`](https://github.com/sneham18/fast_api-poc/blob/main/config.py) (Configuration), [`with_groq.py`](https://github.com/sneham18/fast_api-poc/blob/main/with_groq.py) (Groq integration), [`ind_std_env_file.py`](https://github.com/sneham18/fast_api-poc/blob/main/ind_std_env_file.py) (Environment variables)

## Diagram (Mermaid)

```mermaid
flowchart TD

subgraph group_api["API service"]
  node_fastapi_app{{"FastAPI app &amp; routes<br/>ASGI entry point<br/>[main.py]"}}
  node_contracts["Validation contracts<br/>Pydantic models<br/>[pydantic_basic.py]"]
  node_return_types["Response types<br/>return contracts"]
end

subgraph group_app["Application modules"]
  node_async_execution["Async execution<br/>async module<br/>[async_await.py]"]
  node_decorators["Function decorators<br/>cross-cutting module<br/>[decorators.py]"]
  node_config["Configuration<br/>settings module<br/>[config.py]"]
  node_environment["Environment variables<br/>environment boundary"]
  node_groq_integration["Groq integration<br/>LLM client module<br/>[with_groq.py]"]
end

subgraph group_runtime["Runtime &amp; deployment"]
  node_docker["Docker image<br/>container"]
  node_dependencies["Dependencies<br/>dependency manifest<br/>[pyproject.toml]"]
  node_uv_lock["Locked dependencies<br/>lockfile<br/>[uv.lock]"]
  node_requirements["Requirements<br/>dependency manifest<br/>[requirements.txt]"]
  node_python_version["Python version<br/>runtime version<br/>[.python-version]"]
end

node_groq(("Groq API<br/>external AI service"))
node_http_clients(("HTTP clients<br/>request source"))

node_docker -->|"starts main:app"| node_fastapi_app
node_dependencies -->|"locks"| node_uv_lock
node_requirements -.->|"provides runtime packages"| node_fastapi_app
node_python_version -.->|"selects runtime"| node_fastapi_app
node_http_clients -->|"HTTP requests"| node_fastapi_app
node_fastapi_app -->|"validates payloads"| node_contracts
node_fastapi_app -->|"serializes typed responses"| node_return_types
node_fastapi_app -->|"invokes async work"| node_async_execution
node_fastapi_app -->|"applies wrappers"| node_decorators
node_fastapi_app -->|"reads settings"| node_config
node_fastapi_app -->|"calls LLM module"| node_groq_integration
node_environment -->|"supplies variables"| node_config
node_config -->|"provides provider settings"| node_groq_integration
node_groq_integration -->|"LLM requests"| node_groq
node_fastapi_app -->|"HTTP responses"| node_http_clients

click node_docker "https://github.com/sneham18/fast_api-poc/blob/main/Dockerfile"
click node_dependencies "https://github.com/sneham18/fast_api-poc/blob/main/pyproject.toml"
click node_uv_lock "https://github.com/sneham18/fast_api-poc/blob/main/uv.lock"
click node_requirements "https://github.com/sneham18/fast_api-poc/blob/main/requirements.txt"
click node_fastapi_app "https://github.com/sneham18/fast_api-poc/blob/main/main.py"
click node_contracts "https://github.com/sneham18/fast_api-poc/blob/main/pydantic_basic.py"
click node_return_types "https://github.com/sneham18/fast_api-poc/blob/main/return_data_type.py"
click node_async_execution "https://github.com/sneham18/fast_api-poc/blob/main/async_await.py"
click node_decorators "https://github.com/sneham18/fast_api-poc/blob/main/decorators.py"
click node_config "https://github.com/sneham18/fast_api-poc/blob/main/config.py"
click node_environment "https://github.com/sneham18/fast_api-poc/blob/main/ind_std_env_file.py"
click node_python_version "https://github.com/sneham18/fast_api-poc/blob/main/.python-version"
click node_groq_integration "https://github.com/sneham18/fast_api-poc/blob/main/with_groq.py"

classDef toneNeutral fill:#f8fafc,stroke:#334155,stroke-width:1.5px,color:#0f172a
classDef toneBlue fill:#dbeafe,stroke:#2563eb,stroke-width:1.5px,color:#172554
classDef toneAmber fill:#fef3c7,stroke:#d97706,stroke-width:1.5px,color:#78350f
classDef toneMint fill:#dcfce7,stroke:#16a34a,stroke-width:1.5px,color:#14532d
classDef toneRose fill:#ffe4e6,stroke:#e11d48,stroke-width:1.5px,color:#881337
classDef toneIndigo fill:#e0e7ff,stroke:#4f46e5,stroke-width:1.5px,color:#312e81
classDef toneTeal fill:#ccfbf1,stroke:#0f766e,stroke-width:1.5px,color:#134e4a
class node_fastapi_app,node_contracts,node_return_types toneBlue
class node_async_execution,node_decorators,node_config,node_environment,node_groq_integration toneAmber
class node_docker,node_dependencies,node_uv_lock,node_requirements,node_python_version toneMint
class node_groq,node_http_clients toneNeutral
```

## Components

### API service

- [FastAPI app & routes](https://github.com/sneham18/fast_api-poc/blob/main/main.py): ASGI entry point · Uvicorn serves main:app and dispatches HTTP routes. · `main.py`
- [Validation contracts](https://github.com/sneham18/fast_api-poc/blob/main/pydantic_basic.py): Pydantic models · Defines request validation and typed response serialization. · `pydantic_basic.py`
- [Response types](https://github.com/sneham18/fast_api-poc/blob/main/return_data_type.py): return contracts · `return_data_type.py`

### Application modules

- [Async execution](https://github.com/sneham18/fast_api-poc/blob/main/async_await.py): async module · `async_await.py`
- [Function decorators](https://github.com/sneham18/fast_api-poc/blob/main/decorators.py): cross-cutting module · `decorators.py`
- [Configuration](https://github.com/sneham18/fast_api-poc/blob/main/config.py): settings module · Centralizes application configuration. · `config.py`
- [Environment variables](https://github.com/sneham18/fast_api-poc/blob/main/ind_std_env_file.py): environment boundary · `ind_std_env_file.py`
- [Groq integration](https://github.com/sneham18/fast_api-poc/blob/main/with_groq.py): LLM client module · Isolates provider-specific AI client usage. · `with_groq.py`

### Runtime & deployment

- [Docker image](https://github.com/sneham18/fast_api-poc/blob/main/Dockerfile): container · Packages and exposes the service on port 8000. · `Dockerfile`
- [Dependencies](https://github.com/sneham18/fast_api-poc/blob/main/pyproject.toml): dependency manifest · Python dependencies and locked resolution. · `pyproject.toml`
- [Locked dependencies](https://github.com/sneham18/fast_api-poc/blob/main/uv.lock): lockfile · `uv.lock`
- [Requirements](https://github.com/sneham18/fast_api-poc/blob/main/requirements.txt): dependency manifest · `requirements.txt`
- [Python version](https://github.com/sneham18/fast_api-poc/blob/main/.python-version): runtime version · `.python-version`

### Other components

- **Groq API**: external AI service
- **HTTP clients**: request source

## Connections

- Docker image → FastAPI app & routes: starts main:app
- Dependencies → Locked dependencies: locks
- Requirements → FastAPI app & routes: provides runtime packages
- Python version → FastAPI app & routes: selects runtime
- HTTP clients → FastAPI app & routes: HTTP requests
- FastAPI app & routes → Validation contracts: validates payloads
- FastAPI app & routes → Response types: serializes typed responses
- FastAPI app & routes → Async execution: invokes async work
- FastAPI app & routes → Function decorators: applies wrappers
- FastAPI app & routes → Configuration: reads settings
- FastAPI app & routes → Groq integration: calls LLM module
- Environment variables → Configuration: supplies variables
- Configuration → Groq integration: provides provider settings
- Groq integration → Groq API: LLM requests
- FastAPI app & routes → HTTP clients: HTTP responses