# tayyabsiddique77/langchain-production-api architecture

> Architecture diagram of the GitHub repository tayyabsiddique77/langchain-production-api, generated by GitDiagram from its file tree, README and a sample of source files (last updated 2026-09-25). It is an AI-made overview: check details against the source.

- Interactive diagram: https://gitdiagram.com/tayyabsiddique77/langchain-production-api
- Repository: https://github.com/tayyabsiddique77/langchain-production-api

## Overview

This is a FastAPI chat service whose main workflow validates a request, applies rate limiting and input security, checks the response cache, invokes the LangGraph agent on a miss, validates the model output, and returns it while recording metrics and logs. The agent attempts Groq first and may use Gemini as fallback. Health, metrics, and cache-stat endpoints are additional product capabilities. The graph follows README-documented capabilities where source excerpts are incomplete; deployment and tracing internals are not expanded beyond the available evidence.

Main entry points: [`app/main.py`](https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/main.py) (FastAPI endpoints), [`app/agent.py`](https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/agent.py) (LangGraph agent), [`app/config.py`](https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/config.py) (Settings), [`app/security.py`](https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/security.py) (Security pipeline)

## Diagram (Mermaid)

```mermaid
flowchart TD

subgraph group_api["API service"]
  node_api["FastAPI endpoints<br/>[main.py]"]
  node_schemas["Request schemas<br/>[models.py]"]
  node_limiter["Rate limiter<br/>[main.py]"]
  node_config["Settings<br/>[config.py]"]
end

subgraph group_security["Security and cache"]
  node_security["Security pipeline<br/>[security.py]"]
  node_cache[("Response cache<br/>[cache.py]")]
end

subgraph group_inference["Agent and models"]
  node_agent["LangGraph agent<br/>[agent.py]"]
  node_groq["Groq primary model"]
  node_gemini["Gemini fallback model"]
end

subgraph group_operations["Operations"]
  node_metrics["Metrics collector<br/>[monitoring.py]"]
  node_logging["Structured logger<br/>[monitoring.py]"]
  node_langsmith["LangSmith tracing"]
end

node_client(("Chat client"))
node_environment["Environment settings"]

node_client -->|"sends requests"| node_api
node_api -->|"validates payload"| node_schemas
node_api -->|"limits requests"| node_limiter
node_api -->|"loads settings"| node_config
node_config -->|"reads values"| node_environment
node_api -->|"checks input"| node_security
node_api -->|"looks up response"| node_cache
node_cache -->|"returns hit"| node_api
node_api -->|"invokes on miss"| node_agent
node_agent -->|"loads model settings"| node_config
node_agent -->|"invokes primary"| node_groq
node_agent -->|"invokes on failure"| node_gemini
node_api -->|"validates output"| node_security
node_api -->|"stores response"| node_cache
node_api -->|"records and reads"| node_metrics
node_api -->|"writes events"| node_logging
node_api -->|"returns response"| node_client
node_api -.->|"traces endpoint"| node_langsmith
node_security -.->|"traces checks"| node_langsmith
node_agent -.->|"traces invocation"| node_langsmith

click node_api "https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/main.py"
click node_schemas "https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/models.py"
click node_limiter "https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/main.py"
click node_config "https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/config.py"
click node_security "https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/security.py"
click node_cache "https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/cache.py"
click node_agent "https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/agent.py"
click node_metrics "https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/monitoring.py"
click node_logging "https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/monitoring.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_api,node_schemas,node_limiter,node_config,node_client toneBlue
class node_security,node_cache toneAmber
class node_agent,node_groq,node_gemini toneMint
class node_metrics,node_logging,node_langsmith toneRose
class node_environment toneIndigo
```

## Components

### API service

- [FastAPI endpoints](https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/main.py): `app/main.py`
- [Request schemas](https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/models.py): `app/models.py`
- [Rate limiter](https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/main.py): `app/main.py`
- [Settings](https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/config.py): `app/config.py`

### Security and cache

- [Security pipeline](https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/security.py): `app/security.py`
- [Response cache](https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/cache.py): `app/cache.py`

### Agent and models

- [LangGraph agent](https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/agent.py): `app/agent.py`
- **Groq primary model**
- **Gemini fallback model**

### Operations

- [Metrics collector](https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/monitoring.py): `app/monitoring.py`
- [Structured logger](https://github.com/tayyabsiddique77/langchain-production-api/blob/main/app/monitoring.py): `app/monitoring.py`
- **LangSmith tracing**

### Other components

- **Chat client**
- **Environment settings**

## Connections

- Chat client → FastAPI endpoints: sends requests
- FastAPI endpoints → Request schemas: validates payload
- FastAPI endpoints → Rate limiter: limits requests
- FastAPI endpoints → Settings: loads settings
- Settings → Environment settings: reads values
- FastAPI endpoints → Security pipeline: checks input
- FastAPI endpoints → Response cache: looks up response
- Response cache → FastAPI endpoints: returns hit
- FastAPI endpoints → LangGraph agent: invokes on miss
- LangGraph agent → Settings: loads model settings
- LangGraph agent → Groq primary model: invokes primary
- LangGraph agent → Gemini fallback model: invokes on failure
- FastAPI endpoints → Security pipeline: validates output
- FastAPI endpoints → Response cache: stores response
- FastAPI endpoints → Metrics collector: records and reads
- FastAPI endpoints → Structured logger: writes events
- FastAPI endpoints → Chat client: returns response
- FastAPI endpoints → LangSmith tracing: traces endpoint
- Security pipeline → LangSmith tracing: traces checks
- LangGraph agent → LangSmith tracing: traces invocation