Templates
You can use any template engine you want with FastAPI.
A common choice is Jinja2, the same one used by Flask and other tools.
There are utilities to configure it easily that you can use directly in your FastAPI application (provided by Starlette).
Install dependencies
Section titled “Install dependencies”Add jinja2 to your project:
$ uv add jinja2
---> 100%Using Jinja2Templates
Section titled “Using Jinja2Templates”- Import
Jinja2Templates. - Create a
templatesobject that you can reuse later. - Declare a
Requestparameter in the path operation that will return a template. - Use the
templatesyou created to render and return aTemplateResponse, pass the name of the template, the request object, and a "context" dictionary with key-value pairs to be used inside of the Jinja2 template.
from fastapi import FastAPI, Request
from fastapi.responses import HTMLResponse
from fastapi.staticfiles import StaticFiles
from fastapi.templating import Jinja2Templates
app = FastAPI()
app.mount("/static", StaticFiles(directory="static"), name="static")
templates = Jinja2Templates(directory="templates")
@app.get("/items/{id}", response_class=HTMLResponse)
async def read_item(request: Request, id: str):
return templates.TemplateResponse(
request=request, name="item.html", context={"id": id}
)Writing templates
Section titled “Writing templates”Then you can write a template at templates/item.html with, for example:
<html><head> <title>Item Details</title> <link href="{{ url_for('static', path='/styles.css') }}" rel="stylesheet"></head><body> <h1><a href="{{ url_for('read_item', id=id) }}">Item ID: {{ id }}</a></h1></body></html>Template Context Values
Section titled “Template Context Values”In the HTML that contains:
Item ID: {{ id }}...it will show the id taken from the "context" dict you passed:
{"id": id}For example, with an ID of 42, this would render:
Item ID: 42Template url_for Arguments
Section titled “Template url_for Arguments”You can also use url_for() inside of the template, it takes as arguments the same arguments that would be used by your path operation function.
So, the section with:
<a href="{{ url_for('read_item', id=id) }}">...will generate a link to the same URL that would be handled by the path operation function read_item(id=id).
For example, with an ID of 42, this would render:
<a href="/items/42">Templates and static files
Section titled “Templates and static files”You can also use url_for() inside of the template, and use it, for example, with the StaticFiles you mounted with the name="static".
<html><head> <title>Item Details</title> <link href="{{ url_for('static', path='/styles.css') }}" rel="stylesheet"></head><body> <h1><a href="{{ url_for('read_item', id=id) }}">Item ID: {{ id }}</a></h1></body></html>In this example, it would link to a CSS file at static/styles.css with:
h1 { color: green;}And because you are using StaticFiles, that CSS file would be served automatically by your FastAPI application at the URL /static/styles.css.
More details
Section titled “More details”For more details, including how to test templates, check Starlette's docs on templates.