{"id":5990,"date":"2026-10-12T03:03:35","date_gmt":"2026-10-12T06:03:35","guid":{"rendered":"https:\/\/tucumandevelopers.com\/index.php\/2026\/10\/12\/fastapi-jwt-authentication-in-2026-a-complete-login-api-in-one-file-argon2-pyjwt-tested\/"},"modified":"2026-10-12T03:03:35","modified_gmt":"2026-10-12T06:03:35","slug":"fastapi-jwt-authentication-in-2026-a-complete-login-api-in-one-file-argon2-pyjwt-tested","status":"publish","type":"post","link":"https:\/\/tucumandevelopers.com\/index.php\/2026\/10\/12\/fastapi-jwt-authentication-in-2026-a-complete-login-api-in-one-file-argon2-pyjwt-tested\/","title":{"rendered":"FastAPI JWT Authentication in 2026: A Complete Login API in One File (Argon2 + PyJWT, Tested)"},"content":{"rendered":"<div>\n<div>\n<p>The flow: the client sends a username and password to <code>\/token<\/code>, gets back a signed JWT, then sends it as <code>Authorization: Bearer &lt;token&gt;<\/code> on every protected request. One dependency, <code>get_current_user()<\/code>, does all the checking, so protecting a new route is a single line.<\/p>\n<h2> <a name=\"1-install\" href=\"#1-install\"> <\/a> 1. Install <\/h2>\n<p><code>requirements.txt<\/code>: <\/p>\n<div>\n<pre><code>fastapi&gt;=0.115.0 uvicorn[standard]&gt;=0.30.0 pyjwt&gt;=2.9.0 pwdlib[argon2]&gt;=0.2.0 python-multipart&gt;=0.0.9 python-dotenv&gt;=1.0.1 <\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<div>\n<pre><code>python3.12 <span>-m<\/span> venv .venv <span>&amp;&amp;<\/span> <span>source<\/span> .venv\/bin\/activate pip <span>install<\/span> <span>-r<\/span> requirements.txt <\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<ul>\n<li> <strong>PyJWT<\/strong> signs and verifies tokens. (FastAPI&#8217;s docs moved from python-jose to PyJWT.)<\/li>\n<li> <strong>pwdlib[argon2]<\/strong> hashes passwords with Argon2, the modern replacement for passlib.<\/li>\n<li> <strong>python-multipart<\/strong> is needed because the login endpoint reads an HTML-style form.<\/li>\n<\/ul>\n<p>Use Python 3.10 or newer: the code uses <code>str | None<\/code> type hints, which Pydantic rejects on 3.9.<\/p>\n<h2> <a name=\"2-config-secret-algorithm-expiry\" href=\"#2-config-secret-algorithm-expiry\"> <\/a> 2. Config: secret, algorithm, expiry <\/h2>\n<div>\n<pre><code><span>load_dotenv<\/span><span>()<\/span> <span>app<\/span> <span>=<\/span> <span>FastAPI<\/span><span>(<\/span><span>title<\/span><span>=<\/span><span>\"<\/span><span>FastAPI JWT Authentication<\/span><span>\"<\/span><span>,<\/span> <span>version<\/span><span>=<\/span><span>\"<\/span><span>1.0.0<\/span><span>\"<\/span><span>)<\/span> <span>JWT_SECRET<\/span> <span>=<\/span> <span>os<\/span><span>.<\/span><span>getenv<\/span><span>(<\/span><span>\"<\/span><span>JWT_SECRET<\/span><span>\"<\/span><span>,<\/span> <span>\"<\/span><span>dev-only-secret-change-me<\/span><span>\"<\/span><span>)<\/span> <span>ALGORITHM<\/span> <span>=<\/span> <span>\"<\/span><span>HS256<\/span><span>\"<\/span> <span>ACCESS_TOKEN_EXPIRE_MINUTES<\/span> <span>=<\/span> <span>30<\/span> <span>password_hash<\/span> <span>=<\/span> <span>PasswordHash<\/span><span>.<\/span><span>recommended<\/span><span>()<\/span> <span>oauth2_scheme<\/span> <span>=<\/span> <span>OAuth2PasswordBearer<\/span><span>(<\/span><span>tokenUrl<\/span><span>=<\/span><span>\"<\/span><span>token<\/span><span>\"<\/span><span>)<\/span> <\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<p><code>PasswordHash.recommended()<\/code> picks Argon2. <code>OAuth2PasswordBearer(tokenUrl=\"token\")<\/code> tells FastAPI where tokens come from. It also powers the <strong>Authorize<\/strong> button in Swagger UI.<\/p>\n<p><strong>Generate a real secret<\/strong> and put it in <code>.env<\/code>. More on why below: <\/p>\n<div>\n<pre><code>python <span>-c<\/span> <span>\"import secrets; print(secrets.token_urlsafe(32))\"<\/span> <\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<div>\n<pre><code>JWT_SECRET=paste-the-output-here <\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<h2> <a name=\"3-users-models-and-password-checks\" href=\"#3-users-models-and-password-checks\"> <\/a> 3. Users, models and password checks <\/h2>\n<p>For the demo, users live in a dict, and the password is hashed when the app starts, so no plain-text password is ever stored: <\/p>\n<div>\n<pre><code><span>DEMO_USERS<\/span> <span>=<\/span> <span>{<\/span> <span>\"<\/span><span>demo<\/span><span>\"<\/span><span>:<\/span> <span>{<\/span> <span>\"<\/span><span>username<\/span><span>\"<\/span><span>:<\/span> <span>\"<\/span><span>demo<\/span><span>\"<\/span><span>,<\/span> <span>\"<\/span><span>full_name<\/span><span>\"<\/span><span>:<\/span> <span>\"<\/span><span>Demo User<\/span><span>\"<\/span><span>,<\/span> <span>\"<\/span><span>hashed_password<\/span><span>\"<\/span><span>:<\/span> <span>password_hash<\/span><span>.<\/span><span>hash<\/span><span>(<\/span><span>\"<\/span><span>demo123<\/span><span>\"<\/span><span>),<\/span> <span>}<\/span> <span>}<\/span> <span>class<\/span> <span>Token<\/span><span>(<\/span><span>BaseModel<\/span><span>):<\/span> <span>access_token<\/span><span>:<\/span> <span>str<\/span> <span>token_type<\/span><span>:<\/span> <span>str<\/span> <span>class<\/span> <span>User<\/span><span>(<\/span><span>BaseModel<\/span><span>):<\/span> <span>username<\/span><span>:<\/span> <span>str<\/span> <span>full_name<\/span><span>:<\/span> <span>str<\/span> <span>|<\/span> <span>None<\/span> <span>=<\/span> <span>None<\/span> <span>def<\/span> <span>authenticate_user<\/span><span>(<\/span><span>username<\/span><span>:<\/span> <span>str<\/span><span>,<\/span> <span>password<\/span><span>:<\/span> <span>str<\/span><span>)<\/span> <span>-&gt;<\/span> <span>User<\/span> <span>|<\/span> <span>None<\/span><span>:<\/span> <span>record<\/span> <span>=<\/span> <span>DEMO_USERS<\/span><span>.<\/span><span>get<\/span><span>(<\/span><span>username<\/span><span>)<\/span> <span>if<\/span> <span>record<\/span> <span>is<\/span> <span>None<\/span><span>:<\/span> <span>return<\/span> <span>None<\/span> <span>if<\/span> <span>not<\/span> <span>password_hash<\/span><span>.<\/span><span>verify<\/span><span>(<\/span><span>password<\/span><span>,<\/span> <span>record<\/span><span>[<\/span><span>\"<\/span><span>hashed_password<\/span><span>\"<\/span><span>]):<\/span> <span>return<\/span> <span>None<\/span> <span>return<\/span> <span>get_user<\/span><span>(<\/span><span>username<\/span><span>)<\/span> <\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<p>Notice that <code>User<\/code> has no password field. Because the routes declare <code>response_model=User<\/code>, the hash can never leak into a response by accident.<\/p>\n<h2> <a name=\"4-creating-the-token\" href=\"#4-creating-the-token\"> <\/a> 4. Creating the token <\/h2>\n<div>\n<pre><code><span>def<\/span> <span>create_access_token<\/span><span>(<\/span><span>data<\/span><span>:<\/span> <span>dict<\/span><span>,<\/span> <span>expires<\/span><span>:<\/span> <span>timedelta<\/span> <span>|<\/span> <span>None<\/span> <span>=<\/span> <span>None<\/span><span>)<\/span> <span>-&gt;<\/span> <span>str<\/span><span>:<\/span> <span>payload<\/span> <span>=<\/span> <span>data<\/span><span>.<\/span><span>copy<\/span><span>()<\/span> <span>if<\/span> <span>expires<\/span> <span>is<\/span> <span>None<\/span><span>:<\/span> <span>expires<\/span> <span>=<\/span> <span>timedelta<\/span><span>(<\/span><span>minutes<\/span><span>=<\/span><span>ACCESS_TOKEN_EXPIRE_MINUTES<\/span><span>)<\/span> <span>payload<\/span><span>[<\/span><span>\"<\/span><span>exp<\/span><span>\"<\/span><span>]<\/span> <span>=<\/span> <span>datetime<\/span><span>.<\/span><span>now<\/span><span>(<\/span><span>timezone<\/span><span>.<\/span><span>utc<\/span><span>)<\/span> <span>+<\/span> <span>expires<\/span> <span>return<\/span> <span>jwt<\/span><span>.<\/span><span>encode<\/span><span>(<\/span><span>payload<\/span><span>,<\/span> <span>JWT_SECRET<\/span><span>,<\/span> <span>algorithm<\/span><span>=<\/span><span>ALGORITHM<\/span><span>)<\/span> <\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<p>Use <code>datetime.now(timezone.utc)<\/code>, not the deprecated <code>utcnow()<\/code>. PyJWT checks <code>exp<\/code> for you when it decodes.<\/p>\n<h2> <a name=\"5-the-dependency-that-guards-every-route\" href=\"#5-the-dependency-that-guards-every-route\"> <\/a> 5. The dependency that guards every route <\/h2>\n<div>\n<pre><code><span>async<\/span> <span>def<\/span> <span>get_current_user<\/span><span>(<\/span><span>token<\/span><span>:<\/span> <span>Annotated<\/span><span>[<\/span><span>str<\/span><span>,<\/span> <span>Depends<\/span><span>(<\/span><span>oauth2_scheme<\/span><span>)])<\/span> <span>-&gt;<\/span> <span>User<\/span><span>:<\/span> <span>error<\/span> <span>=<\/span> <span>HTTPException<\/span><span>(<\/span> <span>status_code<\/span><span>=<\/span><span>status<\/span><span>.<\/span><span>HTTP_401_UNAUTHORIZED<\/span><span>,<\/span> <span>detail<\/span><span>=<\/span><span>\"<\/span><span>Could not validate credentials<\/span><span>\"<\/span><span>,<\/span> <span>headers<\/span><span>=<\/span><span>{<\/span><span>\"<\/span><span>WWW-Authenticate<\/span><span>\"<\/span><span>:<\/span> <span>\"<\/span><span>Bearer<\/span><span>\"<\/span><span>},<\/span> <span>)<\/span> <span>try<\/span><span>:<\/span> <span>payload<\/span> <span>=<\/span> <span>jwt<\/span><span>.<\/span><span>decode<\/span><span>(<\/span><span>token<\/span><span>,<\/span> <span>JWT_SECRET<\/span><span>,<\/span> <span>algorithms<\/span><span>=<\/span><span>[<\/span><span>ALGORITHM<\/span><span>])<\/span> <span>except<\/span> <span>InvalidTokenError<\/span><span>:<\/span> <span>raise<\/span> <span>error<\/span> <span>username<\/span> <span>=<\/span> <span>payload<\/span><span>.<\/span><span>get<\/span><span>(<\/span><span>\"<\/span><span>sub<\/span><span>\"<\/span><span>)<\/span> <span>if<\/span> <span>username<\/span> <span>is<\/span> <span>None<\/span><span>:<\/span> <span>raise<\/span> <span>error<\/span> <span>user<\/span> <span>=<\/span> <span>get_user<\/span><span>(<\/span><span>username<\/span><span>)<\/span> <span>if<\/span> <span>user<\/span> <span>is<\/span> <span>None<\/span><span>:<\/span> <span>raise<\/span> <span>error<\/span> <span>return<\/span> <span>user<\/span> <\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<p>Two details matter here:<\/p>\n<ul>\n<li> <strong><code>algorithms=[ALGORITHM]<\/code> is a list you pass explicitly.<\/strong> Never let the token&#8217;s own header decide the algorithm.<\/li>\n<li> <strong>Every failure returns the same 401.<\/strong> A bad signature, an expired token and an unknown user all look identical to the client, which gives attackers nothing to learn from.<\/li>\n<\/ul>\n<h2> <a name=\"6-the-endpoints\" href=\"#6-the-endpoints\"> <\/a> 6. The endpoints <\/h2>\n<div>\n<pre><code><span>@app.post<\/span><span>(<\/span><span>\"<\/span><span>\/token<\/span><span>\"<\/span><span>,<\/span> <span>response_model<\/span><span>=<\/span><span>Token<\/span><span>)<\/span> <span>async<\/span> <span>def<\/span> <span>login<\/span><span>(<\/span><span>form<\/span><span>:<\/span> <span>Annotated<\/span><span>[<\/span><span>OAuth2PasswordRequestForm<\/span><span>,<\/span> <span>Depends<\/span><span>()]):<\/span> <span>user<\/span> <span>=<\/span> <span>authenticate_user<\/span><span>(<\/span><span>form<\/span><span>.<\/span><span>username<\/span><span>,<\/span> <span>form<\/span><span>.<\/span><span>password<\/span><span>)<\/span> <span>if<\/span> <span>user<\/span> <span>is<\/span> <span>None<\/span><span>:<\/span> <span>raise<\/span> <span>HTTPException<\/span><span>(<\/span><span>status_code<\/span><span>=<\/span><span>401<\/span><span>,<\/span> <span>detail<\/span><span>=<\/span><span>\"<\/span><span>Incorrect username or password<\/span><span>\"<\/span><span>)<\/span> <span>token<\/span> <span>=<\/span> <span>create_access_token<\/span><span>({<\/span><span>\"<\/span><span>sub<\/span><span>\"<\/span><span>:<\/span> <span>user<\/span><span>.<\/span><span>username<\/span><span>})<\/span> <span>return<\/span> <span>Token<\/span><span>(<\/span><span>access_token<\/span><span>=<\/span><span>token<\/span><span>,<\/span> <span>token_type<\/span><span>=<\/span><span>\"<\/span><span>bearer<\/span><span>\"<\/span><span>)<\/span> <span>@app.get<\/span><span>(<\/span><span>\"<\/span><span>\/me<\/span><span>\"<\/span><span>,<\/span> <span>response_model<\/span><span>=<\/span><span>User<\/span><span>)<\/span> <span>async<\/span> <span>def<\/span> <span>read_me<\/span><span>(<\/span><span>user<\/span><span>:<\/span> <span>Annotated<\/span><span>[<\/span><span>User<\/span><span>,<\/span> <span>Depends<\/span><span>(<\/span><span>get_current_user<\/span><span>)]):<\/span> <span>return<\/span> <span>user<\/span> <span>@app.get<\/span><span>(<\/span><span>\"<\/span><span>\/protected<\/span><span>\"<\/span><span>)<\/span> <span>async<\/span> <span>def<\/span> <span>protected<\/span><span>(<\/span><span>user<\/span><span>:<\/span> <span>Annotated<\/span><span>[<\/span><span>User<\/span><span>,<\/span> <span>Depends<\/span><span>(<\/span><span>get_current_user<\/span><span>)]):<\/span> <span>return<\/span> <span>{<\/span> <span>\"<\/span><span>message<\/span><span>\"<\/span><span>:<\/span> <span>f<\/span><span>\"<\/span><span>Hello <\/span><span>{<\/span><span>user<\/span><span>.<\/span><span>username<\/span><span>}<\/span><span>, your JWT is valid.<\/span><span>\"<\/span><span>,<\/span> <span>\"<\/span><span>framework<\/span><span>\"<\/span><span>:<\/span> <span>\"<\/span><span>FastAPI<\/span><span>\"<\/span><span>,<\/span> <span>\"<\/span><span>language<\/span><span>\"<\/span><span>:<\/span> <span>\"<\/span><span>Python<\/span><span>\"<\/span><span>,<\/span> <span>}<\/span> <\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<p>To protect any new route, add <code>user: Annotated[User, Depends(get_current_user)]<\/code> to its parameters. That&#8217;s the whole pattern.<\/p>\n<h2> <a name=\"7-run-it\" href=\"#7-run-it\"> <\/a> 7. Run it <\/h2>\n<div>\n<pre><code>uvicorn app:app <span>--reload<\/span> <\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<p>Open <code>http:\/\/127.0.0.1:8000\/docs<\/code>, click <strong>Authorize<\/strong>, and log in with <code>demo<\/code> \/ <code>demo123<\/code>. Or test it with curl, as I did below.<\/p>\n<h2> <a name=\"8-real-test-results-the-happy-path\" href=\"#8-real-test-results-the-happy-path\"> <\/a> 8. Real test results: the happy path <\/h2>\n<p>Log in: <\/p>\n<div>\n<pre><code>curl <span>-X<\/span> POST http:\/\/127.0.0.1:8000\/token <span>-d<\/span> <span>\"username=demo&amp;password=demo123\"<\/span> <\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<div>\n<pre><code><span>{<\/span><span>\"access_token\"<\/span><span>:<\/span><span>\"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdW...\"<\/span><span>,<\/span><span>\"token_type\"<\/span><span>:<\/span><span>\"bearer\"<\/span><span>}<\/span><span> <\/span><\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<p>A JWT is three base64url parts separated by dots: header, payload, signature. Decoding the first two: <\/p>\n<div>\n<pre><code><span>{<\/span><span>\"alg\"<\/span><span>:<\/span><span>\"HS256\"<\/span><span>,<\/span><span>\"typ\"<\/span><span>:<\/span><span>\"JWT\"<\/span><span>}<\/span><span> <\/span><span>{<\/span><span>\"sub\"<\/span><span>:<\/span><span>\"demo\"<\/span><span>,<\/span><span>\"exp\"<\/span><span>:<\/span><span>1791785986<\/span><span>}<\/span><span> <\/span><\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<p><strong>The payload is readable by anyone.<\/strong> It&#8217;s signed, not encrypted, so never put passwords or private data in it.<\/p>\n<p>Use the token: <\/p>\n<div>\n<pre><code>curl <span>-H<\/span> <span>\"Authorization: Bearer <\/span><span>$TOKEN<\/span><span>\"<\/span> http:\/\/127.0.0.1:8000\/me <\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<div>\n<pre><code><span>{<\/span><span>\"username\"<\/span><span>:<\/span><span>\"demo\"<\/span><span>,<\/span><span>\"full_name\"<\/span><span>:<\/span><span>\"Demo User\"<\/span><span>}<\/span><span> <\/span><\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<div>\n<pre><code>curl <span>-H<\/span> <span>\"Authorization: Bearer <\/span><span>$TOKEN<\/span><span>\"<\/span> http:\/\/127.0.0.1:8000\/protected <\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<div>\n<pre><code><span>{<\/span><span>\"message\"<\/span><span>:<\/span><span>\"Hello demo, your JWT is valid.\"<\/span><span>,<\/span><span>\"framework\"<\/span><span>:<\/span><span>\"FastAPI\"<\/span><span>,<\/span><span>\"language\"<\/span><span>:<\/span><span>\"Python\"<\/span><span>}<\/span><span> <\/span><\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<h2> <a name=\"9-real-test-results-the-failure-cases\" href=\"#9-real-test-results-the-failure-cases\"> <\/a> 9. Real test results: the failure cases <\/h2>\n<p>This is the part that tells you your auth actually works.<\/p>\n<div>\n<table>\n<thead>\n<tr>\n<th>Test<\/th>\n<th>Status<\/th>\n<th>Response<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td> <code>\/me<\/code> with <strong>no token<\/strong> <\/td>\n<td>401, <code>www-authenticate: Bearer<\/code> <\/td>\n<td><code>{\"detail\":\"Not authenticated\"}<\/code><\/td>\n<\/tr>\n<tr>\n<td>Login with a <strong>wrong password<\/strong> <\/td>\n<td>401<\/td>\n<td><code>{\"detail\":\"Incorrect username or password\"}<\/code><\/td>\n<\/tr>\n<tr>\n<td> <code>\/me<\/code> with the <strong>last character of the token changed<\/strong> <\/td>\n<td>401<\/td>\n<td><code>{\"detail\":\"Could not validate credentials\"}<\/code><\/td>\n<\/tr>\n<tr>\n<td> <code>\/me<\/code> with a token that <strong>expired 1 minute ago<\/strong> <\/td>\n<td>401<\/td>\n<td><code>{\"detail\":\"Could not validate credentials\"}<\/code><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>Changing a single character breaks the signature, and the expired token is rejected by PyJWT&#8217;s built-in <code>exp<\/code> check. Neither needed any extra code.<\/p>\n<h2> <a name=\"the-warning-pyjwt-215-gave-me\" href=\"#the-warning-pyjwt-215-gave-me\"> <\/a> The warning PyJWT 2.15 gave me <\/h2>\n<p>When I signed a token with the fallback secret, PyJWT printed: <\/p>\n<div>\n<pre><code>InsecureKeyLengthWarning: The HMAC key is 25 bytes long, which is below the minimum recommended length of 32 bytes for SHA256. See RFC 7518 Section 3.2. <\/code><\/pre>\n<div>\n<\/p><\/div>\n<\/p><\/div>\n<p><code>\"dev-only-secret-change-me\"<\/code> is only 25 bytes. For HS256 your secret should be <strong>at least 32 bytes<\/strong>. <code>secrets.token_urlsafe(32)<\/code> gives you 43 characters, which is plenty. Set <code>JWT_SECRET<\/code> in <code>.env<\/code> and the warning disappears.<\/p>\n<h2> <a name=\"before-you-ship-this\" href=\"#before-you-ship-this\"> <\/a> Before you ship this <\/h2>\n<p>This is a learning foundation, not a finished security system:<\/p>\n<ul>\n<li> <strong>Move users into a real database<\/strong>, and hash passwords at signup, not at startup.<\/li>\n<li> <strong>Keep the secret out of the repo.<\/strong> Use a secrets manager in production, and rotate it.<\/li>\n<li> <strong>Add refresh tokens<\/strong>, so the 30-minute access token can stay short-lived.<\/li>\n<li> <strong>Rate-limit <code>\/token<\/code><\/strong> to slow down password guessing.<\/li>\n<li> <strong>Use HTTPS.<\/strong> A bearer token is as good as a password while it&#8217;s valid.<\/li>\n<li> <strong>Keep the failure tests<\/strong> from section 9 in your test suite.<\/li>\n<\/ul>\n<h2> <a name=\"full-video\" href=\"#full-video\"> <\/a> Full video <\/h2>\n<p>Every line is typed on screen, then tested live in Swagger UI: <a href=\"https:\/\/youtu.be\/5cb6I6crZ1Q\" target=\"_blank\" rel=\"noopener noreferrer\">FastAPI JWT Authentication Tutorial (2026)<\/a>.<\/p>\n<p>Stuck on an error? Paste the traceback in the comments and I&#8217;ll take a look.<\/p>\n<hr>\n<p><em>Drafted with AI assistance. The code is from my own project, and every response above comes from a real run I did on October 12, 2026.<\/em><\/p>\n<\/p><\/div>\n<\/div>\n<\/div>\n<\/div>\n<p>Fuente: <a href=\"https:\/\/dev.to\/rainytechlab\/fastapi-jwt-authentication-in-2026-a-complete-login-api-in-one-file-argon2-pyjwt-tested-1ii6\">Art\u00edculo original<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The flow: the client sends a username and password to \/token, gets back a signed JWT, then sends it as Authorization: Bearer &lt;token&gt; on every protected request. One dependency, get_current_user(), does all the checking, so protecting a new route is a single line. 1. Install requirements.txt: fastapi&gt;=0.115.0 uvicorn[standard]&gt;=0.30.0 pyjwt&gt;=2.9.0 pwdlib[argon2]&gt;=0.2.0 python-multipart&gt;=0.0.9 python-dotenv&gt;=1.0.1 python3.12 -m venv [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":5989,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"webixso_pending_account_ids":""},"categories":[41],"tags":[],"class_list":["post-5990","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-devto"],"jetpack_publicize_connections":[],"_links":{"self":[{"href":"https:\/\/tucumandevelopers.com\/index.php\/wp-json\/wp\/v2\/posts\/5990","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tucumandevelopers.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tucumandevelopers.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tucumandevelopers.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tucumandevelopers.com\/index.php\/wp-json\/wp\/v2\/comments?post=5990"}],"version-history":[{"count":0,"href":"https:\/\/tucumandevelopers.com\/index.php\/wp-json\/wp\/v2\/posts\/5990\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/tucumandevelopers.com\/index.php\/wp-json\/wp\/v2\/media\/5989"}],"wp:attachment":[{"href":"https:\/\/tucumandevelopers.com\/index.php\/wp-json\/wp\/v2\/media?parent=5990"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tucumandevelopers.com\/index.php\/wp-json\/wp\/v2\/categories?post=5990"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tucumandevelopers.com\/index.php\/wp-json\/wp\/v2\/tags?post=5990"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}