rustango 0.23.0

Django-shaped batteries-included web framework for Rust: ORM + migrations + auto-admin + multi-tenancy + audit log + auth (sessions, JWT, OAuth2/OIDC, HMAC) + APIs (ViewSet, OpenAPI auto-derive, JSON:API) + jobs (in-mem + Postgres) + email + media (S3 / R2 / B2 / MinIO + presigned uploads + collections + tags) + production middleware (CSRF, CSP, rate-limiting, compression, idempotency, etc.).
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
# rustango

**A Django-shaped, batteries-included web framework for Rust.**

ORM with auto-migrations, multi-tenancy, auto-admin, sessions + JWT + OAuth2/OIDC + HMAC auth, signals, caching, first-class media (Postgres rows + S3/R2/B2/MinIO + presigned uploads + collections + tags), email pipeline (renderer + jobs + Mailable), background jobs (in-mem + Postgres), webhook delivery, OpenAPI 3.1 auto-derive from serializers + viewsets, JSON:API + RFC 7807 Problem Details, scheduled tasks, RFC 6238 TOTP, signed URLs, Prometheus metrics, OTel-shape tracing, distributed locks + rate limits + feature flags, every standard middleware (CSRF, CSP nonce, gzip/deflate, body limit, real-IP, idempotency, maintenance, trailing slash, static files, method override, server-timing, …) — all shipped, all opt-out via cargo features.

```toml
[dependencies]
rustango = "0.22"
```

---

## Table of contents

- [Quick start](#quick-start)
- [Project layout](#project-layout)
- [`manage` CLI reference](#manage-cli-reference)
- [ORM cookbook](#orm-cookbook)
- [Migrations](#migrations)
- [Auto-admin](#auto-admin)
- [APIs (ViewSet + Serializer + JWT)](#apis-viewset--serializer--jwt)
- [Forms](#forms)
- [Multi-tenancy](#multi-tenancy)
- [Authentication & permissions](#authentication--permissions)
- [Security middleware](#security-middleware)
- [Caching](#caching)
- [Email + storage + scheduling](#email--storage--scheduling)
- [Signals](#signals)
- [i18n](#i18n)
- [Testing](#testing)
- [Feature flags](#feature-flags)
- [Production checklist](#production-checklist)

---

## Quick start

### 1. Install the scaffolder

```bash
cargo install cargo-rustango
```

### 2. Create a project

```bash
cargo rustango new myblog                   # default: ORM + admin
cargo rustango new myapi --template api     # JSON-only, no admin
cargo rustango new shop --template tenant   # multi-tenancy + operator console
```

### 3. First-time setup

```bash
cd myblog
cp .env.example .env                        # edit DATABASE_URL
docker compose up -d                        # starts Postgres
cargo run --bin manage -- migrate           # apply bootstrap migrations
cargo run                                   # http://localhost:8080
```

**Autoreload during development** — recompiles + restarts on every file save:

```bash
cargo install cargo-watch
cargo watch -x run

# Or with bacon (faster, nicer UI):
cargo install bacon
bacon run
```

You should see the **welcome page** confirming rustango is wired up. Replace `welcome_router()` in `src/main.rs` once you mount your own `/` route.

### 4. Add an app + model

```bash
cargo run --bin manage -- startapp blog     # scaffolds src/blog/
```

Edit `src/blog/models.rs`:

```rust
use rustango::{Auto, Model};
use chrono::{DateTime, Utc};

#[derive(Model, Clone)]
#[rustango(
    table = "posts",
    display = "title",
    admin(list_display = "id, title, published_at", search_fields = "title, body"),
    audit(track = "title, body"),
    index("published_at, author_id"),
)]
pub struct Post {
    #[rustango(primary_key)]
    pub id: Auto<i64>,
    #[rustango(max_length = 200)]
    pub title: String,
    pub body: String,
    pub author_id: i64,
    #[rustango(auto_now_add)]
    pub published_at: Auto<DateTime<Utc>>,
}
```

```bash
cargo run --bin manage -- makemigrations    # generates migration JSON
cargo run --bin manage -- migrate           # applies it
```

### 5. Generate a viewset + serializer

```bash
cargo run --bin manage -- make:viewset PostViewSet --model Post
cargo run --bin manage -- make:serializer PostSerializer --model Post
```

Edit the generated files to fill in field lists, then mount in `src/urls.rs`.

---

## Project layout

A scaffolded project looks like:

```
myblog/
├── Cargo.toml                  # rustango + axum + tokio + sqlx
├── .env / .env.example         # DATABASE_URL, SECRET_KEY, RUSTANGO_ENV
├── docker-compose.yml          # Postgres in a container for local dev
├── README.md
├── migrations/                 # JSON files written by `manage makemigrations`
├── src/
│   ├── main.rs                 # HTTP entry point — Builder chain
│   ├── lib.rs                  # `pub mod` registry of every app module
│   ├── urls.rs                 # top-level Router composition
│   ├── models.rs               # OR per-app: src/blog/models.rs
│   ├── views.rs
│   ├── urls.rs
│   └── bin/manage.rs           # CLI dispatcher (re-exports user models)
└── tests/                      # integration tests using test_client
```

Per-app structure (created by `manage startapp <name>`):

```
src/blog/
  ├── mod.rs
  ├── models.rs                 # #[derive(Model)] structs
  ├── views.rs                  # axum handlers
  └── urls.rs                   # router for this app
```

---

## `manage` CLI reference

Every command has `--help`. Exit code is non-zero on validation/IO/system-check errors.

### Migrations

```bash
manage makemigrations [name]                   # diff registry → next JSON
manage makemigrations --app <app> [name]       # per-app migration dir
manage makemigrations --empty <name>           # scaffold for hand-authored data ops
manage migrate                                  # apply every pending
manage migrate <target>                         # forward or back to <target>; `zero` wipes
manage migrate --dry-run                        # print SQL without writing
manage downgrade [N]                            # step back N (default 1)
manage showmigrations | status                  # [X] applied / [ ] pending list
```

### Data migrations

```bash
manage add-data-op \
    --sql "UPDATE posts SET slug = lower(title)" \
    --reverse-sql "UPDATE posts SET slug = NULL" \
    --name backfill_post_slugs

manage add-data-op --to 0003_add_slug --sql "UPDATE posts SET slug = id::text"
```

### Scaffolders

```bash
manage startapp <name> [--with-manage-bin]
manage make:viewset PostViewSet --model Post
manage make:serializer PostSerializer --model Post
manage make:form ContactForm
manage make:job EmailDigestJob
manage make:notification WelcomeEmail
manage make:middleware AuditLog
manage make:test post_smoke
```

### System

```bash
manage about                # version, model count, registered apps, DB connectivity
manage check                # pending migrations, missing models, DB reachable
manage check --deploy       # + SECRET_KEY length, RUSTANGO_ENV, DATABASE_URL
manage docs                 # opens https://docs.rs/rustango in browser
manage version | --version  # framework version
```

### Tenancy (only with `tenancy` feature)

```bash
manage create-tenant acme --display-name "ACME Corp"
manage create-operator admin --password letmein
manage create-user acme alice --password hunter2 --superuser
manage list-tenants
manage audit-cleanup --days 90
manage audit-cleanup --keep-last 50 --tenant acme
```

---

## ORM cookbook

### Model declaration

```rust
use rustango::{Auto, Model};
use rustango::sql::ForeignKey;
use chrono::{DateTime, Utc};
use uuid::Uuid;

#[derive(Model, Clone)]
#[rustango(
    table = "posts",
    display = "title",                            // shown when post is FK target
    admin(
        list_display = "id, title, published_at",
        search_fields = "title, body",
        list_filter = "author_id",
        ordering = "-published_at",
        list_per_page = 50,
    ),
    audit(track = "title, body, status"),         // per-field before/after diff
    permissions,                                  // auto-create CRUD codenames
    index("published_at, author_id"),             // composite index
    check(name = "valid_status",
          expr = "status IN ('draft', 'published')"),
    m2m(name = "tags", to = "tags", through = "post_tags",
        src = "post_id", dst = "tag_id"),
)]
pub struct Post {
    #[rustango(primary_key)]
    pub id: Auto<i64>,

    #[rustango(max_length = 200, index)]
    pub title: String,

    pub body: String,
    pub status: String,

    pub author: ForeignKey<Author>,                // typed FK, lazy-loadable

    #[rustango(auto_now_add)]                      // NOW() on INSERT, immutable
    pub created_at: Auto<DateTime<Utc>>,
    #[rustango(auto_now)]                          // NOW() on every save
    pub updated_at: Auto<DateTime<Utc>>,
    #[rustango(soft_delete)]                       // stamp instead of hard-DELETE
    pub deleted_at: Option<DateTime<Utc>>,
    #[rustango(auto_uuid)]                         // server-generated UUIDv4
    pub external_id: Auto<Uuid>,

    #[rustango(default = r#"'{}'::jsonb"#)]
    pub data: serde_json::Value,
}
```

### Querying

```rust
use rustango::core::Column as _;
use rustango::sql::Fetcher as _;

// Filter + order
let recent = Post::objects()
    .where_(Post::status.eq("published"))
    .where_(Post::deleted_at.is_null())
    .order_by(Post::published_at, true)            // true = DESC
    .limit(20)
    .fetch(&pool).await?;

// Pagination
let page = Post::objects().page(2, 50).fetch(&pool).await?;

// Aggregation
let count = Post::objects().where_(Post::author_id.eq(42)).count(&pool).await?;
let avg = Post::objects().avg(Post::view_count, &pool).await?;

// IN / NOT IN
let some = Post::objects()
    .where_(Post::id.in_(&[1, 2, 3]))
    .fetch(&pool).await?;

// Pattern lookups
let drafts = Post::objects()
    .where_(Post::title.icontains("draft"))       // ILIKE %draft%
    .fetch(&pool).await?;

// Pre-load FKs (no N+1)
let with_authors = Post::objects()
    .select_related("author")
    .fetch(&pool).await?;
```

### Mutations

```rust
// Insert
let mut p = Post {
    id: Auto::default(),
    title: "Hello".into(),
    body: "World".into(),
    status: "draft".into(),
    // ... other fields
};
p.save_on(&pool).await?;
println!("inserted id = {}", p.id.get().copied().unwrap_or(0));

// Update — same `save_on()`, dispatched by Auto<T> PK state
p.title = "Hello world".into();
p.save_on(&pool).await?;

// Bulk insert
Post::bulk_insert_on(&pool, vec![p1, p2, p3]).await?;

// Bulk update
Post::objects()
    .where_(Post::status.eq("draft"))
    .update()
    .set(Post::status, "published")
    .execute_on(&pool).await?;

// Upsert (ON CONFLICT)
post.upsert_on(&pool, &["external_id"]).await?;

// Delete (soft if model has #[rustango(soft_delete)])
p.soft_delete_on(&pool).await?;
p.restore_on(&pool).await?;
```

### Transactions

```rust
rustango::sql::transaction(&pool, |conn| async move {
    p1.save_on(&mut *conn).await?;
    p2.save_on(&mut *conn).await?;
    Ok(())
}).await?;
```

### Bi-dialect (Postgres + MySQL) via `&Pool`

The classic API takes `&PgPool` (Postgres-only). The v0.23.0 series
adds a parallel `&Pool` API that targets either backend; pick MySQL
8.0+ or Postgres at runtime via the connection URL.

```toml
# Cargo.toml — opt in to MySQL alongside the default postgres feature
rustango = { version = "0.23", features = ["mysql"] }
```

```rust
use rustango::sql::{Pool, FetcherPool, CounterPool};

// Connect from URL (postgres:// or mysql://) or from split env vars
// (DB_DRIVER + DB_HOST + DB_PORT + DB_USER + DB_PASSWORD + DB_NAME +
// DB_PARAMS — passwords are auto percent-encoded).
let pool = Pool::connect_from_env().await?;

// Schema bootstrap (CREATE TABLE per registered model — dialect-aware
// type names, BIGINT AUTO_INCREMENT vs BIGSERIAL, JSON vs JSONB, etc.).
rustango::migrate::apply_all_pool(&pool).await?;

// Or run the file-based ledger runner — full Django-shape lifecycle.
rustango::migrate::migrate_pool(&pool, dir).await?;
rustango::migrate::migrate_to_pool(&pool, dir, "0005_x").await?;
rustango::migrate::downgrade_pool(&pool, dir, 1).await?;
rustango::migrate::unapply_pool(&pool, dir, "0005_x").await?;

// Macro-emitted CRUD against either backend (every #[derive(Model)] type).
let mut user = User { id: Auto::Unset, name: "alice".into(), .. };
user.insert_pool(&pool).await?;        // Auto<i64> populated via
                                       // RETURNING (PG) / LAST_INSERT_ID() (MySQL)
user.name = "Alice".into();
user.save_pool(&pool).await?;          // INSERT-or-UPDATE; audited models
                                       // emit a transactional diff audit row
user.delete_pool(&pool).await?;        // DELETE (transactional with audit
                                       // emit when the model is audited)

// QuerySet read path — single-table, select_related joins, prefetch,
// pagination, and aggregates all bi-dialect.
let posts: Vec<Post> = Post::objects()
    .filter(Post::is_published.eq(true))
    .select_related(&[Post::author])   // joins decoded automatically
    .order_by(&[Post::created_at.desc()])
    .limit(20)
    .fetch_pool(&pool).await?;
let n: i64 = User::objects().count_pool(&pool).await?;
let page = rustango::sql::fetch_paginated_pool(
    Post::objects().limit(20).offset(40),
    &pool,
).await?;
let with_kids: Vec<(User, Vec<Post>)> =
    rustango::sql::fetch_with_prefetch_pool::<User, Post>(
        User::objects(),
        "user_id",
        &pool,
    ).await?;

// Cross-table atomicity — open a backend-tagged transaction.
let mut tx = rustango::sql::transaction_pool(&pool).await?;
match &mut tx {
    rustango::sql::PoolTx::Postgres(t) => { /* $1 placeholders */ }
    rustango::sql::PoolTx::Mysql(t)    => { /* ?  placeholders */ }
}
tx.commit().await?;
```

**Operator translations:** `ILIKE` → `LOWER(col) LIKE LOWER(?)`,
`IS DISTINCT FROM` → `NOT (col <=> ?)`, JSONB `@>` → `JSON_CONTAINS`,
JSONB `?`/`?|`/`?&` → `JSON_CONTAINS_PATH(col, 'one'|'all', CONCAT('$.', ?))`,
`UPDATE … FROM (VALUES …)` → `UPDATE … INNER JOIN (VALUES ROW(?, ?), …)`.
`ON CONFLICT DO UPDATE SET col = EXCLUDED.col` → `ON DUPLICATE KEY UPDATE
col = VALUES(col)` (with `target: vec![]`; `MySQL`'s upsert can't take a
target column list).

**MySQL caveats:**
- requires MySQL 8.0+ (window functions for `fetch_paginated_pool`,
  `JSON` column type, `VALUES ROW(…)` syntax for `bulk_update_pool`)
- `fetch_paginated_pool` uses `COUNT(*) OVER ()` — needs 8.0
- `LAST_INSERT_ID()` reports one auto-assigned column per connection,
  so models with multiple `Auto<T>` PKs error at runtime on MySQL
  (Postgres `RETURNING` is unaffected)

**Migration story:** the `&PgPool` API stays exactly as it was — every
existing app keeps working unchanged on upgrade. Adopt `&Pool` at
your own pace (or never, if you only target Postgres).

### Many-to-many

```rust
// All declared via #[rustango(m2m(...))] — junction table auto-created
let tag_ids = post.tags_m2m().all(&pool).await?;
post.tags_m2m().add(42, &pool).await?;
post.tags_m2m().remove(42, &pool).await?;
post.tags_m2m().set(&[1, 2, 3], &pool).await?;     // replace all
post.tags_m2m().clear(&pool).await?;
let has = post.tags_m2m().contains(42, &pool).await?;
```

### ContentTypes — generic relations + composite-key FKs + soft-FK prefetch

Django-shape framework for "any registered model" pointers. Lets one
table point at *any* other model via `(content_type_id, object_pk)`
(comments-on-anything, audit log targets, activity streams, tag
generic relations) and lets a single FK constraint span multiple
columns. Sub-slices F.1 / F.2 / F.3 of v0.15.0.

#### Bootstrap

```rust
// Registers one row per #[derive(Model)] type in `rustango_content_types`.
// Idempotent — re-runs on a populated DB return Ok(0). Run once at startup
// after `migrate(&pool, dir).await?`.
let inserted = rustango::contenttypes::ensure_seeded(&pool).await?;
```

#### Lookups

```rust
use rustango::contenttypes::ContentType;

// By Rust type
let ct = ContentType::for_model::<Post>(&pool).await?;       // Option<ContentType>

// By natural key (parsed permission codenames, admin URLs, etc.)
let ct = ContentType::by_natural_key(&pool, "blog", "post").await?;

// By id (FK joins from audit log / permissions / generic FK rows)
let ct = ContentType::by_id(&pool, 7).await?;

// Full listing for admin sidebars / API
let all_cts = ContentType::all(&pool).await?;                 // ordered (app, model)
```

#### Composite-key foreign keys (F.2)

Multi-column FKs declared on the model, not the field. Each
participating column keeps its plain Rust type — the FK metadata
records which columns participate and where they reference.

```rust
#[derive(Model)]
#[rustango(
    table = "audit_log",
    fk_composite(
        name = "target",
        to   = "ct_live_pair",
        from = ("entity_table", "entity_pk"),
        on   = ("table_name",   "row_pk"),
    ),
)]
pub struct AuditLog {
    #[rustango(primary_key)]
    pub id: Auto<i64>,
    pub entity_table: String,
    pub entity_pk: i64,
}

// Emits on migrate / apply_all:
//   ALTER TABLE "audit_log" ADD CONSTRAINT "audit_log_target_fkey"
//     FOREIGN KEY ("entity_table", "entity_pk")
//     REFERENCES "ct_live_pair" ("table_name", "row_pk");
```

Both Postgres and MySQL emit the standard composite FK syntax —
only identifier quoting differs. Single-column FKs continue to use
the existing per-field `Relation::Fk` machinery; composite FKs sit
on `ModelSchema.composite_relations` so the existing single-FK
machinery (admin display, snapshot diff) stays untouched.

#### GenericForeignKey + soft-FK prefetch (F.3)

```rust
use rustango::contenttypes::{GenericForeignKey, prefetch_soft, prefetch_generic};

// `GenericForeignKey` — a runtime pointer at any registered model's row.
let gfk = GenericForeignKey::for_target::<Post>(&pool, post_id).await?;
// gfk.content_type_id  ← Post's ContentType row id
// gfk.object_pk        ← post_id
```

**Soft-FK prefetch** — for integer columns that conceptually point at
another model's PK without a declared `Relation::Fk` (audit log
`entity_pk`, denormalized snapshots, optional cross-app refs):

```rust
let parent_pks: Vec<i64> = posts.iter().map(|p| p.id.get().copied().unwrap()).collect();

// One batched SELECT + group-by-extractor → HashMap<i64, Vec<C>>
let by_post = prefetch_soft::<Comment, _>(
    &pool,
    &parent_pks,
    "post_id",            // soft-FK column on Comment
    |c| c.post_id,        // extractor: how to read the value off &Comment
).await?;

for post in &posts {
    let pk = post.id.get().copied().unwrap();
    let comments = by_post.get(&pk).map(Vec::as_slice).unwrap_or(&[]);
    // ...
}
```

**Generic-FK prefetch** — for `(content_type_id, object_pk)` pointers
that vary their target type per row. Single-target-type variant —
caller picks the concrete `T: Model` to hydrate; pairs whose
`content_type_id` doesn't match are filtered out:

```rust
let pairs: Vec<(i64, i64)> = audit_rows.iter()
    .map(|a| (a.target.content_type_id, a.target.object_pk))
    .collect();

let posts: HashMap<(i64, i64), Post> =
    prefetch_generic::<Post>(&pool, &pairs).await?;

for row in &audit_rows {
    if let Some(post) = posts.get(&(row.target.content_type_id, row.target.object_pk)) {
        println!("{} → {}", row.id.get().copied().unwrap(), post.title);
    }
}
```

Both prefetch helpers short-circuit on empty input (no DB round trip)
and use a single batched SELECT for the actual fetch.

**What this unblocks:**
- **Permissions (Option G, v0.16.0)** — `permission.content_type_id`
  is a real FK to `rustango_content_types.id` instead of a
  hard-coded `app.action_model` string that breaks when two apps
  register the same model name.
- **Audit history admin panels** — `User.history.all()`-style
  queries become composite-FK joins instead of raw SQL.
- **Comments / tags / generic FK** — one `Comment` model points
  at any `Post` / `Photo` / `Article` via `(content_type_id,
  object_pk)`, queried + admin-rendered in one shape.
- **Activity stream / "recently changed" feeds** — the target of
  each entry hydrates in one batched `prefetch_generic` call per
  target type, no N+1.

**Deferred (follow-up slice):**
- Boxed-trait dynamic decoder registry → `prefetch_generic_dyn`
  for mixed-target hydration in one query.
- Admin renderer for `GenericForeignKey` columns (clickable target
  links in list/detail).
- `composite_relations` snapshot/diff support in `make_migrations`.

---

## Migrations

```bash
manage makemigrations              # diff inventory ↔ snapshot, emit JSON
manage migrate                     # apply pending
manage migrate --dry-run           # print SQL only
manage migrate <target>            # forward or back to specific name
manage downgrade 2                 # step back 2 migrations
manage showmigrations              # status
```

Migration files are JSON in `migrations/`, lex-sorted by name. They:

- **Embed the full schema snapshot** — any one file is a self-contained starting state
- **Include both schema ops AND data ops** in the `forward` list, in any order
- **Are invertible** when each op carries `reverse_sql` (or has a natural inverse)
- **Run atomically per file** by default — partial progress recoverable

### Auto-detected schema changes

| Change | Op generated | Notes |
|---|---|---|
| New struct | `CreateTable` | + deferred FK constraints |
| Removed struct | `DropTable` | CASCADE |
| New field | `AddColumn` | rejects NOT NULL without `default` |
| Removed field | `DropColumn` | |
| Type changed | `AlterColumnType` | with `USING ::pg_type` cast |
| Nullable flipped | `AlterColumnNullable` | |
| Default changed | `AlterColumnDefault` | |
| `max_length` changed | `AlterColumnMaxLength` | VARCHAR(N) ↔ TEXT |
| `unique` toggled | `AlterColumnUnique` | |
| New `#[rustango(index)]` / composite index | `CreateIndex` | unique flag respected |
| New `#[rustango(check(...))]` | `AddCheckConstraint` | |
| New M2M relation | `CreateM2MTable` | composite PK + 2 FKs ON DELETE CASCADE |
| Renames | NOT auto-detected | use `manage makemigrations --empty` and edit JSON |

### Hand-authored data migrations

```bash
# Quick path — one-liner
manage add-data-op \
    --sql "UPDATE posts SET slug = lower(title)" \
    --reverse-sql "UPDATE posts SET slug = NULL" \
    --name backfill_post_slugs

# Or append to an existing migration
manage add-data-op --to 0003_add_slug --sql "UPDATE posts SET slug = id::text"

# Or scaffold an empty file and edit manually
manage makemigrations --empty seed_initial_categories
```

---

## Auto-admin

Mount once and every `#[derive(Model)]` is fully editable:

```rust
let app = rustango::admin::Builder::new(pool.clone())
    .title("My App Admin")
    .show_only(["post", "author", "tag"])
    .read_only(["audit_log"])
    .build();
```

Lives at `/__admin/`. Per-model customization via `#[rustango(admin(...))]`:

| Knob | Effect |
|---|---|
| `list_display = "f1, f2, f3"` | Columns on list view (FKs render display-name) |
| `search_fields = "f1, f2"` | `?q=...` search box |
| `list_filter = "fk_field, status"` | Right-rail facet filters with counts |
| `ordering = "field, -other"` | Default sort (`-` prefix = DESC) |
| `list_per_page = 50` | Pagination size |
| `readonly_fields = "created_at"` | Shown but not editable |
| `fieldsets = "Group A: f1, f2 \| Group B: f3"` | Form layout |
| `actions = "delete_selected, my_action"` | Bulk actions |

### Bulk actions

```rust
use rustango::bulk_actions::{BulkActionRegistry, BulkDeleteAction, BulkSoftDeleteAction};
use std::sync::Arc;

let registry = BulkActionRegistry::new()
    .register(Arc::new(BulkDeleteAction))
    .register(Arc::new(BulkSoftDeleteAction { column: "deleted_at" }));

// In a handler:
let result = registry.run("delete_selected", "posts", &[1, 2, 3], &pool).await?;
println!("affected {} rows", result.affected);
```

---

## APIs (ViewSet + Serializer + JWT)

### `#[derive(ViewSet)]` — full CRUD in 5 lines

```rust
use rustango::ViewSet;

#[derive(ViewSet)]
#[viewset(
    model         = Post,
    fields        = "id, title, body, author_id, published_at",
    filter_fields = "author_id, status",
    search_fields = "title, body",
    ordering      = "-published_at",
    page_size     = 20,
    permissions(
        list     = "post.view",
        retrieve = "post.view",
        create   = "post.add",
        update   = "post.change",
        destroy  = "post.delete",
    ),
)]
pub struct PostViewSet;

// Mount:
let app = Router::new()
    .merge(PostViewSet::router("/api/posts", pool.clone()));
```

### Endpoints

| Method | Path | Action |
|---|---|---|
| `GET` | `/api/posts` | List (page-number or cursor pagination) |
| `POST` | `/api/posts` | Create |
| `GET` | `/api/posts/{pk}` | Retrieve |
| `PUT` | `/api/posts/{pk}` | Update |
| `PATCH` | `/api/posts/{pk}` | Partial update |
| `DELETE` | `/api/posts/{pk}` | Delete (soft when model carries `#[rustango(soft_delete)]`) |

### Query params (list endpoint)

```
?page=2&page_size=50                            # page-number pagination
?cursor=eyJpZCI6MTAwfQ&page_size=50             # cursor pagination (opt-in)
?search=rust&ordering=-published_at             # search + sort
?author_id=42                                    # exact filter
?published_at__gte=2026-01-01                    # Django-style lookup operators
?title__icontains=draft                          # gt, gte, lt, lte, ne, in, not_in,
                                                 # contains, icontains, startswith,
                                                 # istartswith, endswith, iendswith, isnull
```

### Serializers

```rust
use rustango::Serializer;
use rustango::serializer::ModelSerializer;

#[derive(Serializer, serde::Deserialize, Default)]
#[serializer(model = Post)]
pub struct PostSerializer {
    pub id: i64,
    pub title: String,

    #[serializer(read_only)]
    pub created_at: chrono::DateTime<chrono::Utc>,

    #[serializer(write_only)]
    pub draft_password: String,

    #[serializer(source = "body")]                // read from model.body
    pub content: String,

    #[serializer(skip)]                            // user sets manually
    pub tag_ids: Vec<i64>,
}

// Use:
let s = PostSerializer::from_model(&post);
let json = s.to_value();
let array = PostSerializer::many_to_value(&posts);
```

### JWT lifecycle

```rust
use rustango::tenancy::jwt_lifecycle::{JwtLifecycle, JwtTokenPair};
use serde_json::json;

let jwt = JwtLifecycle::new(secret).with_access_ttl(900).with_refresh_ttl(7 * 86400);

// Login: embed roles + scope in the token
let pair = jwt.issue_pair_with(user_id, json!({
    "roles":  ["admin", "editor"],
    "tenant": "acme",
    "scope":  "read:posts write:posts",
}).as_object().unwrap().clone())?;

// Authenticated request — no DB lookup needed:
let claims = jwt.verify_access(&access_token).ok_or(StatusCode::UNAUTHORIZED)?;
let roles: Vec<String> = claims.get_custom("roles").unwrap();

// Refresh — preserves custom claims:
let new_pair = jwt.refresh(&refresh_token).ok_or(StatusCode::UNAUTHORIZED)?;

// Refresh with re-evaluated permissions:
let downgraded = jwt.refresh_with(&refresh_token, json!({"roles": ["viewer"]})...)?;

// Logout:
jwt.revoke(&access_token);
jwt.revoke(&refresh_token);
```

Reserved-claim defense: `sub`, `exp`, `jti`, `typ` cannot appear in `custom` (returns `JwtIssueError::ReservedClaim`).

---

## Forms

```rust
use rustango::forms::{Form, FormErrors, ModelForm};
use rustango::Form as DeriveForm;

// Typed form via derive
#[derive(DeriveForm)]
pub struct ContactForm {
    #[form(min_length = 1, max_length = 200)]
    pub name: String,
    #[form(required = false)]
    pub message: Option<String>,
}

// In a handler:
match ContactForm::parse(&form_data) {
    Ok(form) => { /* form.name, form.message */ }
    Err(errors) => { /* errors.fields() per-field map */ }
}

// Or schema-driven for any model
let form = ModelForm::new(Post::SCHEMA, form_data);
match form.save(&pool).await {
    Ok(pk) => redirect_to_detail(pk),
    Err(ModelFormError::Validation(errors)) => render_with_errors(errors),
    Err(ModelFormError::Database(e)) => server_error(e),
}
```

---

## Multi-tenancy

```rust
use rustango::server::Builder;

#[rustango::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    Builder::from_env().await?
        .admin_title("My SaaS Admin")
        .migrate(".")
        .await?
        .api(my_app::urls::router())
        .seed_with(seed)
        .await?
        .serve("0.0.0.0:8080")
        .await
}
```

| Env var | Default | Purpose |
|---|---|---|
| `DATABASE_URL` | — | Registry Postgres (orgs, operators, users) |
| `RUSTANGO_APEX_DOMAIN` | `localhost` | Subdomain root → `<slug>.<apex>` |
| `RUSTANGO_BIND` | `0.0.0.0:8080` | Bind address |
| `RUSTANGO_SESSION_SECRET` | random (warns) | Base64-encoded 32-byte HMAC key |

Generate a secret: `openssl rand -base64 32`.

### Tenant resolver chain

Auto-resolves `Tenant` from request via, in order:
1. Subdomain (`acme.myapp.com`)
2. URL path prefix (`/t/acme/...`)
3. Custom header (`X-Tenant-Slug: acme`)
4. Port (rare; for testing)

### Storage modes

- **Schema mode** — one Postgres schema per tenant, single database
- **Database mode** — full database per tenant; `TenantPools` lazily opens connections

### Programmatic provisioning

```rust
use rustango::tenancy::manage::api::*;

let org = create_tenant_if_missing(&pools, &registry_url, "migrations", "acme",
    CreateTenantOpts {
        mode: StorageMode::Schema,
        display_name: Some("ACME Corp".into()),
        ..Default::default()
    },
).await?;

create_operator_if_missing(&pools, "admin", "letmein").await?;
create_user_if_missing(&pools, "acme", "alice", "hunter2", true).await?;
```

---

## Authentication & permissions

### Auth backends (pluggable)

```rust
use rustango::tenancy::auth_backends::{ModelBackend, ApiKeyBackend, JwtBackend};
use rustango::tenancy::middleware::{RouterAuthExt, CurrentUser};
use std::sync::Arc;

let backends = vec![
    Arc::new(ModelBackend) as _,                  // username + password (Basic Auth)
    Arc::new(ApiKeyBackend) as _,                  // Bearer <prefix>.<secret>
    Arc::new(JwtBackend::new(secret)) as _,        // Bearer <jwt>
];

let app = Router::new()
    .route("/me", get(profile))
    .require_auth(backends.clone(), pool.clone())  // 401 if no backend authenticates
    .route("/posts/new", post(create_post))
    .require_perm("post.add", pool.clone())        // gate by codename
    .require_auth(backends, pool);

async fn profile(CurrentUser(u): CurrentUser) -> impl IntoResponse {
    match u {
        Some(user) => format!("hello {}", user.username).into_response(),
        None => StatusCode::UNAUTHORIZED.into_response(),
    }
}
```

### Typed permission helpers (v0.16.0)

Permissions today use `{table}.{action}` string codenames
(`"post.change"`, `"comment.delete"`, …). The
`rustango::permissions` facade adds typed convenience over the
existing engine so callers reach for permissions by their
`T: Model` type instead of hand-typing the codename:

```rust
use rustango::permissions;

// Old (still supported):
rustango::tenancy::permissions::has_perm(uid, "post.change", &pool).await?;

// New, typed:
permissions::has_perm_for_model::<Post>(uid, "change", &pool).await?;

// Bulk helpers exist for grant/revoke/set_user_perm/clear_user_perm too:
permissions::grant_role_perm_for_model::<Post>(editor_role, "change", &pool).await?;
permissions::set_user_perm_for_model::<Post>(uid, "delete", false, &pool).await?;

// Build the four standard codenames for a model:
let [add, change, delete, view] = permissions::model_codenames_for::<Post>();
```

The full underlying engine (`Role`, `RolePermission`, `UserRole`,
`UserPermission`, `has_perm` / `has_any_perm` / `has_all_perms`,
`assign_role` / `grant_role_perm` / `auto_create_permissions`)
lives at [`rustango::tenancy::permissions`] — re-exported from
the top-level `rustango::permissions` for the conceptually-cleaner
path. Requires the `tenancy` feature (the underlying tables live
in the tenancy bootstrap migration).

### TOTP / 2FA

```rust
use rustango::totp::{TotpSecret, otpauth_url, generate, verify};

// Enrollment:
let secret = TotpSecret::generate();
user.totp_secret = secret.to_base32();
let qr_url = otpauth_url("MyApp", &user.email, &secret);   // encode as QR

// Verification on login:
if !verify(&secret, &user_supplied_code, 30, 6, 1) {
    return Err("bad TOTP code");
}
```

### API keys

```rust
use rustango::api_keys::{generate_key, verify_key, split_token};

// Issue:
let (full_token, prefix, hash) = generate_key()?;
// Show full_token to user once. Store prefix + hash in your DB.

// Verify on request:
let (prefix, secret) = split_token(&inbound).ok_or(BadRequest)?;
let row = db_lookup_by_prefix(prefix).await?;
if verify_key(secret, &row.hash)? { /* ok */ }
```

### Signed URLs (magic links / file downloads)

```rust
use rustango::signed_url::{sign, verify};
use std::time::Duration;

// Issue:
let url = sign(
    "https://app.example.com/login?email=alice@x.com",
    secret,
    Some(Duration::from_secs(3600)),
);

// Verify on callback:
match verify(&incoming_url, secret) {
    Ok(()) => { /* identity confirmed */ }
    Err(e) => { /* expired or tampered */ }
}
```

---

## Security middleware

All optional, all chainable on any axum Router.

```rust
use rustango::security_headers::{SecurityHeadersLayer, SecurityHeadersRouterExt, CspBuilder};
use rustango::cors::{CorsLayer, CorsRouterExt};
use rustango::rate_limit::{RateLimitLayer, RateLimitRouterExt};
use rustango::ip_filter::{IpFilterLayer, IpFilterRouterExt};
use rustango::request_id::{RequestIdLayer, RequestIdRouterExt};
use rustango::access_log::{AccessLogLayer, AccessLogRouterExt};
use rustango::etag::{EtagLayer, EtagRouterExt};
use std::time::Duration;

let app = Router::new()
    .route("/api/posts", get(list_posts).post(create_post))
    .security_headers(                                          // HSTS + XFO + CSP + Permissions-Policy
        SecurityHeadersLayer::strict()
            .csp(CspBuilder::strict_starter().build()),
    )
    .cors(                                                      // CORS allowlist
        CorsLayer::new()
            .allow_origins(vec!["https://app.example.com"])
            .allow_methods(vec!["GET", "POST", "PUT", "DELETE"])
            .allow_credentials(true),
    )
    .rate_limit(RateLimitLayer::per_ip(60, Duration::from_secs(60)))   // 60 req/min/IP
    .ip_filter(                                                 // optional allowlist
        IpFilterLayer::block(vec!["203.0.113.42"]).unwrap(),
    )
    .request_id(RequestIdLayer::default())                      // X-Request-Id for log correlation
    .access_log(AccessLogLayer::default())                      // tracing::info per request
    .etag(EtagLayer::default());                                // 304 Not Modified
```

### Security headers presets

| Preset | When to use |
|---|---|
| `SecurityHeadersLayer::strict()` | Production: HSTS preload + XFO=DENY + nosniff + Referrer-Policy=no-referrer |
| `SecurityHeadersLayer::relaxed()` | Embeddable apps: SAMEORIGIN + 1y HSTS |
| `SecurityHeadersLayer::dev()` | Local: nosniff only (no HSTS lockout) |
| `SecurityHeadersLayer::empty()` | Build up from scratch |

### CORS presets

```rust
CorsLayer::permissive()                          // dev: any origin, common methods
CorsLayer::new().allow_origins(vec!["..."])      // prod: explicit allowlist
```

---

## Caching

```rust
use rustango::cache::{Cache, BoxedCache, InMemoryCache, get_json, set_json, get_or_set};
use std::sync::Arc;
use std::time::Duration;

// Build a shared cache
let cache: BoxedCache = Arc::new(
    InMemoryCache::with_default_ttl(Duration::from_secs(300))
);

// Raw strings
cache.set("greeting", "hello", Some(Duration::from_secs(60))).await?;
let val: Option<String> = cache.get("greeting").await?;

// Typed JSON helpers
set_json(&*cache, "user:1", &user, None).await?;
let user: Option<User> = get_json(&*cache, "user:1").await?;

// Fetch-or-compute pattern
let posts: Vec<Post> = get_or_set(
    &*cache,
    "posts:recent",
    || async { Post::objects().fetch(&pool).await.unwrap() },
    Some(Duration::from_secs(60)),
).await?;
```

### Redis backend (`cache-redis` feature)

```rust
use rustango::cache::redis_backend::RedisCache;

let cache: BoxedCache = Arc::new(
    RedisCache::new("redis://127.0.0.1/").await?
);
```

---

## Email + storage + scheduling

### Email

```rust
use rustango::email::{Mailer, Email, ConsoleMailer, InMemoryMailer, NullMailer};

let mailer: Arc<dyn Mailer> = Arc::new(ConsoleMailer);   // dev: prints to stdout

let email = Email::new()
    .to("user@example.com")
    .from("noreply@app.example.com")
    .reply_to("support@app.example.com")
    .subject("Welcome")
    .body("Plain text version")
    .html_body("<h1>Welcome</h1>");
mailer.send(&email).await?;
```

### File storage

The framework ships three layers, each useful on its own:

1. **`Storage` trait + backends** — write/read/delete/url + presign.
2. **`StorageRegistry`** — named "disks" (Laravel-style) with optional CDN prefixes. Pick the right backend per call site by name.
3. **`Media` model + `MediaManager`** — first-class Postgres-backed file references with direct browser uploads, soft delete, and orphan sweeps.

#### Storage backends

```rust
use rustango::storage::{Storage, BoxedStorage, LocalStorage};
use rustango::storage::s3::{S3Storage, S3Config};
use std::sync::Arc;

// Local disk:
let local: BoxedStorage = Arc::new(
    LocalStorage::new("./uploads".into())
        .with_base_url("https://cdn.example.com/uploads")
);
local.save("avatars/alice.png", &png_bytes).await?;

// AWS S3 (or Cloudflare R2 / Backblaze B2 / MinIO — same struct):
let s3: BoxedStorage = Arc::new(S3Storage::new(S3Config {
    bucket: "my-bucket".into(),
    region: "us-east-1".into(),
    endpoint: None,                    // Some("https://...") for R2/B2/MinIO
    access_key_id: env::var("AWS_ACCESS_KEY_ID")?,
    secret_access_key: env::var("AWS_SECRET_ACCESS_KEY")?,
    path_style: false,                 // true for R2/MinIO
}));

// Trait methods are identical across backends — swap in config.
s3.save("avatars/alice.png", &png_bytes).await?;
let bytes = s3.load("avatars/alice.png").await?;
let public_url = s3.url("avatars/alice.png");
```

The S3 backend is hand-rolled SigV4 over `reqwest` — no `aws-sdk-s3` dependency. Behind the `storage-s3` feature flag (default-on).

#### Presigned URLs (private files + direct browser uploads)

```rust
use std::time::Duration;

// Time-limited GET: paste into <img src=...> or <a href=...>
let download_url = s3
    .presigned_get_url("invoices/2026.pdf", Duration::from_secs(3600))
    .await
    .expect("S3 backend signs");

// Time-limited PUT: browser uploads directly, server never proxies the body.
// Content-Type binding — browser MUST send a matching header (S3 enforces).
let upload_url = s3
    .presigned_put_url("uploads/x.png", Duration::from_secs(300), Some("image/png"))
    .await
    .unwrap();
```

`LocalStorage` and `InMemoryStorage` return `None` from these methods (they can't sign). `S3Storage` (and any S3-compatible API) does. AWS caps presign expiry at 7 days; we clamp.

#### `StorageRegistry` — named disks

```rust
use rustango::storage::StorageRegistry;

let registry = StorageRegistry::new()
    .set("avatars", Arc::new(s3))
    .cdn("avatars", "https://cdn.example.com/avatars")
    .set("docs",    Arc::new(docs_s3))
    .set("cache",   Arc::new(local))
    .with_default("avatars");

let s = registry.disk("avatars").unwrap();
let url = registry.cdn_url("avatars", "alice.png");
//        → "https://cdn.example.com/avatars/alice.png"

let internal = registry.origin_url("avatars", "alice.png");
//        → bypasses CDN — for internal admin tools
```

#### First-class `Media` model

`Media` is a Postgres-backed row. User models reference it via a normal integer FK (`Option<ForeignKey<Media>>`) — all metadata (disk, key, MIME, size, filename, free-form JSONB) lives on the `Media` row, so deletes are atomic and one file can be referenced by N parents without duplication.

```rust
use rustango::media::{Media, MediaManager, SaveOpts, UploadIntent};

// Once at startup:
Media::ensure_table(&pool).await?;
let manager = MediaManager::new(pool.clone(), registry);

// Server-side save: writes to S3 + inserts a Media row in one call.
let m = manager.save_bytes(SaveOpts {
    disk: "avatars".into(),
    key_prefix: "users/".into(),
    bytes: png_bytes.clone(),
    mime: "image/png".into(),
    original_filename: "alice.png".into(),
    uploaded_by_id: Some(user.id),
    metadata: serde_json::json!({"alt": "alice headshot"}),
}).await?;

// CDN-aware URL (falls back to backend URL when no CDN configured):
let url = manager.url(&m).expect("url");

// Time-limited download link for private files:
let dl = manager.presigned_get(&m, Duration::from_secs(3600)).await;
```

#### Direct browser uploads (no proxying through your server)

Two-step flow: server issues a presigned PUT URL, browser uploads to S3 directly, server confirms. Big files don't tie up handler bandwidth; you keep server-side gating on size/MIME via the pre-creation step.

```rust
// 1. Server: issue a presigned upload ticket.
let ticket = manager.begin_upload(UploadIntent {
    disk: "avatars".into(),
    key_prefix: "uploads/".into(),
    mime: "image/png".into(),
    original_filename: "selfie.png".into(),
    size_bytes: 12_345,
    uploaded_by_id: Some(user.id),
    ttl: Duration::from_secs(300),
}).await?;
// ticket.media_id    -> the Pending Media row id
// ticket.upload_url  -> hand to the browser
// ticket.expires_at  -> show client a deadline

// 2. Browser:
//    fetch(ticket.upload_url, {
//        method: 'PUT',
//        headers: { 'Content-Type': 'image/png' },
//        body: file
//    })

// 3. Server: confirm the object landed; flips Pending → Ready
//    (or → Failed if the browser abandoned).
let m = manager.finalize_upload(ticket.media_id).await?;
assert!(m.is_ready());
```

#### Lifecycle + cleanup

```rust
// Soft delete: marks deleted_at = NOW() but preserves the storage object.
manager.delete(&m).await?;

// Hard purge: removes both the row AND the storage object. Typical
// "clean up after soft delete grace period" pattern.
manager.purge(&m).await?;

// Background sweeps — wire to rustango::scheduler:
manager.purge_orphans(Duration::from_secs(7 * 86400)).await?;  // 7-day grace
manager.purge_pending(Duration::from_secs(86400)).await?;      // abandoned uploads
```

The `MediaStatus` enum (`Pending` / `Ready` / `Failed`) is stored as TEXT so admins can filter / order without bespoke type handling. Soft-deleted rows are excluded from `manager.get(...)` by default; `manager.get_including_deleted(...)` brings them back for restore flows.

#### Collections (folders) + tags

`MediaCollection` is a hierarchical "where the file lives" folder — one Media row belongs to at most one collection; collections nest via `parent_id`. `MediaTag` is a flat M2M label — one Media has any number of tags. Both are first-class Postgres tables, so the auto-admin lists/filters/searches them with no extra wiring.

```rust
use rustango::media::ensure_all_tables;

// Bootstrap rustango_media + rustango_media_collections +
// rustango_media_tags + rustango_media_tag_links in one call.
ensure_all_tables(&pool).await?;

// Folders (hierarchical).
let products = manager.create_collection("Products", "products", None, "").await?;
let cid = match products.id { rustango::sql::Auto::Set(v) => v, _ => unreachable!() };
let launch = manager.create_collection("2026 Launch", "2026-launch", Some(cid), "").await?;

// Drop a file into a folder at save-time.
let m = manager.save_bytes(SaveOpts {
    disk: "avatars".into(),
    key_prefix: "products".into(),
    bytes: png,
    mime: "image/png".into(),
    original_filename: "hero.png".into(),
    uploaded_by_id: Some(user.id),
    collection_id: launch.id.into(),     // folder
    metadata: serde_json::json!({}),
}).await?;

// Move it later.
let mid = match m.id { rustango::sql::Auto::Set(v) => v, _ => unreachable!() };
manager.move_to_collection(mid, Some(cid)).await?;

// Walk the folder path.
let path = manager.collection_path(cid).await?;          // "products"

// List media in a folder, optionally recursive.
let in_folder = manager.list_in_collection(cid, true).await?;

// Tags (M2M, free-form labels).
manager.tag(mid, &["featured", "approved", "homepage-hero"]).await?;
manager.untag(mid, "homepage-hero").await?;

// Replace the entire tag set:
manager.set_tags(mid, &["featured", "draft"]).await?;

// Find media by tag, paginated.
let featured = manager.list_with_tag("featured", 50, 0).await?;

// Top tags by usage:
let popular = manager.popular_tags(10).await?;           // Vec<(MediaTag, i64)>
```

Deleting a collection orphans its Media (sets `collection_id = NULL`) — the rows + storage objects survive, just lose their folder. Deleting a tag cascades the junction rows away (tags are cheap to recreate).

#### REST router

The `media_router` exposes the manager surface as JSON endpoints — drop it under any prefix you like:

```rust
use rustango::media::router::media_router;

let app = axum::Router::new()
    .nest("/media", media_router(manager));
```

| Method | Path | Purpose |
|---|---|---|
| `POST` | `/uploads/begin` | Issue a presigned PUT ticket for browser upload |
| `POST` | `/uploads/{id}/finalize` | Confirm storage object landed → flips `pending → ready` |
| `GET` | `/media/{id}` | Single Media row with `url`, `presigned_url`, `tags` |
| `DELETE` | `/media/{id}` | Soft-delete (storage preserved) |
| `POST` | `/media/{id}/move` | Move to another collection: `{collection_id?}` |
| `POST` | `/media/{id}/tags` | Replace tag set: `{slugs: [...]}` |
| `DELETE` | `/media/{id}/tags/{slug}` | Remove a single tag |
| `POST` | `/collections` | Create folder: `{name, slug, parent_id?, description?}` |
| `GET` | `/collections` | List all (non-deleted) folders |
| `GET` | `/collections/{id}` | Single folder |
| `DELETE` | `/collections/{id}` | Soft-delete (Media inside orphaned, NOT deleted) |
| `GET` | `/collections/{id}/contents` | Media in folder. `?recursive=1` includes sub-folders |
| `POST` | `/tags` | Create / upsert tag: `{slug}` |
| `GET` | `/tags` | All tags |
| `GET` | `/tags/popular` | Top tags by use count. `?limit=N` |
| `GET` | `/tags/{slug}/media` | Media carrying the tag. `?limit=N&offset=N` |

`MediaError` implements `IntoResponse` so unknown disks return `400`, storage transport errors `502`, and "not found" errors `404`.

Behind the `media` feature flag (default-on, implies `storage` + `postgres`); `media_router` additionally needs the `admin` feature for axum.

### Scheduled tasks

```rust
use rustango::scheduler::Scheduler;
use std::time::Duration;

let s = Scheduler::new();

s.every("cleanup_sessions", Duration::from_secs(300), || async {
    cleanup_expired().await.ok();
});

s.every("rotate_logs", Duration::from_secs(86_400), || async {
    rotate().await.ok();
});

let handle = s.start();   // each task runs in its own tokio task with panic isolation
// ... app runs ...
handle.shutdown().await;
```

---

## Signals

```rust
use rustango::signals::{connect_post_save, send_post_save, PostSaveContext};

// Register at startup:
connect_post_save::<Post, _, _>(|post, ctx| async move {
    if ctx.created {
        tracing::info!("New post #{}", post.id.get().copied().unwrap_or(0));
    }
});

// Fire after save (until macro auto-fires it for you):
post.save_on(&pool).await?;
send_post_save(&post, PostSaveContext { created: true }).await;
```

Available: `connect_pre_save`, `connect_post_save`, `connect_pre_delete`, `connect_post_delete`. Disconnect via the returned `ReceiverId`.

---

## i18n

```rust
use rustango::i18n::{Translator, Locale, negotiate_language};

// Load catalogs from disk
let t = Translator::from_directory("./locales".as_ref(), Locale::new("en"))?;

// Or build manually
let t = Translator::new(Locale::new("en"))
    .add_locale(Locale::new("en"), HashMap::from([
        ("welcome".into(), "Welcome, {name}!".into()),
    ]))
    .add_locale(Locale::new("fr"), HashMap::from([
        ("welcome".into(), "Bienvenue, {name} !".into()),
    ]));

// Translate
let s = t.translate("fr-FR", "welcome", &[("name", "Alice")]);
// → "Bienvenue, Alice !"  (fr-FR falls back to fr)

// Pick from Accept-Language
let lang = negotiate_language(
    "fr-FR,fr;q=0.9,en;q=0.8",
    &t.locales(),
);
```

---

## Testing

### Test client

```rust
use rustango::test_client::TestClient;

#[tokio::test]
async fn create_post_returns_201() {
    let app = build_app().await;
    let client = TestClient::new(app);

    let response = client.post("/api/posts")
        .header("authorization", "Bearer eyJ...")
        .json(&serde_json::json!({"title": "Hi"}))
        .send().await;

    assert_eq!(response.status, 201);
    let post: serde_json::Value = response.json();
    assert_eq!(post["title"], "Hi");
}
```

### Fixtures

```rust
use rustango::fixtures::{Fixture, load_all};

let users = Fixture::new("users").from_file("fixtures/users.json")?;
let posts = Fixture::new("posts").from_file("fixtures/posts.json")?;

load_all(&[
    ("rustango_users", &users),         // load parents first
    ("posts", &posts),
], &pool).await?;
```

`fixtures/users.json`:

```json
[
    {"username": "alice", "email": "a@x.com"},
    {"username": "bob",   "email": "b@x.com"}
]
```

---

## Feature flags

The default features cover everything most apps need. Trim them when shipping a slim binary:

```toml
# Default — everything except tenancy + cache-redis
rustango = "0.22"

# Multi-tenant
rustango = { version = "0.22", features = ["tenancy"] }

# With Redis cache
rustango = { version = "0.22", features = ["cache-redis"] }

# Bare ORM only (no admin, no forms, no email, no storage)
rustango = { version = "0.22", default-features = false, features = ["postgres"] }
```

| Feature | What it adds | On by default? |
|---|---|---|
| `postgres` | sqlx + Postgres driver | yes |
| `admin` | `rustango::admin` HTTP layer (axum, Tera) | yes |
| `config` | layered TOML config + env overrides | yes |
| `forms` | `rustango::forms` parsers + ModelForm | yes |
| `serializer` | `#[derive(Serializer)]` | yes |
| `cache` | `Cache` trait + InMemoryCache + NullCache | yes |
| `cache-redis` | + RedisCache | no |
| `signals` | pre/post save/delete dispatcher | yes |
| `email` | `Mailer` trait + console/in-memory/null | yes |
| `storage` | `Storage` trait + Local/InMemory | yes |
| `scheduler` | in-process cron-shape scheduler | yes |
| `secrets` | `Secrets` trait + Env/InMemory | yes |
| `totp` | RFC 6238 2FA | yes |
| `webhook` | inbound HMAC signature verification | yes |
| `api_keys` | `{prefix}.{secret}` argon2 keys | yes |
| `passwords` | argon2 hash + strength check | yes |
| `signed_url` | HMAC-SHA256 signed URLs | yes |
| `tenancy` | multi-tenancy + operator console + permissions | no |
| `csrf` | CSRF middleware (depends on `forms`) | implied by admin |

---

## Production checklist

Run before deploy:

```bash
cargo run --bin manage -- check --deploy
```

Audits:
- ✅ DEBUG-style env (`RUSTANGO_ENV` is `prod` or `production`)
- ✅ `SECRET_KEY` set and ≥ 32 bytes
- ✅ `DATABASE_URL` set
- ✅ Pending migrations applied
- ✅ Models registered in inventory

Then verify your stack has:

| Layer | Required | Tool in rustango |
|---|---|---|
| HTTPS termination | yes | (reverse proxy — nginx / cloudflare / aws ALB) |
| Security headers | yes | `SecurityHeadersLayer::strict()` |
| Rate limiting | yes | `RateLimitLayer::per_ip(...)` |
| Access logging | yes | `AccessLogLayer::default()` (PII-redacted by default) |
| Health endpoints | yes | `health::health_router(pool)` → `/health`, `/ready` |
| Request IDs | recommended | `RequestIdLayer::default()` |
| CORS allowlist | if you have a JS frontend | `CorsLayer::new().allow_origins(...)` |
| ETag caching | optional | `EtagLayer::default()` |
| Backups | yes | external — `pg_dump` |

---

## Comparison

| | rustango | Django | Laravel | Rocket | Cot |
|---|:-:|:-:|:-:|:-:|:-:|
| ORM | ✅ | ✅ | ✅ | ❌ | ✅ |
| Auto-migrations | ✅ | ✅ | ✅ | ❌ | ✅ |
| Auto-admin | ✅ | ✅ | ⚠️ Filament | ❌ | ✅ |
| Multi-tenancy | ✅ | ⚠️ ext | ⚠️ ext | ❌ | ❌ |
| JWT lifecycle (refresh + blacklist + custom claims) | ✅ | ⚠️ ext | ⚠️ Sanctum/Passport | ❌ | ❌ |
| TOTP / 2FA | ✅ | ⚠️ ext | ✅ Fortify | ❌ | ❌ |
| Signals | ✅ | ✅ | ✅ Events | ❌ | ❌ |
| Cache backends | ✅ | ✅ | ✅ | ❌ | ⚠️ optional |
| Email backends | ✅ | ✅ | ✅ | ❌ | ❌ |
| File storage | ✅ | ⚠️ ext | ✅ Flysystem | ❌ | ❌ |
| Scheduled tasks | ✅ | ⚠️ Celery beat | ✅ | ❌ | ❌ |
| Security headers | ✅ | ✅ | ⚠️ middleware | ✅ Shield | ❌ |
| Test client | ✅ | ✅ | ✅ | ✅ Client | ✅ |
| Project scaffolder | ✅ `cargo rustango new` | ✅ `startproject` | ✅ Laravel installer | ❌ | ✅ `cot new` |
| File generators | ✅ `make:*` | ⚠️ ext | ✅ artisan | ❌ | ❌ |

✅ shipped · ⚠️ partial / via extension · ❌ not shipped

---

## Documentation

- **API docs**: <https://docs.rs/rustango>
- **Tutorial**: see `docs/getting-started.md`
- **CHANGELOG**: see `CHANGELOG.md`
- **Source**: <https://github.com/cot-rs/rustango>

---

## License

MIT OR Apache-2.0