Loco 1.2.0

1.2.0 is on crates.io. Most of it came from people building real apps on 1.1 and sending PRs, which is my favorite kind of release.

A Loco skill for coding agents. A lot of Loco code gets written by an agent now, and agents guess. They reach for a crate Loco already ships, hand-wire a queue, or invent an API name that sounds right. loco new now writes a skill into every app under .claude/skills/loco/: the framework’s doctrine, ten task recipes, and an API index for loco-rs and Sea-ORM generated from rustdoc. It matches the crate version your app compiles against, and you can read it at loco.rs/skills/loco.

We wrote up how we built it, including the parts that didn’t work:

1. Rails had twenty years of training data. Loco has a skill.
2. What’s in the Loco skill
3. Writing the doctrine down
4. Ten eval runs and an honest null
5. The eval kept finding bugs in Loco

Presigned storage URLs. ctx.storage.presign_get and presign_put give a client a time-limited URL that talks to S3, Azure or GCS directly, so a large upload skips your app. From @robertazzopardi.

Row-level multi-tenancy. Turn on the multi-tenancy feature, mark an entity’s tenant column with TenantEntity, and scope queries with .in_tenant(id). set_tenant fills the key on new records and refuses to move a record to another tenant. Scoping stays explicit, so a query without .in_tenant is unscoped. From @shuvroroy. The guide walks through it.

Tera components. TeraView::render_component renders one Tera 2 component by name. @schungx also wrote a guide to moving Tera 1 templates to Tera 2 with an AI assistant, including the spots where it gets things subtly wrong.

Postgres-only builds. SQLite is its own db-sqlite feature now, on by default. Leave it out and you skip libsqlite3-sys and its C toolchain. Also from @robertazzopardi.

Batch enqueueing. perform_all_later enqueues a list of jobs in one round trip, atomically, on every backend. From @mccormickt.

Fixed

The generated app got the most attention. A fresh server-side app answered 404 at /. The SPA had no sign-up page, a dev proxy stuck on port 5150, and a build that never typechecked. Scaffolded create and delete answered GET. The generated model test asserted nothing, and the Dockerfile pinned a Rust older than our MSRV. All fixed, with tests that fail without the fix.

A Redis worker could also quit on a slow or dropped connection while the process stayed up. It now retries until shutdown. Thanks @mikosco4real for tracking that one down.

Full list in the changelog.

Upgrading

Bump loco-rs to 1.2. Most apps need nothing else. Two changes might touch you:

• perform_later_with_priority returns Error::QueueProviderMissing when no queue is configured. It used to log and hand back a made-up job id.
• ExprTrait left the prelude. It attached itself to every value, so n.max(1) stopped compiling. Import it by name if you use it.

Thanks to everyone who sent code this round, and keep the PRs coming.