# What is built

A feature that isn't built yet is the error `toolchain.not_built_yet`
where an app uses it.

| Feature | Status |
|---|---|
| Checking routes | Built: `jadpo check` checks route groups, their prefixes and APIs (with `idempotency:`), methods and typed placeholders, the one input (from the query string for `GET` and `DELETE`, the JSON body otherwise, and `header:` fields), `output:` and `status:`, `deadline:`'s range and what `run:` calls, every route of the project against the others and the health paths, and each API's record. |
| OpenAPI | Built: `jadpo check` writes one OpenAPI document per API to `build/openapi/`, and the failure wording for client apps beside it. Each API serves its own document at `<prefix>/openapi.json` (`serve_openapi: false` turns it off), listed in its record, its document and `jadpo routes`, and the documents carry the `x-jadpo` fields the OpenAPI importer reads ([OpenAPI](openapi.md)). OpenAPI derives each route's responses from what it runs and shows `ZonedTime`, `Zone` and a mixed enum as they are sent. |
| Serving a request | Built: the runtime's HTTP component routes a request, decodes and checks its input (each problem as `{ field, rule }`), runs the action or query, and answers with the output or the failure envelope, its `request_id` and `x-request-id`, with the status the failure's kind sets; it answers `HEAD` and `OPTIONS` itself and counts the default rate limits. It reads a body only as JSON, and refuses a query string or body a route doesn't read, a header it can't read and a body over 1 MB. |
| Deadlines and concurrent changes | Built: the runtime stops a route at its deadline without committing, even work that never waits, and runs an action again on a concurrent change found as it commits. |
| Health endpoints | Built: `/health/live` and `/health/ready`. |
| Idempotent writes | Built: the runtime keeps each write's `Idempotency-Key` with its response. |
| Commands | Built: `jadpo dev` serves the routes and reloads on save, `jadpo routes` lists them and `jadpo api update` writes the records, each `api/<api>.jadpo_record` in the record format with no `version:` line; the OpenAPI version is a hash of it. |
| Native connection limits | Built: natively, a client has 10 seconds for its headers and 30 for its body, a write waits at most 30 seconds for it to read, and the server holds at most 1,024 connections and 10 database connections per store per worker. |
| Sign-in | Built: every route needs a signed-in caller unless it says `authentication: RouteAuthentication.none`; each API lists the sign-in methods it accepts, named in its record; a route passes `current_principal` to what it runs; a signed-in caller's requests count against its own rate limit, and its idempotency keys are its own; a request with a credential on a route anyone may call counts against its address before it runs ([Identity](identity.md)). |
| Policy | Built: policy decides what each route reaches, and OpenAPI lists the 403 `not_permitted` on every route that runs an action that writes or is listed under `actions:` ([Policy](policy.md)). |
| Issued tokens and keys | Built: a `GET` runs `sessions.tokens` and `<Service>.keys` itself, and the record and OpenAPI describe the `IssuedToken` and `IssuedKey` it sends ([Service credentials](service-credentials.md)). |
| Map layers | Built: a route may send a `FeatureCollection<G, P>` bare, its properties held to what an `Output` may hold and, where an action returns it, to the fields every caller may read ([Field restrictions](field-restrictions.md)); OpenAPI describes RFC 7946's object and the record names it with its type arguments. A `GET` sends one a query gives ([Reads and writes](reads-and-writes.md), "A query giving a map layer"), held to field policy where the query is declared. |
| `settle:` | Built: a route waits for the work its action set off ([Waiting for follow-on work](waiting-for-follow-on-work.md), and `route.settle_invalid`). |
| Streaming | Built: a route whose action returns an `AiStream` sends a model's answer as server-sent events ([Streaming a model's answer](streaming-a-model-s-answer.md), and `route.stream_invalid`). |
| Failure wording from a build | Not built yet: `jadpo check` writes `<api>.failures.<locale>.json` beside each OpenAPI document, and `jadpo build` is to write it too. |
| `x-jadpo-events` | Not built yet: it waits for publishing events outward ([Where events travel](where-events-travel.md)). |
| A route's own `rate_limit:` and the Redis store for rate limits | Not built yet ([Rate limits](rate-limits.md)). |
| Classifying breaking changes and their acceptances | Not built yet ([Acceptances](acceptances.md)). |
| The `Jadpo-Revision` header | Not built yet: it comes with caches ([Write revisions](write-revisions.md)). |