Jadpo is experimental and not ready for production. These docs follow the compiler's main branch as of 30 Oct 2026. What's built · Install 0.1.0
jadpo

Reference

Version 0.1.0, from Jadpo's main branch at a707efb. Jadpo's CI compiles every example on these pages, so each one works.

New to Jadpo?

This path builds one app, a todo list with sign-in, from an empty folder to a deployed server. Each page adds one idea and ends with the app running.

Learn Jadpo The one-page primer

The primer is the whole language on one page: what an agent reads first, and a summary for you once you've started.

For agents

Every page is also Markdown: add .md to its address. Start at /llms.txt, read /docs/primer.md, follow /learn.md to teach a person, then find pages by title and summary in /docs/index.json.

A compiler error names its rule; its page is /docs/errors/<rule>. There are 661, listed in the error index.

By task

  • Build an API

    Routes with one typed input and output, the failures callers see, and the OpenAPI document written for you.

  • Store data

    Entities, references and migrations, then the queries and writes that read and change them.

  • Sign people in and decide who sees what

    Sessions, magic links and passkeys; then grants, roles, tenancy and the permissions report.

  • Call another service

    Typed provider packages, connections, calls, webhooks, and the fakes your tests use.

  • Run background work

    Schedules, events and subscribers, batches that keep their progress, retries and what an operator sees.

  • Test it

    Tests beside the code, a real database per test, a controlled clock and provider fakes.

  • Configure and deploy

    Settings and secrets, then a native build or a Cloudflare Workers build.

By part of the language

  • Project layout and modules

    How a Jadpo project is laid out on disk, how one file sees declarations from another, and the naming rules every name follows.

  • Values and types

    What kinds of value a Jadpo program works with, how you give a value a meaning in your business, and when one type can stand in for another.

  • Logic

    How you write what your app does: functions and actions, variables and constants, statements, operators, match, attempt and loops, and what Jadpo allows for passing functions.

  • Failures

    Your code says what went wrong, by name, and Jadpo decides how each failure reaches whoever called: the HTTP status, the response body and what is logged.

  • Data

    How you declare the records your app keeps, where they are stored, and how their shape changes over time.

  • Reads and writes

    How a program reads and changes stored records: named queries, filters, order and pages, totals, related records, the operations every entity gets, what a refused write reports.

  • HTTP

    A Jadpo app answers HTTP requests with routes.

  • Identity

    Identity is how Jadpo knows who is calling.

  • Policy

    Policy says who may do what to which stored records.

  • Configuration and time

    This page covers the values your app reads from its environment, such as a database address or an API key, and everything to do with time: the current time, dates and time zones.

  • External services

    An external service is another company's API, such as Stripe, a courier or another Jadpo app, that your actions call.

  • Jobs and events

    This page covers the work your app does outside a request: schedules that run an action on a timer, events an action announces, subscribers that react to them, and what happens when that work fails.

  • Testing

    A Jadpo test runs your real application against a real database.

  • Tooling

    The jadpo command and everything around it: the formatter, the editor support, how errors are shown, the generated build/ folder.

  • Personal data

    Your app says which data is about a person, and Jadpo does the rest: it exports that data when the person asks for a copy, erases it when they ask to be forgotten, deletes it when its time is up.

  • Built-in services

    Jadpo gives your app some common backend features itself, so you don't install a library or write your own: feature flags, rate limits, files, an audit trail, telemetry, email, documents.

  • Debugging and review

    Jadpo code is written mainly by coding agents and read by people, so two jobs matter most.

  • Records and manifest

    Besides your running app, the compiler writes two kinds of file, and it keeps them apart so that every change can be reviewed and every production event traced back to its source.

  • Standard library

    The standard library is the set of types and operations every program can use without declaring them, such as Money, list.count(items) and temporal.in_zone(at, zone).

  • Geospatial

    Geospatial values say where things are, and what is near or inside what: a bakery's position, the patches it delivers to, the shops within five kilometres of a customer.

  • AI

    Your app can ask a language model for an answer, a stream of text or an embedding (a list of numbers that stands for a text's meaning).

Commands