The HEART standard

Everything that defines HEART: how to reach a system, what lives inside it, and how it is tested. Each document is also available as Markdown.

Start here: you do not have to read it all

Pick the track for your product. Each lists the exact sections to read, in order, and where to stop. Not sure which? Answer four questions.

1 Basic

Track 1: Basic

Products that watch themselves and tell a person.

A dog collar that reports its own faults, a birdhouse camera, a soil sensor, a PLC you only watch.

HEART Basic · A1 · about 1 hour 45 minutes

Read Track 1 →2 Intermediate

Track 2: Intermediate

Products people log in to, change, update, approve and connect.

A thermostat with an owner's app, a collar with lost mode, signed updates, a Gateway, MQTT sensors.

HEART Connected · A1 or A2 · 1 hour 30 minutes to 2 hours more

Read Track 2 →3 Advanced

Track 3: Advanced

Products that act on their own, use an AI brain, run fleets, or move.

Self-healing Playbooks, an AI that proposes fixes, fleet rollouts, robots, heavy machines, spacecraft.

HEART Full · A3 to A5 · 1 hour 20 minutes to 4 hours more, in three stops

Read Track 3 →

Show the documents of one track, with the sections it reads: Track 1: Basic · Track 2: Intermediate · Track 3: Advanced

Other

HEART Command Center

3 Advancedspec/HEART-Command-Center-1.0.md

Start here: three reading tracks

Start Here: Which HEART Track Are You On?

1 Basic2 Intermediate3 Advancedspec/HEART-Start-Here.md

HEART Track 1: Basic

1 Basicspec/HEART-Track-1-Basic.md

HEART Track 2: Intermediate

2 Intermediatespec/HEART-Track-2-Intermediate.md

HEART Track 3: Advanced

3 Advancedspec/HEART-Track-3-Advanced.md

Standard

HEART API Standard

1 Basic2 Intermediate3 Advancedspec/README.md

The HEART Standards Family

1 Basic2 Intermediate3 Advancedspec/HEART-Standards-Family.md

HEART API Standard 1.0

1 Basic2 Intermediate3 Advancedspec/HEART-API-Standard-1.0.md

HEART Core Standard 1.0

3 Advancedspec/HEART-Core-Standard-1.0.md

HEART Part 1: Basics

1 Basic2 Intermediate3 Advancedspec/HEART-Part-1-Basics-1.0.md

HEART Part 2: Autonomy Levels

1 Basic2 Intermediate3 Advancedspec/HEART-Part-2-Autonomy-Levels-1.0.md

HEART Part 3: Information Model

1 Basic2 Intermediate3 Advancedspec/HEART-Part-3-Information-Model-1.0.md

HEART Part 4: Connections

1 Basic2 Intermediatespec/HEART-Part-4-Connections-1.0.md

HEART Part 6: Human Control and Safety

1 Basic2 Intermediate3 Advancedspec/HEART-Part-6-Human-Control-and-Safety-1.0.md

HEART Part 9: Testing and Certification

1 Basic2 Intermediate3 Advancedspec/HEART-Part-9-Testing-and-Certification-1.0.md

HEART Signal Tables

2 Intermediatespec/HEART-Signal-Tables-1.0.md

Profiles

HEART Hub

1 Basic2 Intermediatespec/HEART-Monitor-1.0.md

Advisories

HEART Security Advisory HEART-2026-001

2 Intermediate3 Advancedspec/HEART-Security-Advisory-2026-001.md

Design notes

HEART Design Note 1: The Brain and the Heart

3 Advancedspec/HEART-Design-Note-1-Brain-and-Heart.md

HEART Core, the reference runtime in Rust

HEART Core (Rust)

3 Advancedheart-core-rs/README.md

Changelog

3 Advancedheart-core-rs/CHANGELOG.md

Code of Conduct

3 Advancedheart-core-rs/CODE_OF_CONDUCT.md

Conformance statement

3 Advancedheart-core-rs/CONFORMANCE.md

Contributing

3 Advancedheart-core-rs/CONTRIBUTING.md

Configuring heartd

3 Advancedheart-core-rs/docs/CONFIGURATION.md

Security Policy

3 Advancedheart-core-rs/SECURITY.md

Testing HEART Core

3 Advancedheart-core-rs/TESTING.md

Guides

Building a HEART-Embedded System: worked guides

1 Basic2 Intermediate3 Advancedguides/README.md

Guide 9: A HEART-Embedded 3D printer

1 Basicguides/3D-Printer.md

Guide 1: A HEART-Embedded air-conditioner controller

3 Advancedguides/AC-Temperature-Controller.md

Guide 3: A HEART-Embedded birdhouse camera

3 Advancedguides/Birdhouse-Camera.md

Guide 11: A HEART-Embedded dog tracking collar

2 Intermediateguides/Dog-Tracking-Collar.md

Guide 8: A HEART-Embedded EV charger

1 Basicguides/EV-Charger.md

Guide 6: A HEART-Embedded greenhouse irrigation system

3 Advancedguides/Greenhouse-Irrigation.md

Guide 10: A HEART-Embedded online shop server

3 Advancedguides/Online-Shop-Server.md

Guide 4: A HEART-Embedded pacemaker system

1 Basicguides/Pacemaker.md

Guide 2: HEART-Embedded photo editing software

3 Advancedguides/Photo-Editing-Software.md

Guide 5: A HEART-Embedded smart thermostat

2 Intermediate3 Advancedguides/Thermostat.md

Guide 7: A HEART-Embedded water pump station

1 Basic3 Advancedguides/Water-Pump-Station.md

Machine-readable

OpenAPI description of the HEART APIYAML

Problem typesthe type of every HEART error

Fault codesevery standard code, with causes and fixes; also as JSON

JSON schemas 1.0, at their $id addresses
action · aipolicy · api-index · arrhythmia · artifact · ask-request · audit · batch-request · brain-lease · brain-offline-request · brain-signal · brain · card · common · component · config · consent · consultation · control · core · custom-definition · custom · decision-request · diagnostic · envelope · evolution · export · fleet-request · fleet · grant · intent · invoke-request · lesson · lifecycle-request · lifecycle · log · memory · metric · native-request · page · peer · platform · policy · presence-method · problem · property · proposal · pulse · reason-request · reason-response · receipt · rhythm · rule · schedule · security · serve-request · serve-response · signal-table · software · subscription · trial · update · usage