How do I install the State Machine skill?

Run npx skillmds@latest add ashfordeou/state-machine in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is State Machine safe to use?

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Which AI agents work with State Machine?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is State Machine free to use?

Yes. Installing skills from SkillMD is free. This skill is licensed under Apache-2.

Who published State Machine?

ashfordeOU (@ashfordeou) published this skill. Their other Agent Skills are listed on their SkillMD profile.

State Machine by ashfordeou — Agent Skill

Name: State Machine
Author: ashfordeOU

State Machine

Use when you must model or verify SysML state machine behavior in an aerospace systems engineering model: build state machines with states, transitions, events, guards, and actions, simulate an event sequence to produce the firing trace, compute the reachable state set from the initial state, and detect unreachable states and transition conflicts where two guards enable the same event. Produces the firing trace, the reachable set, and the conflict list that gate the behavioral model review. Trigger: state machine, statechart, transitions, guards, events, reachability, SysML behavior.

ashfordeOU 9350dbd 3 files · 12.1 KB Updated Sep 17, 2026

File contents

SysML State Machine Modeling (systems-engineering-safety/mbse/state-machine)

Use when the task is behavioral modeling with SysML state machines: states, transitions, events, guards, actions, and the reachability or conflict review of the resulting model.

Domain quick reference

A state machine models behavior as states connected by transitions.
A transition fires on an event when its guard condition is true; firing may run actions and moves the machine to a target state.
The initial state is the entry point; a state is reachable when a chain of transitions leads to it from the initial state.
A transition conflict exists when one event enables more than one transition from the same state and no priority resolves the choice.
Review checks that every state is reachable and no event is ambiguous, per the behavioral model review in the ARP4754A development process.

Workflow

Collect the states, initial state, and the transition list with events, guards, and actions.
Validate the machine so every transition endpoint exists.
Simulate the event sequence and record the firing trace.
Compute the reachable state set from the initial state.
List the unreachable states and any transition conflicts, then gate the behavioral model review.

Pitfalls

Firing a transition without checking its guard; a false guard must leave the machine in its current state.
Two enabled transitions on one event with no priority; the model is ambiguous and the conflict must be resolved.
A guard missing from the evaluation context; treat an absent guard as blocking, not as enabled.
Declaring a state that no transition chain can reach; the review must list it as unreachable.

Behavior contract (gate 3)

The firing, trace, and reachability logic is exercised by the gate 3 contract test: scripts/test_state_machine.py against scripts/state_machine_logic.py (stdlib unittest, offline). Run: python3 scripts/test_state_machine.py

Compliance

Standards referenced, not reproduced: ARP4754A text is proprietary (SAE); summary-only per standards-map.yaml. SysML state machine semantics are common modeling methodology.
compliance: STANDARDS-REF, gated: false.

---name: state-machinedescription: Use when you must model or verify SysML state machine behavior in an aerospace systems engineering model: build state machines with states, transitions, events, guards, and actions, simulate an event sequence to produce the firing trace, compute the reachable state set from the initial state, and detect unreachable states and transition conflicts where two guards enable the same event. Produces the firing trace, the reachable set, and the conflict list that gate the behavioral model review. Trigger: state machine, statechart, transitions, guards, events, reachability, SysML behavior.license: Apache-2.0---# SysML State Machine Modeling (systems-engineering-safety/mbse/state-machine)Use when the task is behavioral modeling with SysML state machines:states, transitions, events, guards, actions, and the reachability orconflict review of the resulting model.## Domain quick reference- A state machine models behavior as states connected by transitions.- A transition fires on an event when its guard condition is true; firing may run actions and moves the machine to a target state.- The initial state is the entry point; a state is reachable when a chain of transitions leads to it from the initial state.- A transition conflict exists when one event enables more than one transition from the same state and no priority resolves the choice.- Review checks that every state is reachable and no event is ambiguous, per the behavioral model review in the ARP4754A development process.## Workflow1. Collect the states, initial state, and the transition list with events, guards, and actions.2. Validate the machine so every transition endpoint exists.3. Simulate the event sequence and record the firing trace.4. Compute the reachable state set from the initial state.5. List the unreachable states and any transition conflicts, then gate the behavioral model review.## Pitfalls- Firing a transition without checking its guard; a false guard must leave the machine in its current state.- Two enabled transitions on one event with no priority; the model is ambiguous and the conflict must be resolved.- A guard missing from the evaluation context; treat an absent guard as blocking, not as enabled.- Declaring a state that no transition chain can reach; the review must list it as unreachable.## Behavior contract (gate 3)The firing, trace, and reachability logic is exercised by the gate 3contract test: scripts/test_state_machine.py againstscripts/state_machine_logic.py (stdlib unittest, offline). Run:python3 scripts/test_state_machine.py## Compliance- Standards referenced, not reproduced: ARP4754A text is proprietary (SAE); summary-only per standards-map.yaml. SysML state machine semantics are common modeling methodology.- compliance: STANDARDS-REF, gated: false.

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