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Halowerk State Machine Step
x402
Halowerk State Machine Step is a paid API for AI agents from agent.halowerk.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-11).
Computes a single deterministic state-machine transition given a machine definition, current state, and an event, with optional guard conditions evaluated against context or payload fields.
Price / call$0.002
Success—
StatusUnknown
How this service works
Takes a machine definition, the current state, one event and an optional context, and computes a single step. Transitions may carry a guard, which is a declared comparison — field, operator, value — and never an expression: the field is a dotted path into context or payload, so a machine handed in by a stranger cannot execute anything on this server.
Output
Returns the next state name the machine transitions to, along with any action labels declared on the taken transition, or an indication that no transition was taken (e.g. guard failed or no matching event handler in the current state).
Example use cases
Order fulfillment workflow step
“I have an order fulfillment state machine with states 'pending', 'paid', 'shipped', and 'delivered'. The order is currently in 'paid', and I just received a 'ship' event with payload {trackingId: 'TRK123'}. Advance it one step and tell me the next state and any actions triggered.”
Retry logic with guard condition
“My retry state machine is in the 'waiting' state and I need to apply a 'retry' event. There's a guard that only allows the transition to 'retrying' if context.attempts is less than 3 — the current context has attempts set to 2. Compute the next step.”
Agent task handoff gate
“I'm orchestrating an agent pipeline. The machine is in 'awaiting_approval' and the event is 'approved' with payload {score: 0.92}. The guard requires payload.score to be greater than or equal to 0.8 before moving to 'executing'. Run the state machine step and confirm whether we transition.”
Technical details
Endpoint
POSThttps://agent.halowerk.com/v1/state-machine-step?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a stateless, sandboxed, single-step FSM evaluation that cannot execute arbitrary code — guard conditions are declarative comparisons (field, operator, value), never expressions, so it is safe to hand in externally-supplied machine definitions. Prefer it over full workflow engines when you want lightweight, per-step control with explicit action labels rather than side-effectful execution.
Side effects
- Guard condition not met — no transition taken, machine stays in current state
- Event name does not match any transition in current state — no-op response
- Current state is marked final — no events accepted, returns error or no-op
- Invalid dotted path in guard field — field resolution fails
- Machine definition missing required 'initial' or 'states' fields — validation error
- State referenced in transition target does not exist in machine definition
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| event | object | The event to apply. |
| context | object | Machine context, addressable in guards as context.<field>. Never modified. |
| machine | object | The automaton definition. |
| current_state | string | The state the machine is in right now. |
| elapsed_in_state_s | number | Seconds already spent in current_state. Supplied by you, so the result does not depend on this server clock. |
| timeout_precedence | string | Which side wins when the deadline is breached and an event transition also matches. |
Tags
x402
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