Patterns

Code owns the control flow. Jers appears where the code needs a judgment. Four patterns from stateless decision APIs, then two that exist because of the memory.

Speculative fan-out

Send every question that might matter in one request, including the ones that only apply to some outcomes, and let the code pick. A ticket: category (choice), bug_severity (score), has_steps (noul), refund_requested (noul), frustration (score) in one call; the code reads severity only when the category is bug_report. One engine pass, one round trip.

Confidence-gated routing

The answer says what; the confidence says whether. check_balance at confidence 0.6 runs; approve_transfer at 0.6 to 0.85 asks the user to confirm; at 0.85 and above it runs; below 0.6 anything goes to a person.

Composite scoring

Break a judgment into dimensions, one Score each, normalise to 0 to 1, combine with weights in code. A senior engineer: 0.4 × python + 0.1 × leadership + 0.4 × design + 0.1 × generalist; a manager: other weights, same answers.

Intent routing

A Choice over intents and a Score of complexity, then: simple lookups to deterministic code, domain questions to a specialist model with the right context, uncertain or complex cases to a person. The expensive resource is called only when the cheap decision says so.

Memory-first routing

Write the account's standing facts once, then route every message with the subject named. Measured in the escalation cookbook: "escalate to a person" went from 20% to 82% for a priority account once two lines about its standing were in memory; the control account did not move. The same code, no per-request packing.

Conditions in code

The engine does not compare numbers or dates. Put the condition in code and let Jers hand the engine a sentence only when it holds: a memory rule with when ("session_result <= -30", optionally expiring) checked at every decision on the request's values and the state's fields, or derive in the request ("reading.bearing_temperature_c > limit"). An unpaid invoice, a stop-loss reached, a threat to cancel: facts your software knows become facts the engine reads, the moment they hold. See Rules in memory and Request options.