--- id: SVC-MBR-STR-terms title: Term Engine product_area: membership module: structure repository: services-membership source_module: modules/terms revision: 1 status: draft design_intent: confirmed origin: >- D-45 (decided 2026-10-17): services-membership:README.md#The term engine (the engine imports nothing of Membership and is extracted later) implementation_evidence: observed source_sha: services-membership: 5994c270e8a37a30f848e99ba5b5ee6b87c08893 react-console: baf6dae382d6f41dce976c7f848667ccc37e076f inference: [] owns: - DOM-MBR-STR-005 does_not_own: - 'the memberships module owns holdings, terms, lifecycle events, stored caches and sweep records.' - the memberships module owns scheduled sweep execution and published membership events. - the memberships module and Commerce own purchase preparation and billing execution. - Configuration owns the lifecycle reason catalogue's storage and HTTP routes. operations: - operation_id: getTermsTenantHealth intent: Report the deployed term API build for a workspace the caller can access through Membership. access: console permission: membership.application.access realises: - CAP-MBR-STR-019 published_to_submissions: 'not published: a build and access health check collects no submission' - operation_id: computeTermPeriod intent: 'Calculate purchased term dates from a supplied rule, business date and continuation context.' access: internal permission: none; called by Membership code that has already authorised its caller realises: - CAP-MBR-STR-015 published_to_submissions: 'not published: an internal calculation or SQL template is not submitter intake' - operation_id: termRuleProblems intent: Return the complete set of problems found in a proposed term rule. access: internal permission: none; called by the configuration service realises: - CAP-MBR-STR-015 published_to_submissions: 'not published: an internal calculation or SQL template is not submitter intake' - operation_id: statusOf and episodesOf intent: Compute date-specific standing and effective continuity episodes from supplied term facts and settings. access: internal permission: none; called by Membership code that has already authorised its caller realises: - CAP-MBR-STR-016 published_to_submissions: 'not published: an internal calculation or SQL template is not submitter intake' - operation_id: cacheOf intent: >- Recompute a holding cache from terms and current domain settings; the caller compares and persists differences. access: internal permission: none realises: - CAP-MBR-STR-016 published_to_submissions: 'not published: an internal calculation or SQL template is not submitter intake' - operation_id: 'sweep.boundariesOf, sweep.needsCatchUp and sweep.detectionsOf' intent: 'Supply boundary dates, catch-up decisions and expiry or lapse detections for a requested sweep date.' access: internal permission: none realises: - CAP-MBR-STR-016 published_to_submissions: 'not published: an internal calculation or SQL template is not submitter intake' - operation_id: migrationSql intent: Produce the adopting domain's SQL function templates without executing a migration. access: internal permission: none realises: - CAP-MBR-STR-016 published_to_submissions: 'not published: an internal calculation or SQL template is not submitter intake' events: [] jobs: [] integrations: - system: Memberships module (the engine's one adopting domain) direction: inbound contract: >- The adopting domain names its tables and classification and offering columns and supplies rule, grace, benefit, continuity and eligibility hooks. It takes locks and persists decisions; engine facade methods can call those domain hooks. consistency: - rule: >- Pure helpers make decisions without persisted reads or writes; facade methods obtain inputs through domain hooks, and transaction consistency belongs to the caller. kind: transactional compensation: There is no engine-owned persisted result to undo. - rule: >- Current-input resolution and stored cache are distinct; repeated missed sweeps can leave caches stale until successful catch-up. kind: eventual compensation: A later successful full sweep refreshes the holding cache. evidence: - >- services-membership at 5994c270: aws/terms/terms.routes.ts; modules/terms/services/define-term-engine.ts, term-rules.ts, status.ts, holding-cache.ts, sweep.ts, sql-templates.ts; modules/terms/tests/unit/isolation.spec.ts; modules/memberships/services/membership-engine.ts, membership-caches.ts, sweep/status-sweep.ts (callers); README.md#The term engine. controls: [TC-AVL-002, TC-AVL-003, TC-AZ-001, TC-AZ-002, TC-AZ-003, TC-AZ-004, TC-AZ-005, TC-AZ-006, TC-CHG-001, TC-CHG-002, TC-CHG-003, TC-CHG-004, TC-CRY-001, TC-CRY-002, TC-CRY-003, TC-DAT-001, TC-DAT-007, TC-IAM-001, TC-IAM-002, TC-IAM-004, TC-IAM-005, TC-LOG-001, TC-LOG-002, TC-LOG-003, TC-LOG-004, TC-MON-001, TC-MON-003, TC-MON-004, TC-PI-001, TC-PI-003, TC-PI-005, TC-SEC-001, TC-SEC-004, TC-TEN-001, TC-TEN-002, TC-TEN-003] --- # Term Engine ## What This Service Is For The term engine supplies reusable calculations for term dates, standing, continuity and scheduled boundary work. Membership is the current adopter, with an explicit isolation boundary intended to support later reuse. ## Boundary Pure helpers own the shared interpretation, while the adopting domain owns holdings, terms, events, locking and persistence. The facade uses domain hooks for current allowances and rules. Configuration stores reasons, and Memberships implements the operational purchase and billing flows. ## Operations in Words One workspace HTTP health route checks access and reports build information. Internal interfaces calculate periods, validate rules, resolve status and episodes, compute caches, decide sweep work and generate SQL templates. The engine's Commerce participant and billing members still fail as unbuilt; they are not evidence of completed operational flows. ## Events and Jobs The engine publishes no event and schedules no job. Memberships calls its decisions, records unique detections and publishes termination when lapse is first recorded. ## Consistency Guarantees The caller supplies the transaction around domain reads and writes. Pure decision functions are repeatable for identical inputs, while facade calls depend on the hooks they receive. A missed sweep delays persisted cache and detection work without changing how current-input resolution calculates standing.