Domain packs (external)

Domain packs let teams layer interpretation and reusable derived signals without changing SignalQL core grammar.

Purpose

• Keep SignalQL core domain-agnostic.
• Enable reusable higher-level logic for specific domains.
• Version interpretation artifacts independently from language version.

Examples

• Analytics pack: sessions, funnels, retention patterns.
• Work intelligence pack: work_item, signal(risk_score), probability(delay), ownership_gap, dependency_chain.
• Security pack: anomaly_detection, threat_signals.
• Memory/knowledge pack: memory_object, decision, claim, context_bundle, provenance conventions.

What a domain pack may include

• Derived signal definitions.
• Reusable query templates.
• Interpretation prompts/policies.
• Validation and confidence metadata.
• Namespaced entity catalogs (for example work.memory_item, analytics.session, code.architecture_decision).

What a domain pack must not do

• Modify SignalQL core grammar.
• Introduce core-only domain keywords.
• Add mutating actions to SignalQL execution.

Metric definition contract (v0.3)

A governed metric(name) reference resolves, at bind time, to a metric definition supplied by a domain pack or metrics registry. The core language carries only the reference — the formula lives in the definition and is versioned independently from the language version. Resolved metric name and version are emitted in result-envelope metadata (metadata.metrics) so a re-run can detect definition drift.

Field	Required	Meaning
name	yes	Qualified metric identifier, e.g. analytics.weekly_active_users.
version	yes	Definition version, independent of the SignalQL language version.
source	yes	Underlying SourceRef the metric is computed from (e.g. events).
measure	yes	SignalQL aggregate return expression, e.g. count_distinct(user_id).
filter	no	SignalQL predicate scoping the metric, e.g. event_name = "session_start".
grain	no	Natural reporting grain (h/d/w/m).
unit	no	Reporting unit, e.g. users.
owner	no	Owning team/person for governance.
dimensions	no	Dimensions the metric may be grouped by.

Binding semantics: a query FROM metric(name) … RETURN timestamp, metric_value is rewritten to FROM <source> WHERE <filter> … RETURN timestamp, <measure> — the reserved token metric_value in RETURN is replaced by the metric's measure; the caller's DURING/AS OF/BUCKET BY/GROUP BY/ORDER BY/LIMIT are preserved. Unknown metrics raise a typed MetricBindingError (code: "unknown_metric"). Metric formulas never enter the core grammar.

Catalog records for DESCRIBE (v0.3)

A catalog provider answers DESCRIBE introspection queries with machine-readable records so an agent can discover schema headlessly. Required fields are always present; optional fields are populated per adapter capability.

Field	Required	Meaning
identifier	yes	Entity/event/signal/metric/relationship identifier.
kind	yes	One of entity, event, signal, metric, relationship.
fields	yes	Column descriptors: name, type, unit, nullable.
relationships	no	Traversable edges: { name, target }.
description	no	Human-readable description.
unit	no	Reporting unit (for signals/metrics).
version	no	Definition version (for kind: "metric").

Without a configured catalog provider, DESCRIBE is capability-gated and returns an explicit CapabilityError (tier v0.3-capability).