Context envelope

A context_envelope is the top-level snapshot for one context boundary. It answers: which context records belong to this turn, task, tool invocation, review, or handoff?

Required fields

Field	Purpose
schema_version	Agent Context schema version.
context_id	Stable snapshot id.
scope	Boundary such as turn, task, session, tool_invocation, review, or handoff.
lifecycle	Current lifecycle state.
created_at	Snapshot timestamp.

Recommended refs

Use refs rather than embedding complete records when envelopes travel across systems: surface_refs, item_refs, selection_refs, budget_ref, assembly_refs, injection_refs, compaction_refs, missing_context_refs, policy_refs, evidence_refs, artifact_refs, tool_refs, runtime_refs, and telemetry_refs.

Fixed rule

The envelope is a snapshot, not a mutable memory store. If context changes, create a new event and, when needed, a new envelope revision.