Runtime Capabilities (Issue #75)

The runtime storage contract is intentionally platform-owned. Every operation accepts an explicit tenant_id; IDs and namespace prefixes are not a security boundary. PostgreSQL uses composite tenant keys and foreign keys, while the in-memory implementation uses the same key shape and error semantics for local development and conformance tests.

Contract Surface

trpcservice/runtime/storage defines tenant-scoped contracts for Session, Memory, Summary, Knowledge, Artifact, Audit, Vector, and Object storage. Each record is defensively copied at the boundary. Writes use stable IDs and idempotent upserts where a retry can be safely replayed. Versioned summaries reject an older event sequence, and memory writes enqueue their durable record for asynchronous vector indexing (the explicit EnqueueMemoryIndex operation is also available for retries).

Session state and immutable event history are published through the neutral trpcservice/storage/session contract. The agent/sessionstore adapter and runtime storage implementations depend on that contract; runtime-specific message/reply capabilities remain separate.

Backend profiles select session, memory, summary, knowledge, artifact, and audit bindings. runtime/storage/factory.CapabilitySet exposes typed accessors for those capabilities; providers are resolved only under the requested tenant and are closed by the owning set. Vector and object adapters travel with their source knowledge and artifact capabilities so a provider cannot accidentally cross a tenant namespace.

Commit Ordering

The durable execution barrier is:

event/state -> durable memory -> reply outbox -> asynchronous summary/vector index

An index or summary failure does not roll back the source event or memory. A retry uses the stable memory/document ID and version, so an older queued index cannot overwrite a newer record. PostgreSQL readers observe committed rows from any worker process; NewBackend in the in-memory adapter provides the equivalent shared-state view for multi-node tests. Closing one NewWithBackend view does not stop the shared index worker while another view remains active; the backend owner and all views must be closed before the worker exits.

PostgreSQL Tables

Migration 0012_runtime_capabilities.up.sql adds tenant-keyed Memory, Summary, Knowledge, Artifact, Audit, Vector Index, and Object rows. Every table has a composite primary key beginning with tenant_id, explicit tenant foreign keys, bounded fields, JSON shape checks, and grants limited to the runtime role.

The vector index is an eventually consistent projection. Its composite key is tenant_id, source, document_id, so memory and knowledge records may safely use the same document identifier. Knowledge documents remain the source of truth; migration or reindexing can rebuild the projection by source, document ID, and digest without changing tenant authorization. Object content is returned through an io.ReadCloser and is never mixed into control-plane configuration or execution snapshots.