Architecture

This section is a technical reference for contributors. It describes the current runtime and persistence boundaries, not a product tutorial or a configuration guide.

Signet has one canonical state layer: agent-scoped SQLite rows and user-facing workspace artifacts. Search indexes, embeddings, caches, and projections are derived from that state. The daemon owns writes and exposes the HTTP surface; the CLI, dashboard, and harness integrations are clients of that daemon.

In this section

• Packages and data flow: repository ownership and the current evidence-to-retrieval path.
• Pipeline and storage: active workers, persistence, and retired worker boundaries.
• Platform services: authentication, connectors, diagnostics, and repair.
• Data lifecycle: normalization, retention, projections, and workspace layout.
• Interfaces and agents: public runtime boundaries and agent scoping.

Database owner boundary

The daemon-facing database contract is an asynchronous, serializable job protocol. A job contains an operation name, lane (read, write, or maintenance), enqueue timestamp, absolute deadline, estimated work units, cancellation state, and a query request. The first implementation runs one killable owner process. The lane is part of the frozen interface so a future transport can route recall reads to parallel readers and writes or maintenance to one writer without changing callers.

The owner process is the only place that imports SQLite or runs synchronous SQL. The daemon client exposes submit, awaitResult, cancel, health, and close; it never exposes a database handle or callback. The parent kills the owner at a hard deadline, reports owner_died when the process exits unexpectedly, and starts a fresh owner for the next job. Pending jobs fail closed rather than waiting behind a dead process. Owner construction failures are reported as unavailable and do not silently fall back to main-thread SQLite.

The wire messages are newline-delimited JSON: submit(job), cancel(jobId), and shutdown from the daemon, with ready, result, and fatal events from the owner. Results are completed, cancelled, timed_out, failed, or owner_died. This boundary is the migration seam for recall, writes, integrity and repair, index and embedding work, FTS maintenance, and source ingestion. The core rollout proves the seam with an owner-routed recall query; category migrations must not reintroduce synchronous SQLite in the daemon.

For product concepts, start with What Is Signet, Memory and recall, and Knowledge architecture.