FAQ

What is Arqen?

Arqen is backend infrastructure for HTTP services. It provides application composition, configuration, authentication helpers, validation, Thingd adapters, durable jobs, health checks, observability, OpenAPI helpers, and an optional agent-tool layer.

Do I need to use AI?

No. Agent tools are optional. You can use Arqen for a conventional web or mobile backend, internal service, or automation worker.

Which storage mode should I use?

• Use memory for tests, examples, and disposable local development.
• Use native only for local development or migration, with Arqen’s optional thingd-native feature.
• Use http when Thingd should run as a separate service with its own memory, schema, index, backup, and operational lifecycle.

Native mode is compile-time coupled to the supported Thingd Cargo range. Compatible patch updates do not require an Arqen release. HTTP mode is coupled to the public Thingd v1 API; call HttpThingdBackend::check_compatibility() during startup and fail readiness if it returns an error.

• Do not use cloud as a current production mode; the public cloud adapter is not implemented.

See Configuration and Deployment.

Do I need to use Rust in my client?

The Arqen implementation is Rust-first. Clients can call the HTTP API from other languages. Machine-readable manifests are available for clients and agents; broader SDKs and templates are future work.

What does Thingd store?

Through the adapter, Arqen works with objects, events, search, links, and queues. Thingd owns its durable storage, replication semantics, tombstones, and conflict handling. The application owns domain meaning, authorization, tenant ownership, backups, and audit requirements.

See Thingd integration.

How do I use a schema?

Keep a versioned .thingd file with the application, validate it with arqen thingd schema-validate, and inspect the remote schema and migration history with arqen thingd schema-remote. Applying a migration is an explicit operator action; it does not happen automatically at startup.

See Thingd schema.

Is cloud hosting available?

Not through the current Arqen package. Use HTTP Thingd for a separate data service and evaluate any hosted integration against a versioned public contract.

Does arqen dev hot reload?

No. It starts the server with development settings. Use an external watcher, such as cargo watch, if the project needs automatic restarts.