referencing

The referencing package does one thing well: resolving JSON Schema references efficiently. In production, it handles $ref resolution without the bloat of full validation libraries. Memory footprint is reasonable - registries are lightweight and reusable across requests when properly cached. The Resource and Registry APIs are straightforward once you grasp the pattern, though the initial learning curve is steeper than expected.

Performance-wise, it's fast enough for most workloads. We process hundreds of schema validations per second without bottlenecks. The library is stateless by design, which makes connection pooling a non-issue, but you need to manage registry lifecycle yourself - there's no built-in caching or resource cleanup hooks. Error messages when references fail are decent but could be more actionable in complex nested scenarios.

Observability is the weak spot. There are no logging hooks or instrumentation points, so tracking resolution paths or debugging circular references requires external tooling. Timeout handling is absent since operations are synchronous and typically fast. It's stable across versions with minimal breaking changes, which is appreciated in production environments.

The `referencing` package is the low-level foundation for JSON Schema validation libraries like `jsonschema`. It handles JSON references ($ref resolution) competently, but you'll rarely need to interact with it directly unless you're building schema validation tools or working with complex reference scenarios.

The documentation exists but assumes familiarity with JSON Schema concepts and reference resolution. There's minimal hand-holding for common use cases—you'll spend time reading through the Registry and Resource APIs to understand how to wire things together. Error messages are technically accurate but terse, often requiring you to trace through your schema structure to understand what went wrong. Stack Overflow coverage is sparse since most developers interact with higher-level wrappers.

Debugging reference resolution issues requires understanding the package's internal resource model. When things work, they work well, but troubleshooting mismatched specifications or circular references takes patience. If you're just validating JSON schemas, stick with `jsonschema` directly.

The `referencing` package is the underlying engine for JSON Schema reference resolution, extracted from `jsonschema` to be reusable. In practice, this means you're working with a low-level library that requires understanding JSON Reference mechanics deeply. The API centers around `Registry` and `Resource` objects, which feel unintuitive initially - you need to understand the distinction between anchors, URI resolution, and resource retrieval before anything clicks.

Documentation exists but assumes significant prior knowledge of JSON Reference specifications. There aren't many standalone tutorials or cookbook examples showing common patterns like "how do I resolve references in my OpenAPI spec" or "how do I add custom schemas to a registry." Most learning happens by reading `jsonschema` source code or GitHub issues, which is frustrating for onboarding.

Error messages are technically accurate but cryptic if you don't know the spec terminology. When debugging reference resolution failures, you're often left adding print statements to understand what the registry contains. For its intended use case (being a foundation library for other tools), it works, but direct usage requires patience and specification knowledge most developers lack.