# Stability Policy
This chapter describes what users can expect from Spargio and companion-crate versioning.
## Versioning Expectations
- Breaking API changes use a major version bump for the affected crate.
- Additive APIs ship in minor releases.
- Patch releases are for fixes and low-risk behavioral corrections.
## Behavior Compatibility
For async APIs, behavior is part of the contract. In particular:
- timeout behavior
- cancellation behavior
- error mapping/typing
If these change materially, you should treat it as semver-relevant.
## Deprecation Policy
- APIs are deprecated before removal.
- Removals happen on a major release.
- Compatibility shims may be kept temporarily to ease migration.
## Companion Crates
Companion crates may release independently of core runtime, so check each crate's version and changelog when upgrading:
- `spargio-tls`
- `spargio-ws`
- `spargio-quic`
- `spargio-process`
- `spargio-signal`
- `spargio-protocols`
## Upgrade Guidance
When upgrading:
1. read changelogs for all upgraded crates
2. re-run your integration and load tests
3. validate timeout/cancel/error behavior in critical flows