Support policy
Ambiq supports the current and previous heliaRT minor releases. Use the latest patch release of a supported minor when reproducing or reporting an issue.
This table takes effect when 2.5.0 is published. Until then, 2.2.x and 2.1.x remain the supported minor tracks.
| Track | Version | Status |
|---|---|---|
| Current minor | v2.5.x |
Supported |
| Previous minor | v2.2.x |
Supported |
| Older minors | v2.1.x and earlier |
Not supported |
v1.18.0 is withdrawn because its heliaCORE pin is defective for the float32 and float16 kernels, including NaN handling and FP16 LSTM. It does not count as a supported minor. Upgrade to a supported release; its tag remains for reproducibility.
These commitments follow the recorded support decision and approved policy. Release versions are maintained with the runtime’s changelog.
Versions 2.3 and 2.4 were skipped; they are not released support tracks. Publication of 2.5.0 does not restart the 2.2 critical/security-fix clock. See Migrate to heliaRT 2.5 for source and build changes. The deprecation notice requirement below remains the default; the explicit exception applies only to 2.5.0.
Critical and security fixes
Section titled “Critical and security fixes”Ambiq provides critical/security fixes for 12 months from the minor release date, within the current and previous minor window. Older minors are not eligible simply because fewer than 12 months have passed.
A critical defect is a security vulnerability or a wrong-inference/data-corruption defect with no workaround. If a later patch of the supported minor already fixes the issue, upgrade to that patch.
Report security issues to support.aitg@ambiq.com rather than opening a public issue, as described in the repository’s security policy. Use GitHub issues for ordinary bug reports and integration questions.
Deprecation notice
Section titled “Deprecation notice”Ambiq gives at least 90 days notice before removing a supported public API, build option, toolchain or target. Notices appear in release notes, CHANGELOG.md and a documentation-site banner.
One-release notice exception: 2.5.0
Section titled “One-release notice exception: 2.5.0”For heliaRT 2.5.0 only, Ambiq waives the usual 90-day advance-notice period for the documented upstream compatibility changes: C++17 becoming mandatory, the schema-header relocation, runtime-class forward-declaration changes, and changes to custom context integrations and bundled dependencies.
This allows the upstream update to ship after qualification, while 2.2.x remains supported under the existing support window. The exception does not change the notice requirement for future releases.
The approved transition decision covers notice timing only; release qualification and publication approval remain separate.
See Migrate to heliaRT 2.5 for the affected integration surfaces.
Stateful quantized LSTM
Section titled “Stateful quantized LSTM”The quantized HELIA UNIDIRECTIONAL_SEQUENCE_LSTM state-persistence fix first shipped in v1.18.0 and is carried by later releases. Because v1.18.0 is withdrawn, obtain the fix from a supported release. Treat quantized HELIA LSTM in v1.17.0 and earlier as single-shot. See the fix.
That statement is quantized-only. FP32 and FP16 LSTM behavior has its own RT/kernel version and operator restrictions; check Floating point and model compatibility.
License scope
Section titled “License scope”Support and licensing are separate. Development and validation on a host or simulator do not establish support for production deployment on that CPU. See Attribution and licensing and the governing license.