The AirIndex Identifier License.

1. Definitions

For the purposes of this License:

• “AIX-ID” means an AirIndex Facility Identifier in the format aix:<asset_type>:<identifier>, as defined in the AIX-ID Methodology Paper (the “Methodology Paper”).
• “AirIndex” means AirIndex, the publisher of the AIX-ID System and the licensor under this License.
• “Licensee” means any person or entity exercising the rights granted under this License.
• “Registry” means the canonical record of all minted AIX-IDs maintained by AirIndex, accessible at airindex.io/aix and through the AirIndex API.

2. Grant of Rights

Subject to the terms of this License, AirIndex grants Licensee a worldwide, royalty-free, non-exclusive, perpetual, sublicensable license to:

• Look up any AIX-ID through the public Registry, the public API, or any other AirIndex-published resolution interface.
• Resolve external identifiers (FAA site number, ICAO designation, SEC CIK, ticker symbol, and any other cross-reference identifiers documented in the Methodology Paper) to their corresponding AIX-IDs through the public resolution interface.
• Cite AIX-IDs in any document, presentation, contract, regulatory filing, research artifact, or other written work, in print or digital form, for commercial or non-commercial purposes.
• Use AIX-IDs as join keys in any data system, workflow, or analysis to link records across registries, including in commercial products and services.
• Display AIX-IDs publicly as labels on facilities, sites, maps, dashboards, or any other surface where the identifier serves an identification purpose.
• Reproduce and redistribute the Methodology Paper, this License, and the published schema documentation, in whole or in part, with attribution to AirIndex.

The above rights apply to all AIX-IDs minted by AirIndex, whether currently active or retired. Retired AIX-IDs continue to resolve and continue to be citable; the License covers them on the same terms as active AIX-IDs.

3. Reservation of Rights

AirIndex retains all rights not expressly granted under Section 2. The following are not granted by this License and require a separate paid agreement with AirIndex:

• Access to historical score data per AIX-ID, including factor-state time-series.
• Access to the classifier rationale and source-record linkage behind any AirIndex-published score, factor value, or classification.
• Programmatic API access at rate-limit tiers above the public free tier (Pro, Institutional, Enterprise).
• Access to the AirIndex Ecosystem Intelligence Database (EID) counterparty graph beyond the multi-operator surface published as part of the public AIX-ID Registry.
• Full audit-trail access for litigation discovery, insurance underwriting documentation, regulatory submission, or other use cases requiring AirIndex’s complete record of facts, sources, and corrections per AIX-ID over time.

A separate subscriber agreement governs the above paid services. Where a subscriber agreement and this License conflict regarding the paid services, the subscriber agreement controls.

4. Restrictions

Licensee shall not:

• Relicense the AIX-ID namespace under terms more restrictive than this License. The free-to-cite character of AIX-IDs is a structural property of the system; downstream licensees must receive the same rights granted here.
• Re-issue, re-mint, or otherwise create new AIX-IDs in a way that conflicts with AirIndex’s mint logic or that would compromise the Registry’s never-reuse guarantee. Only AirIndex mints AIX-IDs.
• Misattribute third-party data, claims, or analyses to AirIndex when those data, claims, or analyses were not generated by the AirIndex pipeline. Citing an AIX-ID is permitted; representing third-party content as AirIndex output is not.
• Reverse-engineer AirIndex’s mint logic, classifier internals, or scoring engine for the purpose of producing competing identifiers or competing scoring outputs that claim compatibility with the AirIndex Registry.

5. AirIndex’s Audit-Trail Commitment

AirIndex commits to the audit-trail discipline described in Section 6 of the Methodology Paper. Every score, factor value, and classification AirIndex publishes for an AIX-ID-tagged entity is reproducible from source on a specific date. The five tables forming the audit chain (ScoreSnapshot, ScoringOverride, ChangelogEntry, ClassificationResult, and the AixIdentifier registry itself) are append-only or succession-only, and these invariants are enforced at the database level.

This commitment is the basis on which AIX-IDs can be cited in litigation discovery, regulatory filings, insurance underwriting documentation, and other use cases requiring an unimpeachable historical record. The commitment runs in favor of all Licensees and is not contingent on a paid subscription.

6. Disclaimer of Warranty

The AIX-ID System is provided “AS IS”, without warranty of any kind, express or implied, including but not limited to warranties of merchantability, fitness for a particular purpose, or non-infringement. AirIndex’s sole obligations under this License are those expressly stated in Section 5 (Audit-Trail Commitment). No other obligations are created or implied.

AirIndex does not warrant that the Registry will be free of errors, omissions, or interruptions; nor that any specific entity will be present in or absent from the Registry; nor that any AIX-ID will resolve at any particular time. AirIndex’s remedies for errors are the succession and supersedure mechanisms described in the Methodology Paper. To the maximum extent permitted by law, AirIndex’s liability under this License is limited to the supersedure of any erroneous record by a corrective record in the audit chain.

7. Versioning and Continuity

This License is Version 1.0, effective May 11, 2026. Future versions (1.1, 1.2, 2.0, etc.) will be published at the same canonical URL (airindex.io/methodology/aix-id-license); Version 1.0 will be preserved at a versioned URL for citation continuity.

Substantive changes to this License — to the grants in Section 2, the reservations in Section 3, or the restrictions in Section 4 — will be announced through the same public channels as the AirIndex Methodology Paper and will be subject to a public-comment window before becoming effective. Existing citations and uses of AIX-IDs made under prior versions of this License remain valid under the version in effect at the time of citation; License revisions do not retroactively restrict prior valid uses.

Should AirIndex cease operations or transfer the Registry to a successor entity, AirIndex commits that the namespace and the rights granted under this License will not be relicensed under terms more restrictive than this License. A succession plan for the Registry will be published as a future governance update.

8. Acceptance and Contact

No formal acceptance is required to exercise the rights granted under this License. Use of any AIX-ID in any of the manners described in Section 2 constitutes acceptance of the terms of this License.

License questions, requests to mint a new AIX-ID for a facility or entity not yet in the Registry, and inquiries about paid services not granted under this License route through the contact form.