# No-new-cost flight access — checked October 19, 2026

The owner permits using an existing Vercel Pro subscription but authorizes no new paid services. Neon was provisioned on Free (free_v3), with managed auth and realtime add-ons off. Self-hosted Better Auth uses the same database. Free-plan quotas and existing Vercel included usage remain finite; no unlimited $0 traffic guarantee is made. Do not upgrade services or activate paid flight adapters without a new instruction.

| Source | Verified path | Fit for Farehound |
| --- | --- | --- |
| [KAYAK](https://affiliates.kayak.com/apis) | Free sandbox; affiliate application for production | Candidate only. Obtain written production cost, aggregation and background-monitoring permission. No live access or free production entitlement is established. |
| [Travelpayouts / Aviasales eligibility](https://support.travelpayouts.com/hc/en-us/articles/210995808-How-to-get-access-to-the-Aviasales-Search-API) | 50,000 confirmed monthly active users | Prelaunch project does not meet the published threshold. |
| [Travelpayouts usage rules](https://support.travelpayouts.com/hc/en-us/articles/34788165535250-Search-API-usage-rules) | User-initiated searches; no automated collection; cannot combine with other flight metasearch APIs | Incompatible with the requested combined background monitoring product. Cached price data is not a substitute for live offers. |
| [Duffel](https://duffel.com/pricing) | Live commercial account; fees and search-to-book economics | Disabled under the cost policy. |
| [AirGateway](https://airgateway.com/pricing/?type=agw-api) | Commercial agency agreement | Disabled under the cost policy; adapter additionally excludes unverified child-age queries. |
| [Skyscanner](https://www.partners.skyscanner.net/contact/travel-api) | Selective partner approval | Not a guaranteed free new-account launch path. |

## What access must establish

A provider agreement must permit this consumer-facing product, combined source results, the intended search-to-book ratio, background monitoring and price retention. Confirm production access carries no fees or mandatory booking commitments. Verify exact child-age handling, full-party currency totals, availability timestamps, request limits and genuine booking links. Then add the approved provider's documented adapter and contract tests. Do not repurpose a sandbox, cached trend endpoint, scraped consumer page, or guessed endpoint as live inventory.

The system currently returns an explicit unavailable response for live prices. It cannot truthfully guarantee the lowest available market price, even after partner access is approved.