Metodologia

Where the answers come from

Every result on Horvera is produced by a deterministic rules engine. A ruleset is a versioned set of parameters (distance bands, amounts, delay thresholds, notice windows, re-routing margins, care thresholds) and rules, each tied to the article, judgment or official guidance it implements. No language model takes part in a legal decision; the only place a model is used is to extract facts from an airline’s reply that a passenger pastes in, and even then the classification and the response come from the deterministic engine.

Three rulesets are active: EU261 (Regulation (EC) No 261/2004 with Court of Justice case law), UK261 (the retained UK version, amounts in pounds) and the Swiss application through the EU–Switzerland Air Transport Agreement. The proposed EU reform is modelled as a fourth, inactive ruleset with no effective date, so its effect can be measured before it applies.

How a result is produced

1. The route is resolved from the real airport coordinates and the great-circle distance is computed — the same computation the route pages show.
2. The applicable regime is selected from the departure airport, the arrival airport and the operating carrier’s licence.
3. The ruleset in force on the flight date is selected; historic flights are assessed under the rules that applied when they operated.
4. The rules run in order and each step is recorded: the fact it looked at, the rule it applied, the source it relies on.
5. The result names the ruleset version, the sources and the date the rules were last reviewed. Every evaluation is stored with its full trace so it can be reproduced later.

How the rules are tested

The engine is checked against more than one hundred legal scenarios every time the code changes: distance bands and their edges, the 3-hour threshold measured at the final destination, the long-haul reduction, cancellation notice windows and re-routing margins, denied boarding, the extraordinary-circumstances table (technical faults, crew, strikes by type, weather, air-traffic control, bird strikes), UK and Swiss scope, connecting journeys on one booking, third-country carriers and pre-Brexit UK flights. A regression suite records the outcome of every scenario under every ruleset and reports any change.

Sources

Only primary sources: the Regulation on EUR-Lex, judgments of the Court of Justice on CURIA, the UK retained regulation and statutory instruments on legislation.gov.uk, and guidance from the European Commission, the UK Civil Aviation Authority and the Swiss Federal Office of Civil Aviation. Every source has a verification date; any source not re-verified within 180 days is flagged and re-checked. Every content page lists the sources it uses.

How content is written and reviewed

Pages are written from the rules and the sources, not from other websites. Each page shows the date its legal content was last reviewed and the date its text was last edited. When a rule changes, the previous version stays applicable to earlier flights, and the page is updated with a new review date. Corrections sent to contact@horvera.com are checked against the sources before the page changes.

What Horvera does not claim

No success rates, average payouts or processing times are published, because with the free tools and the Claim Pack Horvera does not submit claims and cannot observe the airline’s decision. A result is what the rules say about the facts entered; the airline, an ADR body or a court makes the final decision.

API and assistants

The rules engine behind the checker is exposed, unchanged, as a public JSON API and as a minimal Model Context Protocol endpoint, so that other software and AI assistants can run the same deterministic check instead of guessing:

• POST /api/v1/eligibility — the flight facts in; eligible (true, false or “uncertain”), the regulation, the amount, the reasons, what is missing and the next action out.
• POST /api/v1/compensation-estimate — the Article 7 amount the route would earn, with the conditions the claim must meet.
• POST /api/v1/claim-draft — regulation, amount, evidence, claim basis and an editable claim letter written only from the facts supplied.
• GET /api/v1/regulations/EU261 (or UK261, CH261) — a machine-readable description of the regime, read from the ruleset in force.
• POST /api/mcp — an MCP server (Streamable HTTP, stateless) with four tools: check_flight_compensation, calculate_flight_compensation, prepare_flight_claim, get_claim_evidence_requirements.

GET /api/v1 returns the contract. Calls are rate-limited per client address, return the same “uncertain” answers the website shows when the facts do not support certainty, and store no personal data. Rule ids, traces and internal identifiers are not exposed.

Open data

The airline claim registry — claim channels, postal addresses, ADR schemes and national enforcement bodies for every airline in Horvera’s database — is published as open data under CC BY 4.0: airlines.json · airlines.csv. Attribute “Horvera (horvera.com)” when you reuse it, and send corrections to contact@horvera.com.