Show HN: Hermes – RyanAir price API with historical data

Hermes · REST + MCP · free, no signup.

Hermes is an unofficial REST API and MCP server for Ryanair flight prices. Every observation is kept, so it knows what a fare cost last week. Ryanair’s own endpoints only know today.

Swagger UI · OpenAPI 3.1 · ReDoc · llms.txt

Fare observations

87.1M

append-only, never overwritten

Active routes

5278

224 airports, 36 countries

Requests served

99726

all-time, across every endpoint

Last 24 hours

20257

hourly buckets, peak-normalised

Point an AI assistant at Hermes and it answers flight questions for you.

https://hermes.brinkhorst.dev/mcp

claude mcp add --transport http hermes https://hermes.brinkhorst.dev/mcp

Or any client that takes JSON config:

{
  "mcpServers": {
    "hermes": {
      "type": "http",
      "url": "https://hermes.brinkhorst.dev/mcp"
    }
  }
}

Six read-only tools:

get_cheapest_fares cheapest fare per day for a routeget_price_history the observed price time seriesfind_price_drops fares that just moved, network-wideexplore_destinations where can I go from here, cheapest firstsearch_airports / list_routes network lookup Try: “is €60 a good price for Dublin to Barcelona in October?”

curl https://hermes.brinkhorst.dev/api/v1/routes/DUB/BCN/cheapest
curl "https://hermes.brinkhorst.dev/api/v1/anomalies/?kind=drop&limit=10"

GET /api/v1/airports/ list airports (filter by country, base)GET /api/v1/routes/ list directed routesGET /api/v1/routes/{origin}/{destination}/cheapest`` GET /api/v1/routes/{origin}/{destination}/history price time seriesGET /api/v1/anomalies/ recent price drops and spikesGET /api/v1/explore?country=es cheapest destinations from a country Guest tier: no key, 90 days of history per route, the full 90-day look-ahead window, 120 list/detail and 30 time-series requests per minute.

These URLs return a page to a browser, JSON to a client.

Full lists: [all 5278 routes](/api/v1/routes/),
[all 224 airports](/api/v1/airports/),
[latest price drops](/api/v1/anomalies/).


Not a public one for fares. Ryanair's internal endpoints are undocumented
and unstable; Hermes wraps them behind a versioned
[OpenAPI 3.1](/openapi.json) contract.


Yes — [this one](#mcp). Streamable HTTP at
`/mcp`, six read-only tools, no key required.

No, and not endorsed by Ryanair. Fares are observations, not offers — confirm on ryanair.com before booking.

Nothing, and no signup. Limits under [guest tier](#guest-tier).