cheapdates

Cheapest dates to fly a route, straight from Google Flights. CLI + MCP server.

Why this exists: Google's price calendar (GetCalendarGraph) is signed per-request by BotGuard, so every pure-HTTP client (fli dates, google-flights-mcp, …) has returned empty results since mid-2026. cheapdates has two backends:

graph — drives headless Chromium to the route page, opens Price graph, and reads the calendar the page itself receives. One call ≈ 60 departure dates, one-way or round-trip. ~3 s per 60 days.
sweep — one fast-flights search per date, no browser. ~0.5 s per date with 4 workers; also tells you the airline.

auto (default) uses graph when Playwright + Chromium are installed, else sweep; if graph fails it falls back to sweep.

Install

git clone https://github.com/afgoes/cheapdates.git && cd cheapdates && uv sync   # see INSTALL.md
python -m playwright install chromium       # for the graph backend

CLI

cheapdates JFK LHR 2026-10-01 2026-11-30            # one-way
cheapdates JFK LHR 2026-10-01 2026-11-30 -r 7       # round trip, 7 nights
cheapdates JFK LHR 2026-10-01 2026-11-30 --nonstop --json
cheapdates JFK LHR 2026-10-01 2026-11-30 -b sweep   # force fast-flights

MCP (Claude Code)

claude mcp add cheapdates -- uv run --directory /path/to/cheapdates cheapdates-mcp

Tool: cheapest_dates_tool(origin, destination, start, end, trip_length?, currency?, nonstop?, seat?, backend?).

Python

import datetime as dt
from cheapdates import cheapest_dates
r = cheapest_dates("JFK", "LHR", dt.date(2026,10,1), dt.date(2026,11,30), trip_length=7)
print(r.cheapest)

Caveats

Reverse-engineered; Google can change the page or response at any time. The parser is fixture-tested (pytest), and the graph backend falls back to sweep on failure.