The day's safety advice for one place on the frontier, readable without signal.

The people most exposed to heat, floods, rough seas and mountain roads on India's frontiers are often the ones with the weakest signal. In July 2022 the Union Cabinet approved 4G coverage for 24,680 villages that still had no mobile service, in remote and difficult areas (Digital Bharat Nidhi, saturation of 4G mobile services). Where coverage exists it is often patchy along rivers, coasts and passes.

The advice itself already exists, but in different places: a heat forecast here, a river board there, IMD fishermen warnings as PDFs, official alerts on NDMA's SACHET portal. A patrol leader or a village volunteer needs one answer for one place, in their own language, before the signal goes.

• Lets a person pick their place from about 120 towns, river points, fishing harbours and road points, or find the nearest one with the phone's location, worked out on the phone.
• Shows one screen of cards for that place: heat, cold and storm stress for today and tomorrow with safer hours for outdoor work; the river against its usual level with safer hours for boat crossings; sea state and distance to the maritime boundary; active official alerts for the district as issued; and the 72-hour outlook for roads and passes nearby.
• Gives every card its level as the source product sets it (normal, watch, warning, danger), a plain action line, the product's name and the time of its data.
• Keeps working without signal: the app and the chosen place's files are saved on the phone, refreshed in the background when there is signal, and a banner says when the saved advice is from.
• Lists emergency numbers with their sources: 112 everywhere, the Coast Guard's 1554 at the coast, and district and state disaster control rooms where the state publishes them.
• Speaks English, Hindi, Bengali, Assamese, Tamil and Gujarati, and installs to the home screen like an app.

1. Products publishRaksha, Varuna, Matsya, Sandesha and Marga write public files a few times a day: per-town heat series, the river board, per-harbour sea forecasts, official alerts, the road board.
2. Places are matchedA build step reads every product's list of places and links each place to the files that serve it: same place, or a river point or harbour within 15 km, roads within 25 km, alerts by district name.
3. The phone savesA service worker keeps the app (about 330 kB, 100 kB to download, plus a 100 kB font) and only the chosen place's files (55 to 270 kB, median 195 kB, about 20 kB to download). Choosing another place removes the old place's files.
4. One screenCards are drawn on the phone from those files in the reader's language. Product text, such as an alert as issued, is shown as published.

The place index is built by saathi/tools/build_places.py and lives at /saathi/data/places.json; every product file Saathi reads is also published under /api/v1/. Method and rules: about Saathi.

• Patrol and post commanders check heat, cold and storm risk and the safer hours before a patrol leaves, then read it again at the post without signal.
• Border-village residents and volunteers see whether the river is high, when crossing is less risky, and which official alerts are in force for the district.
• Fishing families and cooperatives read the sea state for their harbour and how far the boundary is, in Tamil, Gujarati or Bengali.
• District officials share one link that works offline in six languages during heat waves, floods and storms.

• The phone's position never leaves it: "Use my location" finds the nearest place on the device and keeps only the place id.
• Nothing about the person is collected: no account, no analytics, no cookies, no tracking. The phone keeps the place, the language and, if chosen, the Day view.
• The static host sees each file download, as for any website. A town's heat file or a harbour's sea file shows which place was fetched; Saathi adds nothing to those requests.
• Advice keeps its meaning: levels are the products' own, official alerts are shown as issued with a link to the original, and every card names its source and time.
• Every card says it is advisory and points to IMD, CWC, INCOIS, NDMA, the Coast Guard and the district administration.
• Translations are marked as drafts until checked locally; English remains the reference.

• Saathi is only as current as the products' last run and the phone's last signal; each card shows its age and warns after 36 hours.
• Forecasts are model estimates for a town or the nearest model point and miss local storms and conditions at a particular bank or harbour mouth.
• It covers the places its products cover. A person far from all of them gets the nearest place with the distance stated.
• District and state control-room numbers are listed only for Assam, Tamil Nadu and Tripura so far, where an official source was found.
• Offline use needs a browser with service workers and one visit with signal; some browsers clear saved site data after weeks without use.

We are looking for a district administration or a border-village network to pilot Saathi for a season, including a local review of the Hindi, Bengali, Assamese, Tamil and Gujarati text. contact@trinetra.in