Selat: Live AIS for the Malacca and Singapore Straits

Overview

Selat is Malay for the strait, which is the whole scope: this covers one waterway, the busiest shipping lane on earth, rather than claiming an ocean. It listens to AIS, the radio system ships broadcast on, and turns it into an operations screen for port agents, chandlers and terminal planners. A Next.js 16 and React 19 front end draws the fleet on a MapLibre chart; behind it a Python MCP server holds the websocket, keeps a SQLite history and answers fourteen tools covering search, vessels near a port, tracks, port calls, anchorage clustering, traffic density, congestion and observed passage times across nineteen sea areas. The product argument is about honesty. AIS carries two kinds of information in one stream: position, speed, course and rate of turn are measured by instruments, while destination, draught and arrival time are typed in by the crew. Most trackers print all six in one table, which quietly claims a guess and a measurement are equivalent. Here the measured values sit in panels grouped by how fast they change, and the three the crew enters sit apart on amber under an Unverified heading. The same discipline runs through the rest: every sentinel that AIS uses for not reported is checked rather than passed through, so a draught of zero is absence and not a ship drawing nothing, and an IMO number is kept only when its check digit verifies. Absence is the normal case, since identity messages arrive far less often than position, so the interface says Not reported plainly instead of guessing. A position fix older than six minutes dims to amber, because that ship is no longer where her marker sits. Deployed as a single container behind a Cloudflare Tunnel.

Key features

• Live AIS over a websocket, around 270 vessels across the Singapore and Malacca Straits
• Measured values kept visibly apart from the destination, draught and arrival a crew types in
• Every AIS not reported sentinel checked rather than passed through, including IMO check digits
• Vessels coloured by what they are doing, with a fix older than six minutes dimmed to amber
• Fourteen MCP tools: port calls, anchorage clustering, traffic density, congestion and observed passage times
• Nineteen selectable sea areas, each measured against a throughput budget before it is offered
• 356 tests against 274 real AIS messages captured over the Strait of Malacca, no network needed
• Single container behind a Cloudflare Tunnel, with recorded history surviving restarts

Tech stack

TypeScript · Next.js · React · Tailwind CSS · MapLibre GL · Python · MCP · SQLite · WebSockets · Docker · Cloudflare Tunnel

Project info

Year

2026

Duration

2026

Team

Solo project

Role

Software Engineer

Status

Live

Category

Maritime SaaS

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