Gullivr has three separate answers to that, and picking the wrong one is the usual reason people find it confusing. Here they are, shortest first.

A share link, for people who only need to look

Turn on sharing for a trip and you get a public read-only link. Anyone with the URL sees the itinerary as it stands — days, places, times — without an account and without being able to change anything.

Use it for the people who are coming but not planning: parents who want to know where you'll be, a friend joining for two days, the group chat that just wants the address of the hotel. Turn sharing off and the link stops working.

An invite, for people who are actually planning

Inviting a collaborator by email adds them to the trip properly. They get one of two roles:

• Editor — can add and move places, edit days, add flights and accommodation, change anything you can change.
• Viewer — sees everything inside the app, including the parts the public link does not show, but cannot edit.

Roles are not permanent. Promote a viewer to editor when they start pulling their weight, or demote an editor who keeps reordering day 4. You can also cancel an invitation before it is accepted, and remove a collaborator afterwards.

The rule of thumb: editor for the two or three people building the plan, viewer for everyone else. A trip with six editors is a trip where nobody knows who moved the museum.

Edits show up as they happen

When two people have the same trip open, changes appear on both screens without a refresh. This matters more than it sounds like it should: the reason collaborative planning usually happens in a chat window is that people do not trust a shared document to be current. Watching a place land on day 2 while someone else adds it removes that doubt.

Where the AI agent fits

If you have connected an AI agent, it acts with your permissions on your trips. So "ask Claude to find three restaurants near the hotel and add them to day 3" produces edits your collaborators see immediately, the same as if you had added them by hand.

Which is the actual point: the agent is another editor on the trip, not a separate app you have to copy results out of.

The short version

So: a blog. Three kinds of post will live here.

Travel guides

Itineraries and destination write-ups. Not the SEO-shaped kind that lists twelve cities and tells you nothing about any of them — the kind you would actually copy into a planner and follow. Where the good coffee is. Which museum is worth the queue and which one is not.

How to use Gullivr

The app has more in it than the landing page admits: shared trips with editor and viewer roles, flights and transfers, a packing list, expenses that settle up between travellers, public share links. Most of it is discoverable, but "discoverable" is not the same as "discovered". These posts walk through one feature at a time.

What's new

Short notes when something ships, and the occasional longer one about how it was built. This post is the first of them.

How this works

Posts are Markdown files in the repository. Publishing one is a pull request, which means the blog is versioned, reviewable and diffable like the rest of the app. It also means there is no comment section — if you want to argue with something here, the issue tracker is right there.

Everything is published in English and Italian. Use the language switch at the top of any post.

Lisbon is built on hills. An itinerary that ignores them is a day of pointless climbing. This one is arranged by neighbourhood and by altitude: each day stays roughly on one level, and you descend rather than ascend wherever there is a choice.

Day 1 — Baixa, Chiado, Bairro Alto

Start low and end high, once.

Begin in Praça do Comércio, at the river. It is flat, it is enormous, and it is the only part of central Lisbon laid out on a grid — the result of the 1755 earthquake, which flattened everything and gave the Marquês de Pombal a blank sheet.

Walk north through Baixa to Rossio, then take the Elevador de Santa Justa up to Chiado if the queue is short and the stairs beside it if it is not. The lift is a nice piece of iron and a bad use of forty minutes.

Chiado is for the afternoon: bookshops, the Bertrand (the oldest still trading anywhere), coffee standing up at a counter. Then walk uphill into Bairro Alto as it gets dark. The neighbourhood is dead until about nine and unrecognisable by eleven.

Evening: dinner in Bairro Alto, then down to Cais do Sodré if you want the night to continue.

Day 2 — Belém, and only Belém

Belém is six kilometres west and people try to fit it into a morning. It does not fit.

Take the tram or the train along the river. The three things worth your time are the Mosteiro dos Jerónimos (go at opening or after three; the middle of the day is a queue), the Torre de Belém from the outside — the interior is a stairwell with a view you can get elsewhere — and the Padrão dos Descobrimentos.

Eat a pastel de nata at Pastéis de Belém because you have to, then eat a better one somewhere else later in the trip. The original is good. The queue is not proportional to how much better it is.

Afternoon: the MAAT if you like modern architecture, the Coach Museum if you want the strangest collection in the city. Then back east along the river as the light goes.

Day 3 — Alfama, downhill

The mistake with Alfama is entering from the bottom. Do the opposite.

Start at Castelo de São Jorge, at the top. Get there for opening; the castle itself is mostly walls and peacocks, but the view is the point and it belongs to whoever arrives first.

Then walk down through Alfama, with no route. This is the one part of the city the earthquake spared, which is why the streets make no sense — they are medieval, and they were never redrawn. Getting lost is the intended experience. You will come out somewhere near the river eventually; the hill only goes one way.

On the way down: Miradouro de Santa Luzia for the tiles, the Sé cathedral if it is open, and any of the small places serving grilled sardines that do not have a menu in four languages.

Late afternoon: the Feira da Ladra flea market if it is Tuesday or Saturday.

What to skip

• Tram 28 as a sightseeing trip. It is a commuter tram full of tourists and pickpockets. Ride one stop if you want the photograph, then walk.
• Fado dinners with a set menu. The food subsidises the music and neither is good. Find a small place in Alfama that starts at ten.
• Sintra as a day trip inside three days. It deserves its own day and you do not have one.

Copying this into Gullivr

Three days, three neighbourhoods, one day per day. If you are planning this trip in Gullivr, the shape that works is one day per section above, with the sights added as places in walking order — then let the route distances tell you where you have been optimistic. Lisbon walking times are always longer than the map says, because the map is flat and the city is not.