# Maps inside parts > Give a part a map of its own, such as a payment service's modules and what they call, and go in and out of it like zooming into the card. A part on a big map often hides a whole system of its own. Payments on a shop’s map is a service with its own endpoints, modules and databases, and a module there might hide a map of its code. Any part can open into a map that shows what’s inside it, so a set of maps reads as one picture you can zoom through: the whole platform for a manager, one service for its team, the code for a new starter. ## Try it 1. Open **Templates** from home, and use the **Pantry delivery platform** showcase. 2. Find the **Checkout** part. Pages are stacked behind its card, and a badge at its lower right names the map inside. Click the badge. 3. The camera flies into the card, and Checkout’s own map opens: its endpoints, modules and databases. The trail at the top centre reads **Pantry delivery platform › Checkout**. 4. Press `⌘↑`, or select **Pantry delivery platform** in the trail, to come back out. Now run **Black Friday** on Pantry and go into Checkout again. The scenario comes with you, so you can see which module inside struggles when the whole platform is busy. ![Pantry's Checkout map open inside its part, with the trail Pantry delivery platform › Checkout at the top left, Slot holds overloaded at 114%, and Black Friday, from Pantry delivery platform, along the timeline.](https://docs.flozu.app/_astro/inside-scenario-light.UmY9aMEi_Z29kKVl.webp) The map inside is an ordinary map. You can open, present, share and export it on its own, and several parts can open the same one, such as one sign-in service used by every team. ## Go in and out To go in, do any of these: - Click the badge. - Select the part and press `⌘↓` (`Ctrl+↓` on Windows and Linux). - Select **Open inside** in the **Map inside** section. The camera flies into the card, and the map inside grows into place and joins your open maps beside this one. Going back out, the map above settles back where you left it. With reduced motion, it simply opens. ![The Payments map open, with Checkout system › Payments as a trail above it and Orders API drawn faded on the left, calling in.](https://docs.flozu.app/_astro/map-inside-light.7aJ1C1t1_eheyQ.webp) The maps above show as a trail before the map’s name at the canvas’s top left, such as **Checkout system › Payments**. Select one, or press `⌘↑`, to go back out, with the part you came from selected. A map that several parts open goes back out the way you came in. Presenting works the same way, so you can walk an audience from the big picture into one service and back. ## How the card shows it ![The Payments card with pages stacked behind it and a badge at its lower right reading Payments 4.](https://docs.flozu.app/_astro/inside-badge-light.De8jQuVw_8XYXC.webp) A part that opens into a map has pages stacked behind its card and a badge at its lower right, with the map’s name and how many parts it holds. Unless you picked a drawing for the part, its panel shows a small drawing of the map inside. If the map isn’t here, such as one that was deleted or didn’t come with the file or link, the badge says **Map not here**. **Make its map** or **Link a map** gives the part a new one. ## Give a part a map Select the part and open its **About** tab. The **Map inside** section offers two ways: - **Make its map** saves a new map in the same folder, named after the part and holding one part like it, links the part to it, and opens it. It’s one step to undo. - **Link a map** picks one of your saved maps, for a service you’ve already mapped. Once a part has a map, the section shows a small preview of it with **Open inside**, **Unlink** and **Link another map**. **Unlink** only drops the link: the map stays where it is. ## Scenarios carry through While a scenario runs, it plays inside the maps your parts open into too, on the same timeline. Each way into the map inside gets as much busier as the lines that reach it on the map above, so Black Friday on the shop is Black Friday inside the payment service. - **The badge says how the inside copes.** It reads **Tight** in amber, or **2 over** in red when parts inside can’t keep up, at the moment the playhead is on. - **Going in takes the scenario with you.** Open the part’s map while a scenario runs and the same scenario plays there, at the same moment. The timeline names where it came from, such as **Black Friday, from Checkout system**. Opening the scenario panel there gives that map a scenario of its own instead. ## Where it sits stays in view The part’s neighbours on the map above are drawn faded at the edges of the map inside: what calls in on the left, and what it calls on the right, with their lines. They aren’t part of this map, so they can’t be selected or moved, and clicking one takes you to it. Each of those lines joins one part inside. Flozu works it out: a line in joins the map’s only way in, a part nothing flows into, and a line out leaves from its only way out. To choose for yourself, select the line on the map above and set **Lands on** or **Leaves from** in its **About** tab. ## Parts for inside a service The library’s **Inside a service** family has parts for what a service is made of: endpoints, modules, code files, interfaces, libraries and tables. A dotted **uses** line says one depends on another, such as a module using a library, and carries no traffic. See [lines](https://docs.flozu.app/guides/lines.md). The **Inside a payment service** template shows one put together. ## In the Projects panel On a map’s own menu, **Maps inside** shows them in the panel. In the **Projects** panel, select the arrow beside a map to see the maps its parts open into, under **Maps inside**, with a layers mark. In their folder they’re listed there, under the map that opens them, rather than beside it; a map kept in another folder is listed in that folder too. Moving or renaming either map never breaks the link, because a part names its map by id, not by name or place. A project’s page shows **How the maps fit**: each map that opens others, with the parts that open them and the maps inside, as links. > **Tip** > > Exporting a map **with its history**, or a project, takes the maps inside its parts along, even ones kept in another folder, so the links still work wherever it’s imported. See [import and export](https://docs.flozu.app/guides/import-export.md).