---
title: "Blueprint API - BuildPrint wiki"
description: "Let your mod keep a blueprint in BuildPrint, so the builds it makes show up as a build to follow."
url: https://voxelsprout.com/buildprint/wiki/blueprints-api
---

[BuildPrint](https://voxelsprout.com/buildprint) [Wiki](https://voxelsprout.com/buildprint/wiki)Blueprint API

# Blueprint API

Let your mod keep a blueprint in BuildPrint, so the builds it makes show up as a build to follow.

For a mod that makes builds, such as trees, paths or generated structures, and wants them in BuildPrint as a build to follow instead of placing them in the world. From BuildPrint **0.1.12**.

## How it works

* Each owner id gets one blueprint per world and dimension. Every write goes into that same placement and file, also after a restart.
* The player cannot turn or flip it, because your blocks sit where you put them in the world.
* If the player removes it in BuildPrint, the file stays in their library and the next write starts a new one.
* Air in the blueprint is ignored, so the ground around your blocks is not shown as blocks in the way.

## Write blocks

Positions are world x, y, z triples, one block state string per position. `minecraft:air` clears a block. The call returns what those blocks were before, which is what you need for undo, or null when it was refused.

```java
String why = BuildprintBlueprints.problem("mymod");
if (why != null) {
    player.displayClientMessage(Component.literal(why), true); // already in the player's language
    return;
}
String[] before = BuildprintBlueprints.set("mymod", "My trees",
        new int[]{10, 64, -3,  10, 65, -3},
        new String[]{"minecraft:oak_log[axis=y]", "minecraft:oak_leaves[distance=1,persistent=true,waterlogged=false]"});
```

The file is written 200 ms after the last change, so a stroke of many writes is one write to disk. Call `flush()` if you need it on disk now.

## Keep your own data

The five-argument `set` keeps a string of your own with the blueprint, for example which trees are in it. Pass null to leave it as it was, and read it back with `data(owner)`.

## Without a compile dependency

Every call takes plain Java types, so reflection is enough:

```java
static Method set;

static void bind() {
    if (!FabricLoader.getInstance().isModLoaded("buildprint")) return;
    try {
        Class<?> api = Class.forName("com.buildprint.api.BuildprintBlueprints");
        set = api.getMethod("set", String.class, String.class, int[].class, String[].class);
    } catch (ReflectiveOperationException | LinkageError e) {
        set = null; // BuildPrint is older than 0.1.12. Nothing to do.
    }
}
```

## Reference

| BuildprintBlueprints                                                               | What it does                                                                       |
| ---------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- |
| isAvailable()                                                                      | In a world, with its placements restored, so a write lands in the right blueprint. |
| problem(String owner)                                                              | Why set would refuse right now, in the player's language. Null when it would not.  |
| set(String owner, String displayName, int\[\] xyz, String\[\] states)              | Write blocks. Returns what they were before, or null when refused.                 |
| set(String owner, String displayName, int\[\] xyz, String\[\] states, String data) | The same, and keep a string of your own with it. Null leaves it as it was.         |
| blockCount(String owner)                                                           | How many blocks your blueprint holds here.                                         |
| data(String owner)                                                                 | Your string, or null.                                                              |
| ownerName(String owner) / displayName(String owner)                                | The names the player sees.                                                         |
| flush()                                                                            | Write pending changes to disk now.                                                 |

[Previous For mod developers](https://voxelsprout.com/buildprint/wiki/api) [Next Placements API](https://voxelsprout.com/buildprint/wiki/placements-api)

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