# Build a prompt

*Put blocks together on the Build screen, check the result in the preview, and save it as a prompt.*

Online version: https://promptmason.ai/docs/build-prompt

The Build screen is where you put blocks together into a prompt. You pick blocks from a list, put them in order, and watch the finished text build up in the preview. Most people save the result as a dynamic prompt, which keeps up with later changes to its blocks (see [Static prompts, dynamic prompts and documents](https://promptmason.ai/docs/static-and-dynamic)).

## Open the Build screen

Any of these opens Build with an empty prompt:

- Click **Build** in the sidebar (or press Ctrl+2).
- On the Prompts screen with no prompts yet, click **Build a prompt**.
- If the Home screen is turned on, click **New Dynamic Prompt** there.

To change a dynamic prompt you've already saved, open it from the Prompts screen: click it, then click the pencil (**Open in Build**), or double-click it.

On the Free plan, if you already have 15 prompts, **Build a prompt** and **New Dynamic Prompt** open the **Free plan limit** window instead. See [Plans and limits](https://promptmason.ai/docs/plans).

## The screen at a glance

- **Blocks**, on the left: your library blocks, to pick from.
- **The canvas**, in the middle: the blocks in this prompt, in order. It says **Drag blocks here to build your prompt** while it's empty.
- **Visual** and **Code**, above the canvas: Visual shows the blocks as cards; Code shows the same prompt as text ([Edit a prompt as code](https://promptmason.ai/docs/code-view)). **Embedded Block**, on the right of that row, adds a block for this prompt only.
- **Preview** and **Properties**, on the right: the finished text, and the prompt's settings.
- **The name box and the Save buttons**, along the top.

![The Build screen: the block list on the left, three blocks on the canvas in the middle, and the Preview and Properties panes on the right.](https://promptmason.ai/images/docs/build-prompt-screen.webp)

Drag the lines between the parts to make any of them wider.

If the **Markdown editor** feature is on, a new item shows two tabs, **Canvas** and **Markdown**. This page is about the **Canvas** tab. The **Markdown** tab is for documents ([Markdown documents and Skills](https://promptmason.ai/docs/markdown-documents)). Switching tabs drops what is on the side you leave. If it has unsaved work, PromptMason asks **Discard your changes?** first.

## Find a block

The **Blocks** list shows your library blocks. Archived blocks, and blocks embedded in other prompts, aren't listed.

![The block list on the Build screen with its search box, type filter and sort buttons.](https://promptmason.ai/images/docs/build-prompt-block-list-toolbar.webp)

- **Search:** type in the **Search…** box (Ctrl+F). It looks at each block's name, text, type and tags.
- **Filter by type:** click the funnel and choose a type, for example **Role**. Ctrl+click to choose several. Choose **All** to see every type again.
- **Sort:** click the sort button to sort by **Name**, **Rating** (only when the Favorites & ratings feature is on), **Date created** or **Last modified**, and the arrow next to it to reverse the order.
- **Read the whole block:** each card shows the first two lines. Click **more…** on the card to read all of it.
- **More than one page:** the list shows 50 blocks at a time. Under it, use **Show** to choose 25, 50, 75 or 100, and the **Previous page** and **Next page** arrows to move between pages.

The list also follows the folder, tag, favorites and rating filters chosen in the sidebar. If a block you expect isn't there, check the sidebar, and see [No blocks are listed](#no-blocks-are-listed).

## Add blocks

- **Drag** a block from the list onto the canvas. A blue line shows where it will go.
- Or **double-click** a block to add it at the end.

You can add the same block more than once. To write text for this prompt only, without making a library block, click **Embedded Block** ([Library blocks and embedded blocks](https://promptmason.ai/docs/embedded-blocks)).

## Put blocks in order

- Drag a block by its handle (the dotted grip on its left) to a new place.
- Or use the up and down arrows on the block.

The number on each block is its place in the prompt.

## Remove blocks

- Click the X on a block (**Remove from prompt**). It's removed straight away, without asking.
- Click **Clear** at the top to remove every block. This doesn't ask either.

Removing a block from a prompt doesn't delete the block. It stays on the Blocks screen.

To bring back library blocks you removed, click **Undo** (or press Ctrl+Z). **Redo** (Ctrl+Shift+Z or Ctrl+Y) puts the change back. Undo and Redo work for adding, removing and reordering blocks, for the **Include Name** and **Include Type** boxes, and for tags. While the cursor is in a text box, Ctrl+Z and Ctrl+Shift+Z undo and redo your typing instead, so use the **Undo** and **Redo** buttons at the top for changes to the blocks. Don't count on Undo to bring back an [embedded block](https://promptmason.ai/docs/embedded-blocks) you've written but not saved: copy its text first if you want to keep it.

## Block headers: Include Name and Include Type

Each block on the canvas has two boxes, **Include Name** and **Include Type**. Tick them to put a header line above that block's text in the prompt, for example:

| Ticked | Header in the prompt |
|---|---|
| **Include Type** | `### ROLE ###` |
| **Include Name** | `### Support agent ###` |
| Both | `### ROLE: Support agent ###` |
| Neither | No header |

![A block card with Include Name and Include Type ticked, and the preview showing the header line above its text.](https://promptmason.ai/images/docs/build-prompt-include-name-and-type.webp)

Headers help an AI model see where one part of the prompt ends and the next begins. Each block in the prompt has its own choice, even when the same block is used twice.

A block with a header starts a new section, with the blank lines from Settings above it. A block with no header continues the section above it, with no blank line in between. To keep several blocks together in one section, give the first one a header and leave the others without.

New blocks start with both boxes unticked. To change that, and to change the `###` marker or the space between blocks, see [Formatting, block headers and hidden notes](https://promptmason.ai/docs/text-formatting#block-headers).

## Check the preview

**Preview**, on the right, shows the prompt's text as it builds up, with the block headers and with [hidden notes](https://promptmason.ai/docs/text-formatting#hidden-notes) left out.

- [Variables](https://promptmason.ai/docs/variables) with a fixed value are filled in. A variable that asks for a value each time shows its default value, or its name in brackets, such as `[audience]`, if it has none. You type the real value when you copy the prompt.
- When the Variables feature is on, a variable name that doesn't exist shows a warning, **Unresolved variable:** followed by the name. Check the spelling, or click **Create variable “name”** in the warning to make it on the Variables screen.
- A block marked **Archived** still adds its text to the prompt. To change that, take it out of the prompt.

Under the preview, a line counts the lines, words and characters, and estimates the tokens. A token is the unit AI models measure text in; four characters is roughly one token, so the count is an estimate.

## Set a character limit

Some AI tools only take a certain number of characters. To be warned when the prompt is too long:

1. Under **Properties**, tick **Enforce a character limit**.
2. Type the limit under **Max characters**.

    ![The preview with a red message saying the prompt exceeds the character limit, and the limit box in Properties.](https://promptmason.ai/images/docs/build-prompt-character-limit-warning.webp)

When the prompt is longer, a red box under the preview says by how much, for example **Exceeds 8,000-character limit by 120 characters.** It's a warning only: you can still save and copy the prompt.

## Properties

Under **Properties**, on the right:

- **Type**: what kind of prompt this is, for example **User Prompt** or **System Prompt** ([Block types, prompt types and defaults](https://promptmason.ai/docs/types-and-defaults)).
- **Location**: the folder for a new prompt. To move a saved prompt, use **Move** on the Prompts screen ([Folders, moving and copying](https://promptmason.ai/docs/folders)).
- **Description**: a note about what the prompt is for.
- **Tags**: shown when the Tags feature is on.
- **Enforce a character limit**: see [Set a character limit](#set-a-character-limit).

[Expected output](https://promptmason.ai/docs/expected-output) is under the preview, and, when the Comments feature is on, a saved prompt also has [Comments](https://promptmason.ai/docs/comments) under the canvas.

## Save the prompt

1. Type a name in the box at the top left.
2. Click one of the buttons at the top right:

| Button | When it shows | What it does |
|---|---|---|
| **Save as Dynamic** | New prompt | Saves a dynamic prompt and goes to the Prompts screen. |
| **Save as Static** | New prompt | Saves the text as it is now, as a static prompt, and goes to the Prompts screen. |
| **Update Prompt** | Saved prompt | Saves your changes and goes to the Prompts screen. |
| **Apply** | Always | Saves as a dynamic prompt and keeps you on Build. |

Ctrl+S does the same as **Save as Dynamic** or **Update Prompt**.

After **Apply** on a new prompt, it counts as saved: the button changes to **Update Prompt**, **Location** goes away, and the **Comments** panel appears.

To choose between dynamic and static, see [Static prompts, dynamic prompts and documents](https://promptmason.ai/docs/static-and-dynamic). Choose dynamic unless you have a reason not to. PromptMason has no button to change a saved prompt's kind, so choose before you save.

To copy the finished prompt, save it, then copy it from the Prompts screen ([Copy and use a prompt](https://promptmason.ai/docs/use-prompts)).

## Leave without saving

When you're changing a saved prompt, click **Cancel** at the top (or press Esc) to go back to the Prompts screen.

If you have unsaved changes and you click **Cancel**, click another screen in the sidebar, or switch tabs, PromptMason asks **Discard your changes?** Click **Keep Editing** to go back and save, or **Discard Changes** to lose them.

## If something goes wrong

### The Save buttons are grayed out

The prompt needs at least one block. Each embedded block you've added also needs a name, a type and some text.

### Give this prompt a name to save it.

Type a name in the box at the top, then save again.

### Failed to save.

The save didn't go through. Try again. If it keeps happening, contact support@promptmason.ai.

### Saved, but an expected output couldn't be saved

The message starts **Saved.** and says how many expected outputs couldn't be saved. The prompt was saved, but a result you added under **Expected Output** wasn't, and Build stays open. Add the result again from the saved prompt ([Expected output](https://promptmason.ai/docs/expected-output)).

### The Free plan limit window opens

On the Free plan you can have 15 prompts and 25 blocks. A new prompt counts toward the 15, and each new block you save to the Block Library counts toward the 25. See [Plans and limits](https://promptmason.ai/docs/plans).

### The Your library is paused window opens

Your library is over the Free plan's limits, so saving is turned off. See [When your library is paused](https://promptmason.ai/docs/paused-library).

### No blocks are listed

If the list says **No blocks yet. Create some on the Blocks screen.**, you haven't made any library blocks yet. See [Create and edit blocks](https://promptmason.ai/docs/blocks).

If it says **No blocks match the current filters.**, clear the search box, choose **All** in the type filter, and check the folder, tag and favorites filters in the sidebar.

## Want a hand?

Paste this prompt into Claude, ChatGPT or another AI assistant, together with this guide, to be walked through it step by step:

> I have some blocks in PromptMason and want to put them together into a prompt on the Build screen. Walk me through adding and ordering the blocks, the block headers, and which Save button to use.