Note: Open a document you can edit and have the supporting source files available in your program's Data Room. This guide covers changes inside a program document, not creating a new master template. Program-level edits do not update your organization's master template or other programs.
Choose the right block
In Weave, a custom block is a block you add and configure for your own task. Choose the type based on what you want in the document:
- AI Text: Generate narrative content from source material, such as a study summary or conclusion.
- AI Table: Generate a table from source material. Define the table structure and instructions for filling it.
- Text: Add fixed wording or boilerplate that should appear as written, without AI generation.
AI blocks need both instructions and a source assignment. The instructions tell Weave what to write; the sources provide the evidence.
The steps below focus on creating an AI block. For fixed text, choose Text at the insertion step and enter the wording you want to keep.
Add your block in Template mode
1. Open Template mode
Open your dossier document in the Editor while in Editing mode. Select the Template tab next to Content.
Opening the document's template instructions.
2. Find the insertion point
Find the section where the new block belongs. Use the + control beside the existing heading or block at the insertion point.
Choosing where the custom block will appear.
Tip: Add the block under the appropriate existing section. You do not need to change the document's section numbering to add another prompt block.
3. Select the block type
Choose AI Text for narrative content or AI Table for a generated table. Click into the new instruction block to edit it.
Adding an AI instruction block to the template.
For an AI Table block, also set up the required rows, columns, and headers. See How to set up and work with tables in Weave for the table-specific workflow.
Once your block is in place, tell Weave what to produce and which sources to use.
Configure the instructions and sources
4. Write a focused instruction
Describe the task in plain language. Include the topic, the information to cover, the level of detail, and the output format. Tell Weave what to omit when the section has a narrow purpose.
For an AI Text block, adapt this example:
Using the selected source reports, write a concise summary of the repeat-dose toxicity study design and key findings. Include the species, dosing duration, dose groups, major findings, and reported NOAEL where available. Use two short paragraphs. Do not invent missing values or repeat the full study methods. 
Defining the task and the expected output.
Tip: Keep each block focused on one task. If you need a detailed study-design summary and a separate discussion of results, consider separate blocks with distinct instructions to reduce overlap.
For instructions that should apply throughout the document, such as naming conventions or writing style, use Edit document instructions rather than repeating them in every block.
5. Assign the sources
Choose the evidence the block should use:
- Data tags: Select tags that match the relevant Data Room files. Check the file tags before generating.
- Source files: Use the block's Source files picker to select specific files when you want precise control.
- Dossier content: Choose an appropriate document source when the block should summarize content already drafted in Weave.
Connecting the block to its source material.
Note: Naming a report or section in your instruction does not by itself attach it as source evidence. Assign the sources separately. When using file-type tags, files must match all selected tags; adding more tags can narrow the available source set.
For help choosing between tags and specific files, see How to use source files.
6. Choose how to handle multiple files
Open the block's settings and choose the generation behavior that fits your task:
- Generate separate results for each file: Apply the instructions to each source file individually, such as creating one summary per study report.
- Combine all files and generate one result: Use the sources together for a single synthesis or overview.
Check that the block type still matches your intended output. An AI Text block is for narrative; an AI Table block is for a table.
Your block is now configured. Save it before leaving Template mode, or generate a first draft to test the setup.
Save and test your custom block
7. Save the configuration
Choose Save and generate to save the instructions and generate content immediately.
If you want to generate later, open the arrow beside Save and generate and select Save. Saving instructions alone does not rewrite existing generated content.
Saving the block without generating content yet.
Note: If an unsaved-changes message appears when you switch blocks or leave Template mode, save the changes you want to keep before continuing.
8. Generate a first draft
If you saved without generating, return to Content and use the block's Generate control. Use Review sources to check the source files for the block before generation.
Testing the custom block with the intended source files.
Generate the new block on its own while testing so you can assess its instructions and sources without regenerating the whole document.
9. Review the output
Check the first draft for accuracy, completeness, length, and format. Confirm that it covers the intended task and does not repeat neighboring sections unnecessarily.
If the result needs a different task or source scope, return to Template and update the block. For a targeted change to the generated wording, use Refinement.
Once the output meets your needs, keep the saved block configuration for future generation in this document.
Frequently asked questions
Q: Do I need to learn template syntax to build or edit a block?
A: No. Use the insertion menu, write plain-language instructions, and select sources in the block controls. Weave handles the underlying template formatting.
Q: Can I have the AI write from another Weave document instead of Data Room files?
A: Yes. Assign the relevant dossier document as a source and explain what material to summarize in your instruction. Draft the supporting content before generating the block that depends on it.
Q: Can I point an AI block to content already written earlier in the same document?
A: Yes. Select Current Document as the source type when configuring the block. Use a focused instruction to identify the content you want it to synthesize.
Q: How do I insert a note-to-writer block?
A: Use + to add a plain Text block and enter your guidance. This is fixed document text, not an AI instruction, so remove note-to-writer content before final delivery.
Quick Reference: Create a custom template block
- Open your document in Editing mode and select Template.
- Find the insertion point and open +.
- Choose AI Text or AI Table.
- Write a focused instruction.
- Assign data tags, specific source files, or dossier content.
- Choose separate results per file or one combined result.
- Select Save, or Save and generate.
- Review the sources and generate the block if you saved for later.
- Review the output and adjust the configuration as needed.