Prompt Library

The Prompt Library is a powerful feature that lets you create, manage, and version prompts for AI agents. It ensures consistency across your organization and allows you to optimize prompts over time.

Why Use a Prompt Library?

Without a Library

• Each team member writes prompts differently
• No way to share effective prompts
• Can't track what worked and what didn't
• Prompts get lost in chat history

With Fabric's Prompt Library

• Consistency — Everyone uses the same optimized prompts
• Versioning — Track changes and rollback if needed
• Sharing — Share effective prompts across teams
• Analytics — See which prompts perform best
• Templates — Use variables for dynamic content

Prompt Types

System Prompts (Read-Only)

Platform-provided prompts optimized for specific tasks:

• PRD Generator — Creates Product Requirement Documents
• Technical Spec — Generates technical specifications
• Architecture Doc — Designs system architecture documents
• User Story — Creates user stories with acceptance criteria
• API Documentation — Documents API endpoints

These prompts are:

• Tested and optimized by Fabric
• Can't be edited directly
• Can be forked to create custom versions

User Prompts (Editable)

Custom prompts created by you or your organization:

• Full editing control
• Version history
• Organization-wide or personal scope
• Can be based on system prompts

Creating Prompts

You are writing a PRD for {{projectName}}.

The target audience is {{audience}}.

Requirements:
{{#each requirements}}
- {{this}}
{{/each}}

{{#if includeTimeline}}
Include a timeline section with milestones.
{{/if}}

Template Variables

Template variables make prompts dynamic and reusable.

Syntax

{{variableName}}           — Simple variable
{{#if condition}}...{{/if}} — Conditional block
{{#each items}}...{{/each}} — Loop over array
{{#unless condition}}...{{/unless}} — Negative conditional

Built-in Variables

Fabric automatically provides these variables:

Custom Variables

Define your own variables when using prompts:

Create a {{documentType}} for {{featureName}}.

Target users: {{targetUsers}}
Priority: {{priority}}

When using this prompt, you'll be asked to provide values for each variable.

Prompt Scopes

Every prompt belongs to one of three scopes that control who can see and use it.

System

System prompts are provided by Fabric and available to all users. They serve as the platform defaults for each document type. System prompts cannot be edited, but you can fork one to create your own customized version.

Organization

Organization prompts are visible to every member of that organization. When you're working inside an organization workspace, you see System prompts and your organization's prompts. Personal prompts from your own workspace are not visible in this context.

Personal

Personal prompts are private to you and only appear in your personal workspace. When you switch to an organization workspace, your personal prompts are not visible there, and the organization's prompts are not visible in your personal workspace.

Visibility by context

Personal and organization prompts are kept completely separate. A prompt created in one organization is never visible in another organization, even if you belong to both.

Prompt Bindings and Defaults

A binding connects a prompt to a specific agent and document type, making it available in the prompt selector when generating that type of document. You can also mark a binding as the default, so it is automatically selected.

Setting a default

You can set a prompt as the default from two places:

• Prompts page — Use the document type tabs to filter by type, then select Set as Default from the prompt's menu.
• Document editor — When generating a document, pick a prompt from the dropdown and click Bind as Default.

When setting a default, you choose a binding scope:

• Personal — This default applies only to you.
• Organization — This default applies to every member of the organization.

How defaults are resolved

When you generate a document, Fabric looks for the best prompt to use by checking each level in order and stopping at the first match:

This means:

• A personal default always takes priority over the organization and system defaults.
• An organization default takes priority over the system default for all members who haven't set their own personal default.
• The system default is the final fallback.

Example: team with mixed defaults

Suppose your organization has three team members generating PRDs:

Alice's personal default does not affect Bob or Carol. If the organization admin later updates the organization default, Bob and Carol see the change immediately, while Alice continues using her own.

Versioning

Every prompt maintains a version history.

Automatic Versioning

When you edit a prompt:

1. A new version is created automatically
2. Previous versions are preserved
3. You can view the diff between versions
4. Rollback is available anytime

Version History

v3 (current) — Added timeline section
v2           — Improved formatting
v1           — Initial version

Rollback

To rollback to a previous version:

1. Open the prompt
2. Click Version History
3. Select the version to restore
4. Click Restore This Version

A new version is created (rollbacks don't delete history).

Organization Prompts

Sharing a prompt with your team

To make a prompt available to your entire organization:

1. Create or edit a prompt
2. Set the scope to Organization
3. Save the prompt

All organization members can now view, use, and fork the prompt to create their own versions.

Setting organization-wide defaults

Organization admins can set a prompt as the default for a document type across the entire organization:

1. Open the prompt in the Prompt Library
2. Select Set as Default from the menu
3. Choose the document type and agent
4. Set the binding scope to Organization

Members who haven't set their own personal default will automatically use this prompt when generating that document type.

Best Practices

Writing Effective Prompts

Be Specific

❌ "Write a document about the feature"
✅ "Write a PRD for {{featureName}} that includes:
    - Problem statement
    - Proposed solution
    - User stories
    - Success metrics"

Use Context

❌ "Create user stories"
✅ "Based on the PRD for {{projectName}}, create user stories
    that follow the format:
    As a [user type], I want [goal] so that [benefit]"

Include Examples

"Format the output like this example:

## User Story 1
**As a** customer
**I want** to reset my password
**So that** I can regain access to my account

### Acceptance Criteria
- [ ] User receives reset email within 1 minute
- [ ] Reset link expires after 24 hours"

Prompt Organization

Naming Convention

[Type] - [Purpose] - [Version/Variant]

Examples:
"PRD - Feature Request - Technical"
"Story - Bug Fix Template"
"Spec - API Documentation - REST"

Categories

• Document generation prompts
• Code review prompts
• Analysis prompts
• Communication prompts

Testing Prompts

Before making a prompt organization-wide:

1. Test with various inputs
2. Check output quality
3. Verify variable handling
4. Get feedback from team members
5. Iterate based on results

Analytics

Track prompt performance:

Access analytics in Settings → Prompt Library → Analytics.

Next Steps