veritas-kanban/docs/SOP-prompt-registry.md

SOP: Prompt Template Registry

Create, version, and manage prompt templates with variable injection.

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Overview

The Prompt Template Registry provides a centralized store for prompt templates used by agents. Key capabilities:

• Version history — every update creates a new version automatically
• Variable extraction — {{variable_name}} syntax for dynamic injection
• Usage tracking — record which model ran which template and with what token costs
• Preview rendering — test variable injection before using in production

Template categories: system · agent · tool · evaluation

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Prerequisites

• VK server running (v4.0+)
• Prompt content ready to store (use {{variable}} syntax for injection points)

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Step-by-Step Procedure

1. Create a Template

curl -X POST http://localhost:3001/api/prompt-registry \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Task Completion Summary",
    "description": "Generates a completion summary for a finished task.",
    "category": "agent",
    "content": "You completed task {{task_title}}. Write a 2-3 sentence summary of what was done. Acceptance criteria: {{acceptance_criteria}}. Agent: {{agent_name}}."
  }'

Response: 201 with template object including id, version (starts at 1), and extracted variables list.

2. List Templates

curl http://localhost:3001/api/prompt-registry

Response: Array of all templates with metadata but not full content (for performance).

3. Get a Template

curl http://localhost:3001/api/prompt-registry/tmpl_abc123

Response: Full template with current content, version number, variables list, and metadata.

4. Preview with Variables

Test variable injection before using the template in production:

curl -X POST http://localhost:3001/api/prompt-registry/tmpl_abc123/render-preview \
  -H "Content-Type: application/json" \
  -d '{
    "templateId": "tmpl_abc123",
    "sampleVariables": {
      "task_title": "Add OAuth login",
      "acceptance_criteria": "Users can log in with Google and GitHub.",
      "agent_name": "TARS"
    }
  }'

Response: { "rendered": "You completed task Add OAuth login. Write a 2-3 sentence summary..." }

5. Update a Template

Every update automatically creates a new version:

curl -X PATCH http://localhost:3001/api/prompt-registry/tmpl_abc123 \
  -H "Content-Type: application/json" \
  -d '{
    "content": "You completed task {{task_title}} (Task ID: {{task_id}}). Write a 2-3 sentence summary. Acceptance criteria: {{acceptance_criteria}}. Agent: {{agent_name}}.",
    "changelog": "Added task_id variable for traceability"
  }'

Response: Updated template with incremented version number.

6. List Version History

curl http://localhost:3001/api/prompt-registry/tmpl_abc123/versions

Response: Array of version objects with versionNumber, changelog, and createdAt. Use this to identify which version to roll back to.

7. Roll Back (by Pinning an Old Version)

There's no automatic rollback endpoint — to use an older version, retrieve it from the versions list and create a new update with the old content:

# 1. Get the target version's content from the versions list
curl http://localhost:3001/api/prompt-registry/tmpl_abc123/versions

# 2. Update the template with the old content and note the rollback
curl -X PATCH http://localhost:3001/api/prompt-registry/tmpl_abc123 \
  -H "Content-Type: application/json" \
  -d '{
    "content": "<content from old version>",
    "changelog": "Rolled back to v2 — v3 introduced regression in output quality"
  }'

8. Record Usage

After using a template, record the usage for analytics:

curl -X POST http://localhost:3001/api/prompt-registry/tmpl_abc123/record-usage \
  -H "Content-Type: application/json" \
  -d '{
    "usedBy": "TARS",
    "model": "anthropic/claude-sonnet-4-6",
    "inputTokens": 320,
    "outputTokens": 145,
    "renderedPrompt": "You completed task Add OAuth login..."
  }'

Response: 201 with usage record.

9. View Usage History and Stats

# Usage history (last 50 uses)
curl http://localhost:3001/api/prompt-registry/tmpl_abc123/usage

# Stats summary
curl http://localhost:3001/api/prompt-registry/tmpl_abc123/stats

# Aggregate stats across all templates
curl http://localhost:3001/api/prompt-registry/stats/all

10. Delete a Template

curl -X DELETE http://localhost:3001/api/prompt-registry/tmpl_abc123

Response: 204 No Content.

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API Endpoints

Method	Path	Description
GET	/api/prompt-registry	List all templates
POST	/api/prompt-registry	Create a new template
GET	/api/prompt-registry/:id	Get a template
PATCH	/api/prompt-registry/:id	Update a template (auto-versions)
DELETE	/api/prompt-registry/:id	Delete a template
GET	/api/prompt-registry/:id/versions	List all versions of a template
GET	/api/prompt-registry/:id/usage	Get usage history
GET	/api/prompt-registry/:id/stats	Get usage statistics
GET	/api/prompt-registry/stats/all	Aggregate stats across all templates
POST	/api/prompt-registry/:id/render-preview	Render a preview with variables
POST	/api/prompt-registry/:id/record-usage	Record a usage event

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Template Schema

Field	Type	Required	Description
name	string	✅	Template name
description	string	❌	What the template is for
category	enum	✅	system, agent, tool, or evaluation
content	string	✅	Template body with {{variable}} placeholders
changelog	string	❌	Description of changes (for update operations)

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Common Issues

Variables not being extracted: Ensure you use {{variable_name}} double-brace syntax. Single braces or other formats won't be recognized.

Stats endpoint returns empty: Stats are only populated after record-usage calls. The system does not auto-track usage — you must call record-usage explicitly.

Version history growing large: Each PATCH creates a new version. This is by design — don't update for cosmetic reasons. Batch changes into single updates.

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Related Docs

• FEATURES.md — Prompt Template Registry
• API-REFERENCE.md — Prompt Registry
• SOP: Output Evaluation