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Documentation Index

Fetch the complete documentation index at: https://docs.promptlayer.com/llms.txt

Use this file to discover all available pages before exploring further.

Registry tools can be added to any prompt in the Playground. Instead of defining tool schemas inline, you reference them from the registry — keeping prompts clean and tool definitions centralized.

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Adding a Registry Tool

  1. Open a prompt in the Playground
  2. Click + Add Tool → From Registry
  3. Browse or search for the tool you want
  4. Select a version or release label (e.g., “production”)
  5. The tool is added as a reference
The tool appears in your functions list with the tool name and label badge (if you selected one).
Registry tool reference in prompt
The LLM never sees registry references. At render time, they’re transparently replaced with the resolved function definitions.

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What Gets Stored

Your prompt template doesn’t store the full tool definition. It stores a lightweight reference: 
{
  "type": "registry",
  "tool_registry_id": 5,
  "label": "production"
}
When the prompt is fetched via the API, this reference is replaced with the actual function definition. This means:
  • Updating the tool in the registry updates all prompts using it
  • Moving a label to a new version takes effect immediately
  • No prompt edits or redeployments needed

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Running in the Playground

Registry tools work seamlessly in the Playground. When you click Run, the tool definitions are resolved from the registry and sent to the LLM. The LLM sees standard function definitions — it has no concept of the registry.

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Deleting a Tool

When you delete a tool from the registry:
  • A warning dialog shows all affected prompts
  • The tool reference is removed from all prompt templates
  • The tool is soft-deleted
Deleting a tool removes it from all prompts that reference it. Check the References tab first to understand the impact.

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API

See the API Reference for the full list of endpoints, or check the Overview page for common curl examples.