LangSmith PromptInstall

Overview

This node, named "LangSmith Prompt," allows users to fill in a prompt template stored in their LangSmith account by substituting parameters dynamically. It fetches a prompt template by its name from LangSmith and replaces placeholders within the template with user-provided values. This is useful for automating text generation workflows where prompts need to be customized on the fly based on input data.

Common scenarios:

• Dynamically generating prompts for AI language models based on variable inputs.
• Automating content creation where templates are reused with different parameters.
• Integrating LangSmith prompt templates into larger automation workflows in n8n.

Example:
If you have a prompt template named "WelcomeMessage" that contains "Hello {name}, welcome to {company}!", you can use this node to substitute {name} and {company} with actual values like "Alice" and "Acme Corp" respectively, producing the final prompt text.

Properties

• Input Parameters supports multiple entries, each requiring:
  • Name: The placeholder name in the template (e.g., name).
  • Value: The string to substitute in place of the placeholder.

Output

The node outputs an array containing one item with a JSON object. The JSON object has a single property whose key is the prompt name and whose value is the filled-in prompt string after substitution.

Example output JSON structure:

{
  "WelcomeMessage": "Hello Alice, welcome to Acme Corp!"
}

No binary data output is produced by this node.

Dependencies

• Requires an API key credential for LangSmith to authenticate requests.
• Uses internal helper functions to fetch the prompt template by name and perform the substitution.
• The node depends on network access to communicate with the LangSmith service.

Troubleshooting

• Prompt not found error: If the specified prompt name does not exist in the LangSmith account, the node throws an error stating Prompt with name "<promptName>" not found. Verify the prompt name spelling and existence in your LangSmith account.
• Credential issues: Ensure the API key credential is correctly configured and valid; otherwise, authentication errors may occur.
• Parameter mismatch: If required placeholders in the prompt template are not provided in the input parameters, the resulting prompt may contain unsubstituted placeholders or cause unexpected results.

Links and References

• LangSmith Documentation (hypothetical link for reference)
• n8n documentation on creating custom nodes