Getting started with the Prompt Library

Your agent depends on prompts that change frequently. The Prompt Library lets you manage them outside your codebase, version each change automatically, and link the exact version that ran to its trace.

Adding the Prompt Library to your code

$
npx skills add comet-ml/opik-skills

Version my prompts in Opik using the /instrument command.

Choosing a version

Pass the version parameter to control which version is returned:

• Omit version (default) — The most recently created version. Useful when you want the agent to pick up new prompt edits automatically.
• "v3" (or any v<N> name) — A specific version. Useful when you want the prompt to stay fixed regardless of newer edits — for example, when reproducing a past run or comparing versions.

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# Fetch a specific version
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v3 = client.get_prompt(name="system_prompt", version="v3", project_name="my-agent")
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# Fetch the most recent version (omit `version`)
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latest = client.get_prompt(name="system_prompt", project_name="my-agent")

Chat prompts

For multi-turn agents with system, user, and assistant roles, use create_chat_prompt / createChatPrompt and the matching get_chat_prompt / getChatPrompt. See Text and chat prompts for a deeper comparison, multimodal content, and template engines.

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client.create_chat_prompt(
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    name="support_assistant",
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    messages=[
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        {"role": "system", "content": "You are a helpful support agent for {{company}}."},
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        {"role": "user", "content": "{{user_query}}"},
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    ],
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    project_name="my-agent",
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)
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chat_prompt = client.get_chat_prompt(
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    name="support_assistant",
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    version="v3",
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    project_name="my-agent",
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)
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messages = chat_prompt.format(
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    variables={"company": "Acme", "user_query": "How do I reset my password?"},
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)