This feature is available on all Portkey plans.
The Portkey Prompts API allows you to seamlessly integrate your saved prompts directly into your applications. This powerful feature lets you separate prompt engineering from application code, making both easier to maintain while providing consistent, optimized prompts across your AI applications. With the Prompt API, you can:
  • Use versioned prompts in production applications
  • Dynamically populate prompts with variables at runtime
  • Override prompt parameters as needed without modifying the original templates
  • Retrieve prompt details for use with provider-specific SDKs

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API Endpoints

Portkey offers two primary endpoints for working with saved prompts:
  1. Prompt Completions (/prompts/{promptId}/completions) - Execute your saved prompt templates directly, receiving model completions
  2. Prompt Render (/prompts/{promptId}/render) - Retrieve your prompt template with variables populated, without executing it

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Prompt Completions

The Completions endpoint is the simplest way to use your saved prompts in production. It handles the entire process - retrieving the prompt, applying variables, sending it to the appropriate model, and returning the completion.

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Making a Completion Request

from portkey_ai import Portkey

portkey = Portkey(
  api_key="PORTKEY_API_KEY"
)

# Execute the prompt with provided variables
completion = portkey.prompts.completions.create(
    prompt_id="YOUR_PROMPT_ID",
    variables={
        "user_input": "Hello world"
    },
    max_tokens=250,
    presence_penalty=0.2
)

print(completion)

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Streaming Support

The completions endpoint also supports streaming responses for real-time interactions: 
import Portkey from 'portkey-ai';

const portkey = new Portkey({
    apiKey: "PORTKEY_API_KEY"
});

// Create a streaming completion
const streamCompletion = await portkey.prompts.completions.create({
    promptID: "YOUR_PROMPT_ID",
    variables: {
        "user_input": "Hello world"
    },
    stream: true
});

// Process the stream
for await (const chunk of streamCompletion) {
    console.log(chunk);
}

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Prompt Render

You can retrieve your saved prompts on Portkey using the /prompts/$PROMPT_ID/render endpoint. Portkey returns a JSON containing your prompt or messages body along with all the saved parameters that you can directly use in any request. This is helpful if you are required to use provider SDKs and can not use the Portkey SDK in production. (Example of how to use Portkey prompt templates with OpenAI SDK)

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Using the Render Endpoint/Method

  1. Make a request to https://api.portkey.ai/v1/prompts/$PROMPT_ID/render with your prompt ID
  2. Pass your Portkey API key with x-portkey-api-key in the header
  3. Send up the variables in your payload with { "variables": { "VARIABLE_NAME": "VARIABLE_VALUE" } }
That’s it! See it in action: 
curl -X POST "https://api.portkey.ai/v1/prompts/$PROMPT_ID/render" \
-H "Content-Type: application/json" \
-H "x-portkey-api-key: $PORTKEY_API_KEY" \
-d '{
  "variables": {"movie":"Dune 2"}
}'
The Output:
{
    "success": true,
    "data": {
        "model": "gpt-4",
        "n": 1,
        "top_p": 1,
        "max_tokens": 256,
        "temperature": 0,
        "presence_penalty": 0,
        "frequency_penalty": 0,
        "messages": [
            {
                "role": "system",
                "content": "You're a helpful assistant."
            },
            {
                "role": "user",
                "content": "Who directed Dune 2?"
            }
        ]
    }
}

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Updating Prompt Params While Retrieving the Prompt

If you want to change any model params (like temperature, messages body etc) while retrieving your prompt from Portkey, you can send the override params in your render payload. Portkey will send back your prompt with overridden params, without making any changes to the saved prompt on Portkey. 
curl -X POST "https://api.portkey.ai/v1/prompts/$PROMPT_ID/render" \
-H "Content-Type: application/json" \
-H "x-portkey-api-key: $PORTKEY_API_KEY" \
-d '{
 "variables": {"movie":"Dune 2"},
 "model": "gpt-3.5-turbo",
 "temperature": 2
}'
Based on the above snippet, model and temperature params in the retrieved prompt will be overridden with the newly passed valuesThe New Output:
{
    "success": true,
    "data": {
        "model": "gpt-3.5-turbo",
        "n": 1,
        "top_p": 1,
        "max_tokens": 256,
        "temperature": 2,
        "presence_penalty": 0,
        "frequency_penalty": 0,
        "messages": [
            {
                "role": "system",
                "content": "You're a helpful assistant."
            },
            {
                "role": "user",
                "content": "Who directed Dune 2?"
            }
        ]
    }
}

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Using the render Output in a New Request

Here’s how you can take the output from the render API and use it for making a call. We’ll take example of OpenAI SDKs, but you can use it simlarly for any other provider SDK as well. 
import Portkey from 'portkey-ai';
import OpenAI from 'openai';

// Retrieving the Prompt from Portkey

const portkey = new Portkey({
    apiKey: "PORTKEY_API_KEY"
})

async function getPromptTemplate() {
    const render_response = await portkey.prompts.render({
        promptID: "PROMPT_ID",
        variables: { "movie":"Dune 2" }
    })
    return render_response.data;
}

// Making a Call to OpenAI with the Retrieved Prompt

const openai = new OpenAI({
    apiKey: 'OPENAI_API_KEY',
    baseURL: 'https://api.portkey.ai/v1',
    defaultHeaders: {
      'x-portkey-provider': 'openai',
      'x-portkey-api-key': 'PORTKEY_API_KEY',
      'Content-Type': 'application/json',
    }
});

async function main() {
    const PROMPT_TEMPLATE = await getPromptTemplate();
    const chatCompletion = await openai.chat.completions.create(PROMPT_TEMPLATE);
    console.log(chatCompletion.choices[0]);
}

main();

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CRUD: coming soon 🚀

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API Reference

For complete API details, including all available parameters and response formats, refer to the API reference documentation:

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Next Steps

Now that you understand how to integrate prompts into your applications, explore these related features: