NVIDIA NIM Discover And Chat

arazzo: 1.0.1
info:
  title: NVIDIA NIM Discover And Chat
  summary: List the served models, confirm a target model's metadata, then run a chat completion against it.
  description: >-
    A model-grounded chat flow for NVIDIA NIM. The workflow first lists the
    models exposed by the NIM endpoint, retrieves the metadata for the desired
    model id to confirm it is actually served, and then issues an
    OpenAI-compatible chat completion using that confirmed model. Discovering
    the exact `model` string before inference avoids 404s from passing a model
    the endpoint does not host. Every step spells out its request inline so the
    flow can be read and executed without opening the underlying OpenAPI
    description.
  version: 1.0.0
sourceDescriptions:
- name: chatApi
  url: ../openapi/nvidia-nim-chat-api-openapi.yml
  type: openapi
- name: modelsApi
  url: ../openapi/nvidia-nim-models-api-openapi.yml
  type: openapi
workflows:
- workflowId: discover-and-chat
  summary: Discover a served model and run a chat completion against it.
  description: >-
    Lists the NIM model catalog, retrieves the chosen model to confirm it is
    available, and then sends a chat completion request using that model.
  inputs:
    type: object
    required:
    - apiKey
    - modelId
    - prompt
    properties:
      apiKey:
        type: string
        description: NVIDIA developer API key (nvapi-...) sent as a Bearer token.
      modelId:
        type: string
        description: The model id to confirm and use (e.g. meta/llama-3.3-70b-instruct).
      prompt:
        type: string
        description: The user prompt to send to the chat model.
      maxTokens:
        type: integer
        description: Maximum number of tokens to generate.
        default: 1024
  steps:
  - stepId: listAvailableModels
    description: >-
      List the models exposed by this NIM endpoint to discover the exact model
      strings that can be passed to chat completions.
    operationId: listModels
    parameters:
    - name: Authorization
      in: header
      value: Bearer $inputs.apiKey
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      models: $response.body#/data
  - stepId: confirmModel
    description: >-
      Retrieve metadata for the requested model id to confirm the endpoint
      actually serves it before attempting inference.
    operationId: getModel
    parameters:
    - name: Authorization
      in: header
      value: Bearer $inputs.apiKey
    - name: model_id
      in: path
      value: $inputs.modelId
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      confirmedModelId: $response.body#/id
      ownedBy: $response.body#/owned_by
  - stepId: chatWithModel
    description: >-
      Send a chat completion request using the confirmed model id and the
      supplied user prompt.
    operationId: createChatCompletion
    parameters:
    - name: Authorization
      in: header
      value: Bearer $inputs.apiKey
    requestBody:
      contentType: application/json
      payload:
        model: $steps.confirmModel.outputs.confirmedModelId
        messages:
        - role: user
          content: $inputs.prompt
        max_tokens: $inputs.maxTokens
        stream: false
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      completionId: $response.body#/id
      answer: $response.body#/choices/0/message/content
      finishReason: $response.body#/choices/0/finish_reason
      totalTokens: $response.body#/usage/total_tokens
  outputs:
    confirmedModelId: $steps.confirmModel.outputs.confirmedModelId
    answer: $steps.chatWithModel.outputs.answer
    totalTokens: $steps.chatWithModel.outputs.totalTokens