NVIDIA NIM

NVIDIA NIM Reranking API

NeMo Retriever cross-encoder reranking endpoint (/v1/ranking) for scoring candidate passages against a query. Improves retrieval relevance on RAG pipelines and supports the llama-3.2-nv-rerankqa-1b and NV-RerankQA-Mistral-4B-v3 models. Accepts a query plus a list of passages and returns a sorted list of relevance scores.

NVIDIA NIM Reranking API is one of 10 APIs that NVIDIA NIM publishes on the APIs.io network, described by a machine-readable OpenAPI specification.

This API exposes 1 machine-runnable capability that can be deployed as REST, MCP, or Agent Skill surfaces via Naftiko.

Tagged areas include AI, Artificial Intelligence, Reranking, Retrieval, and RAG. The published artifact set on APIs.io includes API documentation, an OpenAPI specification, and 1 Naftiko capability spec.

GitHub OpenAPI

Documentation

📖
Documentation
https://docs.nvidia.com/nim/nemo-retriever/text-reranking/latest/api-reference.html

Specifications

⚙
OpenAPI
https://raw.githubusercontent.com/api-evangelist/nvidia-nim/refs/heads/main/openapi/nvidia-nim-reranking-api-openapi.yml

Other Resources

🔗
NaftikoCapability
https://raw.githubusercontent.com/api-evangelist/nvidia-nim/refs/heads/main/capabilities/reranking-reranking.yaml

OpenAPI Specification

nvidia-nim-reranking-api-openapi.yml Raw ↑ 
openapi: 3.1.0
info:
  title: NVIDIA NIM Reranking API
  description: >
    NVIDIA NeMo Retriever cross-encoder reranking endpoint. Given a query and a
    list of candidate passages, returns each passage's relevance score so RAG
    pipelines can re-order retrieved chunks before they hit the LLM context.
  version: '2026-05-25'
  contact:
    name: NVIDIA Developer Support
    url: https://forums.developer.nvidia.com/c/ai-data-science/nemo-llm-service/
  license:
    name: NVIDIA AI Enterprise License
    url: https://www.nvidia.com/en-us/data-center/products/ai-enterprise/
servers:
  - url: https://integrate.api.nvidia.com
    description: NVIDIA-hosted NIM endpoint
  - url: http://localhost:8000
    description: Self-hosted NIM container default
security:
  - BearerAuth: []
tags:
  - name: Reranking
    description: Cross-encoder reranking operations
paths:
  /v1/ranking:
    post:
      summary: Rank Candidate Passages
      description: Score candidate passages against a query using a NeMo Retriever reranker.
      operationId: rankPassages
      tags:
        - Reranking
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/RankingRequest'
      responses:
        '200':
          description: Ranked passages with relevance scores.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/RankingResponse'
        '400':
          description: Invalid request.
        '401':
          description: Missing or invalid API key.
        '429':
          description: Rate limit exceeded.
components:
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      bearerFormat: nvapi-...
  schemas:
    RankingRequest:
      type: object
      required: [model, query, passages]
      properties:
        model:
          type: string
          description: e.g. `nvidia/llama-3.2-nv-rerankqa-1b-v2`, `nvidia/nv-rerankqa-mistral-4b-v3`.
        query:
          type: object
          required: [text]
          properties:
            text:
              type: string
        passages:
          type: array
          items:
            type: object
            required: [text]
            properties:
              text:
                type: string
        truncate:
          type: string
          enum: [NONE, END]
          default: END
    RankingResponse:
      type: object
      properties:
        rankings:
          type: array
          items:
            type: object
            properties:
              index:
                type: integer
                description: Original index in the request `passages` array.
              logit:
                type: number
                description: Raw cross-encoder relevance logit (higher = more relevant).