Nex

Nex Relationships API

The Relationships API from Nex — 4 operation(s) for relationships.

GitHub OpenAPI

Operations 5

POST /v1/relationships Create a relationship definition #
GET /v1/relationships List relationship definitions #
DELETE /v1/relationships/{id} Delete a relationship definition #
POST /v1/records/{record_id}/relationships Create a relationship instance #
DELETE /v1/records/{record_id}/relationships/{rel_id} Delete a relationship instance #

Documentation

📖
Documentation
https://docs.nex.ai
📖
APIReference
https://docs.nex.ai/api-reference/introduction

Specifications

⚙
OpenAPI
https://raw.githubusercontent.com/api-evangelist/nex/refs/heads/main/openapi/nex-relationships-api-openapi.yml

Work with this as data

Every API here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for apis

7 MCP tools reach this
  • find_apisBrowse and filter every API in the catalog.
  • get_api_artifactsOne API's artifacts, grouped by type.
  • get_openapiThe primary OpenAPI for this API.
  • find_similar_apisAPIs that look like this one.
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools →

Call it yourself

curl for this page
This API 
curl "https://apis.io/api/v1/apis/nex-relationships-api"
All apis 
curl "https://apis.io/api/v1/apis?limit=25"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.

OpenAPI Specification

nex-relationships-api-openapi.yml Raw ↑ 
openapi: 3.2.0
info:
  description: REST API for accessing and managing your Nex data. Generate API keys from the Nex web UI and use them to authenticate requests.
  title: Nex Developer AI Lists Relationships API
  contact: {}
  version: '1.0'
servers:
- url: https://app.nex.ai/api/developers
tags:
- name: Relationships
paths:
  /v1/relationships:
    post:
      security:
      - ApiKeyAuth: []
      description: Creates a new relationship definition between two object types
      tags:
      - Relationships
      summary: Create a relationship definition
      operationId: createRelationshipDefinition
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/developer.CreateRelationshipDefinitionRequest'
        description: Relationship definition to create
        required: true
      responses:
        '200':
          description: Created relationship definition
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/developer.RelationshipDefinitionResponse'
        '400':
          description: Bad request - Invalid data
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
        '401':
          description: Unauthorized - Invalid or missing API key
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
        '500':
          description: Internal server error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
    get:
      security:
      - ApiKeyAuth: []
      description: Retrieves all relationship definitions in the workspace
      tags:
      - Relationships
      summary: List relationship definitions
      operationId: listRelationshipDefinitions
      responses:
        '200':
          description: List of relationship definitions
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/developer.ListRelationshipDefinitionsResponse'
        '401':
          description: Unauthorized - Invalid or missing API key
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
        '500':
          description: Internal server error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
  /v1/relationships/{id}:
    delete:
      security:
      - ApiKeyAuth: []
      description: Permanently deletes a relationship definition
      tags:
      - Relationships
      summary: Delete a relationship definition
      operationId: deleteRelationshipDefinition
      parameters:
      - description: Relationship definition ID
        name: id
        in: path
        required: true
        schema:
          type: string
      responses:
        '200':
          description: Relationship definition deleted
        '400':
          description: Bad request
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
        '401':
          description: Unauthorized - Invalid or missing API key
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
        '404':
          description: Relationship definition not found
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
        '500':
          description: Internal server error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
  /v1/records/{record_id}/relationships:
    post:
      security:
      - ApiKeyAuth: []
      description: Creates a relationship instance between two records
      tags:
      - Relationships
      summary: Create a relationship instance
      operationId: createRelationshipInstance
      parameters:
      - description: Record ID
        name: record_id
        in: path
        required: true
        schema:
          type: integer
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/developer.CreateRelationshipRequest'
        description: Relationship instance to create
        required: true
      responses:
        '200':
          description: Created relationship instance
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/developer.RelationshipInstanceResponse'
        '400':
          description: Bad request - Invalid data
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
        '401':
          description: Unauthorized - Invalid or missing API key
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
        '404':
          description: Record not found
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
        '500':
          description: Internal server error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
  /v1/records/{record_id}/relationships/{rel_id}:
    delete:
      security:
      - ApiKeyAuth: []
      description: Deletes a relationship instance between two records
      tags:
      - Relationships
      summary: Delete a relationship instance
      operationId: deleteRelationshipInstance
      parameters:
      - description: Record ID
        name: record_id
        in: path
        required: true
        schema:
          type: integer
      - description: Relationship instance ID
        name: rel_id
        in: path
        required: true
        schema:
          type: string
      responses:
        '200':
          description: Relationship instance deleted
        '400':
          description: Bad request
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
        '401':
          description: Unauthorized - Invalid or missing API key
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
        '404':
          description: Relationship instance not found
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
        '500':
          description: Internal server error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/httpx.APIError'
components:
  schemas:
    httpx.APIError:
      type: object
      properties:
        code:
          type: integer
        message:
          type: string
    developer.ListRelationshipDefinitionsResponse:
      type: object
      properties:
        data:
          type: array
          items:
            $ref: '#/components/schemas/developer.RelationshipDefinitionResponse'
    developer.CreateRelationshipDefinitionRequest:
      type: object
      required:
      - type
      - entity_definition_1_id
      - entity_definition_2_id
      properties:
        type:
          type: string
          description: Relationship cardinality
          enum:
          - one_to_one
          - one_to_many
          - many_to_many
        entity_definition_1_id:
          type: string
          description: First object definition ID
        entity_definition_2_id:
          type: string
          description: Second object definition ID
        entity_1_to_2_predicate:
          type: string
          description: Label for 1→2 direction (e.g., 'has')
        entity_2_to_1_predicate:
          type: string
          description: Label for 2→1 direction (e.g., 'belongs to')
      example:
        type: one_to_many
        entity_definition_1_id: '123'
        entity_definition_2_id: '456'
        entity_1_to_2_predicate: has
        entity_2_to_1_predicate: belongs to
    developer.CreateRelationshipRequest:
      type: object
      required:
      - definition_id
      - entity_1_id
      - entity_2_id
      properties:
        definition_id:
          type: string
          description: Relationship definition ID
        entity_1_id:
          type: string
          description: First record ID
        entity_2_id:
          type: string
          description: Second record ID
      example:
        definition_id: '789'
        entity_1_id: '1001'
        entity_2_id: '2002'
    developer.RelationshipDefinitionResponse:
      type: object
      properties:
        id:
          type: string
        type:
          type: string
          enum:
          - one_to_one
          - one_to_many
          - many_to_many
        entity_definition_1_id:
          type: string
        entity_definition_2_id:
          type: string
        entity_1_to_2_predicate:
          type: string
        entity_2_to_1_predicate:
          type: string
        created_at:
          type: string
          format: date-time
      example:
        id: '789'
        type: one_to_many
        entity_definition_1_id: '123'
        entity_definition_2_id: '456'
        entity_1_to_2_predicate: has
        entity_2_to_1_predicate: belongs to
        created_at: '2024-01-15T10:00:00Z'
    developer.RelationshipInstanceResponse:
      type: object
      properties:
        id:
          type: string
        definition_id:
          type: string
        entity_1_id:
          type: string
        entity_2_id:
          type: string
        created_at:
          type: string
          format: date-time
      example:
        id: '5001'
        definition_id: '789'
        entity_1_id: '1001'
        entity_2_id: '2002'
        created_at: '2024-01-15T10:00:00Z'
  securitySchemes:
    ApiKeyAuth:
      description: 'API key for authentication (format: "Bearer YOUR_API_KEY")'
      type: apiKey
      name: Authorization
      in: header