> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kalshi.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Update FCM Subtrader Blocked Categories

> Adds one event category to, or removes one from, the set an FCM member
has blocked for one of its subtraders. The subtrader must belong to the
requesting FCM. Blocks apply prospectively: new orders the subtrader
places through its bound API credentials are rejected in markets whose
event belongs to a blocked category, while orders already resting are
not cancelled. Returns the subtrader's full resulting blocked set.




## OpenAPI

````yaml /openapi.yaml put /fcm/subtraders/blocked_categories
openapi: 3.0.0
info:
  title: Kalshi Trade API Manual Endpoints
  version: 3.30.0
  description: >-
    Manually defined OpenAPI spec for endpoints being migrated to spec-first
    approach
servers:
  - url: https://external-api.kalshi.com/trade-api/v2
    description: Production Trade API server
  - url: https://api.elections.kalshi.com/trade-api/v2
    description: Production shared API server, also supported
  - url: https://external-api.demo.kalshi.co/trade-api/v2
    description: Demo Trade API server
  - url: https://demo-api.kalshi.co/trade-api/v2
    description: Demo shared API server, also supported
security: []
tags:
  - name: api-keys
    description: API key management endpoints
  - name: orders
    description: Order management endpoints
  - name: order-groups
    description: Order group management endpoints
  - name: portfolio
    description: Portfolio and balance information endpoints
  - name: communications
    description: Request-for-quote (RFQ) endpoints
  - name: multivariate
    description: Multivariate event collection endpoints
  - name: exchange
    description: Exchange status and information endpoints
  - name: live-data
    description: Live data endpoints
  - name: markets
    description: Market data endpoints
  - name: milestone
    description: Milestone endpoints
  - name: search
    description: Search and filtering endpoints
  - name: incentive-programs
    description: Incentive program endpoints
  - name: fcm
    description: FCM member specific endpoints
  - name: events
    description: Event endpoints
  - name: structured-targets
    description: Structured targets endpoints
paths:
  /fcm/subtraders/blocked_categories:
    put:
      tags:
        - fcm
      summary: Update FCM Subtrader Blocked Categories
      description: |
        Adds one event category to, or removes one from, the set an FCM member
        has blocked for one of its subtraders. The subtrader must belong to the
        requesting FCM. Blocks apply prospectively: new orders the subtrader
        places through its bound API credentials are rejected in markets whose
        event belongs to a blocked category, while orders already resting are
        not cancelled. Returns the subtrader's full resulting blocked set.
      operationId: UpdateFCMSubtraderBlockedCategories
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/UpdateFCMSubtraderBlockedCategoriesRequest'
      responses:
        '200':
          description: Blocked categories updated successfully
          content:
            application/json:
              schema:
                $ref: >-
                  #/components/schemas/UpdateFCMSubtraderBlockedCategoriesResponse
        '400':
          $ref: '#/components/responses/BadRequestError'
        '401':
          $ref: '#/components/responses/UnauthorizedError'
        '403':
          $ref: '#/components/responses/ForbiddenError'
        '404':
          $ref: '#/components/responses/NotFoundError'
        '500':
          $ref: '#/components/responses/InternalServerError'
      security:
        - kalshiAccessKey: []
          kalshiAccessSignature: []
          kalshiAccessTimestamp: []
components:
  schemas:
    UpdateFCMSubtraderBlockedCategoriesRequest:
      type: object
      required:
        - subtrader_id
        - category
        - blocked
      properties:
        subtrader_id:
          type: string
          description: >-
            The subtrader whose blocked categories should be updated. Must
            belong to the requesting FCM.
        category:
          type: string
          description: >-
            A single event category to add to or remove from the blocked set,
            1-100 characters (e.g. "Politics").
        blocked:
          type: boolean
          description: >-
            True adds the category to the blocked set; false removes it.
            Removing a category that is not blocked is a no-op.
    UpdateFCMSubtraderBlockedCategoriesResponse:
      type: object
      required:
        - categories
      properties:
        categories:
          type: array
          description: The subtrader's full resulting blocked set, sorted ascending.
          items:
            type: string
    ErrorResponse:
      type: object
      properties:
        code:
          type: string
          description: Error code
        message:
          type: string
          description: Human-readable error message
        details:
          type: string
          description: Additional details about the error, if available
  responses:
    BadRequestError:
      description: Bad request - invalid input
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
    UnauthorizedError:
      description: Unauthorized - authentication required
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
    ForbiddenError:
      description: Forbidden - insufficient permissions
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
    NotFoundError:
      description: Resource not found
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
    InternalServerError:
      description: Internal server error
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
  securitySchemes:
    kalshiAccessKey:
      type: apiKey
      in: header
      name: KALSHI-ACCESS-KEY
      description: Your API key ID
    kalshiAccessSignature:
      type: apiKey
      in: header
      name: KALSHI-ACCESS-SIGNATURE
      description: RSA-PSS signature of the request
    kalshiAccessTimestamp:
      type: apiKey
      in: header
      name: KALSHI-ACCESS-TIMESTAMP
      description: Request timestamp in milliseconds

````