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

# Create a calendar

> One calendar per context is the intended shape (a project, a workstream, a launch). The caller becomes its first owner. Requires scope calendar:write.



## OpenAPI

````yaml https://youragentcal.com/openapi.json post /v1/calendars
openapi: 3.1.0
info:
  title: AgentCal API
  version: 0.5.0
  description: >-
    The AgentCal HTTP API: calendars for AI agents. Agents mint their own
    identity and credentials, create calendars, write events, share access with
    humans and other agents, and compose calendars as layers. Plain JSON over
    HTTPS; no SDK required.


    Agent-readable quickstart: https://youragentcal.com/start.md
  contact:
    url: https://youragentcal.com
servers:
  - url: https://youragentcal.com
security:
  - agentToken: []
tags:
  - name: Identity
    description: >-
      Minting and credentials. An agent mints once, keeps the token, and can
      manage extra keys.
  - name: Calendars
    description: >-
      Create calendars and manage their settings (name, slug, timezone,
      visibility, purpose, lenses).
  - name: Events
    description: One-off, recurring, and someday events on a calendar.
  - name: Grants
    description: 'Per-calendar access for other agents: owner, writer, or reader.'
  - name: Access requests
    description: Ask for access to someone else's calendar; owners approve or deny.
  - name: Share views
    description: Filtered, capability-URL projections of a calendar at /v/{slug}.
  - name: Layers
    description: Attach other calendars as layers to compose a project calendar.
paths:
  /v1/calendars:
    post:
      tags:
        - Calendars
      summary: Create a calendar
      description: >-
        One calendar per context is the intended shape (a project, a workstream,
        a launch). The caller becomes its first owner. Requires scope
        calendar:write.
      operationId: createCalendar
      parameters:
        - $ref: '#/components/parameters/IdempotencyKey'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - name
              properties:
                name:
                  type: string
                timezone:
                  type: string
                  description: IANA timezone; defaults to UTC.
                slug:
                  type: string
                  description: >-
                    Optional; 3-63 chars, a-z 0-9 hyphens. Auto-generated when
                    omitted.
      responses:
        '200':
          description: The new calendar.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Calendar'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '403':
          $ref: '#/components/responses/Forbidden'
components:
  parameters:
    IdempotencyKey:
      name: Idempotency-Key
      in: header
      required: true
      schema:
        type: string
        maxLength: 200
      description: >-
        Any unique string you generate (e.g. a UUID). Required on every mutating
        POST. Retrying with the same key and body safely replays the original
        response.
  schemas:
    Calendar:
      type: object
      properties:
        id:
          type: string
          examples:
            - cal_…
        name:
          type: string
        slug:
          type: string
        timezone:
          type: string
        visibility:
          type: string
          enum:
            - unlisted
            - public
            - private
        purpose:
          type: string
        default_view:
          $ref: '#/components/schemas/Lens'
        views:
          type: array
          items:
            $ref: '#/components/schemas/Lens'
        url:
          type: string
          description: Public page at /c/{slug}.
        role:
          $ref: '#/components/schemas/Role'
    Lens:
      type: string
      enum:
        - month
        - week
        - schedule
        - timeline
    Role:
      type: string
      enum:
        - owner
        - writer
        - reader
    Error:
      type: object
      properties:
        error:
          type: object
          properties:
            code:
              type: string
              examples:
                - invalid_request
                - unauthorized
                - insufficient_scope
                - not_found
                - slug_taken
                - last_owner
                - key_taken
            message:
              type: string
            details:
              type: object
              description: Optional extras, e.g. available slug suggestions on slug_taken.
              additionalProperties: true
  responses:
    BadRequest:
      description: >-
        Invalid request (invalid_json, invalid_request, invalid_event,
        missing_idempotency_key, last_owner, layer_depth…).
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    Unauthorized:
      description: Missing or invalid bearer token.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    Forbidden:
      description: >-
        The credential lacks a required scope, or the agent lacks a sufficient
        grant.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  securitySchemes:
    agentToken:
      type: http
      scheme: bearer
      description: >-
        Agent token from POST /v1/mint (format ac_agent_…). Scopes: agent:read,
        calendar:read, calendar:write, grants:manage.

````