generated: '2026-09-17'
method: derived
source: >-
  openapi/trello-rest-api-openapi.json (components.schemas, 63 schemas) plus
  https://developer.atlassian.com/cloud/trello/guides/rest-api/object-definitions/
description: >-
  Entity-relationship graph for the Trello domain, derived from the id-reference fields and
  $ref links in Trello's own OpenAPI. Trello's model is a strict containment tree
  (Enterprise > Organization/Workspace > Board > List > Card > Checklist > CheckItem) with
  membership, labels, custom fields and plugins hanging off it as cross-cutting joins.
identifiers:
  scheme: 24-character lowercase hexadecimal MongoDB ObjectId
  schema: TrelloID
  pattern: '^[0-9a-fA-F]{24}$'
  prefixed: false
  note: >-
    Trello uses NO type prefix on its ids — unlike Stripe's cus_/ch_, a Trello id carries no
    indication of what kind of object it points at. An agent holding a bare id cannot tell a
    board from a card without calling the API. The one exception is Card.idShort, a
    per-board integer used in the human-facing short URL.
entities:
  - name: Enterprise
    schema: Enterprise
    relationships:
      - has_many: Organization
        via: idOrganizations
      - has_many: Member
        via: idAdmins
        role: admin
      - has_many: EnterpriseAuditLog
        via: idAction
  - name: Organization
    aka: Workspace
    schema: Organization
    relationships:
      - belongs_to: Enterprise
        via: idEnterprise
      - has_many: Board
        via: idBoards
      - has_many: Membership
        via: memberships
      - has_one: OrganizationPrefs
        via: prefs
  - name: Board
    schema: Board
    relationships:
      - belongs_to: Organization
        via: idOrganization
      - belongs_to: Member
        via: idMemberCreator
        role: creator
      - has_many: TrelloList
        via: TrelloList.idBoard
      - has_many: Card
        via: Card.idBoard
      - has_many: Label
        via: Label.idBoard
      - has_many: Tag
        via: idTags
      - has_one: Prefs
        via: prefs
      - has_one: Limits
        via: limits
      - has_one: BoardBackground
        via: prefs.background
  - name: TrelloList
    aka: List
    schema: TrelloList
    relationships:
      - belongs_to: Board
        via: idBoard
      - has_many: Card
        via: Card.idList
      - has_one: Limits
        via: limits
  - name: Card
    schema: Card
    relationships:
      - belongs_to: Board
        via: idBoard
      - belongs_to: TrelloList
        via: idList
      - has_many: Checklist
        via: idChecklists
      - has_many: Label
        via: idLabels
      - has_many: Member
        via: idMembers
      - has_many: Member
        via: idMembersVoted
        role: voter
      - has_one: Attachment
        via: idAttachmentCover
        role: cover
      - has_many: CustomFieldItems
        via: CustomFieldItems.idModel
      - has_one: Limits
        via: limits
  - name: Checklist
    schema: Checklist
    relationships:
      - has_many: CheckItem
        via: CheckItem.idChecklist
  - name: CheckItem
    schema: CheckItem
    relationships:
      - belongs_to: Checklist
        via: idChecklist
  - name: Label
    schema: Label
    relationships:
      - belongs_to: Board
        via: idBoard
      - has_one: Color
        via: color
  - name: Member
    schema: Member
    relationships:
      - belongs_to: Enterprise
        via: idEnterprise
      - has_many: Board
        via: idBoards
      - has_many: Organization
        via: idOrganizations
      - has_many: Enterprise
        via: idEnterprisesAdmin
        role: admin
      - belongs_to: Member
        via: idMemberReferrer
        role: referrer
      - has_one: MemberPrefs
        via: prefs
      - has_many: BoardStars
        via: BoardStars.idBoard
      - has_many: SavedSearch
      - has_many: CustomEmoji
      - has_many: CustomSticker
  - name: Membership
    schema: Membership
    note: Join entity binding a Member to a Board or Organization with a role.
  - name: Action
    schema: Action
    note: >-
      The activity/event record. Every mutation in Trello produces an Action, and Actions are
      what webhooks deliver and what the Notifications surface reads.
    relationships:
      - belongs_to: Member
        via: idMemberCreator
  - name: Notification
    schema: Notification
    relationships:
      - belongs_to: Action
        via: idAction
      - belongs_to: Member
        via: idMemberCreator
      - has_one: Card
        via: card
      - has_one: Board
        via: board
      - has_one: NotificationChannelSettings
  - name: CustomField
    schema: CustomField
    relationships:
      - belongs_to_polymorphic: idModel
        note: Points at the Board the field is defined on.
      - has_many: CustomFieldItems
  - name: CustomFieldItems
    schema: CustomFieldItems
    relationships:
      - belongs_to: CustomField
        via: idCustomField
      - belongs_to_polymorphic: idModel
        note: Points at the Card carrying the value.
      - has_one: customFieldItemValue
        via: value
  - name: Attachment
    schema: Attachment
    relationships:
      - belongs_to: Member
        via: idMember
      - has_one: Color
        via: edgeColor
  - name: Plugin
    aka: Power-Up
    schema: Plugin
    relationships:
      - has_many: PluginListing
      - has_many: PluginData
  - name: PluginData
    schema: PluginData
    relationships:
      - belongs_to: Plugin
        via: idPlugin
      - belongs_to_polymorphic: idModel
        note: Scoped storage attached to a board, card, member or organization.
  - name: Webhook
    schema: Webhook
    relationships:
      - belongs_to_polymorphic: idModel
        note: >-
          The single most important polymorphic reference in the API — a webhook watches
          exactly one model of any type, and fires for every action on it. There is no
          per-event-type filter.
      - belongs_to: Token
  - name: Token
    schema: Token
    relationships:
      - belongs_to: Member
        via: idMember
      - has_many: TokenPermission
        via: permissions
      - has_many: Webhook
  - name: Limits
    schema: Limits
    note: >-
      Per-object quota envelope returned on Board, TrelloList and Card via ?fields=limits.
      Values vary by board and account, so they must be read at runtime rather than assumed.
polymorphic_references:
  - field: idModel
    used_by: [Webhook, CustomField, CustomFieldItems, PluginData, TokenPermission]
    note: >-
      Trello's central untyped foreign key. Because ids carry no type prefix, an idModel is
      opaque — a consumer must already know, out of band, what kind of object it points at.
      This is the single biggest machine-readability weakness in the Trello data model.
render: null