Fields reference

Every built-in field, every property, and how hidden metadata works. Consistent across all SDKs — the names and shapes below are the same on web, mobile, iframe, and HTML fallback.

System fields

These have built-in types and max-length validation. Use them by name to get the right label and input type for free.

Name	Type	Default label	Max length	Defaults required?
`subject`	`text`	Subject	200	Yes
`description`	`textarea`	Description	5000	Yes
`email`	`email`	Email	254	No
`name`	`text`	Name	100	No
`url`	`url`	URL	2048	No
`phone`	`tel`	Phone	20	No

Field properties

Every field (system or custom) is configured with this shape:

Property	Type	Description
`visible`	`boolean`	Show the field in the form UI. Hidden fields still go through to the issue.
`required`	`boolean`	Only applies when visible: true. Enforced client-side and server-side.
`value`	`string \| any`	Default for visible fields; the actual value for hidden fields.
`label`	`string`	Override the field label in the UI.
`placeholder`	`string`	Placeholder text for visible inputs.
`type`	`'text' \| 'email' \| 'textarea' \| 'url' \| 'tel' \| 'number' \| 'select'`	Override the input type. Defaults to the type of the matching system field.
`options`	`string[]`	Options list for type: "select" fields.
`maxLength`	`number`	Max character count for text/textarea.
`minLength`	`number`	Min character count for text/textarea.
`pattern`	`string (regex)`	Client-side validation pattern.
`validationMessage`	`string`	Message shown when validation fails.

fields: {
  subject: {
    visible: true,
    required: true,
    label: "What's up?",
    placeholder: "e.g. Can't submit my order",
    value: "Bug Report"
  },
  userId: {
    visible: false,
    value: currentUser.id
  }
}

Hidden metadata

Set visible: false with a value to attach context to every submission. The metadata shows up in the body of the created issue, so the engineer picking it up has what they need.

fields: {
  subject:     { visible: true, required: true },
  description: { visible: true, required: true },
  email:       { visible: false, value: currentUser.email },
  userId:      { visible: false, value: currentUser.id },
  plan:        { visible: false, value: currentUser.plan },
  appVersion:  { visible: false, value: APP_VERSION },
  pageUrl:     { visible: false, value: window.location.href },
  sessionId:   { visible: false, value: analytics.sessionId() }
}

Select fields

Render a dropdown by setting type: 'select' and providing options:

fields: {
  priority: {
    visible: true,
    required: true,
    type: 'select',
    label: 'Priority',
    options: ['Low', 'Normal', 'High', 'Blocker']
  }
}

Provider-specific fields

These are only read when your project targets the matching provider. A github_labels field is ignored on a Linear project, and vice versa.

GitHub

github_labels: Comma-separated GitHub label names (case-sensitive).
github_assignees: Comma-separated GitHub usernames. Must have write access to the repo.
github_milestone: GitHub milestone number.

github_labels:    { visible: false, value: "bug,customer" },
github_assignees: { visible: false, value: "johndoe" }

Linear

linear_labels: Comma-separated Linear label IDs(not names). Appended to the project's default labels, not replacing them.

linear_labels: {
  visible: false,
  value: "a1b2c3d4-...,e5f6g7h8-..."
}

More on Linear defaults in the Linear features guide.

Validation

Required visible fields must be non-empty at submit time.
Text and textarea fields enforce maxLength / minLength on both client and server.
Email fields are validated against a standard email regex.
Custom pattern regexes are client-side only — the server accepts the value as-is.
Intercept validation failures with the onValidationError callback.