MCP

Reference

#	Tool	Category	Read-Only
1	`create_project`	Project Management	`false`
2	`get_project`	Project Management	`true`
3	`list_projects`	Project Management	`true`
4	`list_screens`	Screen Management	`true`
5	`get_screen`	Screen Management	`true`
6	`generate_screen_from_text`	AI Generation	`false`
7	`edit_screens`	AI Generation	`false`
8	`generate_variants`	AI Generation	`false`
9	`create_design_system`	Design Systems	`false`
10	`update_design_system`	Design Systems	`false`
11	`list_design_systems`	Design Systems	`true`
12	`apply_design_system`	Design Systems	`false`

Tools

`create_project`

Creates a new Stitch project. A project is a container for UI designs and frontend code.

Annotations

destructive

Input

{
  "type": "object",
  "properties": {
    "title": {
      "type": "string",
      "description": "Optional. The title of the project."
    }
  },
  "required": []
}

Output

Returns the created Project resource with generated name, title, and metadata.

Example Prompts

PROMPT

Create a new Stitch project called ‘Marketing Site’ Start a new design project Set up a new project for my app

`get_project`

Retrieves the details of a specific Stitch project using its project name.

Annotations

readOnly

Input

{
  "type": "object",
  "properties": {
    "name": {
      "type": "string",
      "description": "Required. Resource name. Format: `projects/{project}`. Example: `projects/4044680601076201931`"
    }
  },
  "required": ["name"]
}

Output

Returns a Project resource object.

Example Prompts

PROMPT

Get the details of project 4044680601076201931 Show me the project info What’s in my project?

`list_projects`

Lists all Stitch projects accessible to the user. By default, it lists projects owned by the user.

Annotations

readOnly

Input

{
  "type": "object",
  "properties": {
    "filter": {
      "type": "string",
      "description": "Optional. AIP-160 filter on `view` field. Supported: `view=owned` (default), `view=shared`."
    }
  },
  "required": []
}

Output

Array of Project resource objects.

Example Prompts

PROMPT

List all my Stitch projects Show me my projects List shared projects

`list_screens`

Lists all screens within a given Stitch project.

Annotations

readOnly

Input

{
  "type": "object",
  "properties": {
    "projectId": {
      "type": "string",
      "description": "Required. Project ID (e.g., '4044680601076201931'), without `projects/` prefix."
    }
  },
  "required": ["projectId"]
}

Output

Array of Screen objects.

Example Prompts

PROMPT

List all screens in project 12345 Show me the designs in this project What screens are in my project?

`get_screen`

Retrieves the details of a specific screen within a project.

Annotations

readOnly

Input

{
  "type": "object",
  "properties": {
    "name": {
      "type": "string",
      "description": "Required. Resource name. Format: `projects/{project}/screens/{screen}`"
    },
    "projectId": {
      "type": "string",
      "description": "Required (deprecated). Project ID without prefix."
    },
    "screenId": {
      "type": "string",
      "description": "Required (deprecated). Screen ID without prefix."
    }
  },
  "required": ["name", "projectId", "screenId"]
}

projectId and screenId are deprecated in favor of name (resource name format), but all three are currently required.

Output

Returns a Screen object with htmlCode, screenshot, figmaExport file references and download URLs.

Example Prompts

PROMPT

Get the details of screen abc123 in project 12345 Show me the screen info Check the status of this screen

`generate_screen_from_text`

Generates a new screen from a text prompt. This process normally takes a few minutes. Avoid retrying even when you encounter connection errors. Connection errors don’t necessarily mean failure, try using get_screen after a few minutes. If output_components contains suggestions, present them to the user. If accepted, call again with the suggestion as the new prompt.

Annotations

destructive

Input

{
  "type": "object",
  "properties": {
    "projectId": {
      "type": "string",
      "description": "Required. Project ID without prefix."
    },
    "prompt": {
      "type": "string",
      "description": "Required. Text prompt describing the screen to generate."
    },
    "deviceType": {
      "type": "string",
      "enum": ["DEVICE_TYPE_UNSPECIFIED", "MOBILE", "DESKTOP", "TABLET", "AGNOSTIC"]
    },
    "modelId": {
      "type": "string",
      "enum": ["MODEL_ID_UNSPECIFIED", "GEMINI_3_PRO", "GEMINI_3_FLASH", "GEMINI_3_1_PRO"]
    }
  },
  "required": ["projectId", "prompt"]
}

GEMINI_3_PRO is deprecated. Use GEMINI_3_1_PRO or GEMINI_3_FLASH instead.

Output

Returns generated Screen objects and SessionOutputComponent entries (text, suggestions, or design references).

Example Prompts

PROMPT

Generate a mobile login screen for project 12345 Design a dashboard page with charts and statistics Create a landing page with a hero section, features grid, and footer Build a settings page for a dark-themed app

`edit_screens`

Edits existing screens using a text prompt. Similar to generate_screen_from_text, this process normally takes a few minutes. Avoid retrying even when you encounter connection errors. Connection errors don’t necessarily mean failure, try using get_screen after a few minutes.

Annotations

destructive

Input

{
  "type": "object",
  "properties": {
    "projectId": {
      "type": "string",
      "description": "Required. Project ID without prefix."
    },
    "selectedScreenIds": {
      "type": "array",
      "items": { "type": "string" },
      "description": "Required. Screen IDs to edit, without `screens/` prefix."
    },
    "prompt": {
      "type": "string",
      "description": "Required. Edit instruction."
    },
    "deviceType": {
      "type": "string",
      "enum": ["DEVICE_TYPE_UNSPECIFIED", "MOBILE", "DESKTOP", "TABLET", "AGNOSTIC"]
    },
    "modelId": {
      "type": "string",
      "enum": ["MODEL_ID_UNSPECIFIED", "GEMINI_3_PRO", "GEMINI_3_FLASH", "GEMINI_3_1_PRO"]
    }
  },
  "required": ["projectId", "selectedScreenIds", "prompt"]
}

GEMINI_3_PRO is deprecated. Use GEMINI_3_1_PRO or GEMINI_3_FLASH instead.

Output

Returns the updated Screen objects.

Example Prompts

PROMPT

Change the button color to blue on screen abc123 Make the hero text larger and add a subtitle Add a navigation bar to these screens Switch the layout to a two-column grid

`generate_variants`

Generates design variants of existing screens.

Annotations

destructive

Input

{
  "type": "object",
  "properties": {
    "projectId": {
      "type": "string",
      "description": "Required. Project ID without prefix."
    },
    "selectedScreenIds": {
      "type": "array",
      "items": { "type": "string" },
      "description": "Required. Screen IDs to generate variants for."
    },
    "prompt": {
      "type": "string",
      "description": "Required. Text guiding variant generation."
    },
    "variantOptions": {
      "$ref": "#/$defs/VariantOptions",
      "description": "Required. Variant configuration."
    },
    "deviceType": {
      "type": "string",
      "enum": ["DEVICE_TYPE_UNSPECIFIED", "MOBILE", "DESKTOP", "TABLET", "AGNOSTIC"]
    },
    "modelId": {
      "type": "string",
      "enum": ["MODEL_ID_UNSPECIFIED", "GEMINI_3_PRO", "GEMINI_3_FLASH", "GEMINI_3_1_PRO"]
    }
  },
  "required": ["projectId", "selectedScreenIds", "prompt", "variantOptions"]
}

GEMINI_3_PRO is deprecated. Use GEMINI_3_1_PRO or GEMINI_3_FLASH instead.

`VariantOptions`

{
  "type": "object",
  "properties": {
    "variantCount": {
      "type": "integer",
      "description": "Number of variants (1–5). Default: 3."
    },
    "creativeRange": {
      "type": "string",
      "enum": ["CREATIVE_RANGE_UNSPECIFIED", "REFINE", "EXPLORE", "REIMAGINE"]
    },
    "aspects": {
      "type": "array",
      "items": {
        "type": "string",
        "enum": ["VARIANT_ASPECT_UNSPECIFIED", "LAYOUT", "COLOR_SCHEME", "IMAGES", "TEXT_FONT", "TEXT_CONTENT"]
      }
    }
  }
}

Output

Returns generated variant Screen objects.

Example Prompts

PROMPT

Generate 3 variants of screen abc123 focusing on layout and color Reimagine my landing page with radical variations Create subtle refinements of these screens Show me 5 different color schemes for this design

`create_design_system`

Creates a new design system for a project. Establishes foundational design tokens (colors, typography, shapes, appearance) that apply across all screens.

Annotations

destructive

Input

{
  "type": "object",
  "properties": {
    "designSystem": {
      "$ref": "#/$defs/DesignSystem",
      "description": "Required. The design system to create."
    },
    "projectId": {
      "type": "string",
      "description": "Optional. Project ID. If empty, creates a global (unassociated) asset."
    }
  },
  "required": ["designSystem"]
}

`DesignSystem`

{
  "type": "object",
  "properties": {
    "displayName": {
      "type": "string",
      "description": "Required. Display name."
    },
    "theme": {
      "$ref": "#/$defs/DesignTheme",
      "description": "Required. Theme configuration."
    }
  },
  "required": ["displayName", "theme"]
}

`DesignTheme`

{
  "type": "object",
  "properties": {
    "colorMode": { "type": "string", "enum": ["COLOR_MODE_UNSPECIFIED", "LIGHT", "DARK"] },
    "headlineFont": { "type": "string", "enum": ["FONT_UNSPECIFIED", "INTER", "DM_SANS", "GEIST", "..."] },
    "bodyFont": { "type": "string", "enum": ["FONT_UNSPECIFIED", "INTER", "DM_SANS", "GEIST", "..."] },
    "labelFont": { "type": "string", "enum": ["FONT_UNSPECIFIED", "INTER", "DM_SANS", "GEIST", "..."] },
    "roundness": { "type": "string", "enum": ["ROUNDNESS_UNSPECIFIED", "ROUND_FOUR", "ROUND_EIGHT", "ROUND_TWELVE", "ROUND_FULL"] },
    "customColor": { "type": "string", "description": "Required. Hex color seed for the dynamic color system." },
    "colorVariant": { "type": "string", "enum": ["COLOR_VARIANT_UNSPECIFIED", "MONOCHROME", "NEUTRAL", "TONAL_SPOT", "VIBRANT", "EXPRESSIVE", "FIDELITY", "CONTENT", "RAINBOW", "FRUIT_SALAD"] },
    "overridePrimaryColor": { "type": "string", "description": "Optional. Override primary color (hex)." },
    "overrideSecondaryColor": { "type": "string", "description": "Optional. Override secondary color (hex)." },
    "overrideTertiaryColor": { "type": "string", "description": "Optional. Override tertiary color (hex)." },
    "overrideNeutralColor": { "type": "string", "description": "Optional. Override neutral color (hex)." },
    "designMd": { "type": "string", "description": "Optional. Markdown design instructions." }
  },
  "required": ["colorMode", "headlineFont", "bodyFont", "roundness", "customColor"]
}

Output

Returns the created design system Asset.

Example Prompts

PROMPT

Create a dark mode design system with Inter font and round corners Set up a design system with blue as the primary color Create a brand identity with Geist font and minimal roundness

`update_design_system`

Updates an existing design system. Identifies the asset by its name field.

Annotations

destructive

Input

{
  "type": "object",
  "properties": {
    "name": {
      "type": "string",
      "description": "Required. Resource name. Format: `assets/{asset}`. Example: `assets/15996705518239280238`"
    },
    "projectId": {
      "type": "string",
      "description": "Required. Project ID without prefix."
    },
    "designSystem": {
      "$ref": "#/$defs/DesignSystem",
      "description": "Required. The updated design system content."
    }
  },
  "required": ["name", "projectId", "designSystem"]
}

Uses the same DesignSystem and DesignTheme schemas as create_design_system.

Output

Returns the updated design system Asset.

Example Prompts

PROMPT

Update the design system to use dark mode Change the font to Geist in our design system Update the roundness to fully rounded

`list_design_systems`

Lists all design systems for a project (or global design systems if no projectId).

Annotations

readOnly

Input

{
  "type": "object",
  "properties": {
    "projectId": {
      "type": "string",
      "description": "Optional. Project ID. If empty, lists global design systems."
    }
  },
  "required": []
}

Output

Array of Asset objects containing design systems.

Example Prompts

PROMPT

List all design systems in project 12345 Show me the available design systems What design systems do I have?

`apply_design_system`

Applies a design system to one or more screens, modifying their appearance to match the system’s tokens (colors, fonts, shapes).

Annotations

destructive

Input

{
  "type": "object",
  "properties": {
    "projectId": {
      "type": "string",
      "description": "Required. Project ID without prefix."
    },
    "selectedScreenInstances": {
      "type": "array",
      "items": { "$ref": "#/$defs/SelectedScreenInstance" },
      "description": "Required. Screen instances to update (from `get_project`)."
    },
    "assetId": {
      "type": "string",
      "description": "Required. Design system asset ID (from `list_design_systems`), without `assets/` prefix."
    }
  },
  "required": ["projectId", "selectedScreenInstances", "assetId"]
}

`SelectedScreenInstance`

{
  "type": "object",
  "properties": {
    "id": {
      "type": "string",
      "description": "Required. The screen instance ID (NOT the source screen ID). Available from `get_project`."
    },
    "sourceScreen": {
      "type": "string",
      "description": "Required. Resource name. Format: `projects/{project}/screens/{screen}`"
    }
  },
  "required": ["id", "sourceScreen"]
}

Output

Returns the updated Screen objects.

Example Prompts

PROMPT

Apply the blue design system to all screens in project 12345 Restyle these screens with the brand identity Use design system abc to update my screens

Shared Types

`Screen`

A generated screen design within a Stitch project.

Field	Type	Description
`name`	`string`	Resource name. Format: `projects/{project}/screens/{screen}`
`id`	`string`	(Deprecated) The screen id.
`title`	`string`	Title of the screen.
`prompt`	`string`	Prompt used to generate the screen.
`screenshot`	`File`	Screenshot image of the screen.
`htmlCode`	`File`	HTML code of the screen.
`figmaExport`	`File`	Figma export of the screen.
`theme`	`DesignTheme`	Theme used for generation.
`deviceType`	`DeviceType`	Device type.
`screenType`	`ScreenType`	Screen type.
`screenMetadata`	`ScreenMetadata`	Metadata (agent, status, display mode).
`width`	`string`	Width of the screen.
`height`	`string`	Height of the screen.
`groupId`	`string`	Group id for related screens (e.g., variants).
`groupName`	`string`	Display name of the group.
`generatedBy`	`string`	Generator identifier.
`isCreatedByClient`	`boolean`	`true` if created via API upload, `false` if by agents.

`File`

Field	Type	Description
`name`	`string`	Resource name. Format: `projects/{project}/files/{file}`
`downloadUrl`	`string`	URL for download. FIFE base URL for images.
`mimeType`	`string`	E.g., `"image/png"`, `"text/html"`.
`fileContentBase64`	`string`	(Write-only) Base64-encoded content for uploads.
`uploadBlobId`	`string`	BlobId from upload service.
`userFeedback`	`UserFeedback`	(Read-only) Latest feedback.

`DesignSystem`

Represents visual/functional design guidelines used to generate consistent, branded designs.

Field	Type	Description
`displayName`	`string`	Display name of the design system.
`theme`	`DesignTheme`	Theme configuration.

`Asset`

Wrapper for design system resources (used by update_design_system).

Field	Type	Description
`name`	`string`	Resource name. Format: `assets/{asset}`
`designSystem`	`DesignSystem`	The design system content.
`version`	`string`	(Read-only) Version counter. `0` = unversioned.

`DesignTheme`

Field	Type	Required	Description
`colorMode`	`ColorMode`	`true`	Light or dark mode.
`headlineFont`	`Font`	`true`	Headline typography.
`bodyFont`	`Font`	`true`	Body typography.
`labelFont`	`Font`	`false`	Label typography.
`roundness`	`Roundness`	`true`	Corner roundness.
`customColor`	`string`	`true`	Seed color for dynamic color system (hex, e.g., `"#ff0000"`).
`colorVariant`	`ColorVariant`	`false`	Dynamic color system variant.
`overridePrimaryColor`	`string`	`false`	Override primary color (hex).
`overrideSecondaryColor`	`string`	`false`	Override secondary color (hex).
`overrideTertiaryColor`	`string`	`false`	Override tertiary color (hex).
`overrideNeutralColor`	`string`	`false`	Override neutral color (hex).
`designMd`	`string`	`false`	Markdown design instructions.

`ScreenMetadata`

Field	Type	Description
`agentType`	`AgentTypeEnum`	`TURBO_AGENT`, `PRO_AGENT`, `IMAGE_AGENT`, `GENIE_AGENT`, `IMAGE_PRO_AGENT`, `HATTER_AGENT`, `GEMINI_3_AGENT`
`status`	`ScreenStatusEnum`	`IN_PROGRESS`, `COMPLETE`, `FAILED`
`statusMessage`	`string`	Human-readable status from agent.
`displayMode`	`DisplayModeEnum`	`SCREENSHOT`, `HTML`, `CODE`, `MARKDOWN`, `STICKY_NOTE`
`isRemixed`	`boolean`	Whether screen was created from a remix.
`componentRegions`	`ComponentRegion[]`	Component region annotations.

`SessionOutputComponent`

Returned from generation tools in output_components.

Field	Type	Description
`text`	`string`	Agent text response.
`suggestion`	`string`	Suggested follow-up for the user.
`design`	`Design`	Generated design reference.

`UserFeedback`

Field	Type	Description
`rating`	`string`	`POSITIVE` or `NEGATIVE`.
`comment`	`string`	Additional comment.
`designFeedbackReason`	`string`	`DESIGN_DOESNT_MATCH_PROMPT`, `EDIT_DOESNT_MATCH_PROMPT`, `COMPONENT_ISSUE`, `INCORRECT_THEME`, etc.

`VariantOptions`

Field	Type	Description
`variantCount`	`integer`	Variants to generate (1–5). Default: 3.
`creativeRange`	`CreativeRange`	Creative freedom level.
`aspects`	`VariantAspect[]`	Aspects to focus on.

`SelectedScreenInstance`

Used by apply_design_system.

Field	Type	Required	Description
`id`	`string`	`true`	Screen instance ID (from `get_project`), not the source screen ID.
`sourceScreen`	`string`	`true`	Resource name. Format: `projects/{project}/screens/{screen}`

Enums

`DeviceType` Enum

Value	Description
`DEVICE_TYPE_UNSPECIFIED`	Unspecified.
`MOBILE`	Mobile device.
`DESKTOP`	Desktop device.
`TABLET`	Tablet device.
`AGNOSTIC`	Not tied to a device.

`ModelId` Enum

Value	Description
`MODEL_ID_UNSPECIFIED`	Unspecified.
`GEMINI_3_PRO`	(Deprecated) Gemini 3 Pro. Use `GEMINI_3_1_PRO` or `GEMINI_3_FLASH` instead.
`GEMINI_3_FLASH`	Gemini 3 Flash.
`GEMINI_3_1_PRO`	Gemini 3.1 Pro.

`ScreenType` Enum

Value	Description
`SCREEN_TYPE_UNSPECIFIED`	Defaults to `DESIGN`.
`DESIGN`	A design screen.
`IMAGE`	A pure image.
`PROTOTYPE`	A design prototype.
`DOCUMENT`	A document (e.g., PRD).
`PROTOTYPE_V2`	A design prototype v2.

`ColorMode` Enum

Value	Description
`COLOR_MODE_UNSPECIFIED`	Unspecified.
`LIGHT`	Light mode.
`DARK`	Dark mode.

`ColorVariant` Enum

Value	Description
`COLOR_VARIANT_UNSPECIFIED`	Unspecified.
`MONOCHROME`	Monochrome variant.
`NEUTRAL`	Neutral variant.
`TONAL_SPOT`	Tonal spot variant.
`VIBRANT`	Vibrant variant.
`EXPRESSIVE`	Expressive variant.
`FIDELITY`	Fidelity variant.
`CONTENT`	Content variant.
`RAINBOW`	Rainbow variant.
`FRUIT_SALAD`	Fruit salad variant.

`Font` Enum

29 supported font families:

INTER · DM_SANS · GEIST · SORA · MANROPE · LEXEND · EPILOGUE · BE_VIETNAM_PRO · PLUS_JAKARTA_SANS · PUBLIC_SANS · SPACE_GROTESK · SPLINE_SANS · WORK_SANS · MONTSERRAT · METROPOLIS · SOURCE_SANS_THREE · NUNITO_SANS · ARIMO · HANKEN_GROTESK · RUBIK · IBM_PLEX_SANS · NEWSREADER · NOTO_SERIF · DOMINE · LIBRE_CASLON_TEXT · EB_GARAMOND · LITERATA · SOURCE_SERIF_FOUR

`Roundness` Enum

Value	Description
`ROUNDNESS_UNSPECIFIED`	Unspecified.
`ROUND_TWO`	(Deprecated) Round 2.
`ROUND_FOUR`	Round 4.
`ROUND_EIGHT`	Round 8.
`ROUND_TWELVE`	Round 12.
`ROUND_FULL`	Fully rounded.

`CreativeRange` Enum

Value	Description
`CREATIVE_RANGE_UNSPECIFIED`	Unspecified.
`REFINE`	Subtle refinements, close to original.
`EXPLORE`	Balanced exploration. (Default)
`REIMAGINE`	Radical explorations.

`VariantAspect` Enum

Value	Description
`VARIANT_ASPECT_UNSPECIFIED`	Unspecified.
`LAYOUT`	Element arrangement.
`COLOR_SCHEME`	Color palette.
`IMAGES`	Image usage.
`TEXT_FONT`	Font choices.
`TEXT_CONTENT`	Text content.

MCP Annotations

MCP Annotations are metadata hints that an MCP server attaches to each tool definition to tell the client (the AI agent or host application) about the tool’s behavioral characteristics. They’re part of the MCP spec and help clients make smarter decisions about tool usage without needing to understand the tool’s implementation.

Each tool includes behavior annotations:

Annotation	Meaning
`readOnlyHint`	`true` = read-only, no mutations.
`destructiveHint`	`true` = may create/modify/delete resources.
`idempotentHint`	`true` = repeated calls produce same result.
`openWorldHint`	`true` = interacts with external systems.

How they work with tools in practice

Each tool in the Stitch MCP server declares these as part of its tool registration. For example:

list_projects has readOnlyHint: true — it just fetches data, so an agent can call it without worrying about side effects.
create_project has readOnlyHint: false, destructiveHint: true, idempotentHint: false — it mutates state, so the client should confirm with the user first.
generate_screen_from_text has destructiveHint: true and idempotentHint: false — each call creates a new screen, so retrying on a timeout could produce duplicates.

Why they matter

These are hints, not enforced rules. They allow MCP clients to:

Auto-approve read-only tools without prompting the user
Show confirmation dialogs for destructive operations
Safely retry idempotent tools on network failures
Audit external interactions when openWorldHint is true

In the Stitch server’s case, all tools have openWorldHint: false because they interact only with the Stitch backend — not arbitrary third-party services.

Reference

Tools

create_project

Input

Output

Example Prompts

get_project

Input

Output

Example Prompts

list_projects

Input

Output

Example Prompts

list_screens

Input

Output

Example Prompts

get_screen

Input

Output

Example Prompts

generate_screen_from_text

Input

Output

Example Prompts

edit_screens

Input

Output

Example Prompts

generate_variants

Input

VariantOptions

Output

Example Prompts

create_design_system

Input

DesignSystem

DesignTheme

Output

Example Prompts

update_design_system

Input

Output

Example Prompts

list_design_systems

Input

Output

Example Prompts

apply_design_system

Input

SelectedScreenInstance

Output

Example Prompts

Shared Types

Screen

File

DesignSystem

Asset

DesignTheme

ScreenMetadata

SessionOutputComponent

UserFeedback

VariantOptions

SelectedScreenInstance

Enums

DeviceType Enum

ModelId Enum

ScreenType Enum

ColorMode Enum

ColorVariant Enum

Font Enum

Roundness Enum

CreativeRange Enum

VariantAspect Enum

MCP Annotations

How they work with tools in practice

Why they matter

`create_project`

`get_project`

`list_projects`

`list_screens`

`get_screen`

`generate_screen_from_text`

`edit_screens`

`generate_variants`

`VariantOptions`

`create_design_system`

`DesignSystem`

`DesignTheme`

`update_design_system`

`list_design_systems`

`apply_design_system`

`SelectedScreenInstance`

`Screen`

`File`

`DesignSystem`

`Asset`

`DesignTheme`

`ScreenMetadata`

`SessionOutputComponent`

`UserFeedback`

`VariantOptions`

`SelectedScreenInstance`

`DeviceType` Enum

`ModelId` Enum

`ScreenType` Enum

`ColorMode` Enum

`ColorVariant` Enum

`Font` Enum

`Roundness` Enum

`CreativeRange` Enum

`VariantAspect` Enum