# Start a Live Activity

Up to five concurrent activities per device, including interactive activities. Distinct keys coexist. An active key owned by this requester conflicts unless replace is true; replacement affects only that key. Device capacity returns 422 ACTIVITY_CAPACITY_EXCEEDED with limit: 5. Suggested visible-character budgets, not guaranteed fit or API hard limits: proportional glyphs, device width and accessibility text size change fit. 0 means hidden. Expanded and Lock Screen subtitle replaces status on line 2; compact and small banners retain status. Omitted subtitle uses status. Overflow shares the two-line detail area with explicit detail. Compact percentage takes precedence over status when progress is supplied; terminal shows percentage or its prompt icon and never status. Expanded budgets (title/line 2/detail): standard 32/36/100; ring 32/30/80; hero 24/36/100; terminal 36/40/100; steps 32/36/100. Compact title/subtitle/detail are hidden; status budget is 8 without progress, except terminal 0.

HTML: https://notify.belweave.ai/docs/api/postActivities

Required scopes: `activities:write`

```http
POST /api/agent/activities
Authorization: Bearer ntf_your_token
```

## Operation schema

```json
{
  "summary": "Start a Live Activity",
  "description": "Up to five concurrent activities per device, including interactive activities. Distinct keys coexist. An active key owned by this requester conflicts unless replace is true; replacement affects only that key. Device capacity returns 422 ACTIVITY_CAPACITY_EXCEEDED with limit: 5. Suggested visible-character budgets, not guaranteed fit or API hard limits: proportional glyphs, device width and accessibility text size change fit. 0 means hidden. Expanded and Lock Screen subtitle replaces status on line 2; compact and small banners retain status. Omitted subtitle uses status. Overflow shares the two-line detail area with explicit detail. Compact percentage takes precedence over status when progress is supplied; terminal shows percentage or its prompt icon and never status. Expanded budgets (title/line 2/detail): standard 32/36/100; ring 32/30/80; hero 24/36/100; terminal 36/40/100; steps 32/36/100. Compact title/subtitle/detail are hidden; status budget is 8 without progress, except terminal 0.",
  "operationId": "postActivities",
  "security": [
    {
      "bearer": [
        "activities:write"
      ]
    }
  ],
  "x-notify-scopes": [
    "activities:write"
  ],
  "parameters": [
    {
      "name": "Idempotency-Key",
      "in": "header",
      "schema": {
        "type": "string"
      },
      "required": false
    }
  ],
  "requestBody": {
    "required": true,
    "content": {
      "application/json": {
        "schema": {
          "type": "object",
          "properties": {
            "key": {
              "type": "string",
              "minLength": 1,
              "maxLength": 100
            },
            "replace": {
              "default": false,
              "type": "boolean"
            },
            "title": {
              "type": "string",
              "minLength": 1,
              "maxLength": 80,
              "description": "Task title on line 1. Suggested character budgets: standard: compact 0, expanded 32; ring: compact 0, expanded 32; hero: compact 0, expanded 24; terminal: compact 0, expanded 36; steps: compact 0, expanded 32. Suggested visible-character budgets, not guaranteed fit or API hard limits: proportional glyphs, device width and accessibility text size change fit. 0 means hidden. Expanded and Lock Screen subtitle replaces status on line 2; compact and small banners retain status. Omitted subtitle uses status. Overflow shares the two-line detail area with explicit detail. Compact percentage takes precedence over status when progress is supplied; terminal shows percentage or its prompt icon and never status."
            },
            "subtitle": {
              "type": "string",
              "minLength": 1,
              "maxLength": 120,
              "description": "Optional full-word summary used instead of status on expanded Dynamic Island and Lock Screen line 2 only; compact and small banners retain status. Omit to use status; null clears it on update/end. Suggested character budgets: standard: compact 0, expanded 36; ring: compact 0, expanded 30; hero: compact 0, expanded 36; terminal: compact 0, expanded 40; steps: compact 0, expanded 36. Suggested visible-character budgets, not guaranteed fit or API hard limits: proportional glyphs, device width and accessibility text size change fit. 0 means hidden. Expanded and Lock Screen subtitle replaces status on line 2; compact and small banners retain status. Omitted subtitle uses status. Overflow shares the two-line detail area with explicit detail. Compact percentage takes precedence over status when progress is supplied; terminal shows percentage or its prompt icon and never status."
            },
            "status": {
              "type": "string",
              "minLength": 1,
              "maxLength": 60,
              "description": "Required task state; displayed on line 2 when subtitle is absent. Full status remains available to accessibility. Suggested character budgets: standard: compact 8, expanded 36; ring: compact 8, expanded 30; hero: compact 8, expanded 36; terminal: compact 0, expanded 40; steps: compact 8, expanded 36. Suggested visible-character budgets, not guaranteed fit or API hard limits: proportional glyphs, device width and accessibility text size change fit. 0 means hidden. Expanded and Lock Screen subtitle replaces status on line 2; compact and small banners retain status. Omitted subtitle uses status. Overflow shares the two-line detail area with explicit detail. Compact percentage takes precedence over status when progress is supplied; terminal shows percentage or its prompt icon and never status."
            },
            "detail": {
              "type": "string",
              "minLength": 1,
              "maxLength": 240,
              "description": "Additional context in the two-line detail area, sharing space with line 2 overflow. Suggested character budgets: standard: compact 0, expanded 100; ring: compact 0, expanded 80; hero: compact 0, expanded 100; terminal: compact 0, expanded 100; steps: compact 0, expanded 100. Suggested visible-character budgets, not guaranteed fit or API hard limits: proportional glyphs, device width and accessibility text size change fit. 0 means hidden. Expanded and Lock Screen subtitle replaces status on line 2; compact and small banners retain status. Omitted subtitle uses status. Overflow shares the two-line detail area with explicit detail. Compact percentage takes precedence over status when progress is supplied; terminal shows percentage or its prompt icon and never status."
            },
            "progress": {
              "type": "number",
              "minimum": 0,
              "maximum": 1
            },
            "symbol": {
              "default": "terminal",
              "type": "string",
              "enum": [
                "terminal",
                "code",
                "build",
                "success",
                "warning"
              ]
            },
            "privacyMode": {
              "default": "standard",
              "type": "string",
              "enum": [
                "standard",
                "private"
              ]
            },
            "accentColor": {
              "default": "#246BEB",
              "type": "string",
              "pattern": "^#[0-9a-fA-F]{6}$"
            },
            "style": {
              "default": "standard",
              "type": "string",
              "enum": [
                "standard",
                "ring",
                "hero",
                "terminal",
                "steps"
              ]
            },
            "deviceIds": {
              "minItems": 1,
              "maxItems": 50,
              "type": "array",
              "items": {
                "type": "string",
                "minLength": 1,
                "maxLength": 100
              }
            },
            "group": {
              "type": "string",
              "pattern": "^dgrp_[A-Za-z0-9_-]{8,64}$"
            },
            "expiresInSeconds": {
              "default": 28800,
              "type": "integer",
              "minimum": 60,
              "maximum": 28800
            },
            "staleAfterSeconds": {
              "default": 14400,
              "type": "integer",
              "minimum": 0,
              "maximum": 28800
            }
          },
          "required": [
            "title",
            "status"
          ]
        }
      }
    }
  },
  "responses": {
    "201": {
      "description": "Success",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/LiveActivityMutation"
          }
        }
      }
    },
    "400": {
      "description": "Invalid request",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/Error"
          }
        }
      }
    },
    "401": {
      "description": "Missing, unknown, revoked, or expired token",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/Error"
          }
        }
      }
    },
    "403": {
      "description": "The token lacks a required scope or the account lacks permission",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/Error"
          }
        }
      }
    },
    "404": {
      "description": "Not found for this account",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/Error"
          }
        }
      }
    }
  }
}
```

Resolve schema references against [OpenAPI](https://notify.belweave.ai/openapi.json).