generated: '2026-08-13'
method: searched
source: >-
  https://developers.line.biz/en/reference/messaging-api/,
  https://developers.line.biz/en/docs/liff/,
  https://github.com/line/liff-mock and the validate* operations declared in
  openapi/line-messaging-api-openapi.yml
description: >-
  LINE publishes no separate test-mode environment, no sandbox host and no test
  credentials. There is one set of hosts (api.line.me), one kind of credential
  (a real channel access token for a real LINE Official Account), and a message
  sent in development is a message actually delivered to a real LINE user.
  What LINE does publish instead is a dry-run and simulation layer: server-side
  validators that check a payload without spending message quota, a webhook
  test trigger, a client-side mock for LIFF, and a hosted design simulator.
test_environment:
  separate_host: false
  test_mode_keys: false
  note: >-
    The nearest thing to a sandbox is an unverified LINE Official Account with
    a free Communication Plan (200 free messages per month) and a small set of
    friend accounts — LINE's documented getting-started path. There are no
    published test user IDs, test tokens or magic identifiers.
dry_run_validators:
  description: >-
    Server-side validation endpoints that accept the same body as the real send
    and return 200 or a 400 with details[], without sending anything and
    without consuming the monthly message quota.
  operations:
    - operationId: validateReply
      path: POST /v2/bot/message/validate/reply
    - operationId: validatePush
      path: POST /v2/bot/message/validate/push
    - operationId: validateMulticast
      path: POST /v2/bot/message/validate/multicast
    - operationId: validateNarrowcast
      path: POST /v2/bot/message/validate/narrowcast
    - operationId: validateBroadcast
      path: POST /v2/bot/message/validate/broadcast
    - operationId: validateRichMenuObject
      path: POST /v2/bot/richmenu/validate
    - operationId: validateRichMenuBatchRequest
      path: POST /v2/bot/richmenu/validate/batch
webhook_testing:
  operation: testWebhookEndpoint
  path: POST /v2/bot/channel/webhook/test
  description: >-
    Makes LINE send a test request to the channel's configured webhook URL and
    returns the observed HTTP status, reason and timestamp — the way to verify
    signature handling and reachability without waiting for a real user event.
  rate_limit: 60 requests per hour
client_side_mocks:
  - name: "@line/liff-mock"
    repository: https://github.com/line/liff-mock
    version: 1.0.4
    published: '2025-11-17'
    description: >-
      LIFF plugin that mocks the LIFF API surface so a LIFF app can be
      developed and tested in a normal browser, outside the LINE client.
  - name: "@line/liff-inspector"
    repository: https://github.com/line/liff-inspector
    version: 1.0.3
    published: '2025-11-17'
    description: DevTools for inspecting a LIFF app running in the LINE WebView.
  - name: "@line/liff-cli serve"
    repository: https://github.com/line/liff-cli
    description: Serves a local LIFF app over HTTPS with a public URL for in-app testing.
hosted_simulators:
  - name: Flex Message Simulator
    url: https://developers.line.biz/flex-simulator/
    description: >-
      Hosted designer and previewer for Flex Message JSON, producing the exact
      contents object the send operations accept.
  - name: LINE Bot Designer
    docs: https://developers.line.biz/en/services/bot-designer/
    description: >-
      Desktop tool for prototyping a bot conversation flow without writing
      code.
quota_observability:
  operations:
    - getMessageQuota
    - getMessageQuotaConsumption
  description: >-
    Because development consumes the same quota as production, these two
    operations are the practical guard rail — read them before a broadcast.
gaps:
  - No sandbox host or test-mode credentials.
  - No published test user IDs or magic identifiers.
  - No time simulation or fixture/trigger tooling.
  - >-
    Every development send is a live delivery to a real LINE account and counts
    against the monthly plan quota.