@slack/web-api@8.0.0

Major Changes

• fc98c8c: Drop Node.js 18 support. The minimum supported Node.js version is now 20.

• fc98c8c: Redesigned error handling to use proper Error subclasses instead of plain objects with a code property.

  Migration: Replace if (error.code === ErrorCode.PlatformError) with if (error instanceof WebAPIPlatformError). All error classes extend a common SlackError base class (which extends Error), so you can also catch all SDK errors with if (error instanceof SlackError).

  New error class hierarchy:

  • SlackError (abstract base)
    • WebAPIPlatformError — Slack API returned ok: false
    • WebAPIRequestError — Network/transport failure (original error in cause)
    • WebAPIHTTPError — Non-200 HTTP status from Slack
    • WebAPIRateLimitedError — HTTP 429 with retryAfter seconds
    • WebAPIFileUploadInvalidArgumentsError — Invalid file upload arguments
    • WebAPIFileUploadReadFileDataError — Failed to read file data for upload

  Removed factory functions (these were internal but exported — use new with the corresponding class instead):

  • errorWithCode()
  • platformErrorFromResult() → new WebAPIPlatformError(...)
  • requestErrorWithOriginal() → new WebAPIRequestError(...)
  • httpErrorFromResponse() → new WebAPIHTTPError(...)
  • rateLimitedErrorWithDelay() → new WebAPIRateLimitedError(...)

  Other breaking type changes:

  • WebAPIHTTPError.headers type changed from IncomingHttpHeaders to Record<string, string>.
  • The CodedError interface is deprecated — use instanceof checks with specific error classes instead.
  • Error .name values changed from generic 'Error' to descriptive class names (e.g., 'WebAPIPlatformError').

• fc98c8c: Replaced axios with the standard Fetch API for all HTTP transport. The following options and types have been removed from WebClientOptions:

  • agent — Use the new fetch option to provide a custom fetch implementation with proxy or keep-alive support. For proxies, prefer the built-in http.setGlobalProxyFromEnv() or NODE_USE_ENV_PROXY=1 (Node.js 24+). For advanced use cases:

    import { fetch, Agent } from "undici";
    const client = new WebClient(token, {
      fetch: (url, init) =>
        fetch(url, {
          ...init,
          dispatcher: new Agent({ keepAliveTimeout: 60_000 }),
        }),
    });

  • tls and TLSOptions — Configure TLS via a custom fetch implementation with an undici Agent, or use the NODE_EXTRA_CA_CERTS environment variable.
  • requestInterceptor and RequestInterceptor type — Wrap the fetch function to intercept or modify requests before they are sent.
  • adapter and AdapterConfig type — Use the fetch option instead.
  • RequestConfig type (was an alias for Axios' InternalAxiosRequestConfig) — Removed entirely.
  • attachOriginalToWebAPIRequestError option — Removed. The original error is now always available via the standard cause property on WebAPIRequestError.

  The dependencies axios, form-data, is-electron, and is-stream have been removed. The default fetch implementation is globalThis.fetch (available in Node.js 20+).

  New exported types for custom fetch implementations: FetchFunction, FetchResponse, FetchRequestInit, FetchHeaders.

• fc98c8c: Removed previously-deprecated API methods and their associated request/response types:

  • files.upload — Use filesUploadV2 instead (available since v6.7). The filesUploadV2 method handles the multi-step upload process automatically.
  • rtm.start — Use rtm.connect instead. The rtm.start method was deprecated by Slack in favor of the lighter-weight rtm.connect.
  • workflows.stepCompleted, workflows.stepFailed, workflows.updateStep — These methods supported the retired Steps from Apps feature (deprecated August 2023, retired September 2024). The workflows.featured.* and admin.workflows.* methods for the current Workflow Builder remain available.

Minor Changes

• fc98c8c: feat: expand app manifest types — add agent_view and assistant_view features, recent agent events (app_context_changed, assistant_thread_started, assistant_thread_context_changed), optional OAuth scopes (bot_optional/user_optional), and event metadata_subscriptions

Patch Changes

• bb49d99: fix: apply redact() to API response bodies in debug logs and recurse into nested objects, preventing tokens from leaking into logs when debug logging is enabled
• Updated dependencies [fc98c8c]
• Updated dependencies [fc98c8c]
  • @slack/logger@5.0.0
  • @slack/types@3.0.0