• Tech Dev NotesTech Dev Notes
Track apps
  • App Lookup
  • Compare Apps
Market movement
  • Store Charts
  • Global Rankings
  • Movers
  • Version Changelog
Visual research
  • In-app Screenshots
  • Store Screenshots
  • App Icons
Build intelligence
  • Tool Releases
  • Tech Stack
  • Developers
Tools
  • X Feature Flags
  • Grokipedia
  • Blog
  • Follow on X
Skip to content
Claude Code

Anthropic · CLI

Claude Code 2.1.170

2.1.169→2.1.170·June 13, 2026 at 4:58 AM UTC

Patch release adding support for the Fable model family (including Fable 5) along with related fallback credit handling and minor prompt refinements.

Changelog

  • [new] Added fable as a supported model option for agents, alongside the existing sonnet, opus, and haiku choices.
  • [new] Introduced environment variables for configuring a default Fable model (ANTHROPIC_DEFAULT_FABLE_MODEL and related settings) and the CLAUDE_FABLE group.
  • [changed] Updated model references in context management guidance to include Fable 5 alongside current Opus and Sonnet variants.
  • [changed] Refined several tool-use rejection and interruption messages for clarity when users decline actions.
  • [changed] Adjusted focus mode instructions to emphasize that only the final message is shown to the user.

Models & prompts

The CLI now recognizes fable as a valid model identifier when defining agents. System prompts have been updated to reference Fable 5 in the list of models that trigger automatic context compaction near the 200K window, and guidance around plan mode and read-only exploration phases has been lightly reworded.

Under the hood

New feature flags track Fable 5 launch visibility, fallback credit minting and outcomes, and related refusal handling. A new API beta header (fallback-credit-2026-06-01) accompanies these changes. The internal CLAUDE_CODE_FORCE_SESSION_PERSISTENCE flag has been removed.

Upgrade notes

No manual steps required. Existing configurations continue to work; the new Fable model is available wherever model selection is supported.

Older release← 2.1.169Newer release→ 2.1.172
All Claude Code releases →

© 2026 Tech Dev Notes

RSSAboutAPIPrivacyTermsSitemap@techdevnotes