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FeelFlow Releases ff-dev-toolkit 1.0.0 with a Compatibility Policy

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FeelFlow released ff-dev-toolkit 1.0.0. See what the compatibility policy covers, how future releases are versioned, and how to update your settings when upgrading from 0.x.

On November 10, 2026 (JST), FeelFlow released ff-dev-toolkit 1.0.0, an open-source development plugin for Claude Code and other coding agents. Starting with 1.0.0, changes that break the compatibility contract require a new major version.

What the compatibility contract covers

The bundled PUBLIC-SURFACE.md documents the elements users can rely on and identifies internal implementation details. The contract covers the following elements. Public surface specification

  • Skill invocation names
  • Registered hook triggers and entry points
  • File and directory paths installed in the target environment and listed as part of the contract
  • FF_* environment variables that appear in public documentation and are read by the distributed toolkit
  • Environment variables without the FF_ prefix that are listed as part of the contract

Removing or renaming an element in the contract, or changing its meaning, counts as a breaking change and is recorded in the changelog. At least one minor release before removing a contracted element, the changelog will announce its removal in the next major release. The release that carries the notice will continue to accept the old name. v1.0.0 changelog

Upgrading from 0.x

FeelFlow released v1.1.0 on the same day and dropped support for legacy setting names that had left the contract before 1.0.0. If you customized settings in 0.x, check your Claude Code settings, shell configuration, and CI environment variables before upgrading. v1.1.0 release notes

  • To keep a behavior disabled, migrate the legacy setting to FF_DEV_TOOLKIT_SKIP=<key>. For example, replace FF_DEV_TOOLKIT_SKIP_UPDATE_CHECK=1 with FF_DEV_TOOLKIT_SKIP=update-check to disable update notifications. Separate multiple keys with commas.
  • For one-time approval, use the corresponding FF_<KEY>_ACK=1 variable. See the README for the available variables and keys. Settings reference

Four operations related to automatic updates or recording data (auto-update, codex-auto-update, effort-metrics, and decision-tree) stay disabled while their corresponding legacy setting has a nonempty value. v1.1.0 changelog

If you installed the plugin as ff-dev-toolkit from the public marketplace, run the following commands in order, then restart Claude Code. Update instructions

claude plugin marketplace update
claude plugin update ff-dev-toolkit@ff-dev-toolkit

If you still have the plugin installed under its former name, dev-toolkit, follow the README to reinstall it. Installation instructions

Cite this article

FeelFlow Inc. "FeelFlow Releases ff-dev-toolkit 1.0.0 with a Compatibility Policy." November 10, 2026. https://feelflow.net/en/news/2026-11-ff-dev-toolkit-v1/

This announcement is also available in Japanese.

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FeelFlow Inc.

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