Format on save no longer working after latest Zed update

[secondl1ght]

Summary

Format on save no longer working after latest Zed update.

Description

This feature worked until the release today.

Steps to reproduce:

1. update Zed to today's release
2. edit a file
3. format on save is broken

Expected Behavior: File is formatted like before.
Actual Behavior: Nothing is formatted.

settings.json

{
  "format_on_save": "on",
  "prettier": {
    "allowed": false
  },
  "title_bar": {
    "show_branch_icon": false
  },
  "restore_on_startup": "last_session",
  "features": { "edit_prediction_provider": "zed" },
  "project_panel": { "folder_icons": true,
                     "default_width": 360 },
  "languages": {
    "JavaScript": {
            "formatter": [
                {
                    "code_action": "source.fixAll.eslint"
                }
            ]
        },
    "TypeScript": {
            "formatter": [
                {
                    "code_action": "source.fixAll.eslint"
                }
            ]
        },
    "TSX": {
            "formatter": [
                {
                    "code_action": "source.fixAll.eslint"
                }
            ]
        }
  },
  "formatter": {
    "external": {
      "command": "prettier",
      "arguments": ["--stdin-filepath", "{buffer_path}"]
    }
  },
  "git_panel": {
    "dock": "right"
  },
  "show_edit_predictions": false,
  "edit_predictions": {
    "mode": "subtle",
    "copilot": {
      "proxy": null,
      "proxy_no_verify": null,
      "enterprise_uri": null
    },
    "enabled_in_text_threads": false
  },
  "icon_theme": "Material Icon Theme",
  "agent": {
    "default_profile": "ask",
    "default_model": {
      "provider": "zed.dev",
      "model": "claude-sonnet-4"
    },
    "play_sound_when_agent_done": true
  },
  "minimap": {
    "show": "auto"
  },
  "git": {
    "inline_blame": {
      "enabled": false,
      "delay_ms": 0,
      "padding": 7,
      "min_column": 0,
      "show_commit_summary": false
    }
  },
  "telemetry": {
    "diagnostics": false,
    "metrics": false
  },
  "ui_font_size": 16,
  "buffer_font_size": 16,
  "theme": {
    "mode": "system",
    "light": "One Light",
    "dark": "One Dark"
  }
}

Zed Version and System Specs

Zed: v0.208.4 (Zed)
OS: Linux Wayland ubuntu 24.04
Memory: 62 GiB
Architecture: x86_64
GPU: AMD Radeon Graphics (RADV GFX1150) || radv || Mesa 25.0.7-0ubuntu0.24.04.2

[secondl1ght]

Other points:

• I clicked the "auto-fix deprecated settings" button after updating and that did not solve it.
• The Zed docs about format on save still show the settings I have here as valid, so it should be working.
• There was no instructions on how to fix this breaking change in the release notes either.

[thecrinkles]

I encounter the same issue after updating to the latest version. For me as well, the 'settings' told me there were deprecated settings (e.g. "language_overrides" that held the prettier config). I updated the settings using the "fix deprecated settings" and changed my prettier setup to correspond to the documentation, but the format on save is broken.

{
"languages": {
    "JavaScript": {
      "formatter": {
        "external": {
          "command": "prettier",
          "arguments": ["--stdin-filepath", "{buffer_path}"]
        }
      }
    },
}

[DecampsRenan]

Same issue, I also tried by forcing the formatter to use "prettier" as a formatter (instead of the default "auto")

My config:

"languages": {
    "TypeScript": {
      "format_on_save": "on",
      "formatter": [
        {
          "code_action": "source.fixAll.eslint"
        },
        "prettier",
      ]
    }
  }

And I've got the following error from zed logs:

Caused by:
    0: building prettier request
    1: Cannot format: prettier is not allowed for language Some(Language { name: LanguageName("TypeScript") })
2025-10-16T09:53:36+02:00 ERROR [project::lsp_store] Formatting failed: prettier at "xxxxx/xxx/xxxx/xxxxx" failed to format buffer: building prettier request: Cannot format: prettier is not allowed for language Some(Language { name: LanguageName("TypeScript") })
2025-10-16T09:53:36+02:00 ERROR [editor::editor] prettier at "/xxxxxxxxxx/xxxxxxxxxxxxxxx/xxxxxxxxxxxxx" failed to format buffer

It seems prettier is not allowed anymore for these languages (tested with JavaScript, TSX and TypeScript)

[colinlienard]

I got the same issue after auto-fixing deprecated settings, and adding this fixed it:

"formatter": ["prettier", { "code_action": "source.fixAll.eslint" }],
// or
"formatter": ["auto", { "code_action": "source.fixAll.eslint" }],

[foyarash]

I got the same issue after auto-fixing deprecated settings, and adding this fixed it:

"formatter": ["prettier", { "code_action": "source.fixAll.eslint" }],
// or
"formatter": ["auto", { "code_action": "source.fixAll.eslint" }],

This fixed the issue for me aswell

[cole-miller]

Thanks for the reports!

@secondl1ght @DecampsRenan @colinlienard @foyarash A couple of questions:

• Are your formatting settings all in ~/.config/zed/settings.json, or are they kept in .zed/settings.json inside your project?
• Can you share the contents of settings_backup.json from the same directory as the settings.json where your formatting settings are defined?

Also for @DecampsRenan specifically, do you have a setting for "prettier" at the top level in your settings file?

[colinlienard]

My settings are in ~/.config/zed/settings.json. Here is the backup:

settings_backup.json

// Zed settings
//
// For information on how to configure Zed, see the Zed
// documentation: https://zed.dev/docs/configuring-zed
//
// To see all of Zed's default settings without changing your
// custom settings, run `zed: open default settings` from the
// command palette
{
  "agent": {
    "play_sound_when_agent_done": true,
    "default_profile": "write",
    "default_model": {
      "provider": "zed.dev",
      "model": "claude-sonnet-4-5"
    }
  },
  "toolbar": {
    "quick_actions": false
  },
  "vim_mode": true,
  "vim": {
    "toggle_relative_line_numbers": true
  },
  "ui_font_size": 15,
  "buffer_font_size": 13,
  "theme": {
    "mode": "system",
    "light": "Vitesse Refined Light Soft",
    "dark": "Vitesse Refined Dark Soft"
  },
  "icon_theme": "Material Icon Theme",
  "buffer_font_family": "JetBrains Mono",
  "buffer_font_features": {
    "calt": false
  },
  "tab_size": 2,
  "vertical_scroll_margin": 12,
  "terminal": {
    "dock": "right"
  },
  "tabs": {
    "git_status": true,
    "show_diagnostics": "all",
    "file_icons": true
  },
  "diagnostics": {
    "include_warnings": true,
    "inline": {
      "enabled": true,
      "update_debounce_ms": 0
    }
  },
  "code_actions_on_format": {
    "source.fixAll.eslint": true
  },
  "title_bar": {
    "show_menus": false,
    "show_sign_in": true,
    "show_user_picture": true,
    "show_onboarding_banner": true,
    "show_project_items": true,
    "show_branch_icon": true
  },
  "tab_bar": {
    "show_nav_history_buttons": false,
    "show_tab_bar_buttons": false
  },
  "features": {
    "edit_prediction_provider": "zed"
  },
  "lsp": {
    "tailwindcss-language-server": {
      "settings": {
        "includeLanguages": {
          "svelte": "html"
        }
      }
    }
  },
  "file_types": {
    "JSON": [".prettierrc"],
    "Git Ignore": [".prettierignore"],
    "Git Config": [".npmrc"],
    "Markdown": ["*.mdc"]
  }
}

[foyarash]

Thanks for the reports!

@secondl1ght @DecampsRenan @colinlienard @foyarash A couple of questions:

• Are your formatting settings all in ~/.config/zed/settings.json, or are they kept in .zed/settings.json inside your project?
• Can you share the contents of settings_backup.json from the same directory as the settings.json where your formatting settings are defined?

Also for @DecampsRenan specifically, do you have a setting for "prettier" at the top level in your settings file?

My settings were in ~/.config/zed/settings.json. The backup file had the following related to formatting:

"code_actions_on_format": {
    "source.organizeImports": false,
    "source.fixAll.eslint": true
  },

This was transformed to

"formatter": [
    {
      "code_action": "source.fixAll.eslint"
    }
  ],

[cole-miller]

Thanks @colinlienard @foyarash, we've identified what broke here and are working on getting a fix out ASAP.

[secondl1ght]

@cole-miller Only using .config settings - nothing inside the project.

Here is the backup:

{
  "title_bar": {
    "show_branch_icon": false
  },
  "restore_on_startup": "last_session",
  "features": { "edit_prediction_provider": "zed" },
  "project_panel": { "folder_icons": true,
                     "default_width": 360 },
  "languages": {
    "JavaScript": {
      "code_actions_on_format": {
        "source.fixAll.eslint": true
      }
    },
    "TypeScript": {
      "code_actions_on_format": {
        "source.fixAll.eslint": true
      }
    },
    "TSX": {
      "code_actions_on_format": {
        "source.fixAll.eslint": true
      }
    }
  },
  "formatter": {
    "external": {
      "command": "prettier",
      "arguments": ["--stdin-filepath", "{buffer_path}"]
    }
  },
  "git_panel": {
    "dock": "right"
  },
  "show_edit_predictions": false,
  "edit_predictions": {
    "mode": "subtle",
    "copilot": {
      "proxy": null,
      "proxy_no_verify": null,
      "enterprise_uri": null
    },
    "enabled_in_text_threads": false
  },
  "icon_theme": "Material Icon Theme",
  "agent": {
    "default_profile": "ask",
    "default_model": {
      "provider": "zed.dev",
      "model": "claude-sonnet-4"
    },
    "play_sound_when_agent_done": true
  },
  "minimap": {
    "show": "auto"
  },
  "git": {
    "inline_blame": {
      "enabled": false,
      "delay_ms": 0,
      "padding": 7,
      "min_column": 0,
      "show_commit_summary": false
    }
  },
  "telemetry": {
    "diagnostics": false,
    "metrics": false
  },
  "ui_font_size": 16,
  "buffer_font_size": 16,
  "theme": {
    "mode": "system",
    "light": "One Light",
    "dark": "One Dark"
  }
}

[cole-miller]

We believe the issues here were caused by the most recent settings migration, which could output formatter settings that were missing the default formatting step when you had code_actions_on_format configured--that's why it was fixed for @foyarash and @colinlienard by adding auto or prettier alongside the code_actions steps.

If you're affected by this, you can get formatting back by looking in your settings (after the migration has run) for any "formatter" sections that have only code_actions steps, and inserting "auto" at the end. If you have a formatter section at the top level in your settings, you should use the value of that instead of "auto". For example:

{
    "formatter": "prettier",
    "languages": {
        "TypeScript": {
            "formatter": [
                { "code_action": "source.fixAll.eslint" }
            ]
        }
    }
}

Should become:

{
    "formatter": "prettier",
    "languages": {
        "TypeScript": {
            "formatter": [
                { "code_action": "source.fixAll.eslint" },
                "prettier"
            ]
        }
    }
}

Or if you don't have "formatter": "prettier" at the top level, it should become:

{
    "languages": {
        "TypeScript": {
            "formatter": [
                { "code_action": "source.fixAll.eslint" },
                "auto"
            ]
        }
    }

}

We will also have releases out soon that fix the migration so that it doesn't cause this issue anymore, see #40396.