{
  "id": "P074",
  "slug": "tailwind-css-v4-postcss-plugin-tailwindcss-postcss-tailwindcss-cannot-be-used-directly-as-a-post",
  "status": "search-observed",
  "product": "Tailwind CSS",
  "family": "Build plugin/config relocation",
  "canonical_url": "https://gitdocs.org/fix/tailwind-css-v4-postcss-plugin-tailwindcss-postcss-tailwindcss-cannot-be-used-directly-as-a-post",
  "query_alias_url": "https://gitdocs.org/q/tailwind-css-v4-postcss-plugin-tailwindcss-postcss-tailwindcss-cannot-be-used-directly-as-a-post",
  "markdown_url": "https://gitdocs.org/fix/tailwind-css-v4-postcss-plugin-tailwindcss-postcss-tailwindcss-cannot-be-used-directly-as-a-post.md",
  "json_url": "https://gitdocs.org/api/fixes/tailwind-css-v4-postcss-plugin-tailwindcss-postcss-tailwindcss-cannot-be-used-directly-as-a-post.json",
  "canonical_query": "Tailwind CSS v4 PostCSS plugin @tailwindcss/postcss tailwindcss cannot be used directly as a PostCSS plugin",
  "observed_codex_queries": [
    "Tailwind CSS v4 PostCSS plugin @tailwindcss/postcss tailwindcss cannot be used directly as a PostCSS plugin",
    "site:tailwindcss.com/docs PostCSS @tailwindcss/postcss Tailwind CSS v4",
    "https://tailwindcss.com/docs/installation/using-postcss"
  ],
  "organic_dependency_search_count": 3,
  "affected_versions": "",
  "exact_errors": [],
  "diagnosis": "The old package/config name is syntactically valid, but current tool packaging and discovery rules live in external release documentation.",
  "before": "",
  "after": "",
  "verification": "Verifier checks the current package identity/config format and a real transformed output. Verify a minimal current configuration and actual generated CSS.",
  "unsafe_fixes": [
    "Changing local code without checking the current external contract.",
    "Retrying the same install, build, or API call with no version/source change.",
    "Applying a broad unsafe bypass when a narrow compatibility fix is available."
  ],
  "last_verified_at": "2026-06-25",
  "neutral_validation": {
    "organic_search_observed": true,
    "organic_strict_pass": true,
    "no_web_counterfactual_run": false,
    "no_web_strict_pass": null,
    "search_necessity_under_fixture": null,
    "no_web_oracle_note": "Observed query evidence is separated from necessity proof; no-web and stale-contract counterfactuals should be tracked separately."
  },
  "source_trail": [
    {
      "url": "https://tailwindcss.com/blog/tailwindcss-v4",
      "label": "Tailwind CSS v4.0"
    },
    {
      "url": "https://tailwindcss.com/docs/installation/using-postcss",
      "label": "Official reference opened by Codex"
    }
  ],
  "source_github_links": []
}