{
  "slug": "vercel-flags-split-configures-weighted-flag-variants-6ad495472200",
  "title": "vercel flags split configures weighted flag variants",
  "tools": [
    "vercel"
  ],
  "tags": [
    "agent"
  ],
  "introduced_at": "2026-05-19T16:43:36.000Z",
  "announced_at": "2026-05-19T16:43:36.000Z",
  "effective_at": null,
  "date_basis": "source-publication",
  "status": "unknown",
  "how": {
    "incantation": "When configuring weighted variants for a Vercel Flag in an environment, run `vercel flags split <flag>` with the environment, bucketing attribute, and a weight for every variant. For String, Number, or JSON flags, also set the fallback variant; use `--message` to record a revision message.",
    "examples": [
      "vercel flags split <flag> --environment <environment> --by <entity.attribute> --default-variant <variant> --weight <variant>=<weight> --weight <variant>=<weight> --message \"<revision message>\"",
      "vercel flags split <flag> --environment <environment> --by <entity.attribute> --weight <variant>=<weight> --weight <variant>=<weight>"
    ],
    "gotchas": [
      "Version: 54.2.0",
      "<flag> (required): Flag slug to configure.",
      "--environment, -e (required): Selects the environment for the split.",
      "--by (required): Selects the entity attribute used for stable bucketing, in `<entity.attribute>` form. The entity and attribute must already be defined; timestamp attributes cannot be used.",
      "--weight, -w (required): Use once for every variant, in `VARIANT=WEIGHT` form. Weights are normalized as ratios; `0` excludes a variant from traffic, and at least one weight must be greater than zero.",
      "--default-variant: For String, Number, and JSON flags, chooses the fallback served when the bucketing attribute is unavailable. Boolean splits default to `false`. Accepts a variant ID or value.",
      "--message: Sets an optional revision message.",
      "Prerequisite: Define the entity and bucketing attribute in the Vercel Flags dashboard or with `vercel flags entities` before running the command.",
      "Prerequisite: In non-interactive environments, pass the required split options explicitly.",
      "The interactive flow prompts for the environment, bucketing attribute, weights, fallback variant, and revision message.",
      "A variant with weight `0` is excluded from receiving traffic."
    ]
  },
  "why_it_matters": "Configure weighted variants for a Vercel Flag in an environment during development or testing.",
  "sources": [
    "https://github.com/vercel/vercel/releases/tag/vercel%4054.2.0",
    "https://vercel.com/docs/cli/flags"
  ],
  "rank": 0.98038,
  "judge": {
    "publish": true,
    "judge_model": "codex-cli/gpt-6-luna+typesafe/jev-1.13.0",
    "prompt_version": "extract-v7+enrich-v2+judge-v2x3+jev-publish-v1"
  },
  "review_state": "approved",
  "provenance": {
    "run_id": "backfill-20261007",
    "verdict_id": "backfill-20261007:backfill-20261007-4617de423215c9d1-5:gate",
    "evidence_hash": "ef491a91010b6f737b26e0960009e573db66693d3920bb6b764c7bfc6cf30ccf"
  },
  "review": {
    "draft_hash": "57898e50ae963031322652b5e506e702a151f02e7c977762341422bf5071d5b4",
    "reviewer": "publication-gate",
    "reviewed_at": "2026-10-07T00:00:00.000Z",
    "decision": "backfill-20261007:gate",
    "reason": "3 of 3 judge runs approved with p_yes >= 0.9 (mean 0.98 >= 0.9; 2 needed) and Jev gave 0.74 (>= 0.6 needed)."
  }
}