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/llm-judge

Use when comparing two or more code implementations against a spec or requirements doc. Triggers on \"which repo is better\", \"compare these implementations\", \"evaluate both solutions\", \"rank these codebases\", or \"judge which approach wins\". Also covers choosing between

From plugin
beagle
85139 skills2 commands

Claude Code

$ npx -y skills add existential-birds/beagle --skill llm-judge --agent claude-code

SKILL.md

llm-judge.SKILL.md
name: llm-judge
description: "Use when comparing two or more code implementations against a spec or requirements doc. Triggers on \"which repo is better\", \"compare these implementations\", \"evaluate both solutions\", \"rank these codebases\", or \"judge which approach wins\". Also covers choosing between competing PRs or vendor submissions solving the same problem. Does NOT review a single codebase for quality \u2014 use code review skills instead. Does NOT evaluate strategy docs \u2014 use strategy-review. Requires a spec file and 2+ repo paths."
disable-model-invocation: true

LLM Judge

Compare code implementations across multiple repositories using structured evaluation.

Usage

llm-judge <spec> <repo1> <repo2> [repo3...] [--labels=...] [--weights=...] [--branch=...]

Arguments

| Argument | Required | Description | |----------|----------|-------------| | `spec` | Yes | Path to spec/requirements document | | `repos` | Yes | 2+ paths to repositories to compare | | `--labels` | No | Comma-separated labels (default: directory names) | | `--weights` | No | Override weights, e.g. `functionality:40,security:30` | | `--branch` | No | Branch to compare against main (default: `main`) |

Workflow

1. Parse `$ARGUMENTS` into `spec_path`, `repo_paths`, `labels`, `weights`, and `branch`. 2. Validate the spec file, each repo path, and the minimum repo count. 3. Read the spec document into memory. 4. Load this skill and the supporting reference files. 5. Gather facts per repository (one Phase 1 unit per repo) — facts only, no scoring. 6. Validate the repo-agent JSON results before proceeding. 7. Score each dimension (one Phase 2 unit per dimension). 8. Aggregate scores, compute weighted totals, rank repos, and write the report. 9. Display the markdown summary and verify the JSON report.

Hard gates

Sequenced workflow: **do not start the next phase until the current gate passes.** Each pass condition must be checkable (file on disk, non-empty content, or `json.load` succeeds)—not “I reviewed internally.”

| Gate | Pass condition | Unblocks | |------|----------------|----------| | **A — Inputs** | `spec_path` is a readable file and non-empty; `len(repo_paths) ≥ 2`; each path contains `.git`. | Phase 1 repo agents | | **B — Phase 1 facts** | For **each** repo agent output: stdin/stdout parses as JSON; required keys/shape match `references/fact-schema.md`. | Phase 2 judge agents | | **C — Phase 2 scores** | **Five** judge outputs (one per dimension) each parse as JSON; each includes a score (and justification) for **every** repo label. | Aggregation | | **D — Report file** | `.beagle/llm-judge-report.json` exists; `python3 -c "import json; json.load(open('.beagle/llm-judge-report.json'))"` exits 0. | Markdown summary to the user | | **E — Consistency** | Summary table and verdict use the same labels, weights, and per-dimension scores as the JSON report. | Mark task complete |

Parallelism is allowed **within** a phase (all Phase 1 tasks together; all Phase 2 tasks together), but Phase 2 must not start until Gate B passes, and the user-visible summary must not precede Gate D.

Command Workflow

Step 1: Parse Arguments

Parse `$ARGUMENTS` to extract:

  • `spec_path`: first positional argument
  • `repo_paths`: remaining positional arguments (must be 2+)
  • `labels`: from `--labels` or derived from directory names
  • `weights`: from `--weights` or defaults
  • `branch`: from `--branch` or `main`

**Default Weights:**

{
  "functionality": 30,
  "security": 25,
  "tests": 20,
  "overengineering": 15,
  "dead_code": 10
}

Step 2: Validate Inputs

[ -f "$SPEC_PATH" ] || { echo "Error: Spec file not found: $SPEC_PATH"; exit 1; }

for repo in "${REPO_PATHS[@]}"; do
  [ -d "$repo/.git" ] || { echo "Error: Not a git repository: $repo"; exit 1; }
done

[ ${#REPO_PATHS[@]} -ge 2 ] || { echo "Error: Need at least 2 repositories to compare"; exit 1; }

Step 3: Read Spec Document

SPEC_CONTENT=$(cat "$SPEC_PATH") || { echo "Error: Failed to read spec file: $SPEC_PATH"; exit 1; }
[ -z "$SPEC_CONTENT" ] && { echo "Error: Spec file is empty: $SPEC_PATH"; exit 1; }

Step 4: Load the Skill

Load this **llm-judge** skill and its reference files into context.

Step 5: Phase 1 - Gather Facts Per Repo

**If the agent supports subagents**, dispatch one Phase 1 repo agent per repository in parallel; **otherwise** run the same fact-gathering steps sequentially, one repo at a time — the output is identical either way. Give each unit this brief:

You are a Phase 1 Repo Agent for the LLM Judge evaluation.

**Your Repo:** $LABEL at $REPO_PATH

**Spec Document:**
$SPEC_CONTENT

**Instructions:**
1. Load the **llm-judge** skill's references/repo-agent.md for detailed instructions
2. Follow references/fact-schema.md for the output format
3. Load the **llm-artifacts-detection** skill ([../../../beagle-core/skills/llm-artifacts-detection/SKILL.md](../../../beagle-core/skills/llm-artifacts-detection/SKILL.md), if available) for dead-code/overengineering analysis

Explore the repository and gather facts. Return ONLY valid JSON following the fact schema.

Do NOT score or judge. Only gather facts.

Collect all repo outputs into `ALL_FACTS`.

Step 6: Validate Phase 1 Results

echo "$FACTS" | python3 -c "import json,sys; json.load(sys.stdin)" 2>/dev/null || { echo "Error: Invalid JSON from $LABEL"; exit 1; }

Step 7: Phase 2 - Score Per Dimension

**If the agent supports subagents**, dispatch one judge agent per dimension (five total) in parallel; **otherwise** score each dimension sequentially — identical output. Give each unit this brief:

You are the $DIMENSION Judge for the LLM Judge evaluation.

**Spec Document:**
$SPEC_CONTENT

**Facts from all repos:**
$ALL_FACTS_JSON

**Instructions:**
1. Load the **llm-judge** skill's references/judge-agents.md for detailed instructions
2. Follow references/scoring-rubrics.m
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Questions about llm-judge.

Which coding agents can use llm-judge?
llm-judge installs in Claude Code, Codex, Cursor, Gemini CLI, GitHub Copilot, OpenCode and Windsurf with the skills CLI, using each agent's flag shown on this page. Flowy's auto-invocation, which fires a skill when your prompt matches, runs in Claude Code only.