validate

A read-only command that checks a software feature's specification, implementation plan, task list, and engineering principles for contradictions and missing work. It also reviews possible breaking changes, such as changes that could disrupt an existing API or data format.

In plain words
What is it for?
Use it to review project specs, plans, tasks, principles, APIs, data schemas, environment settings, test coverage, and readiness for implementation.
Why use it?
It catches inconsistencies before implementation or release and shows whether the planned tests and safeguards are sufficient. It produces a report with severity levels and a recommendation about whether to proceed.

Command for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/marcusgoll/spec-flow/validate
Clone the repo
git clone --depth 1 https://github.com/marcusgoll/Spec-Flow

Made for: Claude Code.

Per session 33 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,531 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00033 $0.02531
Opus 5 $0.00016 $0.01265
Sonnet 5 $0.00007 $0.00506
Haiku 4.5 $0.00003 $0.00253

Measured 2d ago against content hash 7ab72513b412, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

validate scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/commands/phases/validate.md · 308 lines

How it starts

The opening of the file, as written. The whole thing — 308 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Current workflow state: Auto-detected from ${BASE_DIR}/*/state.yaml

Feature spec exists: Auto-detected (epics//epic-spec.md OR specs//spec.md)

Plan exists: Auto-detected (epics//plan.md OR specs//plan.md)

Tasks exist: Auto-detected (epics//tasks.md OR specs//tasks.md)

Engineering Principles: !test -f docs/project/engineering-principles.md && echo "✅ Found" || echo "❌ Missing (run /init-project)"

Previous validation: Auto-detected from ${BASE_DIR}/*/analysis-report.md

Analyzes:

  • Spec ↔ Plan ↔ Tasks consistency
  • Constitution compliance (8 engineering principles)
  • Breaking changes (API, schema, env vars)
  • Test coverage completeness
  • Implementation readiness

Outputs:

  • analysis-report.md with CRITICAL/MAJOR/MINOR findings
  • Recommendation: PROCEED | FIX_CRITICAL | FIX_ALL

Operating constraints:

  • STRICTLY READ-ONLY — Never modify spec, plan, or tasks files
  • Constitution Authority — Constitution violations auto-CRITICAL
  • Token Efficient — Max 50 findings, aggregate overflow
  • Deterministic — Consistent finding IDs across runs

Dependencies:

  • Git repository initialized
  • spec.md, plan.md, tasks.md completed
  • Optional: docs/project/engineering-principles.md for principle validation

Step 0: WORKFLOW DETECTION

Detect workflow using centralized skill (see .claude/skills/workflow-detection/SKILL.md):

  1. Run detection: bash .spec-flow/scripts/utils/detect-workflow-paths.sh
  2. Parse JSON: Extract type, base_dir, slug from output
  3. If detection fails (exit code != 0): Use AskUserQuestion fallback
  4. Set paths:
    • Feature: SPEC_FILE="${BASE_DIR}/${SLUG}/spec.md"
    • Epic: SPEC_FILE="${BASE_DIR}/${SLUG}/epic-spec.md"
    • Common: PLAN_FILE, TASKS_FILE, REPORT_FILE all in ${BASE_DIR}/${SLUG}/

Fallback prompt (if detection fails):

  • Question: "Which workflow are you working on?"
  • Options: "Feature" (specs/), "Epic" (epics/)

Read the full file on GitHub · 308 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 308 lines · 0 tokens per session scan A 7ab72513b412

Subscribe to this mod's changes

validate is a command published in the GitHub repository marcusgoll/Spec-Flow (91 stars, last pushed 4mo ago), licensed MIT. It adds 33 tokens to every session and 2,531 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.