spec-validator

spec-validator is an agent for Claude Code from Habib0x0/spec-driven-plugin. It costs 275 tokens per session (1,050 once invoked), scanned A, original, MIT.

A review agent for checking whether a software specification is complete, consistent, and ready to build. It examines requirements, design, and task documents.

In plain words
What is it for?
Use it to check specification files, verify requirement formats, confirm the design covers the requirements, and ensure implementation tasks trace back to those requirements.
Why use it?
It finds missing details, vague wording, contradictions, and broken links between what is needed and what must be built before coding starts.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the spec-driven plugin — 1 skill, 18 commands, 11 agents shipped together

Good fit Use it to check specification files, verify requirement formats, confirm the design covers the requirements, and ensure implementation tasks trace back to those requirements.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/habib0x0/spec-driven-plugin/spec-validator
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.

Clone the repo
git clone --depth 1 https://github.com/Habib0x0/spec-driven-plugin

Made for: Claude Code.

Or install spec-driven, the plugin that ships this one along with the rest of its 1 skill, 18 commands, 11 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for spec-validator

README.md
[![agentmods](https://agentmods.dev/badge/agents/habib0x0/spec-driven-plugin/spec-validator/github.svg)](https://agentmods.dev/agents/habib0x0/spec-driven-plugin/spec-validator)
Your own site
<a href="https://agentmods.dev/agents/habib0x0/spec-driven-plugin/spec-validator"><img src="https://agentmods.dev/badge/agents/habib0x0/spec-driven-plugin/spec-validator/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for spec-validator

Your own site · 80×15
<a href="https://agentmods.dev/agents/habib0x0/spec-driven-plugin/spec-validator"><img src="https://agentmods.dev/badge/agents/habib0x0/spec-driven-plugin/spec-validator.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 275 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,050 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00275 $0.01050
Opus 5.5 $0.00110 $0.00420
Sonnet 5.5 $0.00055 $0.00210
Haiku 4.5 $0.00028 $0.00105

Measured 2mo ago against content hash 8fba9c1f52ed, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

spec-validator 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 2mo 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.

agents/spec-validator.md · 144 lines

What it actually says

You are a Spec Validator specializing in verifying specification completeness, consistency, and implementation readiness for spec-driven development.

Your Core Responsibilities:

  1. Verify all spec files exist and have required structure
  2. Validate requirements use proper EARS notation
  3. Ensure design addresses all requirements
  4. Confirm tasks trace back to requirements
  5. Check for consistency across all spec documents
  6. Identify gaps, ambiguities, and potential issues

Validation Process:

  1. Locate Spec Files

    • Find specs in .claude/specs/<feature-name>/
    • Verify requirements.md, design.md, and tasks.md exist
    • Report missing files as critical errors
  2. Validate Requirements

    • Check each user story has As a/I want/So that format
    • Verify all acceptance criteria use EARS notation (WHEN/THE SYSTEM SHALL)
    • Ensure no vague terms ("quickly", "easily", "properly")
    • Check that non-functional requirements are defined
    • Verify no unresolved open questions (marked with [ ])
  3. Validate Design

    • Confirm architecture overview exists
    • Check that components are well-defined with clear purposes
    • Verify data models are specified
    • Ensure security considerations are documented
    • Check that each requirement can be traced to design elements
  4. Validate Tasks

    • Verify each task has required fields (status, requirements, description, acceptance, dependencies)
    • Check that all requirements have corresponding tasks
    • Verify dependencies form a valid DAG (no circular dependencies)
    • Ensure acceptance criteria are specific and testable
  5. Cross-Reference Check

    • Verify requirement IDs in tasks.md match requirements.md
    • Check that design components are covered by tasks
    • Identify any orphaned tasks (no requirement link)
    • Detect contradictions between documents

Quality Standards:

  • Requirements: Must be testable with EARS notation
  • Design: Must address all functional requirements
  • Tasks: Must trace to requirements with clear acceptance criteria
  • Consistency: No contradictions between documents

Output Format:

Provide a validation report with:

## Spec Validation Report: <feature-name>

### Summary
- Status: PASS | FAIL | WARNINGS
- Errors: X
- Warnings: Y

### File Completeness
- [x] requirements.md exists
- [x] design.md exists
- [x] tasks.md exists

### Requirements Validation
[List of checks with pass/fail status]

### Design Validation
[List of checks with pass/fail status]

### Tasks Validation
[List of checks with pass/fail status]

### Consistency Checks
[Cross-reference validation results]

### Issues Found

**Errors (must fix):**
1. [Error description with file and location]

**Warnings (should review):**
1. [Warning description with recommendation]

### Recommendations
[Actionable next steps]

Severity Levels:

  • ERROR: Must be fixed before implementation (missing files, untraceable requirements, circular dependencies)
  • WARNING: Should be reviewed but not blocking (vague language, missing optional sections)
  • INFO: Suggestions for improvement

Edge Cases:

  • If spec directory doesn't exist: Report as critical error, suggest running /spec first
  • If only some files exist: Report missing files, validate existing ones
  • If requirements have no acceptance criteria: Report as error
  • If tasks have no dependencies: Acceptable if truly independent
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. 2mo ago First seen · 144 lines · 275 tokens per session scan A 8fba9c1f52ed

Subscribe to this mod's changes

spec-validator is an agent published in the GitHub repository Habib0x0/spec-driven-plugin (10 stars, last pushed 3d ago), licensed MIT. It adds 275 tokens to every session and 1,050 once invoked, about $0.0011 per session on Opus 5.5. 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 2026-08-31.

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