validate

A command for checking whether an OpenAPI or Swagger file—the document that describes an API—is valid before generating code from it.

In plain words
What is it for?
Use it to validate a local API file or web URL with the Kubb command-line tool, then decide whether to initialize or generate code.
Why use it?
It catches specification errors early and points to the faulty part when possible, before code generation fails or produces incorrect results.

Command

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/kubb-labs/kubb/validate
Clone the repo
git clone --depth 1 https://github.com/kubb-labs/kubb
Per session 18 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 187 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 $0.00018 $0.00187
Opus 5 $0.00009 $0.00093
Sonnet 5 $0.00004 $0.00037
Haiku 4.5 $0.00002 $0.00019

Measured 2d ago against content hash bd5082f4069b, 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.

tools/claude/commands/validate.md · 22 lines

What it actually says

Validate the OpenAPI/Swagger spec at $ARGUMENTS by running the kubb validate CLI in the terminal (ask for the path or URL if empty).

  1. Run validation:

    npx kubb validate <spec>
    

    The input accepts a local path or a URL.

  2. On success, confirm the spec is valid and offer to run /kubb:init or /kubb:generate.

  3. On failure, report the validation errors clearly and, where possible, point at the offending part of the spec and suggest a fix.

Validation needs @kubb/adapter-oas. If the command reports it is missing, tell the user to install it.

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 · 22 lines · 18 tokens per session scan A bd5082f4069b

Subscribe to this mod's changes

validate is a command published in the GitHub repository kubb-labs/kubb (1,788 stars, last pushed today), licensed MIT. It adds 18 tokens to every session and 187 once invoked, about $0.0001 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.