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A validator is a Markdown checklist written for an AI coding agent. You give it to the agent that works in your repository, and the agent reads your code against every check in the list. For each check it reports PASS, FAIL or N/A, quotes the file and line that proves the result, and explains what breaks and how to fix it. Validators are read-only. The agent searches and reads your code and changes nothing unless you ask it to. These validators are for headless integrations, where your own front end or app talks to Yuno. Stores on the standard plugin flow described in Set up Yuno on VTEX do not need them. Every store with custom checkout CSS or JS should run the upgrade check.

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What to run

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Who runs what

  • Merchant developers run the validator that matches their storefront or app in their own repository, and the upgrade check scanner on their custom checkout files.
  • Technical account managers run the upgrade check console snippet on the live checkout of a store, run the scanner on files the merchant shares, and run a validator when they review a merchant’s repository with them.

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Run a validator with Claude Code

1

Save the validator in your repository root

2

Ask Claude Code to validate

3

Read the report

Claude Code answers with one line per check and a list of failures ordered by impact, each with a one-line fix.
If your repository already has a CLAUDE.md or AGENTS.md, do not overwrite it. Save the validator under another name, such as yuno-validator.md, and ask the agent to validate your integration following that file.

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Run a validator with Cursor, Codex or Copilot

Save the validator as AGENTS.md in the repository root and ask the agent to validate your Yuno integration following AGENTS.md. You can also paste the whole file into the chat as the prompt.

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When a check fails

Fix the failures in the order the report lists them. If you need help from Yuno support or your technical account manager, send:
  • The full validator report.
  • The diagnostics listed in the “Diagnostics to capture” section of the validator you ran. They include the VTEX order ID or order group, the UTC time of the attempt and the network and console errors.
Remove API keys, card data and personal data before you send anything.

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How the checks were built

The checks were derived from the SDK source code and from real support tickets. Where a validator and the public docs disagree, follow the validator. Yuno is fixing those docs pages.