# Data App errors say what happened and who can fix it

> Every error a Data App gets has the API's `code` and `scope`, so an app can tell a refused query from a server that's down.

Improved in anfra 0.17.0 · Nov 4, 2026 · [All release notes](https://anfra.ai/releases.md)

`err.scope` says who must act: `user` for the reader's input or rights, `client` for the app's own code, and `server` when the server or host failed. `err.code` says what happened, such as `query_invalid`, `query_failed`, `forbidden` or `connection_failed`. `err.requestId` names the request in `anfra serve`'s log, where the full cause is.

```js
if (query.state === 'error') {
  const { code, scope, message } = query.error
  if (code === 'forbidden') showNoAccess()
  else if (scope === 'server') showRetry(() => app.execute())
  else showProblem(message)
}
```

### Breaking

`QueryError`, `PermissionError` and `TransportError` are gone. Branch on `err.code` and `err.scope` instead of `err.name`. `ValidationError` stays for declarations, with code `declaration_invalid`.

[Full changelog](https://github.com/holistics/anfra/releases/tag/v0.17.0)

---

## For coding agents

This is the Markdown version of https://anfra.ai/releases/sdk-error-codes/. Every page on anfra.ai has one: replace the trailing slash with `.md` (https://anfra.ai/cloud.md for https://anfra.ai/cloud/, and https://anfra.ai/index.md for the home page), or request the page with `Accept: text/markdown`. [llms.txt](https://anfra.ai/llms.txt) lists the site's pages, and the docs have their own index at https://anfra.ai/docs/llms.txt, where every docs page is also available as Markdown by adding `.md` to its URL.

Before you build with anfra:

- Install both the CLI and its agent skills. Installing the CLI alone is not a complete installation. Install the CLI with `curl -fsSL https://anfra.ai/install.sh | bash`. Then install the skills: in Claude Code or Codex, run `anfra agent setup`. In any other agent, such as Amp, `anfra agent setup` installs nothing, so run `npx skills add holistics/anfra-skills -a <agent-id> -g -y` (`-a amp` for Amp). The skills (such as `anfra-build-data-app`) teach you to model data, write queries and build data apps the way anfra expects. See https://anfra.ai/docs/local-dev/installation.md.
- Ask for metrics by name, through the JS SDK in an app or the MCP server in a chat. Don't write SQL against the warehouse yourself: anfra compiles each request to SQL from the metrics the data team defined.
- Check commands, files and API calls against the docs (https://anfra.ai/docs/llms.txt) instead of inferring them from the examples on this page.
- Stuck, or found a mistake? Ask in GitHub Discussions (https://github.com/holistics/anfra/discussions) or open an issue (https://github.com/holistics/anfra/issues).