---
title: "OpsinErrorCode"
description: "Every warning code opsinjs can emit."
url: "https://opsinjs.pensievelabs.org/reference/api/OpsinErrorCode"
source: "https://opsinjs.pensievelabs.org/reference/api/OpsinErrorCode.md"
section: "Reference"
kind: "reference"
---

> Elements written as `<PascalCase … />` below are opsinjs documentation
> components. Their attributes are the content: the values they render are
> generated from `tokens/*.json` and `registry/catalogue.ts` and are
> published separately at https://opsinjs.pensievelabs.org/r/index.json and under the Reference
> section.
> Nothing is missing from this page. The data simply does not live in
> the prose.

{/* GENERATED - do not edit. Source: the declaration named in the table below.
    Script: scripts/build-reference.mts. Change the doc comment on the symbol. */}

<PageTemplate kind="reference" />

## How this is generated [#how-this-is-generated]

Source: `lib/opsinjs.ts`. Script: `scripts/build-reference.mts`. Command:
`pnpm run generate`.

Everything below is copied from the symbol, so a page is improved by improving
its doc comment. The [API index](./index.mdx) says why there is a page per
symbol and what these pages still do not carry.

{/* opsinjs:generated:begin - everything below is replaced by scripts/build-reference.mts */}

## OpsinErrorCode [#opsinerrorcode]

Every warning code opsinjs can emit.

Flat, allocated in sequence, and permanent: a code is never reused, never renumbered and never removed. The union is what makes `warnOnce("OPSIN-0004")` a compile error when the code does not exist, which is the difference between a stable code and a string somebody typed.

| Kind | Declared in      |
| ---- | ---------------- |
| type | `lib/opsinjs.ts` |

```ts
export type OpsinErrorCode =
  | "OPSIN-0001"
  | "OPSIN-0002"
  | "OPSIN-0003"
  | "OPSIN-0004"
  | "OPSIN-0005"
  | "OPSIN-0006"
  | "OPSIN-0007"
  | "OPSIN-0008"
  | "OPSIN-0009"
  | "OPSIN-0010"
  | "OPSIN-0011"
  | "OPSIN-0012"
  | "OPSIN-0013"
  | "OPSIN-0014"
  | "OPSIN-0015"
  | "OPSIN-0016"
  | "OPSIN-0017"
  | "OPSIN-0018"
  | "OPSIN-0019"
  | "OPSIN-0020"
  | "OPSIN-0021"
```

{/* opsinjs:generated:end */}