> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kash.bot/llms.txt
> Use this file to discover all available pages before exploring further.

# VALIDATION_FAILED

> HTTP 400 — Validation failed

**HTTP status:** 400 · **Title:** "Validation failed"

## When it fires

The request body failed Zod schema parse. One or more fields are missing, malformed, or out of range.

## Why it happens

* Required field is missing or `null`.
* Field has the wrong type (e.g., `amount` sent as a number instead of a string — we use string for arbitrary-precision USDC amounts).
* Field violates a constraint (UUID format, enum value, min/max length).
* An unknown extra field was sent — we accept extras (`.passthrough()`) so this is rarely the cause; if it is, you'll see it called out in `detail`.

## How to fix

* The `detail` field carries the path of the first offending field (e.g., `body.outcomeIndex must be a non-negative integer`).
* Cross-reference with the OpenAPI spec at `https://api.kash.bot/v1/openapi.json` — every endpoint's request body is fully typed there.
* If you're using the TS SDK, you'd have caught this client-side via `KashValidationError` before the request went out.

## Example

```json theme={null}
{
  "type": "https://docs.kash.bot/developer-docs/api-errors/VALIDATION_FAILED",
  "title": "Validation failed",
  "status": 400,
  "code": "VALIDATION_FAILED",
  "detail": "body.amount must be a string matching ^[0-9]+(\\.[0-9]+)?$",
  "instance": "/v1/trades",
  "requestId": "01HX-..."
}
```

## Related codes

* [`AMOUNT_TOO_LARGE`](./AMOUNT_TOO_LARGE.md) — specific case for `amount` exceeding the per-trade cap
* [`OUTCOME_INDEX_INVALID`](./OUTCOME_INDEX_INVALID.md) — specific case for invalid `outcomeIndex`