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

# E1202 — Invalid input to host API call

> Invalid input to host API call

# E1202 — Invalid input to host API call

| Property     | Value                     |
| ------------ | ------------------------- |
| **Code**     | `1202`                    |
| **Slug**     | `E1202`                   |
| **Category** | `validation` (Validation) |

## What happened

Invalid input to host API call.

## Why it happened

An argument passed to a host API function has the wrong shape — most commonly an address that is not exactly 20 bytes.

## How to fix

Check argument shapes against the target actor's schema. Ensure addresses are 20-byte values.

## Receipt example

```json theme={null}
{
  "code": 1202,
  "slug": "E1202",
  "category": "validation",
  "what": "Invalid input to host API call",
  "fix": "Check argument shapes against the target actor's schema.",
  "docs_url": "https://docs.cowboy.inc/errors/E1202"
}
```

***

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