# XO1515: a wasip2/wasm program reaches what its world does not have

A component runs with only the imports of its world: wasi:http/proxy for a program that calls http.serve_component, wasi:cli/command for any other. The message names the call and how the program reaches it. Only code the program can reach counts: a std function nothing calls is not in the build. (Decision 0447.)

## Example

```xo
os.fs.read(path)
```

## Fix

```xo
Remove the call from the handler's path, embed the data with `embed`, or build the program natively.
```

Run `xo explain XO1515` for this text in a terminal, or see
[section 10.6 of the specification](../../spec/core/#106-diagnostic-codes).