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

# forwardableHeaders

```ts theme={null}
function forwardableHeaders(headers, options?): Headers;
```

Defined in: [server/httpContext.ts:138](https://github.com/PrefectHQ/fastmcp-ts/blob/main/src/server/httpContext.ts#L138)

Copy of `headers` that is safe to attach to an outbound request to another
service. Drops credentials (authorization, cookie, proxy-\*), hop-by-hop
headers, message-framing headers (host, content-length, content-type,
expect), and every `mcp-*` protocol header. Deployment-specific credential
headers are covered by `FastMCPOptions.http.redactHeaders`: they are already
absent from `ctx.http.headers`. `include` re-admits specific names.
Re-admitting 'authorization' forwards the caller's credential; the MCP spec
forbids passing the inbound token to upstream APIs, so mint your own
upstream credential instead.

## Parameters

### headers

`Headers`

### options?

#### include?

`string`\[]

## Returns

`Headers`