# Headers

Echo back the request headers your application is sending — useful for debugging authentication and proxy issues.

## Making Requests

Fetch your request headers with the `Headers` method on the `client.Utilities` service. It takes no parameters and no options, and comes in two call styles:

| Method | Return | Description |
|--------|--------|-------------|
| **`GetHeaders()`** | `(*utilities.Headers, error)` | Convenience; uses a background context and discards response metadata. |
| **`Headers(ctx)`** | `(*utilities.Headers, *response.Response, error)` | Context-aware; also returns the raw response plus rate-limit metadata. |

## Headers

```go
func (s *Service) Headers(ctx context.Context) (*utilities.Headers, *response.Response, error)
func (s *Service) GetHeaders() (*utilities.Headers, error)
```

Get the request headers your application is sending, echoed back by the unversioned `/headers/` endpoint. The returned [`Headers`](#headers-type) maps header names to the values the server received, which is useful for debugging authentication and proxy problems.

#### Parameters

- `ctx` (`context.Context`) — request context for cancellation and deadlines (context method only).

This endpoint takes no functional options.

#### Returns

- `*utilities.Headers` — the echoed [`Headers`](#headers-type).
- `*response.Response` — raw response plus rate-limit metadata (context method only).
- `error` — non-nil on request or decoding failure.

#### Notes

- Sensitive header values (such as `Authorization`) are partially redacted by the server for security.
- In the unlikely event the endpoint responds `404`, both call styles return a `nil` result and a `nil` error; with the context method the returned `*response.Response` has its `NoData` field set to `true`.

### Get (simple)

```go
package main

import (
	"fmt"
	"log"

	"github.com/MarketDataApp/sdk-go/v2/marketdata"
)

func main() {
	client, err := marketdata.NewClient() // reads MARKETDATA_TOKEN from env / .env
	if err != nil {
		log.Fatal(err)
	}
	defer client.Close()

	headers, err := client.Utilities.GetHeaders()
	if err != nil {
		log.Fatal(err)
	}
	if _, ok := headers.Headers["Authorization"]; ok {
		fmt.Println("Authorization header is being sent.")
	} else {
		fmt.Println("Authorization header is missing — check MARKETDATA_TOKEN.")
	}
}
```

#### Output

```
Authorization: Bearer 1AB...***REDACTED***
Accept-Encoding: gzip
User-Agent: sdk-go/2.0.0
Host: api.marketdata.app
```

### Context + Response

```go
package main

import (
	"context"
	"fmt"
	"log"

	"github.com/MarketDataApp/sdk-go/v2/marketdata"
)

func main() {
	client, err := marketdata.NewClient(marketdata.WithToken("YOUR_TOKEN"))
	if err != nil {
		log.Fatal(err)
	}
	defer client.Close()

	headers, resp, err := client.Utilities.Headers(context.Background())
	if err != nil {
		log.Fatal(err)
	}
	if resp.NoData || headers == nil {
		fmt.Println("No headers returned.")
		return
	}
	for name, value := range headers.Headers {
		fmt.Printf("%s: %s\n", name, value)
	}
}
```

#### Output

```
Authorization: Bearer 1AB...***REDACTED***
Accept-Encoding: gzip
User-Agent: sdk-go/2.0.0
Host: api.marketdata.app
```

## Headers {#headers-type}

```go
type Headers struct {
	Headers map[string]string `json:"headers"` // Headers maps header names to values.
}
```

`Headers` represents the request headers echoed back by the API. It is useful for debugging authentication issues.

#### Fields

- `Headers` (`map[string]string`) — a map of header name to the value the server received.

#### Methods

- `String() string` — a concise summary of all header name/value pairs, e.g. `Headers{Authorization: Bearer 1AB...***REDACTED***, Host: api.marketdata.app}`.