### start_link(opts \\ [])

Source: https://hexdocs.pm/spandex_datadog/SpandexDatadog.ApiServer.html

Starts the ApiServer with given options.

```APIDOC
## start_link(opts \\ [])

### Description
Starts the ApiServer with given options.

### Function
start_link(opts \\ [])

### Parameters
- **opts** (Keyword.t()) - Optional - Options for starting the server.

### Options
- **:http** (module()) - Optional - The HTTP module to use for sending spans to the agent. Defaults to `HTTPoison`.
- **:host** (string()) - Optional - The host the agent can be reached at. Defaults to `"localhost"`.
- **:port** (integer()) - Optional - The port to use when sending traces to the agent. Defaults to `8126`.
- **:verbose?** (boolean()) - Optional - Only to be used for debugging: All finished traces will be logged. Defaults to `false`.
- **:batch_size** (integer()) - Optional - The number of traces that should be sent in a single batch. Defaults to `10`.
- **:sync_threshold** (integer()) - Optional - The maximum number of processes that may be sending traces at any one time. This adds backpressure. Defaults to `20`.
- **:name** (atom()) - Optional - The name the GenServer should have. Currently only used for testing. Defaults to `SpandexDatadog.ApiServer`.
- **:trap_exits?** (boolean()) - Optional - Whether or not to trap exits and attempt to flush traces on shutdown, defaults to `false`. Useful if you do frequent deploys and you don't want to lose traces each deploy.

### Returns
- **on_start** (GenServer.on_start()) - The result of starting the GenServer.

```

--------------------------------

### Start SpandexDatadog.ApiServer in supervisor

Source: https://hexdocs.pm/spandex_datadog/readme.html

Configure and start the SpandexDatadog.ApiServer as a worker in your application's supervisor. Place ApiServer before other children that might send traces, such as Ecto.Repo and Phoenix.Endpoint.

```elixir
# Example configuration

# Note: You should put ApiServer before any other children in the list that
# might try to send traces before the ApiServer has started up, for example
# Ecto.Repo and Phoenix.Endpoint

spandex_opts =
  [
    host: System.get_env("DATADOG_HOST") || "localhost",
    port: System.get_env("DATADOG_PORT") || 8126,
    batch_size: System.get_env("SPANDEX_BATCH_SIZE") || 10,
    sync_threshold: System.get_env("SPANDEX_SYNC_THRESHOLD") || 100,
    http: HTTPoison
  ]

children = [
  # ...
  {SpandexDatadog.ApiServer, spandex_opts},
  MyApp.Repo,
  MyAppWeb.Endpoint,
  # ...
]

opts = [strategy: :one_for_one, name: MyApp.Supervisor]
Supvervisor.start_link(children, opts)
```

--------------------------------

### child_spec(init_arg)

Source: https://hexdocs.pm/spandex_datadog/SpandexDatadog.ApiServer.html

Returns a specification to start this module under a supervisor. See Supervisor.

```APIDOC
## child_spec(init_arg)

### Description
Returns a specification to start this module under a supervisor. See `Supervisor`.

### Function
child_spec(init_arg)

### Parameters
- **init_arg** (term) - Required - Argument passed to the child specification.

### Returns
- **spec** (Supervisor.child_spec()) - The child specification.

```

--------------------------------

### Add spandex_datadog dependency in mix.exs

Source: https://hexdocs.pm/spandex_datadog/readme.html

Add the :spandex_datadog dependency to your mix.exs file to install the package.

```elixir
def deps do
  [
    {:spandex_datadog, "~> 1.4"}
  ]
end
```

--------------------------------

### send_and_log(traces, state)

Source: https://hexdocs.pm/spandex_datadog/SpandexDatadog.ApiServer.html

Sends traces and logs the result.

```APIDOC
## send_and_log(traces, state)

### Description
Sends traces and logs the result.

### Function
send_and_log(traces, state)

### Parameters
- **traces** ([Spandex.Trace.t()]) - Required - The list of traces to send.
- **state** (SpandexDatadog.ApiServer.State.t()) - Required - The current state.

### Returns
- **:ok** (atom()) - Always returns :ok.

```

--------------------------------

### send_trace(trace, opts \\ [])

Source: https://hexdocs.pm/spandex_datadog/SpandexDatadog.ApiServer.html

Send spans asynchronously to DataDog.

```APIDOC
## send_trace(trace, opts \\ [])

### Description
Send spans asynchronously to DataDog.

### Function
send_trace(trace, opts \\ [])

### Parameters
- **trace** (Spandex.Trace.t()) - Required - The trace to send.
- **opts** (Keyword.t()) - Optional - Options for sending the trace.

### Returns
- **:ok** (atom()) - Always returns :ok.

```

--------------------------------

### inject_context(headers, span_context, opts)

Source: https://hexdocs.pm/spandex_datadog/SpandexDatadog.Adapter.html

Injects Datadog-specific HTTP headers to represent the specified SpanContext. Returns the updated headers list.

```APIDOC
## inject_context(headers, span_context, opts)

### Description
Injects Datadog-specific HTTP headers to represent the specified SpanContext.

### Function Signature
```elixir
@spec inject_context(
  [{term(), term()}],
  Spandex.SpanContext.t(),
  Spandex.Tracer.opts()
) :: [{term(), term()}]
```

### Parameters
- **headers** ([{term(), term()}]) - Required - The headers list to inject into.
- **span_context** (Spandex.SpanContext.t()) - Required - The span context to represent.
- **opts** (Spandex.Tracer.opts()) - Required - Tracer options.

### Returns
- [{term(), term()}] - The updated headers list with Datadog-specific headers injected.
```

--------------------------------

### format(span, priority, baggage)

Source: https://hexdocs.pm/spandex_datadog/SpandexDatadog.ApiServer.html

Formats a span with priority and baggage into a map.

```APIDOC
## format(span, priority, baggage)

### Description
Formats a span with priority and baggage into a map.

### Function
format(span, priority, baggage)

### Parameters
- **span** (Spandex.Span.t()) - Required - The span to format.
- **priority** (integer()) - Required - The priority value.
- **baggage** (Keyword.t()) - Required - The baggage keywords.

### Returns
- **map** (map()) - The formatted map.

```

--------------------------------

### distributed_context(conn, opts)

Source: https://hexdocs.pm/spandex_datadog/SpandexDatadog.Adapter.html

Fetches the Datadog-specific conn request headers if they are present. Returns a SpanContext or an error if no distributed trace is found.

```APIDOC
## distributed_context(conn, opts)

### Description
Fetches the Datadog-specific conn request headers if they are present.

### Function Signature
```elixir
@spec distributed_context(conn :: Plug.Conn.t(), Spandex.Tracer.opts()) ::
  {:ok, Spandex.SpanContext.t()} | {:error, :no_distributed_trace}
```

### Parameters
- **conn** (Plug.Conn.t()) - Required - The connection to fetch headers from.
- **opts** (Spandex.Tracer.opts()) - Required - Tracer options.

### Returns
- `{:ok, Spandex.SpanContext.t()}` - Success with the span context.
- `{:error, :no_distributed_trace}` - Error when no distributed trace headers are present.

### Alternative Signature
```elixir
@spec distributed_context(headers :: Spandex.headers(), Spandex.Tracer.opts()) ::
  {:ok, Spandex.SpanContext.t()} | {:error, :no_distributed_trace}
```

### Parameters (Alternative)
- **headers** (Spandex.headers()) - Required - The headers list to fetch from.
- **opts** (Spandex.Tracer.opts()) - Required - Tracer options.

### Returns (Alternative)
- `{:ok, Spandex.SpanContext.t()}` - Success with the span context.
- `{:error, :no_distributed_trace}` - Error when no distributed trace headers are present.
```

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