# `ExAws.JSON.Codec`
[🔗](https://github.com/ex-aws/ex_aws/blob/v2.7.0/lib/ex_aws/json/codec.ex#L1)

Defines the specification for a JSON codec.

ExAws supports the use of your favorite JSON codec provided it fulfills this specification.
Poison fulfills this spec without modification, and is the default.

See the contents of `ExAws.JSON.JSX` for an example of an alternative implementation.
## Example
Here for example is the code required to make jsx comply with this spec.

In your config you would do:

    config :ex_aws,
      json_codec: ExAws.JSON.JSX

    defmodule ExAws.JSON.JSX do
      @behaviour ExAws.JSON.Codec

      @moduledoc false

      def encode!(%{} = map) do
        map |> :jsx.encode
      end

      def encode(map) do
        try do
          {:ok, encode!(map)}
        rescue
          ArgumentError -> {:error, :badarg}
        end
      end

      def decode!(string) do
        :jsx.decode(string, [:return_maps])
      end

      def decode(string) do
        try do
          {:ok, decode!(string)}
        rescue
          ArgumentError -> {:error, :badarg}
        end
      end
    end

# `decode`

```elixir
@callback decode(String.t()) :: {:ok, %{}} | {:error, %{}}
```

# `decode!`

```elixir
@callback decode!(String.t()) :: %{}
```

# `encode`

```elixir
@callback encode(%{}) :: {:ok, String.t()} | {:error, String.t()}
```

# `encode!`

```elixir
@callback encode!(%{}) :: String.t()
```

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*Consult [api-reference.md](api-reference.md) for complete listing*