# Problems encoding a nested map with poison

**URL:** <https://forum.elixirforum.com/t/problems-encoding-a-nested-map-with-poison/26399>\
**Category:** Questions\
**Tags:** json, poison, troubleshooting\
**Created:** [October 28, 2019, 7:34pm UTC](https://forum.elixirforum.com/t/problems-encoding-a-nested-map-with-poison/26399 "2019-10-28T19:34:33Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![ar0lak](https://forum.elixirforum.com/letter_avatar_proxy/v4/letter/a/b2d939/32.png) [@ar0lak](https://forum.elixirforum.com/u/ar0lak)\
**Post date:** [October 28, 2019, 7:34pm UTC](https://forum.elixirforum.com/t/problems-encoding-a-nested-map-with-poison/26399/1 "2019-10-28T19:34:33Z")

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Can seem to encode this this json with Poison v4, using phoenix v1.4.1, getting error related to erlang.byte\_size(..)

Any help would be appreciated.

```plaintext
** (Mix) Could not start application tradebot: Tradebot.Application.start(:normal, []) returned an error: shutdown: failed to start child: FTX.Client
    ** (EXIT) exited in: WebSockex.call(#PID<0.344.0>, {:text, {:ok, "{\"args\":{\"key\":\"fooooobaaarrrrbazzzzzzzz\",\"sign\":\"d10b5a67a1a941ae9463a60b285ae845cdeac1b11edc7da9977bef0228b96de9\",\"time\":\"1572290285343518000\"},\"op\":[108,111,103,105,110]}"}})
        ** (EXIT) an exception was raised:
            ** (ArgumentError) argument error
                :erlang.byte_size({:ok, "{\"args\":{\"key\":\"fooooobaaarrrrbazzzzzzz\",\"sign\":\"d10b5a67a1a941ae9463a60b285ae845cdeac1b11edc7da9977bef0228b96de9\",\"time\":\"1572290285343518000\"},\"op\":[108,111,103,105,110]}"})
                (websockex) lib/websockex/frame.ex:374: WebSockex.Frame.get_payload_length_bin/1
                (websockex) lib/websockex/frame.ex:324: WebSockex.Frame.encode_frame/1
                (websockex) lib/websockex.ex:897: WebSockex.sync_send/5
                (stdlib) proc_lib.erl:249: :proc_lib.init_p_do_apply/3

```

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<div class="post-metadata">

**Author:** ![idi527](https://forum.elixirforum.com/letter_avatar_proxy/v4/letter/i/85e7bf/32.png) [@idi527](https://forum.elixirforum.com/u/idi527)\
**Post date:** [October 28, 2019, 8:08pm UTC](https://forum.elixirforum.com/t/problems-encoding-a-nested-map-with-poison/26399/2 "2019-10-28T20:08:51Z")

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👋

Seems like you are encoding it just fine, but the result is a tagged tuple, `{:ok, json}`. You can either extract the json value from the tuple or use a “bang” version of the encoding command which returns the value directly.

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<div class="post-metadata">

**Author:** ![ar0lak](https://forum.elixirforum.com/letter_avatar_proxy/v4/letter/a/b2d939/32.png) [@ar0lak](https://forum.elixirforum.com/u/ar0lak)\
**Post date:** [October 28, 2019, 8:19pm UTC](https://forum.elixirforum.com/t/problems-encoding-a-nested-map-with-poison/26399/3 "2019-10-28T20:19:24Z")

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Thanx - this worked.