How to attach SKU to Product via BigCommerce API; The field 'product_option_id' is invalid - ruby

Question

I've been banging my head against this for a while so am hoping someone can help. Ruby/HTTParty/BigCommerce Gem (where it works).
Error is: The field 'product_option_id' is invalid ; when trying to add an SKU via
myresponse = HTTParty.post("#{#store_url}products/800/skus",
:body=>{
:sku => "111204",
:options => [
{
:product_option_id => 16,
:option_value_id => 46
}
]
}.to_json,
:headers => {'Content-Type' => 'application/json' },
:basic_auth => #auth)
Basically I can't see/figure out where 'product_option_id' is referring to; you can't directly link options to products via the API that I can see.
There are two other questions on SO re this issue but neither had useful answers for me.
Prior to this, I've;
Created a product; id is 800, sku is 111240P. Response to \products?sku=111240P is
{"id"=>"800", "keyword_filter"=>"NULL", "name"=>"Opaque Thigh High", "type"=>"physical", "sku"=>"111204P", "description"=>"Opaque nylon thigh high.", "search_keywords"=>nil, "availability_description"=>nil, "price"=>"3.8200", "cost_price"=>"2.1800", "retail_price"=>"0.0000", "sale_price"=>"0.0000", "calculated_price"=>"3.8200", "sort_order"=>"0", "is_visible"=>"true", "is_featured"=>"false", "related_products"=>"NULL", "inventory_level"=>"0", "inventory_warning_level"=>"0", "warranty"=>"NULL", "weight"=>"0.1000", "width"=>"4.0000", "height"=>"0.2500", "depth"=>"8.0000", "fixed_cost_shipping_price"=>"0.0000", "is_free_shipping"=>"false", "inventory_tracking"=>"simple", "rating_total"=>"0", "rating_count"=>"0", "total_sold"=>"0", "date_created"=>"Sat, 27 Sep 2014 11:45:14 +0000", "brand_id"=>"135", "view_count"=>"0", "page_title"=>nil, "meta_keywords"=>"NULL", "meta_description"=>"NULL", "layout_file"=>"product.html", "is_price_hidden"=>"false", "price_hidden_label"=>nil, "categories"=>{"value"=>"2"}, "date_modified"=>"Sat, 27 Sep 2014 11:45:14 +0000", "event_date_field_name"=>nil, "event_date_type"=>"none", "event_date_start"=>nil, "event_date_end"=>nil, "myob_asset_account"=>nil, "myob_income_account"=>nil, "myob_expense_account"=>nil, "peachtree_gl_account"=>nil, "condition"=>"New", "is_condition_shown"=>"true", "preorder_release_date"=>nil, "is_preorder_only"=>"false", "preorder_message"=>nil, "order_quantity_minimum"=>"0", "order_quantity_maximum"=>"0", "open_graph_type"=>"product", "open_graph_title"=>nil, "open_graph_description"=>nil, "is_open_graph_thumbnail"=>"true", "upc"=>"714718006338", "date_last_imported"=>nil, "option_set_id"=>"NULL", "tax_class_id"=>"0", "option_set_display"=>"right", "bin_picking_number"=>nil, "custom_url"=>"/Opaque-Thigh-High/", "primary_image"=>{"id"=>"0", "zoom_url"=>"NULL", "thumbnail_url"=>"NULL", "standard_url"=>"NULL", "tiny_url"=>"NULL"}, "availability"=>"available", "brand"=>{"link"=>{"content"=>"/brands/135", "rel"=>"resource", "href"=>"https://store-w1w68tq.mybigcommerce.com/api/v2/brands/135.xml"}}, "downloads"=>{"link"=>{"content"=>"/products/800/downloads", "rel"=>"resource", "href"=>"https://store-w1w68tq.mybigcommerce.com/api/v2/products/800/downloads.xml"}}, "images"=>{"link"=>{"content"=>"/products/800/images", "rel"=>"resource", "href"=>"https://store-w1w68tq.mybigcommerce.com/api/v2/products/800/images.xml"}}, "discount_rules"=>{"link"=>{"content"=>"/products/800/discountrules", "rel"=>"resource", "href"=>"https://store-w1w68tq.mybigcommerce.com/api/v2/products/800/discountrules.xml"}}, "configurable_fields"=>{"link"=>{"content"=>"/products/800/configurablefields", "rel"=>"resource", "href"=>"https://store-w1w68tq.mybigcommerce.com/api/v2/products/800/configurablefields.xml"}}, "custom_fields"=>{"link"=>{"content"=>"/products/800/customfields", "rel"=>"resource", "href"=>"https://store-w1w68tq.mybigcommerce.com/api/v2/products/800/customfields.xml"}}, "videos"=>{"link"=>{"content"=>"/products/800/videos", "rel"=>"resource", "href"=>"https://store-w1w68tq.mybigcommerce.com/api/v2/products/800/videos.xml"}}, "skus"=>{"link"=>{"content"=>"/products/800/skus", "rel"=>"resource", "href"=>"https://store-w1w68tq.mybigcommerce.com/api/v2/products/800/skus.xml"}}, "rules"=>{"link"=>{"content"=>"/products/800/rules", "rel"=>"resource", "href"=>"https://store-w1w68tq.mybigcommerce.com/api/v2/products/800/rules.xml"}}, "option_set"=>"NULL", "options"=>{"link"=>{"content"=>"/products/800/options", "rel"=>"resource", "href"=>"https://store-w1w68tq.mybigcommerce.com/api/v2/products/800/options.xml"}}, "tax_class"=>{"link"=>{"content"=>"/taxclasses/0", "rel"=>"resource", "href"=>"https://store-w1w68tq.mybigcommerce.com/api/v2/taxclasses/0.xml"}}}},
Created Options and Option Values; The option is called 'Color', id of 25, and the values I want to add to the Option set are; Green (id 46), Black (id 45) and Red (id 44)
HTTParty.get("#{#store_url}options/25", :basic_auth => #auth)
=> #{"id"=>"25", "name"=>"Color", "display_name"=>"Color", "type"=>"RT", "values"=>{"link"=>{"content"=>"/options/25/values", "rel"=>"resource", "href"=>"https://store-w1w68tq.mybigcommerce.com/api/v2/options/25/values.xml"}}}},
Option values:
HTTParty.get("#{#store_url}options/25/values", :basic_auth => #auth)
=> #{"value"=>[{"id"=>"42", "option_id"=>"25", "label"=>"Gold", "sort_order"=>"0", "value"=>"Gold"}, {"id"=>"43", "option_id"=>"25", "label"=>"Silver", "sort_order"=>"0", "value"=>"Silver"}, {"id"=>"44", "option_id"=>"25", "label"=>"Red", "sort_order"=>"0", "value"=>"Red"}, {"id"=>"45", "option_id"=>"25", "label"=>"Black", "sort_order"=>"0", "value"=>"Black"}, {"id"=>"46", "option_id"=>"25", "label"=>"Green", "sort_order"=>"0", "value"=>"Green"}, {"id"=>"47", "option_id"=>"25", "label"=>"White", "sort_order"=>"0", "value"=>"White"}]}}
Created an option set called '111240P'; its id is 26
api.create_optionset(:name=>"111204P")
{"id"=>26, "name"=>"111204P", "options"=>{"url"=>"https://store-w1w68tq.mybigcommerce.com/api/v2/optionsets/26/options.json", "resource"=>"/optionsets/26/options"}}
Linked the Options to the Option Set via;
new_option_set_value = api.create_optionset_option(26, options={
:option_id => 25,
:display_name => "Colors",
:sort_order => 1,
:is_required => true
})
which returns
{"id"=>16, "option_id"=>25, "option_set_id"=>26, "display_name"=>"Colors", "sort_order"=>1, "is_required"=>true, "option"=>{"url"=>"https://store-w1w68tq.mybigcommerce.com/api/v2/options/25.json", "resource"=>"/options/25"}, "values"=>[{"label"=>"Gold", "sort_order"=>0, "value"=>"Gold", "option_value_id"=>42}, {"label"=>"Silver", "sort_order"=>0, "value"=>"Silver", "option_value_id"=>43}, {"label"=>"Red", "sort_order"=>0, "value"=>"Red", "option_value_id"=>44}, {"label"=>"Black", "sort_order"=>0, "value"=>"Black", "option_value_id"=>45}, {"label"=>"Green", "sort_order"=>0, "value"=>"Green", "option_value_id"=>46}, {"label"=>"White", "sort_order"=>0, "value"=>"White", "option_value_id"=>47}]}
So then I go to do the SKU code at the beginning of the question and I get the error mentioned.
I've tried 16, 26, and 25 as the product option ID's without any luck.
The SKU resource is the only one I can see that allows you to tie all this back to a product.
Any help greatly appreciated.
MORE INFO
HTTParty.get("#{#store_url}products/800/options", :basic_auth => #auth)
=> #<HTTParty::Response:0x10 parsed_response=nil, #response=#<Net::HTTPNoContent 204 No Content readbody=true>
CLOSING OUT THE QUESTION
After beret's advice it all works properly. Note that based on my understanding, the below is contrary to the docs.
Put call; 26 being my option_set I'm attaching to the product
myresponse = HTTParty.put("#{#store_url}products/800",
:body=>{
:option_set_id => 26
}.to_json,
:headers => {'Content-Type' => 'application/json' },
:basic_auth => #auth)
Check the options on the product:
HTTParty.get("#{#store_url}products/800/options", :basic_auth => #auth)
Response:
{"options"=>{"option"=>{"id"=>"7", "option_id"=>"25", "display_name"=>"Colors", "sort_order"=>"1", "is_required"=>"true"}}}
Go back to SKU and add it, note the 7 from the product/option;
myresponse = HTTParty.post("#{#store_url}products/800/skus",
:body=>{
:sku => "111204",
:options => [
{
:product_option_id => 7,
:option_value_id => 46
}
]
}.to_json,
:headers => {'Content-Type' => 'application/json' },
:basic_auth => #auth)
Response:
{"sku"=>{"id"=>"7", "product_id"=>"800", "sku"=>"111204", "cost_price"=>"0.0000", "upc"=>nil, "inventory_level"=>"0", "inventory_warning_level"=>"0", "bin_picking_number"=>nil, "options"=>{"option"=>{"product_option_id"=>"7", "option_value_id"=>"46"}}}}

Answer 1

product_option_id is referring to Product Option ID, see Product Option Resource (API Reference).
You should be able to get it by requesting /api/v2/products/800/options.xml
If the endpoint above returns empty content, it means, that the product has not been linked with any Option Set. You can do so, by updating the product via PUT request to /api/v2/products/800 with payload like this:
{ "option_set_id": 14 }
If you are not sure what's the option_set_id, checkout: /api/v2/options
All these features around Options/Option Sets are very generic, which may be confusing at first, but on the other hand handy in some advanced scenarios.