diff --git a/external/resources/yaml/resources.yaml b/external/resources/yaml/resources.yaml
index 56d7cf8..0588102 100644
--- a/external/resources/yaml/resources.yaml
+++ b/external/resources/yaml/resources.yaml
@@ -2418,3 +2418,149 @@ stores:
   get-entity:
     docs: "https://elasticpath.dev/docs/getting-started/api-reference"
     url: "/v2/stores/{settings}"
+custom-apis:
+  singular-name: custom-api
+  json-api-type: custom_api
+  json-api-format: "legacy"
+  docs: "https://elasticpath.dev/docs/api/commerce-extensions/custom-ap-is"
+  delete-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/delete-a-custom-api"
+    url: "/v2/settings/extensions/custom-apis/{custom_apis}"
+  create-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/create-a-custom-api"
+    url: "/v2/settings/extensions/custom-apis/"
+  update-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/update-a-custom-api"
+    url: "/v2/settings/extensions/custom-apis/{custom_apis}"
+  get-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/get-a-custom-api"
+    url: "/v2/settings/extensions/custom-apis/{custom_apis}"
+  get-collection:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/get-all-custom-apis"
+    url: "/v2/settings/extensions/custom-apis"
+  attributes:
+    name:
+      type: STRING
+      autofill: FUNC:Company
+    slug:
+      type: STRING
+    api_type:
+      type: STRING
+    description:
+      type: STRING
+      autofill: FUNC:Phrase
+    relationships.parent_apis[n].type:
+      type: ENUM:api_location,custom_api
+    relationships.parent_apis[n].id:
+      type: RESOURCE_ID:custom-apis
+custom-fields:
+  singular-name: custom-field
+  json-api-type: custom_field
+  json-api-format: "legacy"
+  docs: "https://elasticpath.dev/docs/api/commerce-extensions/custom-fields"
+  delete-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/delete-a-custom-field"
+    url: "/v2/settings/extensions/custom-apis/{custom_apis}/fields/{custom_fields}"
+  create-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/create-a-custom-field"
+    url: "/v2/settings/extensions/custom-apis/{custom_apis}/fields"
+  update-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/update-a-custom-field"
+    url: "/v2/settings/extensions/custom-apis/{custom_apis}/fields/{custom_fields}"
+  get-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/get-a-custom-field"
+    url: "/v2/settings/extensions/custom-apis/{custom_apis}/fields/{custom_fields}"
+  get-collection:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/get-all-custom-fields"
+    url: "/v2/settings/extensions/custom-apis/{custom_apis}/fields/"
+  attributes:
+    name:
+      type: STRING
+      autofill: FUNC:Company
+    slug:
+      type: STRING
+    field_type:
+      type: ENUM:string,integer,boolean,float
+    description:
+      type: STRING
+      autofill: FUNC:Phrase
+    validation.string.min_length:
+      type: INT
+    validation.string.max_length:
+      type: INT
+    validation.string.regex:
+      type: STRING
+    validation.string.allow_null_values:
+      type: BOOL
+    validation.string.unique:
+      type: ENUM:yes,no
+    validation.integer.min_value:
+      type: INT
+    validation.integer.max_value:
+      type: INT
+    validation.integer.allow_null_values:
+      type: BOOL
+    validation.boolean.allow_null_values:
+      type: BOOL
+custom-api-settings-entries:
+  singular-name: custom-api-settings-entry
+  json-api-type: custom_entry
+  json-api-format: "legacy"
+  no-wrapping: true
+  docs: "https://elasticpath.dev/docs/api/commerce-extensions/custom-api-entries"
+  delete-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/delete-a-custom-entry"
+    url: "/v2/settings/extensions/custom-apis/{custom_apis}/entries/{custom_api_setting_entries}"
+  create-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/create-a-custom-entry"
+    url: "/v2/settings/extensions/custom-apis/{custom_apis}/entries"
+  update-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/update-a-custom-entry"
+    url: "/v2/settings/extensions/custom-apis/{custom_apis}/entries/{custom_api_setting_entries}"
+  get-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/get-a-custom-entry"
+    url: "/v2/settings/extensions/custom-apis/{custom_apis}/entries/{custom_api_setting_entries}"
+  get-collection:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/get-all-custom-entries"
+    url: "/v2/settings/extensions/custom-apis/{custom_apis}/entries/"
+  attributes:
+    data.type:
+      type: STRING
+    ^data\.(.+)$:
+      type: STRING
+custom-api-extension-entries:
+  singular-name: custom-api-extension-entry
+  json-api-type: custom_entry
+  json-api-format: "legacy"
+  no-wrapping: true
+  docs: "https://elasticpath.dev/docs/api/commerce-extensions/custom-api-entries"
+  delete-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/delete-a-custom-entry"
+    url: "/v2/extensions/custom-apis/{custom_apis}/entries/{custom_api_extension_entries}"
+    parent_resource_value_overrides:
+      custom_apis: slug
+  create-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/create-a-custom-entry"
+    url: "/v2/extensions/custom-apis/{custom_apis}/entries"
+    parent_resource_value_overrides:
+      custom_apis: slug
+  update-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/update-a-custom-entry"
+    url: "/v2/extensions/custom-apis/{custom_apis}/entries/{custom_api_extension_entries}"
+    parent_resource_value_overrides:
+      custom_apis: slug
+  get-entity:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/get-a-custom-entry"
+    url: "/v2/extensions/custom-apis/{custom_apis}/entries/{custom_api_extension_entries}"
+    parent_resource_value_overrides:
+      custom_apis: slug
+  get-collection:
+    docs: "https://elasticpath.dev/docs/api/commerce-extensions/get-all-custom-entries"
+    url: "/v2/extensions/custom-apis/{custom_apis}/entries/"
+    parent_resource_value_overrides:
+      custom_apis: slug
+  attributes:
+    data.type:
+      type: STRING
+    ^data\.(.+)$:
+      type: STRING