Create new post with meta data using WordPress API

You need to register your meta field first, then you can insert / update it into a post using rest api. https://codex.wordpress.org/Function_Reference/register_meta

$object_type="post";
$args1 = array(
    'type' => 'string', 
    'description' => 'My Meta Key Description',
    'single' => true,
    'show_in_rest' => true,
    );
register_meta( $object_type, 'MyMetaKey', $args1 );

Hope it helps

Related Posts:

  1. Best way to programmatically remove a category/term from a post
  2. Is there a way to get protected meta fields through any of the available built-in WordPress APIs? (xmlrpc, wp-json)
  3. Cannot edit post meta fields with rest API
  4. Login WP – Connect single field to an external api
  5. Buik update custom field values from external API
  6. How To Save Data From Remote APIs To ACF?
  7. WordPress Rest API custom field not updating till i manually update the post
  8. Custom pages or Custom Posts
  9. Retrieve Google API JSON data and store as WordPress Custom Fields
  10. Advanced Custom Fields: how do I check to see if a value is set in an field? [closed]
  11. WP_Query – Order results by meta value
  12. Add filter menu to admin list of posts (of custom type) to filter posts by custom field values
  13. getting all values for a custom field key (cross-post)
  14. How to add a custom field in the advanced menu properties?
  15. Custom query with orderby meta_value of custom field
  16. How to filter post listing (in WP dashboard posts listing) using a custom field (search functionality)?
  17. Using meta query (‘meta_query’) with a search query (‘s’)
  18. Can I exclude a post by meta key using pre_get_posts function?
  19. Add validation and error handling when saving custom fields?
  20. Query to sort a list by meta key first (if it exists), and show remaining posts without meta key ordered by title
  21. Show Custom Fields in Quick Edit
  22. Where are custom field values stored in the database
  23. Validating Custom Meta Box Values & Required Fields
  24. Max length of meta_value
  25. Add custom fields to wp native gallery settings
  26. How to fix missing custom fields after upgrading to WordPress 4.8.1?
  27. How to enable custom fields for pages (if not a bad practice)?
  28. How can I add extra attribute in the ‘Page Attribute’ section in wp-admin for pages?
  29. Is there a way to set default custom fields when creating a post?
  30. Custom post meta field effect on the performance on the post
  31. How to get custom post meta using REST API
  32. Custom field/meta populated by dropdown of existing posts?
  33. Difference between meta keys with _ and without _ [duplicate]
  34. Is there any action filter/hook for validating a custom field before publishing the post?
  35. Remove Dimension from wp_get_attachment_image
  36. Orderby meta_value only returns posts that have existing meta_key
  37. Underscores in custom fields
  38. What is the index [0] for on post meta fields?
  39. What is “meta_input” parameter in wp_insert_post() used for?
  40. Query Posts or Get Posts by custom fields, possible?
  41. How to enable revisions for post meta data?
  42. Sortable Custom Columns in User Panel (users.php)?
  43. Any way to add custom options to Gallery Settings?
  44. The “_encloseme” Meta-Key Conundrum
  45. ORDER BY custom field value
  46. Individual Widgets per Page
  47. Add subtitle to Woocommerce product title
  48. Importing data for advanced custom fields plugin?
  49. Gutenberg add a custom metabox to default blocks
  50. SQL Query to copy value of a meta_key into another meta_key
  51. ‘Preview Changes’ for custom meta boxes?
  52. Adding a custom field to the site identity menu
  53. Using TinyMce with textareas in meta boxes on custom post types
  54. Filter WP_Query for posts having a certain meta-value
  55. How to correctly call custom field dates into a posts_where filter using SQL statements
  56. Using get_post_meta with new_to_publish
  57. Add a Jquery Datepicker to custom field in post edit
  58. add meta box – custom field : which to choose?
  59. Preserving line breaks when saving and displaying custom fields data
  60. How to return Meta data from the REST API?
  61. Advanced Custom Fields – Get custom fields from parent page
  62. Can I query custom meta data through WP_Query
  63. Add custom field to the archive page?
  64. Saving custom data for each user
  65. Is it safe to store a user setting you don’t want the user to ever modify as a user option?
  66. Tabindex on text input immediately after WordPress title input
  67. Including custom fields in search?
  68. Add custom fields to search
  69. SELECT max(meta_value) FROM wp_postmeta WHERE meta_key=’price’… stops working when value is over 999
  70. Attaching Metadata to a Taxonomy Item
  71. Add metabox to document tab in gutenberg
  72. How to display all custom fields associated with a post?
  73. How to add add_meta_box to specific Page Template?
  74. How to rename a custom field?
  75. Apply the_content filter to a custom field with multiple values
  76. Filter post listing by meta value which is a date
  77. Extra profile field as select box?
  78. Matching Serialized Arrays with meta_query
  79. How can I make wp-pagenavi work on a custom query built upon a form submission? [closed]
  80. Custom field metabox not showing in back-end
  81. Meta Query with AND & OR?
  82. Pre-filling custom fields on New Post
  83. Having different sidebar content for MANY pages?
  84. So much data in postmeta
  85. Custom search: by post data and post metadata?
  86. How to access custom order item meta data from a meta key in WooCommerce?
  87. Problem with serialized arrays in custom meta
  88. Show only posts which can be commented OR have custom meta field
  89. Add custom objects/entities to WordPress
  90. explode array within shortcode
  91. Can I count the number of users matching a value in a multiple value key?
  92. Pass all custom fields through the same filter on post load?
  93. Need small coding with Custom Fields Search
  94. Change behavior of “Insert into Post” based on attachment metadata
  95. How can I append custom data to images in the editor?
  96. Using get_posts with arguments found in meta keys
  97. Add custom fields when specific templates are selected
  98. Sort posts by custom field numeric value using dropdown
  99. Adding Custom Field to Taxonomy Input :Panel
  100. How to position a custom field before the editor
Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)