Cross-Posting to Dev.to with API

Let's cross-post this blog post to Dev.to using its API.

Getting Started

We will use the Dev.to API (Version 1) to create a new article on Dev.to. The API requires an API key to authenticate the user. You can get the API key from the Dev.to settings page.

If you have obtained the API key, you can use it to authenticate the API requests via the api-key header. Let's give it a try:

$ curl -sH "api-key: MyVerySecretApiKey" https://dev.to/api/users/me | jq .
{
  "type_of": "user",
  "id": 1431,
  "username": "username480",
  "name": "Willy \"Myron\" \\:/ Herzog",
  "twitter_username": "twitter480",
  "github_username": "github480",
  "summary": null,
  "location": null,
  "website_url": null,
  "joined_at": "Apr 14, 2023",
  "profile_image": "/uploads/user/profile_image/1431/b547e3a6-5076-44dd-a4f6-9b85022b4e76.jpeg"
}

OK, we are ready. Let's create a new article on Dev.to.

Create a New Article

To create a new article, we need to send a POST request to the /articles endpoint. The payload seems to be a JSON object with the following structure:

{
  "article": {
    "title": "string",
    "body_markdown": "string",
    "published": false,
    "series": "string",
    "main_image": "string",
    "canonical_url": "string",
    "description": "string",
    "tags": "string",
    "organization_id": 0
  }
}

The tags field is documented to be a string, but it seems to be an array of strings. Let's do a dry run (published: false):

curl https://dev.to/api/articles \
    -s \
    -H "api-key: MyVerySecretApiKey" \
    -H "content-type: application/json" \
    -X POST \
    -d '{
  "article": {
    "title": "Cross-Posting to Dev.to with API",
    "body_markdown": "Example markdown content",
    "published": false,
    "tags": ["devto", "technical"],
    "canonical_url": "https://example.com/path/to/article"
  }
}'

It worked on my computer!

Scripting?

I have written a small script to automate the process. It consumes the path to the markdown file as an argument and creates a draft article on Dev.to. I am not setting tags as I would like to do it manually as per available tags on Dev.to.

#!/usr/bin/env bash

## Get the path to the Markdown file:
_path="${1}"

## Extract the title from the front-matter of the Markdown file:
_title="$(yq --front-matter=extract .title "${_path}")"

## Convert the Markdown file to target format (commonmark):
_body="$(dev-md-format "${_path}")"

## Get the filename of the Markdown file:
_filename=$(basename -- "${_path}")

## Extract the slug from the filename:
_slug="$(echo "${_filename%.*}" | cut -f 2- -d "_")"

## Build the URL for the post:
_url="https://thenegation.com/posts/${_slug}/"

## Build the payload for the API request:
_payload="$(jq \
  --null-input \
  --arg title "${_title}" \
  --arg body "${_body}" \
  --arg url "${_url}" \
  '{
    "article": {
      "title": $title,
      "body_markdown": $body,
      "published": false,
      "canonical_url": $url
    }
  }'
)"

## Make the API request:
curl \
  -sX POST \
  -H "api-key: ${THENEGATION_DEVTO_APIKEY}" \
  -H "content-type: application/json" \
  -d "${_payload}" \
  "https://dev.to/api/articles" |
  jq -r .url

For my convenience:

1. I added this script to my Nix shell with name dev-cross-post-devto.
2. I updated my .envrc file to export the THENEGATION_DEVTO_APIKEY variable.

So, now I can cross-post to Dev.to with a single command:

dev-cross-post-devto content/posts/2024-08-20_crosspost-api-devto.md