Social Auto Poster#

Cross-platform publishing skill for LinkedIn, X/Twitter, Facebook, WordPress, and Substack. Covers one-time setup, image creation, ARM upload, text entry, and post verification for each platform.

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Prerequisites — One-Time Setup#

Complete these steps once before using this skill for the first time.

1. Browser Login (LinkedIn, X, Facebook, Substack)#

These four platforms use browser session authentication. You must log in manually once and keep the browser session alive.

text

browser start
navigate linkedin.com → log in if prompted
navigate x.com → log in if prompted
navigate facebook.com → log in if prompted
navigate [publication].substack.com → log in if prompted
browser stop

Important rules:

• Never run pkill -f "Google Chrome" or kill the browser process manually — this destroys all saved sessions and forces you to log in again
• Only use browser stop / browser start via OpenClaw to restart the browser safely
• Sessions persist in the browser profile directory and survive restarts as long as you use browser stop

2. WordPress Credentials#

WordPress uses REST API with Application Password — no browser needed.

Create a credentials file at ~/.openclaw/.wp-[yoursite].env:

bash

WP_URL=https://yoursite.com
WP_USER=your_username
WP_APP_PASSWORD=xxxx xxxx xxxx xxxx xxxx xxxx

To generate an Application Password:

1. Go to WordPress Admin → Users → Profile
2. Scroll to "Application Passwords"
3. Enter a name (e.g., "OpenClaw") → click Add New
4. Copy the generated password into the .env file

3. Image Overlay Script#

This skill uses a shell script to generate quote images from your photo library. Locate or install it at:

text

~/workspace/linkedin-assets/create-overlay-image.sh

Verify it works:

bash

bash ~/workspace/linkedin-assets/create-overlay-image.sh "Test quote" /tmp/test-output.png
ls -lh /tmp/test-output.png

Expected output: a PNG file with your quote overlaid on a background photo.

4. Upload Directory#

Ensure the uploads directory exists:

bash

mkdir -p /tmp/openclaw/uploads

Note: /tmp/ is cleared on system reboot. Recreate images if needed after restart.

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Workflow Overview#

For each post, follow this sequence:

text

Step 1: Create images (bash script) — before opening any browser
Step 2: Post to LinkedIn
Step 3: Post to X/Twitter (include LinkedIn link)
Step 4: Post to Facebook
Step 5: Post to WordPress (API, no browser)
Step 6: Post to Substack (browser)
Step 7: Verify all platforms

Always create both images first. Opening and closing the browser repeatedly wastes time and risks losing sessions.

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Step 1 — Create Images#

Run both image commands before opening the browser:

bash

# English image — used for LinkedIn and X
bash ~/workspace/linkedin-assets/create-overlay-image.sh \
  "Your English quote here" \
  /tmp/openclaw/uploads/[topic]-en.png

# Local language image — used for Facebook, WordPress, Substack
bash ~/workspace/linkedin-assets/create-overlay-image.sh \
  "Your local language quote here" \
  /tmp/openclaw/uploads/[topic]-vi.png

Verify both files exist and are non-empty before continuing:

bash

ls -lh /tmp/openclaw/uploads/[topic]-en.png /tmp/openclaw/uploads/[topic]-vi.png

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Step 2 — LinkedIn#

Key constraint: Upload dialog lives inside a Shadow DOM ( div.theme--light). ARM + Playwright native click is required. Never use evaluate input.click().

text

browser start → navigate linkedin.com/feed/ → wait for "Photo" text to appear

ARM upload:
  browser upload paths=["/tmp/openclaw/uploads/[topic]-en.png"]
  (no selector — ARM queues the file for the next file picker that opens)

snapshot → get ref for Photo button (an <A> link to /preload/sharebox/?detourType=IMAGE)
click ref [Photo] → wait for Editor dialog to open

  CHECK: if dialog shows "N of M" (e.g. "1 of 2") → leftover from previous session
  → click Delete button until counter shows "1 of 1"

click Next → wait for "Create post modal" to appear
snapshot → get ref for textbox labeled "Text editor for creating content"
click ref [textbox] → type ref [full post text including hashtags]
snapshot → verify Post button is active (not disabled)
click ref [Post] → wait 8s

Verify:
  navigate linkedin.com/in/[username]/recent-activity/all/
  evaluate: document.querySelectorAll('[data-urn]')[0].innerText → should contain your text

browser close tab → browser stop

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Step 3 — X / Twitter#

Key constraint: ARM interceptor only fires on Playwright native click ( click ref). Never use evaluate btn.click() to trigger the file picker — it breaks ARM and causes the image and text to post as two separate tweets.

280-character limit: Count characters before typing. If over, shorten the text first.

text

browser start → navigate x.com/compose/post → wait 3s

ARM upload:
  browser upload paths=["/tmp/openclaw/uploads/[topic]-en.png"]

snapshot depth=6 → get ref for "Add photos or video" button
  (depth=6 needed to expose buttons nested inside <navigation>)

click ref [Add photos or video] ← Playwright native click, NOT evaluate
wait 5s → evaluate: document.querySelectorAll('img[src*="blob:"]').length
  → must equal 1 before continuing

snapshot → get ref for textbox "Post text" (refs change after image attaches — always re-snapshot)
click ref [textbox] → type ref [text, max 280 characters]

evaluate: verify before posting
  document.querySelector('[data-testid="tweetButton"]').disabled === false
  document.querySelector('[data-testid="tweetTextarea_0"]').innerText.length ≤ 280

evaluate: document.querySelector('[data-testid="tweetButton"]').click()
wait 10s → evaluate: location.href → should be "https://x.com/home"

browser close tab → browser stop

Tip: Include the LinkedIn post URL in the X text to drive cross-platform traffic.

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Step 4 — Facebook#

Key constraint: After the image uploads, Facebook switches to a new screen and the textbox count drops from 3 to 1. Always re-query the textbox AFTER blob=1 is confirmed — typing before that goes into the wrong element.

text

browser start → navigate facebook.com → wait 5s

evaluate: click "What's on your mind?" / "Bạn đang nghĩ gì?" button
  [...document.querySelectorAll('[role="button"]')]
    .find(b => b.textContent.includes('đang nghĩ gì') || b.textContent.includes("on your mind"))
    .click()

wait 2s → verify "Create post" / "Tạo bài viết" dialog is open

ARM upload:
  browser upload paths=["/tmp/openclaw/uploads/[topic]-vi.png"]

evaluate: inside "Tạo bài viết" dialog, click the photo button:
  dialog.querySelector('[aria-label="Ảnh/video"]').click()
  (or "[aria-label='Photo/video']" for English UI)

wait 6s → evaluate: document.querySelectorAll('img[src*="blob:"]').length
  IF blob=0: ARM again + click photo button again (max 2 retries)

Once blob=1:
  evaluate: re-query textbox — after image loads there is exactly 1:
    document.querySelector('[role="dialog"] [role="textbox"][contenteditable="true"]')
  evaluate: tb.click(); tb.focus()
  browser act type selector='[role="dialog"] [role="textbox"][contenteditable="true"]'
    text=[full post text including hashtags]

evaluate: verify blob=1 AND textbox.innerText.length > 0

evaluate: click "Next" / "Tiếp" button
wait 5s
evaluate: click "Post" / "Đăng" button
wait 8s

evaluate: verify compose dialog is gone:
  !document.querySelectorAll('[role="dialog"]').some(d => d.innerText.includes('Tạo bài viết'))

browser close tab → browser stop

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Step 5 — WordPress (REST API)#

No browser needed. Load credentials first:

bash

source ~/.openclaw/.wp-[yoursite].env

5a. Upload featured image:

bash

MEDIA=$(curl -s -X POST "$WP_URL/wp-json/wp/v2/media" \
  -u "$WP_USER:$WP_APP_PASSWORD" \
  -H "Content-Disposition: attachment; filename=post-image.png" \
  -H "Content-Type: image/png" \
  --data-binary @/tmp/openclaw/uploads/[topic]-vi.png)

MEDIA_ID=$(echo $MEDIA | python3 -c "import sys,json; print(json.load(sys.stdin)['id'])")
IMAGE_URL=$(echo $MEDIA | python3 -c "import sys,json; print(json.load(sys.stdin)['source_url'])")

5b. Build post JSON (always use Python — never heredoc, heredoc breaks UTF-8):

bash

python3 -c "
import json
post = {
  'title': 'Your Post Title',
  'content': '<p>Full HTML content here.</p>',
  'status': 'publish',
  'categories': [8],
  'featured_media': $MEDIA_ID
}
with open('/tmp/wp-post.json', 'w') as f:
    json.dump(post, f, ensure_ascii=False)
"

5c. Publish:

bash

POST=$(curl -s -X POST "$WP_URL/wp-json/wp/v2/posts" \
  -u "$WP_USER:$WP_APP_PASSWORD" \
  -H "Content-Type: application/json" \
  --data-binary @/tmp/wp-post.json)

POST_ID=$(echo $POST | python3 -c "import sys,json; print(json.load(sys.stdin)['id'])")
POST_URL=$(echo $POST | python3 -c "import sys,json; print(json.load(sys.stdin)['link'])")
echo "Published: $POST_URL"

5d. Patch Yoast SEO OG image (required — skipping this causes avatar.jpg to show when the post is shared):

bash

curl -s -X POST "$WP_URL/wp-json/wp/v2/posts/$POST_ID" \
  -u "$WP_USER:$WP_APP_PASSWORD" \
  -H "Content-Type: application/json" \
  -d "{\"meta\":{\"_yoast_wpseo_opengraph-image\":\"$IMAGE_URL\",\"_yoast_wpseo_opengraph-image-id\":$MEDIA_ID}}"

5e. Verify OG image:

bash

curl -s "$WP_URL/wp-json/wp/v2/posts/$POST_ID?_fields=yoast_head_json" \
  | python3 -c "import sys,json; d=json.load(sys.stdin); print(d['yoast_head_json']['og_image'][0]['url'])"
# Should print the post image URL, not avatar.jpg

Default category IDs (adjust per site): 8=Business, 6=Marketing, 14=Skills, 10=Lifestyle, 5=Other

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Step 6 — Substack#

Key constraint: Insert the image into the body FIRST, then type text. Opposite of Facebook. Text typed before image insertion gets wiped when ProseMirror re-renders.

text

browser start
navigate [publication].substack.com/publish/post/new → wait 5s
  (NOT substack.com/new — must use the publication subdomain URL)

snapshot → type Title → type Subtitle (if needed)

ARM upload:
  browser upload paths=["/tmp/openclaw/uploads/[topic]-vi.png"]

snapshot → get ref for Image button in ProseMirror toolbar
click ref [Image] → wait for file picker → ARM intercepts → image inserts into body
wait 5s → verify image blob appears in editor content

snapshot → get ref for .ProseMirror-focused editor area
type ref [full post content] (timeoutMs=60000 for long posts)

click Continue → wait 5s
snapshot → click "Send to everyone now" / "Publish now"
wait 8s → verify publish confirmation appears

browser tabs → get targetId → browser close targetId → browser stop

Verify: Navigate to [publication].substack.com — latest post should appear at the top.

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Step 7 — Verification Checklist#

After posting to all platforms:

PlatformVerify byLinkedInrecent-activity page — post text visible + image attachedXx.com/home feed — tweet with image visibleFacebookProfile or Page feed — post with image and full text visibleWordPressVisit post URL — featured image correct, OG image not avatarSubstackPublication homepage — post appears at top

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Error Reference#

SymptomCauseFixX: two posts (1 image-only, 1 text-only)Used evaluate btn.click() for Add photosMust use click ref from snapshotX: Post button stays disabledText over 280 charsCheck tweetTextarea_0.innerText.length, trim and retypeFB: image uploaded but no text in postTyped before blob=1Re-query textbox after blob=1 confirmedFB: blob=0 after 6sARM missed the file inputARM again + click Ảnh/video again (max 2 retries)LinkedIn: "N of M" in EditorLeftover image from previous sessionDelete extras until "1 of 1"LinkedIn: Post button stays greyText not in shadow DOM editorUse type ref not type selectorWP: avatar shows on social shareYoast OG image not patchedRun Step 5d and verify Step 5eSubstack: text missing after publishText typed before image insertionAlways insert image first, then typeSubstack: page not foundWrong URL formatUse [pub].substack.com/publish/post/new not substack.com/newAll platforms: session lost after restartBrowser was killed manuallyNever pkill Chrome; always use browser stop

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Platform Summary#

PlatformImage variantAuth methodToolLinkedInENBrowser sessionbrowser + ARMX/TwitterENBrowser sessionbrowser + ARM (native click only)FacebookLocal/VIBrowser sessionbrowser + ARM + re-query textboxWordPressLocal/VIApp password in .env``curl REST APISubstackLocal/VIBrowser sessionbrowser + ARM (image before text)