LinkedIn API

Schedule and automate LinkedIn posts with RelayAPI — text, images, videos, document carousels, first comments, and company pages.

Quick Reference

Property	Value
Platform key	`linkedin`
Auth method	OAuth 2.0
Character limit	3,000
Images per post	20
Videos per post	1
Documents per post	1 (PDF, PPT, PPTX, DOC, DOCX)
Image formats	JPEG, PNG, GIF
Image max size	10 MB
Video formats	MP4
Video max size	500 MB
Video max duration	10 min (personal), 30 min (company page)
Post types	Text, Image, Multi-image, Video, Document/Carousel
Scheduling	Yes
Analytics	Yes (impressions, reach, likes, comments, shares, clicks, views)

SDK source — TypeScript · Python · Go · Java · REST API

LinkedIn actively suppresses posts with external links — expect a 40-50% reach drop. Always put links in a first_comment instead of the main content. LinkedIn has very strict duplicate detection — even minor rephrasing may not be enough to avoid a 422 error. You cannot mix media types (images + videos, or images + documents) in the same post. GIFs are converted to video and count against the 1-video-per-post limit.

Quick Start

Post to LinkedIn:

import Relay from '@relayapi/sdk';

const client = new Relay();
const post = await client.posts.create({
  content: 'I spent 3 years building the wrong product.\n\nHere is what I learned about validating ideas before writing code...',
  targets: ['linkedin'],
  scheduled_at: 'now',
});

console.log(post.id); // post_abc123

from relay import Relay

client = Relay()
post = client.posts.create(
    content='I spent 3 years building the wrong product.\n\nHere is what I learned about validating ideas before writing code...',
    targets=['linkedin'],
    scheduled_at='now',
)

print(post.id)  # post_abc123

client := relaygo.NewClient()

post, err := client.Posts.New(context.TODO(), relaygo.PostNewParams{
    Content:     relaygo.F("I spent 3 years building the wrong product.\n\nHere is what I learned about validating ideas before writing code..."),
    Targets:     relaygo.F([]string{"linkedin"}),
    ScheduledAt: relaygo.F("now"),
})

fmt.Println(post.ID) // post_abc123

RelayClient client = RelayOkHttpClient.fromEnv();

PostCreateResponse post = client.posts().create(PostCreateParams.builder()
    .content("I spent 3 years building the wrong product.\n\nHere is what I learned about validating ideas before writing code...")
    .addTarget("linkedin")
    .scheduledAt("now")
    .build());

System.out.println(post.id()); // post_abc123

curl -X POST https://api.relayapi.dev/v1/posts \
  -H "Authorization: Bearer $RELAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "content": "I spent 3 years building the wrong product.\n\nHere is what I learned about validating ideas before writing code...",
    "targets": ["linkedin"],
    "scheduled_at": "now"
  }'

Content Types

Text-Only Post

Text posts have the highest organic reach on LinkedIn. First ~210 characters are visible before the "see more" fold, so front-load your hook.

const post = await client.posts.create({
  content: 'I spent 3 years building the wrong product.\n\nHere is what I learned about validating ideas before writing code...',
  targets: ['linkedin'],
  scheduled_at: 'now',
});

post = client.posts.create(
    content='I spent 3 years building the wrong product.\n\nHere is what I learned about validating ideas before writing code...',
    targets=['linkedin'],
    scheduled_at='now',
)

post, err := client.Posts.New(context.TODO(), relaygo.PostNewParams{
    Content:     relaygo.F("I spent 3 years building the wrong product.\n\nHere is what I learned about validating ideas before writing code..."),
    Targets:     relaygo.F([]string{"linkedin"}),
    ScheduledAt: relaygo.F("now"),
})

PostCreateResponse post = client.posts().create(PostCreateParams.builder()
    .content("I spent 3 years building the wrong product.\n\nHere is what I learned about validating ideas before writing code...")
    .addTarget("linkedin")
    .scheduledAt("now")
    .build());

curl -X POST https://api.relayapi.dev/v1/posts \
  -H "Authorization: Bearer $RELAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "content": "I spent 3 years building the wrong product.\n\nHere is what I learned about validating ideas before writing code...",
    "targets": ["linkedin"],
    "scheduled_at": "now"
  }'

Single Image Post

const post = await client.posts.create({
  content: 'Our new office setup!',
  targets: ['linkedin'],
  media: [
    { url: 'https://cdn.example.com/office.jpg', type: 'image' },
  ],
  scheduled_at: 'now',
});

post = client.posts.create(
    content='Our new office setup!',
    targets=['linkedin'],
    media=[
        {'url': 'https://cdn.example.com/office.jpg', 'type': 'image'},
    ],
    scheduled_at='now',
)

post, err := client.Posts.New(context.TODO(), relaygo.PostNewParams{
    Content:     relaygo.F("Our new office setup!"),
    Targets:     relaygo.F([]string{"linkedin"}),
    Media: relaygo.F([]relaygo.PostNewParamsMedia{
        {URL: relaygo.F("https://cdn.example.com/office.jpg"), Type: relaygo.F(relaygo.PostNewParamsMediaTypeImage)},
    }),
    ScheduledAt: relaygo.F("now"),
})

PostCreateResponse post = client.posts().create(PostCreateParams.builder()
    .content("Our new office setup!")
    .addTarget("linkedin")
    .addMedia(PostCreateParams.Media.builder()
        .url("https://cdn.example.com/office.jpg")
        .type(PostCreateParams.Media.Type.IMAGE)
        .build())
    .scheduledAt("now")
    .build());

curl -X POST https://api.relayapi.dev/v1/posts \
  -H "Authorization: Bearer $RELAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "content": "Our new office setup!",
    "targets": ["linkedin"],
    "media": [
      {"url": "https://cdn.example.com/office.jpg", "type": "image"}
    ],
    "scheduled_at": "now"
  }'

Multi-Image Post (Up to 20)

LinkedIn supports up to 20 images per post. Cannot include videos or documents alongside images.

const post = await client.posts.create({
  content: 'Highlights from our team retreat!',
  targets: ['linkedin'],
  media: [
    { url: 'https://cdn.example.com/photo1.jpg', type: 'image' },
    { url: 'https://cdn.example.com/photo2.jpg', type: 'image' },
    { url: 'https://cdn.example.com/photo3.jpg', type: 'image' },
  ],
  scheduled_at: 'now',
});

post = client.posts.create(
    content='Highlights from our team retreat!',
    targets=['linkedin'],
    media=[
        {'url': 'https://cdn.example.com/photo1.jpg', 'type': 'image'},
        {'url': 'https://cdn.example.com/photo2.jpg', 'type': 'image'},
        {'url': 'https://cdn.example.com/photo3.jpg', 'type': 'image'},
    ],
    scheduled_at='now',
)

post, err := client.Posts.New(context.TODO(), relaygo.PostNewParams{
    Content: relaygo.F("Highlights from our team retreat!"),
    Targets: relaygo.F([]string{"linkedin"}),
    Media: relaygo.F([]relaygo.PostNewParamsMedia{
        {URL: relaygo.F("https://cdn.example.com/photo1.jpg"), Type: relaygo.F(relaygo.PostNewParamsMediaTypeImage)},
        {URL: relaygo.F("https://cdn.example.com/photo2.jpg"), Type: relaygo.F(relaygo.PostNewParamsMediaTypeImage)},
        {URL: relaygo.F("https://cdn.example.com/photo3.jpg"), Type: relaygo.F(relaygo.PostNewParamsMediaTypeImage)},
    }),
    ScheduledAt: relaygo.F("now"),
})

PostCreateResponse post = client.posts().create(PostCreateParams.builder()
    .content("Highlights from our team retreat!")
    .addTarget("linkedin")
    .addMedia(PostCreateParams.Media.builder()
        .url("https://cdn.example.com/photo1.jpg")
        .type(PostCreateParams.Media.Type.IMAGE)
        .build())
    .addMedia(PostCreateParams.Media.builder()
        .url("https://cdn.example.com/photo2.jpg")
        .type(PostCreateParams.Media.Type.IMAGE)
        .build())
    .addMedia(PostCreateParams.Media.builder()
        .url("https://cdn.example.com/photo3.jpg")
        .type(PostCreateParams.Media.Type.IMAGE)
        .build())
    .scheduledAt("now")
    .build());

curl -X POST https://api.relayapi.dev/v1/posts \
  -H "Authorization: Bearer $RELAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "content": "Highlights from our team retreat!",
    "targets": ["linkedin"],
    "media": [
      {"url": "https://cdn.example.com/photo1.jpg", "type": "image"},
      {"url": "https://cdn.example.com/photo2.jpg", "type": "image"},
      {"url": "https://cdn.example.com/photo3.jpg", "type": "image"}
    ],
    "scheduled_at": "now"
  }'

Video Post

const post = await client.posts.create({
  content: 'Watch our latest product demo',
  targets: ['linkedin'],
  media: [
    { url: 'https://cdn.example.com/demo.mp4', type: 'video' },
  ],
  scheduled_at: 'now',
});

post = client.posts.create(
    content='Watch our latest product demo',
    targets=['linkedin'],
    media=[
        {'url': 'https://cdn.example.com/demo.mp4', 'type': 'video'},
    ],
    scheduled_at='now',
)

post, err := client.Posts.New(context.TODO(), relaygo.PostNewParams{
    Content: relaygo.F("Watch our latest product demo"),
    Targets: relaygo.F([]string{"linkedin"}),
    Media: relaygo.F([]relaygo.PostNewParamsMedia{
        {URL: relaygo.F("https://cdn.example.com/demo.mp4"), Type: relaygo.F(relaygo.PostNewParamsMediaTypeVideo)},
    }),
    ScheduledAt: relaygo.F("now"),
})

PostCreateResponse post = client.posts().create(PostCreateParams.builder()
    .content("Watch our latest product demo")
    .addTarget("linkedin")
    .addMedia(PostCreateParams.Media.builder()
        .url("https://cdn.example.com/demo.mp4")
        .type(PostCreateParams.Media.Type.VIDEO)
        .build())
    .scheduledAt("now")
    .build());

curl -X POST https://api.relayapi.dev/v1/posts \
  -H "Authorization: Bearer $RELAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "content": "Watch our latest product demo",
    "targets": ["linkedin"],
    "media": [
      {"url": "https://cdn.example.com/demo.mp4", "type": "video"}
    ],
    "scheduled_at": "now"
  }'

Document/Carousel Post (PDF)

LinkedIn uniquely supports document uploads that display as swipeable carousels. Upload a PDF, PPT, PPTX, DOC, or DOCX file. Max 100 MB, up to 300 pages.

const post = await client.posts.create({
  content: 'Download our 2024 Industry Report',
  targets: ['linkedin'],
  media: [
    { url: 'https://cdn.example.com/report.pdf', type: 'document' },
  ],
  scheduled_at: 'now',
  target_options: {
    linkedin: {
      document_title: '2024 Industry Report',
    },
  },
});

post = client.posts.create(
    content='Download our 2024 Industry Report',
    targets=['linkedin'],
    media=[
        {'url': 'https://cdn.example.com/report.pdf', 'type': 'document'},
    ],
    scheduled_at='now',
    target_options={
        'linkedin': {
            'document_title': '2024 Industry Report',
        },
    },
)

post, err := client.Posts.New(context.TODO(), relaygo.PostNewParams{
    Content: relaygo.F("Download our 2024 Industry Report"),
    Targets: relaygo.F([]string{"linkedin"}),
    Media: relaygo.F([]relaygo.PostNewParamsMedia{
        {URL: relaygo.F("https://cdn.example.com/report.pdf"), Type: relaygo.F(relaygo.PostNewParamsMediaTypeDocument)},
    }),
    ScheduledAt: relaygo.F("now"),
    TargetOptions: relaygo.F(map[string]interface{}{
        "linkedin": map[string]interface{}{
            "document_title": "2024 Industry Report",
        },
    }),
})

PostCreateResponse post = client.posts().create(PostCreateParams.builder()
    .content("Download our 2024 Industry Report")
    .addTarget("linkedin")
    .addMedia(PostCreateParams.Media.builder()
        .url("https://cdn.example.com/report.pdf")
        .type(PostCreateParams.Media.Type.DOCUMENT)
        .build())
    .scheduledAt("now")
    .targetOptions(PostCreateParams.TargetOptions.builder()
        .putAdditionalProperty("linkedin", JsonValue.from(Map.of(
            "document_title", "2024 Industry Report"
        )))
        .build())
    .build());

curl -X POST https://api.relayapi.dev/v1/posts \
  -H "Authorization: Bearer $RELAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "content": "Download our 2024 Industry Report",
    "targets": ["linkedin"],
    "media": [
      {"url": "https://cdn.example.com/report.pdf", "type": "document"}
    ],
    "scheduled_at": "now",
    "target_options": {
      "linkedin": {
        "document_title": "2024 Industry Report"
      }
    }
  }'

Document carousels are one of the highest-engagement post formats on LinkedIn. Each page of the PDF becomes a swipeable slide.

Post with First Comment (Put Links Here!)

LinkedIn actively suppresses posts containing external URLs — expect a 40-50% reach drop. Put links in the first comment instead.

const post = await client.posts.create({
  content: 'We just published our guide to API design patterns.\n\nLink in the first comment.',
  targets: ['linkedin'],
  scheduled_at: 'now',
  target_options: {
    linkedin: {
      first_comment: 'Read the full guide here: https://example.com/api-guide',
    },
  },
});

post = client.posts.create(
    content='We just published our guide to API design patterns.\n\nLink in the first comment.',
    targets=['linkedin'],
    scheduled_at='now',
    target_options={
        'linkedin': {
            'first_comment': 'Read the full guide here: https://example.com/api-guide',
        },
    },
)

post, err := client.Posts.New(context.TODO(), relaygo.PostNewParams{
    Content:     relaygo.F("We just published our guide to API design patterns.\n\nLink in the first comment."),
    Targets:     relaygo.F([]string{"linkedin"}),
    ScheduledAt: relaygo.F("now"),
    TargetOptions: relaygo.F(map[string]interface{}{
        "linkedin": map[string]interface{}{
            "first_comment": "Read the full guide here: https://example.com/api-guide",
        },
    }),
})

PostCreateResponse post = client.posts().create(PostCreateParams.builder()
    .content("We just published our guide to API design patterns.\n\nLink in the first comment.")
    .addTarget("linkedin")
    .scheduledAt("now")
    .targetOptions(PostCreateParams.TargetOptions.builder()
        .putAdditionalProperty("linkedin", JsonValue.from(Map.of(
            "first_comment", "Read the full guide here: https://example.com/api-guide"
        )))
        .build())
    .build());

curl -X POST https://api.relayapi.dev/v1/posts \
  -H "Authorization: Bearer $RELAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "content": "We just published our guide to API design patterns.\n\nLink in the first comment.",
    "targets": ["linkedin"],
    "scheduled_at": "now",
    "target_options": {
      "linkedin": {
        "first_comment": "Read the full guide here: https://example.com/api-guide"
      }
    }
  }'

Putting links in the main content field causes a significant reach penalty on LinkedIn. Always use first_comment for external URLs.

Company Page Post

Post to a company page instead of a personal profile by targeting the company account.

const post = await client.posts.create({
  content: 'Update from our organization!',
  targets: ['acc_linkedin_company'],
  scheduled_at: 'now',
});

post = client.posts.create(
    content='Update from our organization!',
    targets=['acc_linkedin_company'],
    scheduled_at='now',
)

post, err := client.Posts.New(context.TODO(), relaygo.PostNewParams{
    Content:     relaygo.F("Update from our organization!"),
    Targets:     relaygo.F([]string{"acc_linkedin_company"}),
    ScheduledAt: relaygo.F("now"),
})

PostCreateResponse post = client.posts().create(PostCreateParams.builder()
    .content("Update from our organization!")
    .addTarget("acc_linkedin_company")
    .scheduledAt("now")
    .build());

curl -X POST https://api.relayapi.dev/v1/posts \
  -H "Authorization: Bearer $RELAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "content": "Update from our organization!",
    "targets": ["acc_linkedin_company"],
    "scheduled_at": "now"
  }'

Media Requirements

Images

Property	Requirement
Max per post	20
Formats	JPEG, PNG, GIF
Max file size	8 MB per image
Recommended	1200 x 627 px (1.91:1)
Min dimensions	552 x 276 px

Videos

Property	Requirement
Max per post	1
Formats	MP4
Max file size	500 MB
Max duration	10 min (personal profile), 30 min (company page)
Recommended	1920 x 1080, H.264, AAC 192kbps, 30fps

Documents

Property	Requirement
Max per post	1
Formats	PDF, PPT, PPTX, DOC, DOCX
Max file size	100 MB
Max pages	300

`target_options` Fields

All fields go inside target_options.linkedin on your post request.

Field	Type	Description
`content`	string	Override content for LinkedIn specifically
`media`	object[]	Override media for LinkedIn specifically
`first_comment`	string	Auto-posted first comment. Put links here to avoid reach suppression.
`document_title`	string	Title displayed on PDF/document carousel posts
`disable_link_preview`	boolean	Suppress URL preview card in the post (default: false)
`organization_urn`	string	Target a specific company page: `urn:li:organization:123456`

Common Errors

Error	Cause	Fix
Content is a duplicate (422)	Identical or very similar content posted recently	Modify text meaningfully. LinkedIn's duplicate detection is very strict.
Preflight checks failed	Rate limiting or validation issue	Space posts further apart.
Publishing failed max retries	All retry attempts failed	Temporary issue — retry manually after a few minutes.
Token expired	OAuth token expired	Reconnect the account via the dashboard or Connect API.
Cannot mix media types	Images + videos or images + documents in same post	Use only one media type per post. GIFs count as video.

Known Quirks

Link suppression — posts with external URLs get 40-50% less reach. Always put links in first_comment.
Very strict duplicate detection — even minor rephrasing may not bypass the 422 duplicate error.
Cannot mix media types — images + videos or images + documents in the same post will fail.
GIFs are converted to video and count against the 1-video-per-post limit.
First ~210 characters visible before the "see more" fold. Front-load your hook.
Company pages get 30-minute video limit, personal profiles get 10 minutes.
Document carousels are the highest-engagement format but require a PDF, PPT, or DOC file.

Automations

LinkedIn automation uses the Versioned REST API (YYYYMM format) — version pinned in api-versions.ts.

The r_member_social scope is currently closed to new apps per Microsoft docs. Only approved Community Management API apps can use the triggers and send nodes below.

Triggers

Type	Fires on
`linkedin_comment`	Comment on your share
`linkedin_mention`	@-mention
`linkedin_reaction`	Reaction added to your share

Send nodes

Base: https://api.linkedin.com/rest with LinkedIn-Version + X-Restli-Protocol-Version: 2.0.0 headers.

Node	Endpoint	Required fields
`linkedin_reply_to_comment`	`POST /socialActions/{urn}/comments`	`text`, `share_urn`
`linkedin_react_to_post`	`POST /reactions?actor={memberUrn}`	`reaction` (default `LIKE`), `share_urn`

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