> Discover all available Postdom documentation from the machine-readable index: https://postdom.com/llms.txt

Destination · publishing reference

# LinkedIn publishing reference for Postdom

This LinkedIn publishing reference explains how to connect an account, what Postdom sends, which limits it checks, and what the returned outcome proves.

[Create a workspace](https://app.postdom.com/signup) [Read publish_video](https://postdom.com/docs/tools/publish-video)

Human authorization boundary

## LinkedIn publishing reference connection requirements

A human completes the destination connection. The agent receives the resulting account ID—not the social credential—and supplies that exact account ID to `publish_video`.

`connection`

OAuth

`prerequisite`

No additional Postdom prerequisite is recorded beyond an eligible account.

`current source surface`

post

Configured output

## What Postdom sends to LinkedIn

The public tool accepts product-level publishing fields. Postdom builds destination settings after validation; callers cannot smuggle an undocumented settings object through `publish_video`.

**`settings`** — **omitted**  Postdom sends no LinkedIn-specific settings. The provider chooses the API-required visibility on the account's behalf.

Postdom does not choose or read LinkedIn's effective visibility value. Missing visibility is unknown, not a promise of public or private reach.

_CURRENT SOURCE ADAPTER OUTPUT · NOT TOOL INPUT_

```
{
  "platform": "linkedin",
  "settings": {}
}
```

Enforced, documented, or unknown

## LinkedIn publishing limits

Every row comes from the current `@postdom/core` registry. “Postdom enforced” means the source contract checks the fact. A recommendation, documented-but-unenforced fact, or unpublished value must not be presented as a passed validation.

 Postdom enforced

### caption max chars

**4000**

Postdom contract · verified 2026-08-21T00:00:00.000Z

Evidence reference retained in the core registry.

 Postdom enforced

### media max bytes

**524,288,000 bytes**

Postdom contract · verified 2026-08-21T00:00:00.000Z

Evidence reference retained in the core registry.

 Postdom enforced

### video max seconds

**600**

Postdom contract · verified 2026-08-21T00:00:00.000Z

Evidence reference retained in the core registry.

 Postdom enforced

### video mime types

**video/mp4, video/quicktime**

Postdom contract · verified 2026-08-21T00:00:00.000Z

Evidence reference retained in the core registry.

 Postdom enforced

### image mime types

**image/jpeg, image/png, image/gif, image/webp**

Postdom contract · verified 2026-08-21T00:00:00.000Z

Evidence reference retained in the core registry.

 Not published

### posts api commentary

**Not published**

Unit: not stated · Field: commentary · Scope: POST /rest/posts

Platform evidence · verified 2026-09-03T00:00:00.000Z

Qualification

LinkedIn documents a FIELD_LENGTH_TOO_LONG error for commentary and never states the length. A limit is known to exist and its value is not published, which is not the same as there being none.

[Official source](https://learn.microsoft.com/en-us/linkedin/marketing/community-management/shares/posts-api)

 Recommendation

### video max bytes

**5,368,709,120 bytes**

Platform evidence · verified 2026-09-02T00:00:00.000Z

[Official source](https://learn.microsoft.com/en-us/linkedin/marketing/community-management/shares/videos-api?view=li-lms-2026-05)

 Postdom enforced

### video mime types

**video/mp4**

Platform evidence · verified 2026-09-02T00:00:00.000Z

[Official source](https://www.linkedin.com/help/linkedin/answer/a1311816)

 Not published

### video max seconds

**Not published**

Platform evidence · verified 2026-09-02T00:00:00.000Z

[Official source](https://learn.microsoft.com/en-us/linkedin/marketing/community-management/shares/videos-api?view=li-lms-2026-05)

 Recommendation

### resolution min pixels

**longest side: 256; shortest side: 144**

Platform evidence · verified 2026-09-02T00:00:00.000Z

[Official source](https://www.linkedin.com/help/linkedin/answer/a548372)

 Recommendation

### resolution max pixels

**longest side: 4096; shortest side: 2304**

Platform evidence · verified 2026-09-02T00:00:00.000Z

[Official source](https://www.linkedin.com/help/linkedin/answer/a548372)

 Recommendation

### aspect ratio

**minimum: 0.4166666666666667; maximum: 2.4**

Platform evidence · verified 2026-09-02T00:00:00.000Z

[Official source](https://www.linkedin.com/help/linkedin/answer/a548372)

Result boundary

## How to verify the LinkedIn outcome

The result records Postdom's LinkedIn destination outcome. It is not evidence of an authenticated end-to-end LinkedIn publication or analytics observation.

### Never collapse a workflow state into success

Store the Postdom post ID, read the exact destination state with `get_publish`, and preserve a missing public URL, approval state, terminal refusal, or provider error exactly as returned.

Nine modeled fields

## LinkedIn metric availability

The matrix records evidence states, not guaranteed live values. Unverified and never remain null with a reason; zero remains a measured zero.

| Metric | State | Baseline | Value behavior |
| --- | --- | --- | --- |
| views Views Required view count in a normalized snapshot. | unverified | Not verified | Always null with an explicit reason. |
| likes Likes Required like count in a normalized snapshot. | unverified | Not verified | Always null with an explicit reason. |
| comments Comments Required comment count in a normalized snapshot. | unverified | Not verified | Always null with an explicit reason. |
| shares Shares Required share count in a normalized snapshot. | unverified | Not verified | Always null with an explicit reason. |
| saves Saves Nullable saved or favorited count. | unverified | Not verified | Always null with an explicit reason. |
| watch_time_s Watch time Nullable total watch time in seconds. | unverified | Not verified | Always null with an explicit reason. |
| avg_watch_pct Average watch Nullable average watched percentage. | unverified | Not verified | Always null with an explicit reason. |
| completion_pct Completion Nullable completion percentage. | unverified | Not verified | Always null with an explicit reason. |
| follower_delta Follower delta Nullable follower-change field. | unverified | Not verified | Always null with an explicit reason. |

Separate search intent

## Related LinkedIn resources

These pages answer separate workflow, specification, or character-limit questions. They support this product reference without replacing it.

### How to schedule LinkedIn posts

Workflow choices and operational checks.

[Open resource](https://postdom.com/blog/how-to-schedule-linkedin-posts)

### LinkedIn video specifications

Search-focused specification research, separate from this product contract.

[Open resource](https://postdom.com/platforms/linkedin/video-specifications)

### LinkedIn metrics availability

Why the normalized performance fields remain unverified.

[Open resource](https://postdom.com/platforms/linkedin/metrics-api-availability)

Verification scope

## LinkedIn evidence boundary

### Contract evidence is not an observed publication

These pages describe source-backed product contracts. They do not represent an authenticated end-to-end publication or analytics test.

Inspect the connected tool schema before acting. Current source may be ahead of the separately published `@postdom/mcp` helper.

Use the contract

## Publish with explicit authority and outcomes

Create a workspace, connect an eligible account, and let the agent use only the fields exposed by the connected schema.

[Start free](https://app.postdom.com/signup) [Read outcome states](https://postdom.com/docs/tools/get-publish)

 VERIFIED · 23 SEPTEMBER 2026  **Current source adapter · Core evidence registries · Modeled metric availability**

Private identifiers and unverified publication claims are excluded. External links are limited to first-party platform sources.