Person Activity Signal

The person_activity signal tells you when a person you track reacts to or comments on anything on LinkedIn: their likes and other reactions, their comments, and their replies to comments, on anyone’s post. Use it to see what a champion, prospect, or competitor’s executive is paying attention to, and to reach out while it is fresh.

person_activity is the opposite direction from person_engagement:

person_activity: what the tracked person does. “Satya liked a post by Ryan Roslansky.”
person_engagement: who engages with the tracked person’s content. “Taylor commented on Satya’s post.”

You can run several person_activity signals, for example one for champions and one for churned customers. Each is identified by its signal_id and can carry a name for display. A person tracked by two signals triggers alerts from both.

How it works

First run: baseline. For each profile, the signal records the person’s current activity and reports nothing. You receive one baseline webhook listing the profiles now being tracked.
Every run after that: each reaction, comment, and reply the person made since the last run is reported once, oldest first.
Runs follow the signal’s schedule (frequency, default once a day). See Create Signal.

occurred_at on each item is when the person reacted or commented, not when the post was published.

Create a person activity signal

POST https://api.datamagnet.co/api/v1/signal/create

Request

string

required

Must be "person_activity".

array

required

LinkedIn profile URLs of the people to track.

["https://www.linkedin.com/in/satyanadella", "https://www.linkedin.com/in/williamhgates"]

array

default:"[\"reactions\", \"comments\"]"

What to report. "reactions", "comments", or both. Replies to comments count as comments.Each type is a separate check per profile per run, so tracking only one halves the cost of each run.

string

A display name for this signal, such as "Champions". Optional; defaults to "Person Activity Monitor". Change it later with the rename action.

boolean

default:"false"

Set to true to create another person_activity signal when you already have one. Without it, profiles are added to your existing signal. See Several signals of one type.

string

Add these profiles to an existing person_activity signal instead of creating one.

string

default:"every_day"

How often the signal runs: "every_hour", "every_2hr", "every_day", or "every_week".

array

Extra email addresses to notify. Your account email is always included.

string

URL to receive activity via POST. See Webhook payload below.

string

HMAC secret for signing webhook payloads. See Verifying webhook signatures.

Request

{
  "signal_type": "person_activity",
  "name": "Champions",
  "profile_urls": ["https://www.linkedin.com/in/satyanadella"],
  "activity_types": ["reactions", "comments"],
  "frequency": "every_day",
  "webhook_url": "https://yourapp.com/webhooks/signals",
  "webhook_secret": "your-hmac-secret"
}

Response

{
  "message": {
    "signal_id": "a1b2c3d4-5e6f-4a7b-8c9d-0e1f2a3b4c5d",
    "signal_type": "person_activity",
    "name": "Champions",
    "status": "active",
    "profile_urls": ["https://www.linkedin.com/in/satyanadella"],
    "activity_types": ["reactions", "comments"],
    "email_recipients": ["user@example.com"],
    "webhook_url": "https://yourapp.com/webhooks/signals"
  },
  "credit_used": 1
}

string

Unique identifier for this signal. Save this: use it to update, add profiles to, or delete this signal.

string

The signal’s display name.

array

All profiles this signal tracks.

array

What the signal reports: "reactions", "comments", or both.

Credits

Creating a signal or adding profiles: 1 credit per profile added.
Each run: one Person Activity request per profile per activity type, billed at that endpoint’s rate. Tracking both reactions and comments is two requests per profile per run. A very active person can need an extra page, which is one more request, capped at 3 pages per type per run.

Credits are charged to the API key the signal was created with.

Webhook payload

Each delivery is a single POST with a JSON body. job_id is the signal’s signal_id, and job_name is its name, so you can tell your signals apart.

Baseline

Sent once per run in which profiles were tracked for the first time.

baseline

{
  "event": "baseline",
  "user_email": "user@example.com",
  "signal_type": "person_activity",
  "job_id": "a1b2c3d4-5e6f-4a7b-8c9d-0e1f2a3b4c5d",
  "job_name": "Champions",
  "profiles": [
    { "profile_url": "https://www.linkedin.com/in/satyanadella", "profile_name": "Satya Nadella" }
  ]
}

New activity

One entry per reaction, comment, or reply, oldest first.

person_activity

{
  "event": "person_activity",
  "user_email": "user@example.com",
  "signal_type": "person_activity",
  "job_id": "a1b2c3d4-5e6f-4a7b-8c9d-0e1f2a3b4c5d",
  "job_name": "Champions",
  "changes": [
    {
      "event_id": "5b0c9d7e-2f4a-4c1b-9e3d-7a8b6c5d4e3f",
      "profile_url": "https://www.linkedin.com/in/satyanadella",
      "profile_name": "Satya Nadella",
      "signal_type": "reaction",
      "change_summary": "Liked a post by Ryan Roslansky",
      "confidence": null,
      "detected_at": "2026-09-18T08:00:12.204518+00:00",
      "change_data": {
        "activity_type": "reaction",
        "occurred_at": "2026-09-17T18:30:42.168Z",
        "reaction_type": "LIKE",
        "target": "post",
        "target_comment_author": null,
        "target_comment_url": null,
        "post_url": "https://www.linkedin.com/posts/ryanroslansky_ai-activity-7506405584091541505-fa6g",
        "post_urn": "urn:li:activity:7506405584091541505",
        "post_text": "AI is helping mathematicians make real progress on Navier-Stokes…",
        "post_author": {
          "name": "Ryan Roslansky",
          "url": "https://www.linkedin.com/in/ryanroslansky",
          "headline": "Executive Vice President at Microsoft"
        }
      }
    },
    {
      "event_id": "8e1f0a2b-3c4d-4e5f-a6b7-c8d9e0f1a2b3",
      "profile_url": "https://www.linkedin.com/in/satyanadella",
      "profile_name": "Satya Nadella",
      "signal_type": "comment",
      "change_summary": "Commented on a post by Kevin Scott: “Congratulations to the whole team on this milestone.”",
      "confidence": null,
      "detected_at": "2026-09-18T08:00:12.204518+00:00",
      "change_data": {
        "activity_type": "comment",
        "occurred_at": "2026-09-17T21:04:10.512Z",
        "comment_text": "Congratulations to the whole team on this milestone.",
        "comment_url": "https://www.linkedin.com/feed/update/urn:li:activity:7506512345678901234?commentUrn=urn%3Ali%3Acomment%3A%28activity%3A7506512345678901234%2C7506598765432109876%29",
        "comment_urn": "urn:li:comment:(activity:7506512345678901234,7506598765432109876)",
        "post_url": "https://www.linkedin.com/posts/kevinscott_milestone-activity-7506512345678901234-ab12",
        "post_urn": "urn:li:activity:7506512345678901234",
        "post_text": "Today we shipped…",
        "post_author": {
          "name": "Kevin Scott",
          "url": "https://www.linkedin.com/in/kevinscott",
          "headline": "CTO at Microsoft"
        }
      }
    }
  ]
}

Fields

string

Unique ID of this item. Use it to de-duplicate on your side.

string

"reaction", "comment", or "reply".

string

One line describing the activity, such as Liked a post by Ryan Roslansky or Replied to a comment on a post by Kevin Scott: "…". Comments and replies quote the start of the comment.

object

Show All activity types

string

"reaction", "comment", or "reply".

string

ISO 8601 time the person reacted or commented, to the millisecond.

string

The post the activity is on.

string | null

The post’s LinkedIn URN.

string | null

The first 300 characters of the post.

object | null

The post’s author: name, url, headline.

Show Reactions

string

LIKE · EMPATHY · PRAISE · APPRECIATION · INTEREST · ENTERTAINMENT

string

"post", or "comment" when the person reacted to a comment on the post.

string | null

Author of the comment reacted to, when target is "comment".

string | null

Link to the comment reacted to, when target is "comment".

Show Comments and replies

string | null

The person’s comment, up to 2,000 characters.

string | null

Direct link to the comment.

string | null

The comment’s LinkedIn URN.

confidence is always null for this signal.

Managing the signal

Use Update Signal with signal_type: "person_activity". Pass signal_id to choose the signal; it can be left out only when you have exactly one.

Action	What it does
`add_profiles` / `remove_profiles`	Change the tracked people. New profiles take a baseline on their first run.
`update_activity_types`	Switch between reactions, comments, or both. Requires `activity_types`.
`rename`	Change the display name. Requires `name`.
`pause` / `resume`	Stop and restart the signal.
`update_webhook` / `update_emails`	Change where alerts go.

To remove a signal completely, use Delete Signal.

Getting Started

Concepts

Person Activity Signal

Person Activity Signal

How it works

Create a person activity signal

Request

Response

Credits

Webhook payload

Baseline

New activity

Fields

Managing the signal

​Person Activity Signal

​How it works

​Create a person activity signal

​Request

​Response

​Credits

​Webhook payload

​Baseline

​New activity

​Fields

​Managing the signal

Person Activity Signal

How it works

Create a person activity signal

Request

Response

Credits

Webhook payload

Baseline

New activity

Fields

Managing the signal