Track a post's growth curve — snapshots, not snapshots-you-take.

A single metrics read tells you where a post is. What a dashboard, a research agent, or a "did this take off?" alert actually wants is where it's going — the trend. The usual answer is a cron job and a database. Here's the no-infrastructure version.

Every fresh read records itself

When Pulse fetches a post's metrics fresh (a cache miss — i.e., there was genuinely new information), it appends a snapshot to that post's series: { t, views, likes, comments, shares }. Profiles record { t, followers, posts }. You don't opt in and you don't store anything — looking is what builds the curve.

curl "https://pulse.walls.sh/history?url=<the same URL you've been reading>"

A real example — a Bluesky post this site's own monitoring has been reading today (every number below is from the live series):

{
  "kind": "post",
  "count": 25,
  "points": [
    { "t": "2026-06-10T00:59:05.996Z", "likes": 10111, "comments": 680 },
    …
    { "t": "2026-06-10T07:30:47.534Z", "likes": 10277, "comments": 687, "shares": 2085 }
  ]
}

Twenty-five snapshots across six and a half hours: likes +166, comments +7. That slope — not the absolute number — is the answer to "is this post still moving?"

Poll the delta, not the series

If you're polling, remember the last t you saw and ask only for what's new:

curl "https://pulse.walls.sh/history?url=<post url>&since=2026-06-10T07:00:00Z"

since takes ISO-8601 or unix milliseconds and returns only points after that moment. An empty delta is a normal answer ("nothing new"), not an error.

URL spelling doesn't fragment the series

The series is keyed by the post's platform identity, not the URL string — the mobile host, a short link, and the canonical URL of the same post all land in one series. Snapshots also only re-record when the numbers actually changed (at most every 10 minutes otherwise), so the curve gains points when there was information to gain.

From an agent

In an MCP client it's the history tool (one line to install: npx -y pulse-mcp). Ask "is this post still growing?" with a link — the agent reads the series and answers from the slope. Profiles work the same way: read a profile a few times across days and history returns the follower curve.

Try it

Read any post twice via the live box or https://pulse.walls.sh/metrics?url=…, then open https://pulse.walls.sh/history?url=… — your curve has started. Docs: https://pulse.walls.sh/docs.