> ## Documentation Index
> Fetch the complete documentation index at: https://docs.speckle.systems/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> These docs contain multiple Speckle product experiences. For Speckle 2026.9, prefer /next/ pages for the topics and changes they cover. The navigation label Current does not override this version-specific precedence.
> Coverage under /next/ is incremental. Use Current documentation for unchanged topics and when a /next/ page says coverage is unavailable or explicitly refers you to Current. Do not infer a feature was removed from a missing page.
> Read the page-specific documentation status, applicability, affected guidance and replacement links in agent-only content. Impacted, changed and superseded apply only to the stated scope; they do not mean the entire feature is deprecated. Historical connector guides apply only to the legacy connector described.
> Match guidance to the customer's deployment version, model data format and connector. Respect plan, permission and compatibility restrictions. If an unknown version or data format changes the answer, ask a focused clarification; do not infer deployment version from the date alone.

# Assess model changes with Speckle Intelligence

> A worked example — ask Chat what changed between two versions, read the report, then filter and colour the model by how significant each change is.

Documentation set: Speckle 2026.9. Status: current. Authority: canonical for this version and the coverage on this page.

Applies to version 2026.9, from 2026-09; this is not a rollout date for every deployment.

Authoritative Speckle 2026.9 documentation for the topic covered here. For Speckle 2026.9, prefer this page over conflicting earlier guidance. Follow linked Current documentation for unchanged topics and where this page says coverage is not yet available. Respect data-format, deployment, plan, permission, and compatibility limitations stated in the page.

<Note>
  This is 2026.9 documentation. Coverage here is incremental: a page exists only where 2026.9
  differs or is newly documented. For any other topic, switch to **Current** (2026.8 and earlier) in
  the version selector.
</Note>

The dedicated diff view is gone in 2026.9 — see [Compare Versions](/3d-viewer/compare-versions).
In its place, Speckle Intelligence can detect what changed between two versions, explain it in
plain language, and — because Chat can also drive the viewer — colour the model by how
significant each change is. This page walks through one real conversation end to end, from the
first question to a scene coloured by change severity, so you know what to expect and can reuse
the pattern on your own models.

<Note>
  Speckle Intelligence Chat is available when your workspace plan includes it. On a self-hosted
  server, it is available only on Speckle Enterprise Server. For deployment setup, see [Enterprise
  license — Intelligence](/developers/server/deployment/enterprise-license#optional-intelligence).
</Note>

## What this workflow does

* **Detect** — find the two versions to compare and diff them, without you opening a versions
  panel or clicking a diff button.
* **Report** — explain what changed in plain language: scale first, then the categories that
  carried the change.
* **Assess impact** — score changed elements by how significant the change is, not just
  changed-or-not.
* **Visualise** — colour the model by that score so the impact is visible, not just written down.

## Walkthrough

<Steps>
  <Step title="Ask what changed">
    In Chat or the viewer sparkle, ask a plain question — no version pickers, no diff button:

    > What is the most significant change between the last two versions of the model?

    Intelligence lists the model's version history, attaches the previous version alongside the
    one you have open, and runs a diff between them. You do not see those as separate steps; they
    happen as part of answering the question.
  </Step>

  <Step title="Read the report">
    The reply is a written summary, not a raw diff dump — scale first, then the categories that
    carried the change, in order of significance. On one structural model, the answer read:

    > The most significant change is a structural steel re-specification that swept through the
    > model. Scale: 6,598 elements modified, 119 added, 105 removed across 66 levels — only \~60%
    > of the model was left untouched. Structural Framing (3,873 modifications) shows beam
    > families replaced en masse, with cross-sections cleared and rebuilt and the material grade
    > upgraded (Steel 43-275 → Steel 345 MPa). Structural Columns (135) and Structural Connections
    > (376 modified, 61 added, 22 removed) shifted to match. Walls (1,753 modified) look like a
    > secondary effect of the structural resizing rather than an independent edit.

    Intelligence reads this from the live model — the same [connected, queryable
    data](/next/analytics/intelligence#how-it-works) Chat uses for any other question — not from a
    static export or a change log someone maintained by hand.
  </Step>

  <Step title="Ask the follow-up in the same plain language">
    Keep going the way you would with a colleague:

    > Filter to just those elements and colour them by how significant.

    You do not have to define "significant" or set a threshold. Intelligence scores each changed
    element by how many of its properties moved, buckets that into tiers, and applies a filter and
    colour-by in the viewer you are already looking at — the same [Filters
    panel](/next/3d-viewer/introduction#filter-and-color) documented for manual use.
  </Step>

  <Step title="Read the result and keep drilling in">
    The reply names the tiers it chose and what landed in each one:

    > 🔴 Major (9+ params changed) — 1,757 elements, the deepest re-specs. 🟠 Moderate (5–8 params)
    > — 2,587 elements. 🟡 Minor (1–4 params) — 2,254 elements. 🟢 Added — 119 new elements.

    The scene is now filtered to only the changed elements, coloured by tier, so the heaviest
    re-specification is visually obvious without you building that filter by hand. From here you
    can ask to isolate one tier, break it down by level, or start a new question — the filter
    stays until you clear it or ask for something that replaces it.
  </Step>
</Steps>

## Turn this into a skill

If your team asks this shape of question often — after every structural issue, before every
coordination meeting — save the pattern instead of retyping it. [Save the chat as a
skill](/next/analytics/intelligence-skills#save-a-chat-as-a-skill) once the conversation behaves
the way you want, or write the significance tiers and vocabulary into a skill by hand so every
comparison uses the same thresholds and the same added/omitted/revised language. See [Reuse
organisation playbooks with Intelligence skills](/next/analytics/intelligence-skills).

You can also save the conversation as a [Report](/next/analytics/reports) if you want a shareable
artefact rather than a one-off chat — bind the two versions as source aliases and the comparison
becomes something you or a teammate can reopen without re-asking Intelligence.

## FAQ

<AccordionGroup>
  <Accordion title="Do I need to pick the two versions myself?">
    No. Ask about "the last two versions", or name one if you want an older baseline — for example
    "compare this to the version from before the coordination meeting." Intelligence finds and
    attaches the versions it needs.
  </Accordion>

  <Accordion title="What counts as 'significant'?">
    Not fixed. In this example Intelligence scored elements by how many properties changed and split
    them into rough tiers. Ask it to explain its thresholds, or tell it to weight geometry changes
    over parameter-only changes, if you want a different definition of significant for your project.
  </Accordion>

  <Accordion title="Does this need a version in the new 2026.9 data format?">
    Yes. Like every other Intelligence query, comparing versions needs both versions in the new data
    format. Versions still in the old format cannot be queried. See [Speckle's data model is
    changing](/workspaces/data-model-migration).
  </Accordion>

  <Accordion title="Can I run this exact walkthrough on my own model?">
    Yes — the questions on this page are plain language, not a script. Ask them in Chat or the
    viewer sparkle on any project with at least two versions in the new data format.
  </Accordion>
</AccordionGroup>

## See also

* [Ask questions about your models with Speckle Intelligence](/next/analytics/intelligence)
* [Create and share Intelligence Reports](/next/analytics/reports)
* [Reuse organisation playbooks with Intelligence skills](/next/analytics/intelligence-skills)
* [Compare Versions](/3d-viewer/compare-versions) — the deprecated Current-viewer diff view this
  replaces
* [3D viewer in 2026.9](/next/3d-viewer/introduction)
