# Mermaid 11.15.0

- Product: Mermaid (https://whatsnew.fyi/product/mermaid)
- Vendor: Mermaid
- Date: 2026-05-11
- Version: 11.15.0
- Original notes: https://github.com/mermaid-js/mermaid/releases/tag/mermaid%4011.15.0
- Permalink: https://whatsnew.fyi/product/mermaid/releases/11.15.0

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

---

- **added** — Add support for decimal start and increment values in the autonumber directive for sequence diagrams
- **added** — Add datastore shape to flowcharts, denoted by a rectangle with only top and bottom borders, usable with A@{ shape: datastore, label: "Datastore" }
- **added** — Add Event Modeling diagram type
- **added** — Expose four fcose layout knobs for architecture-beta diagrams (nodeSeparation, idealEdgeLengthMultiplier, edgeElasticity, numIter) to tune layout density and spread
- **added** — Add nested namespace support for class diagrams via dot notation and syntactic nesting
- **added** — Add outlined label style, configurable nodeWidth/nodePadding, and custom node colors to sankey diagrams
- **fixed** — Prevent unbalanced CSS styles in classDefs
- **fixed** — Create CSS styles using the CSSOM to remove invalid CSS and normalize CSS formatting
- **fixed** — Make end note in stateDiagram only close a note when used on a new line
- **fixed** — Add iteration limit for excludes field in gantt diagrams
- **fixed** — Disallow some CSS at-rules in custom CSS
- **fixed** — Fix unnecessary sanitization of text in wardley diagrams
- **fixed** — Prevent self-referential class multiplicity labels from being rendered multiple times
- **fixed** — Add background box behind alt/else section title labels in sequence diagrams
- **fixed** — Prevent column widths from shrinking when mixing different column spans in block diagrams
- **fixed** — Correct messageAlign label position for right-to-left arrows in sequence diagrams
- **fixed** — Allow hyphens in unquoted component names in wardley diagrams

###### Minor Changes

-   [#7174](https://github.com/mermaid-js/mermaid/pull/7174) [`0aca217`](https://github.com/mermaid-js/mermaid/commit/0aca21739c0d1fcaaa206e04a6cd574ebc415483) Thanks [@milesspencer35](https://github.com/milesspencer35)! - feat(sequence): Add support for decimal start and increment values in the `autonumber` directive

-   [#7512](https://github.com/mermaid-js/mermaid/pull/7512) [`8e17492`](https://github.com/mermaid-js/mermaid/commit/8e17492f7365ba50896382feb69a23efd9d8a22d) Thanks [@aruncveli](https://github.com/aruncveli)! - feat(flowchart): add datastore shape

    In Data flow diagrams, a datastore/warehouse/file/database is used to represent data persistence. It is denoted by a rectangle with only top and bottom borders, and can be used in flowcharts with `A@{ shape: datastore, label: "Datastore" }`.

-   [#6440](https://github.com/mermaid-js/mermaid/pull/6440) [`9ad8dde`](https://github.com/mermaid-js/mermaid/commit/9ad8dde6d049adde85d8ed2d476c09b5820f3f4b) Thanks [@yordis](https://github.com/yordis), [@lgazo](https://github.com/lgazo)! - feat: add Event Modeling diagram

-   [#7707](https://github.com/mermaid-js/mermaid/pull/7707) [`27db774`](https://github.com/mermaid-js/mermaid/commit/27db774627be1cee881961dfd0d2cb21cd01b79d) Thanks [@txmxthy](https://github.com/txmxthy)! - feat(architecture): expose four fcose layout knobs for `architecture-beta` diagrams (`nodeSeparation`, `idealEdgeLengthMultiplier`, `edgeElasticity`, `numIter`) so authors can tune layout density and spread overlapping siblings without changing diagram source

-   [#7604](https://github.com/mermaid-js/mermaid/pull/7604) [`bf9502f`](https://github.com/mermaid-js/mermaid/commit/bf9502fb6012a4b724679b401ac928f5ee55161c) Thanks [@M-a-c](https://github.com/M-a-c)! - feat(class): add nested namespace support for class diagrams via dot notation and syntactic nesting

    If you have namespaces in class diagrams that use `.`s already and want to render them without nesting (≤v11.14.0 behaviour), you can use set `class.hierarchicalNamespaces=false` in your mermaid config:

    ```yaml
    config:
      class:
        hierarchicalNamespaces: false
    ```

-   [#7272](https://github.com/mermaid-js/mermaid/pull/7272) [`88cdd3d`](https://github.com/mermaid-js/mermaid/commit/88cdd3dc0aab9577174561b04e14760c565a232b) Thanks [@xinbenlv](https://github.com/xinbenlv)! - feat(sankey): add outlined label style, configurable nodeWidth/nodePadding, and custom node colors

###### Patch Changes

-   [#7737](https://github.com/mermaid-js/mermaid/pull/7737) [`e9b0f34`](https://github.com/mermaid-js/mermaid/commit/e9b0f34d8d82a6260077764ee45e1d7d90957a0f) Thanks [@ashishjain0512](https://github.com/ashishjain0512)! - fix: prevent unbalanced CSS styles in classDefs

-   [#7737](https://github.com/mermaid-js/mermaid/pull/7737) [`37ff937`](https://github.com/mermaid-js/mermaid/commit/37ff937f1da2e19f882fd1db01235db4d01f4056) Thanks [@ashishjain0512](https://github.com/ashishjain0512)! - fix: create CSS styles using the CSSOM

    This removes some invalid CSS and normalizes some CSS formatting.

-   [#7508](https://github.com/mermaid-js/mermaid/pull/7508) [`bfe60cc`](https://github.com/mermaid-js/mermaid/commit/bfe60cc67b9a6dec64f9161f58e4d24a06c42b65) Thanks [@biiab](https://github.com/biiab)! - fix(stateDiagram): `end note` now only closes a note when used on a new line

-   [#7737](https://github.com/mermaid-js/mermaid/pull/7737) [`faafb5d`](https://github.com/mermaid-js/mermaid/commit/faafb5d49106dd32c367f3882505f2dd625aa30e) Thanks [@ashishjain0512](https://github.com/ashishjain0512)! - fix(gantt): add iteration limit for `excludes` field

-   [#7737](https://github.com/mermaid-js/mermaid/pull/7737) [`65f8be2`](https://github.com/mermaid-js/mermaid/commit/65f8be2a42faf869b811469571983cba7eeeca99) Thanks [@ashishjain0512](https://github.com/ashishjain0512)! - fix: disallow some CSS at-rules in custom CSS

-   [#7726](https://github.com/mermaid-js/mer

_[Truncated at 4000 characters — full notes: https://github.com/mermaid-js/mermaid/releases/tag/mermaid%4011.15.0]_