DamianReeves · Oct 28, 2026 · Oct 27, 2026 · Oct 27, 2026 · Oct 27, 2026
diff --git a/.claude/skills/release-manager/SKILL.md b/.claude/skills/release-manager/SKILL.md
@@ -153,11 +153,17 @@ Before a release, check finos/morphir-elm for a newer `extension/elm/v*` tag and
 finos/morphir-scala for a newer `v*` release, and move the pins.
 
 **WASM extensions (Avro, OpenAPI, Python, Rust).** finos/morphir does not build
-the guests. finos/morphir-rust owns the check that a new bundle works with the
-released CLI. This repository owns the check that a CLI change does not break the
-bundles users already installed: CI downloads the bundles pinned in
+the guests. The repository that owns an extension checks that a new bundle works
+with the released CLI: finos/morphir-rust for Avro, OpenAPI and Rust, and
+finos/morphir-python for Python (crate `rust/crates/morphir-python-binding`,
+release tags `extension/python/v<version>`). Python bundles up to
+`extension/python/v0.4.0` stay in the finos/morphir-rust releases. This
+repository owns the check that a CLI change does not break the bundles users
+already installed: CI downloads the bundles pinned in
 `.config/published-extension-bundles.toml` and runs the ignored extension tests
-against them. Run the same check with the release binary:
+against them. A `[bundles.<id>]` pin names the releasing repository in
+`repository`; a pin without one comes from finos/morphir-rust. Run the same check
+with the release binary:
 
 ```bash
 mise run ci:fetch-published-bundles
@@ -169,10 +175,12 @@ MORPHIR_PYTHON_BUNDLE="$B/python" MORPHIR_RUST_BUNDLE="$B/rust" \
     --test python_extension --test rust_extension -- --ignored
 ```
 
-Before a release, check finos/morphir-rust releases for newer `extension/<id>/v*`
-tags and move the pins. When the CLI changes the extension protocol on purpose,
-publish a compatible bundle from finos/morphir-rust first, then move the pin in
-the same pull request as the CLI change.
+Before a release, check the releases of each owning repository for newer
+`extension/<id>/v*` tags and move the pins: finos/morphir-rust for Avro, OpenAPI
+and Rust, finos/morphir-python for Python. A pin that moves to another repository
+changes `repository` with its tag, artifact and `sha256`. When the CLI changes the
+extension protocol on purpose, publish a compatible bundle from the owning
+repository first, then move the pin in the same pull request as the CLI change.
 
 Then prove one bundle by hand in a clean home. `generate` needs a project
 configuration, so the steps run inside a directory with a `morphir.toml`:

diff --git a/.config/published-extension-bundles.toml b/.config/published-extension-bundles.toml
@@ -1,9 +1,12 @@
-# Published finos/morphir-rust extension bundles that CI runs the CLI against.
+# Published WASM extension bundles that CI runs the CLI against.
 #
 # These are the bundles users install. A CLI change that breaks one of them turns CI red.
+# Each bundle is downloaded from the releases of the repository that owns it. `repository` names
+# that repository as `owner/name`; a pin without one comes from finos/morphir-rust.
 # `sha256` is the digest of the guest `.wasm`. It is checked against the download, so a release
-# asset that someone replaces does not run. For a deliberate protocol change, publish a compatible bundle from finos/morphir-rust first,
-# then move the pin here in the same pull request as the CLI change.
+# asset that someone replaces does not run. For a deliberate protocol change, publish a compatible
+# bundle from the repository that owns it first, then move the pin here in the same pull request
+# as the CLI change.
 
 [bundles.avro]
 tag = "extension/avro/v0.2.0"
@@ -15,10 +18,13 @@ tag = "extension/openapi/v0.2.0"
 artifact = "morphir-openapi-extension-0.2.0"
 sha256 = "ccef0ebcc8f4fff5579c5c28ee4cb44cdec46a6f4ec993a8e6ceb029996f5ec0"
 
+# finos/morphir-python owns the Python extension. Bundles up to extension/python/v0.4.0 remain in
+# the finos/morphir-rust releases.
 [bundles.python]
-tag = "extension/python/v0.4.0"
-artifact = "morphir-python-binding-0.4.0"
-sha256 = "e5bc0d1593eb1b3f7d33d6a627e07c14c0fd21c9274abc22bd326318c602c36b"
+repository = "finos/morphir-python"
+tag = "extension/python/v0.4.1"
+artifact = "morphir-python-binding-0.4.1"
+sha256 = "a04722e16115667fc7c332177805dcb049aef563afcee0e5f80c5fea302f5b4e"
 
 [bundles.rust]
 tag = "extension/rust/v0.3.0"

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -311,9 +311,10 @@ jobs:
 
       - name: Fetch the published extensions
         # The extensions users install, at the tags and digests pinned in
-        # .config/published-extension-bundles.toml: four WASM bundles from
-        # finos/morphir-rust, the Elm process extension from finos/morphir-elm
-        # and the Scala Elm provider from finos/morphir-scala. The owning
+        # .config/published-extension-bundles.toml: four WASM bundles from the
+        # repositories that release them, the Elm process extension from
+        # finos/morphir-elm and the Scala Elm provider from
+        # finos/morphir-scala. The owning
         # repository checks that a new release
         # works with the released CLI; this job checks that a CLI change does
         # not break the published releases.

diff --git a/AGENTS.md b/AGENTS.md
@@ -47,7 +47,7 @@ Current `mise` releases auto-trust project configuration in normal mode; the exp
 - **[finos/morphir-rust](https://github.com/finos/morphir-rust)** — Rust libraries (`morphir-core`, `morphir-common`, etc.) used by the CLI
 - **[finos/morphir-examples](https://github.com/finos/morphir-examples)** — Example Morphir projects
 - **[finos/morphir-moonbit](https://github.com/finos/morphir-moonbit)** — MoonBit implementation of Morphir tooling
-- **[finos/morphir-python](https://github.com/finos/morphir-python)** — Python implementation of Morphir tooling
+- **[finos/morphir-python](https://github.com/finos/morphir-python)** — Python implementation of Morphir tooling, and the owner of the Python compiler and the `morphir-python` WASM extension (new `extension/python/v*` releases; bundles up to `v0.4.0` stay in finos/morphir-rust releases)
 - **[finos/morphir-scala](https://github.com/finos/morphir-scala)** — Scala implementation of Morphir tooling
 - **[finos/morphir-ui](https://github.com/finos/morphir-ui)** — User-interface work for the Morphir project
 

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+- The `morphir-python` extension now comes from finos/morphir-python, which maintains the
+  Python compiler. CI tests the CLI against its `extension/python/v0.4.1` bundle; bundles up to
+  `extension/python/v0.4.0` remain in the finos/morphir-rust releases. Extension bundle pins
+  can name the repository that owns them.
+
 ## [0.4.0-beta.10] - 2026-10-21
 
 ### Added

diff --git a/INSTALLING.md b/INSTALLING.md
@@ -85,17 +85,32 @@ if ($actual -ne $expected) { throw "Checksum verification failed" }
 
 ## Install the Python extension
 
-The CLI ships separately from language extensions. With CLI `0.4.0-beta.7` or
-later, install the `morphir-python` WASM bundle `extension/python/v0.4.0` to compile
-supported Python ADTs, fixed tuples, conditional functions, typed calls and unary
-lambdas to Morphir IR v3 or v4 and generate Python. Its version-2 descriptor needs
-CLI `0.4.0-beta.7` to publish; with CLI `0.4.0-beta.1` to `0.4.0-beta.6`, use
-`extension/python/v0.3.0`. The earlier `v0.1.0` bundle does not compile with this CLI.
-See the [Python extension installation guide](https://github.com/finos/morphir-rust/blob/main/docs/tutorials/python-extension.md)
+The CLI ships separately from language extensions. The `morphir-python` WASM
+extension compiles supported Python ADTs, fixed tuples, conditional functions,
+typed calls and unary lambdas to Morphir IR v3 or v4 and generates Python.
+
+[finos/morphir-python](https://github.com/finos/morphir-python) owns the
+extension. It holds the compiler crate,
+[`morphir-python-binding`](https://github.com/finos/morphir-python/blob/main/rust/crates/morphir-python-binding/README.md),
+and publishes new `extension/python/v<version>` bundles in its releases. The
+bundles up to `extension/python/v0.4.0` were released from finos/morphir-rust and
+stay in the [finos/morphir-rust releases](https://github.com/finos/morphir-rust/releases).
+
+With CLI `0.4.0-beta.7` or later, install the bundle `extension/python/v0.4.0`. Its
+version-2 descriptor needs CLI `0.4.0-beta.7` to publish; with CLI `0.4.0-beta.1`
+to `0.4.0-beta.6`, use `extension/python/v0.3.0`. The earlier `v0.1.0` bundle does
+not compile with this CLI. See the
+[Python extension guide](https://github.com/finos/morphir-python/blob/main/docs/python-extension.md)
 for download, repository publication and installation commands, and the
-[binding README](https://github.com/finos/morphir-rust/blob/main/crates/morphir-python-binding/README.md)
+[binding README](https://github.com/finos/morphir-python/blob/main/rust/crates/morphir-python-binding/README.md)
 for the supported subset and conformance limits.
 
+finos/morphir-python also packages the same compiler for Python. From the first
+`morphir-python` release on PyPI that includes it, `pip install morphir-python`
+gives a Python API and a `morphir-python` command that compile and generate
+without the Morphir CLI. See the
+[Python compiler guide](https://github.com/finos/morphir-python/blob/main/docs/python-compiler.md).
+
 ## Build from source
 
 Building from source requires Git, [mise](https://mise.jdx.dev/), and the

diff --git a/README.md b/README.md
@@ -76,7 +76,7 @@ Morphir consists of a few projects based on the features they provide.
 - **[morphir-bosque](https://github.com/finos/morphir-bosque)** - Integration with the Bosque language.
 - **[morphir-dotnet](https://github.com/finos/morphir-dotnet)** - Integration with .NET via F#.
 - **[morphir-rust](https://github.com/finos/morphir-rust)** - Integration with Rust
-- **[morphir-python](https://github.com/finos/morphir-python)** - Integration with Python
+- **[morphir-python](https://github.com/finos/morphir-python)** - Integration with Python: the IR library and SDK, the Python compiler and the `morphir-python` extension for the Morphir CLI
 - **[morphir-moonbit](https://github.com/finos/morphir-moonbit)** - MoonBit implementation of Morphir tooling
 - **[morphir-go](https://github.com/finos/morphir-go)** - Go implementation of Morphir tooling (CLI, WIT pipeline, Go backends)
 - **[morphir-ui](https://github.com/finos/morphir-ui)** - User-interface work for the Morphir project

diff --git a/crates/morphir/tests/host_compatibility.rs b/crates/morphir/tests/host_compatibility.rs
@@ -305,7 +305,8 @@ fn openapi() {
 #[test]
 #[ignore = "requires MORPHIR_PUBLISHED_BUNDLES"]
 fn python() {
-    // morphir-python-binding/tests/pipeline.rs: backend_accepts_an_independently_authored_sum.
+    // finos/morphir-python, rust/crates/morphir-python-binding/tests/pipeline.rs:
+    // backend_accepts_an_independently_authored_sum.
     wasm(
         "python",
         serde_json::from_str(include_str!(

diff --git a/ecosystem/AGENTS.md b/ecosystem/AGENTS.md
@@ -8,7 +8,7 @@ This directory holds **git submodules** for Morphir ecosystem repositories. Use
 - **morphir-rust** – Rust workspace (morphir-core, morphir-common, morphir-daemon, morphir-ext, etc.). The **morphir** CLI binary lives in this repo under `crates/morphir`, not in the submodule; it depends on morphir-rust crates via path.
 - **morphir-examples** – Example Morphir projects.
 - **morphir-moonbit** – MoonBit implementation of Morphir tooling.
-- **morphir-python** – Python implementation of Morphir tooling.
+- **morphir-python** – Python implementation of Morphir tooling. Owns the Python compiler and the `morphir-python` WASM extension.
 - **morphir-scala** – Scala implementation of Morphir tooling. Mill build, cross-compiled to JVM, JS, and Scala Native.
 - **morphir-ui** – Morphir's UI monorepo: the morphir-desktop (Electron) and morphir-web apps sharing one Svelte + Effect application (moonrepo + mise + bun toolchain).
 - **morphir-typescript** – TypeScript binding for the Morphir IR: the reference semantic model, the version and profile codecs, and its MCK adapter. Shared IR and package runners live in the parent Rust CLI, `morphir mck`. TypeScript retains independent adapters/implementations. PKG-2 moves draft.3 corpus/fixture support to parent Rust MCK and bounded runtime helpers to `morphir-package` in [#852](https://github.com/finos/morphir/issues/852). See [spec/mck/migration.md](../spec/mck/migration.md). Bun workspace; runtime-neutral (Node, Bun, Deno, browser).
@@ -62,6 +62,8 @@ Valid package names: `morphir-sdk`, `morphir-core`, `morphir-moonbit-bindings`
 
 Python implementation of Morphir tooling. Uses `uv` for package management and `behave` for BDD tests.
 
+It also owns the Python compiler, the Rust crate `rust/crates/morphir-python-binding`, and the `morphir-python` WASM extension built from it (extension id `morphir-python`, short id `python`, artifact `morphir-python-binding-<version>`, release tags `extension/python/v<version>`). Bundles up to `extension/python/v0.4.0` were released from finos/morphir-rust and stay in its releases. finos/morphir does not build the bundle: `[bundles.python]` in `.config/published-extension-bundles.toml` pins a published release and names its repository. The guides are `docs/python-extension.md` and `docs/python-compiler.md` in that repository.
+
 ```bash
 cd ecosystem/morphir-python && uv sync && uv run behave
 ```

diff --git a/ecosystem/README.md b/ecosystem/README.md
@@ -10,7 +10,7 @@ This directory contains [git submodules](https://git-scm.com/book/en/v2/Git-Tool
 | **morphir-rust** | [finos/morphir-rust](https://github.com/finos/morphir-rust) | main | Rust libraries (morphir-core, morphir-common, etc.) used by the morphir CLI in this repo |
 | **morphir-examples** | [finos/morphir-examples](https://github.com/finos/morphir-examples) | main | Example Morphir projects; used for docs, tests, and reference |
 | **morphir-moonbit** | [finos/morphir-moonbit](https://github.com/finos/morphir-moonbit) | main | MoonBit implementation of Morphir tooling |
-| **morphir-python** | [finos/morphir-python](https://github.com/finos/morphir-python) | main | Python implementation of Morphir tooling |
+| **morphir-python** | [finos/morphir-python](https://github.com/finos/morphir-python) | main | Python implementation of Morphir tooling; owns the Python compiler and the `morphir-python` WASM extension |
 | **morphir-scala** | [finos/morphir-scala](https://github.com/finos/morphir-scala) | main | Scala implementation of Morphir tooling; Mill build cross-compiled to JVM, JS, and Scala Native |
 | **morphir-ui** | [finos/morphir-ui](https://github.com/finos/morphir-ui) | main | Morphir's UI monorepo: the morphir-desktop (Electron) and morphir-web apps sharing one Svelte + Effect application |
 
@@ -66,7 +66,7 @@ mise run submodules:status
 - **morphir-rust**: The morphir CLI (in `crates/`) depends on morphir-rust crates via Cargo path dependencies (e.g. `morphir-core`, `morphir-common`). The submodule is required to build those crates.
 - **morphir-examples**: Used for examples, documentation, and tests. See each submodule's own README for build and usage.
 - **morphir-moonbit**: MoonBit implementation with packages for SDK, core types, and WASM bindings. See below for build commands.
-- **morphir-python**: Python implementation of Morphir tooling. See the submodule's own README for build and usage.
+- **morphir-python**: Python implementation of Morphir tooling. It owns the Python compiler (the Rust crate `rust/crates/morphir-python-binding`) and the `morphir-python` WASM extension that the CLI installs, and releases new `extension/python/v<version>` bundles. Bundles up to `extension/python/v0.4.0` were released from finos/morphir-rust and stay there. The CLI in this repository does not build the extension; CI runs it against the bundle pinned in `.config/published-extension-bundles.toml`. See the submodule's own README, `docs/python-extension.md` and `docs/python-compiler.md` for build and usage.
 - **morphir-scala**: Scala implementation of Morphir tooling, built with Mill. See below for build commands.
 - **morphir-ui**: Morphir's UI monorepo — the morphir-desktop (Electron) and morphir-web apps sharing one Svelte + Effect application, with `morphir-ir.json` browsing, MORPHIR_HOME-backed configuration, and GitHub token capture. Build from within the submodule (it has its own mise toolchain): `cd ecosystem/morphir-ui && mise install && bun install && moon run :build` (see that repo's README for the full getting-started guide).
 

diff --git a/tests/ci/test_ci_rust_optimizations.py b/tests/ci/test_ci_rust_optimizations.py
@@ -42,8 +42,8 @@ def test_setup_rust_ci_action_shares_cargo_cache(self) -> None:
         self.assertIn("link-arg=-fuse-ld=mold", self.setup_rust_ci_action)
 
     def test_ci_tests_published_bundles_and_builds_no_wasm_guest(self) -> None:
-        # finos/morphir-rust owns the guest builds. This repository checks that a CLI change
-        # does not break the bundles users already installed.
+        # The repository that owns each extension builds its guest. This repository checks
+        # that a CLI change does not break the bundles users already installed.
         self.assertIn("mise run ci:fetch-published-bundles", self.ci_workflow)
         self.assertNotIn("--target wasm32-unknown-unknown", self.ci_workflow)
         self.assertNotIn("package_extension.py", self.ci_workflow)