Release 4.12.15

CHANGELOG.md

@@ -1,14 +1,12 @@
 # Changelog
 
-## Unreleased (4.12.15 in preparation)
+## Version 4.12.15, 9/22/2026
 
-### Changed
-
-- The forwarder's span kind now follows the engines' connected-span-tree rule: the record whose
-  `service` is `http.request` - an engine edge's round-trip record - is the `SERVER` span, and every
-  function execution is `INTERNAL` (a record's `from` no longer decides the kind). A host's own
-  records are function executions, so a backend now shows them as `INTERNAL` hops under the
-  calling engine's edge span.
+The lock-step round with the engines: the pack moves from 4.12.1 to 4.12.15, the number the Java engine and the
+Rust port ship in the same round (`conv-ports-adopt-java-release-number` — a version names content, not a
+cadence). Interop evidence for this release: the four-runtime OpenTelemetry certification drive of 2026-09-22 —
+this host's forwarder and `llm.stream` node under both engines' edges, one connected trace per request, confirmed
+in the backend UI (`docs/test-reports/otel-dynatrace-certification.md`). Off by default; nothing to configure.
 
 ### Added
 
@@ -26,6 +24,12 @@
 
 ### Changed
 
+- The forwarder's span kind now follows the engines' connected-span-tree rule: the record whose
+  `service` is `http.request` - an engine edge's round-trip record - is the `SERVER` span, and every
+  function execution is `INTERNAL` (a record's `from` no longer decides the kind). A host's own
+  records are function executions, so a backend now shows them as `INTERNAL` hops under the
+  calling engine's edge span.
+
 - The demo AI nodes' default Gemini model is the stable alias `gemini-flash-latest`: the dated
   `gemini-3.6-flash` id is no longer served (404 on a current key) - the alias moves with the
   provider's current flash model. `llm.model` / `params.model` still pin a specific id.

README.md

@@ -26,7 +26,7 @@ graph task calls a Python function exactly as if it were local.
 [AI Agent Guide](https://accenture.github.io/mercury-python/guides/ai-agent-guide/)
 for deterministic function generation.
 
-> **Status:** v4.12.1 is on PyPI — `pip install mercury-composable`. This repository was
+> **Status:** v4.12.15 is on PyPI — `pip install mercury-composable`. This repository was
 > repurposed in August 2026 for the polyglot initiative. The legacy Mercury language-pack
 > implementation remains in git history.
 

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "mercury-composable"
-version = "4.12.1"
+version = "4.12.15"
 description = "Lightweight Event-over-HTTP function host and client for Mercury Composable"
 readme = "README.md"
 license = "Apache-2.0"

src/mercury_composable/version.py

@@ -1,3 +1,3 @@
 """Package version - the single Python-side source (pyproject.toml mirrors it)."""
 
-__version__ = "4.12.1"
+__version__ = "4.12.15"