diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 0ee8c01..2537c1f 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.3.0"
+  ".": "0.4.0"
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a527a09..df55efb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,16 @@
 # Changelog
 
+## [0.4.0](https://github.com/mozilla-ai/otari-sdk-python/compare/otari-0.3.0...otari-0.4.0) (2026-09-16)
+
+
+### ⚠ BREAKING CHANGES
+
+* api_base must be the gateway origin with no path prefix, and requests now go to /api/v1 instead of /v1. Upgrade alongside an Otari gateway that serves the /api/v1 prefix.
+
+### Features
+
+* target the /api/v1 prefix + Regenerate SDK client core from Otari OpenAPI spec ([#78](https://github.com/mozilla-ai/otari-sdk-python/issues/78)) ([6119622](https://github.com/mozilla-ai/otari-sdk-python/commit/6119622f5864b9b50bb109f3544f39a7d36f29af))
+
 ## [0.3.0](https://github.com/mozilla-ai/otari-sdk-python/compare/otari-0.2.0...otari-0.3.0) (2026-08-13)
 
 
diff --git a/pyproject.toml b/pyproject.toml
index 527b0da..c74d57e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "otari"
-version = "0.3.0"
+version = "0.4.0"
 description = "Python client for the otari gateway"
 readme = "README.md"
 license = "Apache-2.0"
diff --git a/src/otari/__init__.py b/src/otari/__init__.py
index 82c2c45..515f9a0 100644
--- a/src/otari/__init__.py
+++ b/src/otari/__init__.py
@@ -58,7 +58,7 @@
 try:
     __version__ = version("otari")
 except PackageNotFoundError:
-    __version__ = "0.3.0"
+    __version__ = "0.4.0"
 
 
 __all__ = [