diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 61d831bd..bf7b1f4c 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.31.2"
+  ".": "0.31.3"
 }
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 150d36f4..4e292cfa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## 0.31.3 (2026-08-20)
+
+Full Changelog: [v0.31.2...v0.31.3](https://github.com/openlayer-ai/openlayer-python/compare/v0.31.2...v0.31.3)
+
+### Chores
+
+* **internal:** allow the mock server port to be set with STAINLESS_MOCK_PORT ([66893e7](https://github.com/openlayer-ai/openlayer-python/commit/66893e7b7199fe7ba7ac6555bbc339eb9578faf6))
+
 ## 0.31.2 (2026-08-04)
 
 Full Changelog: [v0.31.1...v0.31.2](https://github.com/openlayer-ai/openlayer-python/compare/v0.31.1...v0.31.2)
diff --git a/pyproject.toml b/pyproject.toml
index 2523fb27..516f8988 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "openlayer"
-version = "0.31.2"
+version = "0.31.3"
 description = "The official Python library for the openlayer API"
 dynamic = ["readme"]
 license = "Apache-2.0"
diff --git a/scripts/mock b/scripts/mock
index feebe5ed..984e1c00 100755
--- a/scripts/mock
+++ b/scripts/mock
@@ -4,6 +4,11 @@ set -e
 
 cd "$(dirname "$0")/.."
 
+if [ "$1" == "--install" ]; then
+  npm exec --package=@stdy/cli@0.22.1 -- steady --version
+  exit 0
+fi
+
 if [[ -n "$1" && "$1" != '--'* ]]; then
   URL="$1"
   shift
@@ -20,16 +25,18 @@ fi
 echo "==> Starting mock server with URL ${URL}"
 
 # Run steady mock on the given spec
+MOCK_PORT="${STAINLESS_MOCK_PORT:-4010}"
+
 if [ "$1" == "--daemon" ]; then
   # Pre-install the package so the download doesn't eat into the startup timeout
   npm exec --package=@stdy/cli@0.22.1 -- steady --version
 
-  npm exec --package=@stdy/cli@0.22.1 -- steady --host 127.0.0.1 -p 4010 --validator-query-array-format=comma --validator-form-array-format=comma --validator-query-object-format=brackets --validator-form-object-format=brackets "$URL" &> .stdy.log &
+  npm exec --package=@stdy/cli@0.22.1 -- steady --host 127.0.0.1 -p "$MOCK_PORT" --validator-query-array-format=comma --validator-form-array-format=comma --validator-query-object-format=brackets --validator-form-object-format=brackets "$URL" &> .stdy.log &
 
   # Wait for server to come online via health endpoint (max 30s)
   echo -n "Waiting for server"
   attempts=0
-  while ! curl --silent --fail "http://127.0.0.1:4010/_x-steady/health" >/dev/null 2>&1; do
+  while ! curl --silent --fail "http://127.0.0.1:$MOCK_PORT/_x-steady/health" >/dev/null 2>&1; do
     if ! kill -0 $! 2>/dev/null; then
       echo
       cat .stdy.log
@@ -48,5 +55,5 @@ if [ "$1" == "--daemon" ]; then
 
   echo
 else
-  npm exec --package=@stdy/cli@0.22.1 -- steady --host 127.0.0.1 -p 4010 --validator-query-array-format=comma --validator-form-array-format=comma --validator-query-object-format=brackets --validator-form-object-format=brackets "$URL"
+  npm exec --package=@stdy/cli@0.22.1 -- steady --host 127.0.0.1 -p "$MOCK_PORT" --validator-query-array-format=comma --validator-form-array-format=comma --validator-query-object-format=brackets --validator-form-object-format=brackets "$URL"
 fi
diff --git a/scripts/test b/scripts/test
index 19acc916..9dbb5cdb 100755
--- a/scripts/test
+++ b/scripts/test
@@ -9,8 +9,10 @@ GREEN='\033[0;32m'
 YELLOW='\033[0;33m'
 NC='\033[0m' # No Color
 
+MOCK_PORT="${STAINLESS_MOCK_PORT:-4010}"
+
 function steady_is_running() {
-  curl --silent "http://127.0.0.1:4010/_x-steady/health" >/dev/null 2>&1
+  curl --silent "http://127.0.0.1:$MOCK_PORT/_x-steady/health" >/dev/null 2>&1
 }
 
 kill_server_on_port() {
@@ -27,7 +29,7 @@ function is_overriding_api_base_url() {
 
 if ! is_overriding_api_base_url && ! steady_is_running ; then
   # When we exit this script, make sure to kill the background mock server process
-  trap 'kill_server_on_port 4010' EXIT
+  trap 'kill_server_on_port "$MOCK_PORT"' EXIT
 
   # Start the dev server
   ./scripts/mock --daemon
@@ -43,7 +45,7 @@ elif ! steady_is_running ; then
   echo -e "To run the server, pass in the path or url of your OpenAPI"
   echo -e "spec to the steady command:"
   echo
-  echo -e "  \$ ${YELLOW}npm exec --package=@stdy/cli@0.22.1 -- steady path/to/your.openapi.yml --host 127.0.0.1 -p 4010 --validator-query-array-format=comma --validator-form-array-format=comma --validator-query-object-format=brackets --validator-form-object-format=brackets${NC}"
+  echo -e "  \$ ${YELLOW}npm exec --package=@stdy/cli@0.22.1 -- steady path/to/your.openapi.yml --host 127.0.0.1 -p $MOCK_PORT --validator-query-array-format=comma --validator-form-array-format=comma --validator-query-object-format=brackets --validator-form-object-format=brackets${NC}"
   echo
 
   exit 1
@@ -52,6 +54,10 @@ else
   echo
 fi
 
+if [ -n "${STAINLESS_MOCK_PORT:-}" ] && ! is_overriding_api_base_url ; then
+  export TEST_API_BASE_URL="http://127.0.0.1:$MOCK_PORT"
+fi
+
 export DEFER_PYDANTIC_BUILD=false
 
 echo "==> Running tests"
diff --git a/src/openlayer/_version.py b/src/openlayer/_version.py
index 3d265be7..ee561d3f 100644
--- a/src/openlayer/_version.py
+++ b/src/openlayer/_version.py
@@ -1,4 +1,4 @@
 # File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
 
 __title__ = "openlayer"
-__version__ = "0.31.2"  # x-release-please-version
+__version__ = "0.31.3"  # x-release-please-version