chore: remove Stainless attribution and infrastructure (#3599)

## Changes

- Remove Stainless attribution from legacy generated-file headers,
README/agent guidance, security reporting, and repository-owned
examples.
- Remove Stainless-only CI/upload infrastructure, obsolete
mirror-specific workflow behavior, and legacy `.stats.yml`.
- Keep Castiron generation metadata, public release workflows, and
mock-server validation intact.

## Out of scope

- Renaming `X-Stainless-*` request headers, retry/idempotency
identifiers, OpenAPI `x-stainless-*` extensions, generated fixture
identifiers, changelog history, or third-party provenance.

Author: apcha-oai

.github/workflows/ci.yml

@@ -5,15 +5,7 @@ on:
       - '**'
       - '!gh-readonly-queue/**'
       - '!integrated/**'
-      - '!stl-preview-head/**'
-      - '!stl-preview-base/**'
-      - '!generated'
-      - '!codegen/**'
-      - 'codegen/stl/**'
   pull_request:
-    branches-ignore:
-      - 'stl-preview-head/**'
-      - 'stl-preview-base/**'
   merge_group:
     types:
       - checks_requested
@@ -30,8 +22,8 @@ jobs:
   lint:
     timeout-minutes: 10
     name: lint
-    runs-on: ${{ startsWith(github.repository, 'stainless-sdks/') && 'depot-ubuntu-24.04' || 'ubuntu-latest' }}
-    if: (github.event_name == 'push' || github.event_name == 'merge_group' || github.event.pull_request.head.repo.fork) && (github.event_name != 'push' || github.event.head_commit.message != 'codegen metadata')
+    runs-on: ubuntu-latest
+    if: github.event_name == 'push' || github.event_name == 'merge_group' || github.event.pull_request.head.repo.fork
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
@@ -48,12 +40,12 @@ jobs:
         run: ./scripts/lint
 
   build:
-    if: (github.event_name == 'push' || github.event_name == 'merge_group' || github.event.pull_request.head.repo.fork) && (github.event_name != 'push' || github.event.head_commit.message != 'codegen metadata')
+    if: github.event_name == 'push' || github.event_name == 'merge_group' || github.event.pull_request.head.repo.fork
     timeout-minutes: 10
     name: build
     permissions:
       contents: read
-    runs-on: ${{ startsWith(github.repository, 'stainless-sdks/') && 'depot-ubuntu-24.04' || 'ubuntu-latest' }}
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
         with:
@@ -96,54 +88,10 @@ jobs:
       - name: Validate HTTPX2 wheel on Python 3.14
         run: python scripts/utils/validate-httpx2-wheel.py
 
-      - name: Stage tarball for Stainless upload
-        if: |-
-          github.repository == 'stainless-sdks/openai-python' &&
-          !startsWith(github.ref, 'refs/heads/stl/')
-        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
-        with:
-          name: stainless-package-tarball
-          path: dist/
-          if-no-files-found: error
-          retention-days: 1
-
-  stainless-upload:
-    name: upload tarball to Stainless
-    needs: build
-    if: github.repository == 'stainless-sdks/openai-python' && !startsWith(github.ref, 'refs/heads/stl/')
-    runs-on: ubuntu-latest
-    permissions:
-      contents: read
-      id-token: write
-
-    steps:
-      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
-        with:
-          persist-credentials: false
-
-      - name: Download tarball
-        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
-        with:
-          name: stainless-package-tarball
-          path: dist/
-
-      - name: Get GitHub OIDC Token
-        id: github-oidc
-        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
-        with:
-          script: core.setOutput('github_token', await core.getIDToken());
-
-      - name: Upload tarball
-        env:
-          URL: https://pkg.stainless.com/s
-          AUTH: ${{ steps.github-oidc.outputs.github_token }}
-          SHA: ${{ github.sha }}
-        run: ./scripts/utils/upload-artifact.sh
-
   test:
     timeout-minutes: 15
     name: test (Python ${{ matrix.python-version }})
-    runs-on: ${{ startsWith(github.repository, 'stainless-sdks/') && 'depot-ubuntu-24.04' || 'ubuntu-latest' }}
+    runs-on: ubuntu-latest
     if: github.event_name == 'push' || github.event_name == 'merge_group' || github.event.pull_request.head.repo.fork
     strategy:
       fail-fast: false
@@ -185,7 +133,7 @@ jobs:
   test-httpx2:
     timeout-minutes: 20
     name: test (HTTPX2)
-    runs-on: ${{ startsWith(github.repository, 'stainless-sdks/') && 'depot-ubuntu-24.04' || 'ubuntu-latest' }}
+    runs-on: ubuntu-latest
     if: github.event_name == 'push' || github.event_name == 'merge_group' || github.event.pull_request.head.repo.fork
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
@@ -223,8 +171,8 @@ jobs:
     timeout-minutes: 10
     name: examples
     environment: ci
-    runs-on: ${{ startsWith(github.repository, 'stainless-sdks/') && 'depot-ubuntu-24.04' || 'ubuntu-latest' }}
-    if: github.repository == 'openai/openai-python' && github.ref != 'refs/heads/release-please--branches--main' && (github.event_name == 'push' || github.event.pull_request.head.repo.fork) && (github.event_name != 'push' || github.event.head_commit.message != 'codegen metadata')
+    runs-on: ubuntu-latest
+    if: github.repository == 'openai/openai-python' && github.ref != 'refs/heads/release-please--branches--main' && (github.event_name == 'push' || github.event.pull_request.head.repo.fork)
 
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6

.stats.yml

@@ -2,7 +2,7 @@
 
 ## Generated SDK
 
-Most SDK source is generated by Stainless. Follow `CONTRIBUTING.md` before
+Most SDK source is generated from the OpenAI API schema. Follow `CONTRIBUTING.md` before
 changing generated files. Handwritten policy, automation, tests, and examples
 should remain small and should not alter exported SDK APIs unless the change
 explicitly requires it.

AGENTS.md

@@ -7,7 +7,7 @@ The OpenAI Python library provides convenient access to the OpenAI REST API from
 application. The library includes type definitions for all request params and response fields,
 and offers both synchronous and asynchronous clients powered by [HTTPX2](https://httpx2.pydantic.dev/).
 
-It is generated from our [OpenAPI specification](https://github.com/openai/openai-openapi) with [Stainless](https://stainlessapi.com/).
+It is generated from our [OpenAPI specification](https://github.com/openai/openai-openapi).
 
 ## Documentation
 

README.md

@@ -2,28 +2,12 @@
 
 ## Reporting Security Issues
 
-This SDK is generated by [Stainless Software Inc](http://stainless.com). Stainless takes security seriously, and encourages you to report any security vulnerability promptly so that appropriate action can be taken.
-
-To report a security issue, please contact the Stainless team at security@stainless.com.
+Please report potential security vulnerabilities through OpenAI's
+[coordinated vulnerability disclosure process](https://openai.com/policies/coordinated-vulnerability-disclosure-policy).
+For questions about that process, contact disclosure@openai.com.
 
 ## Responsible Disclosure
 
-We appreciate the efforts of security researchers and individuals who help us maintain the security of
-SDKs we generate. If you believe you have found a security vulnerability, please adhere to responsible
-disclosure practices by allowing us a reasonable amount of time to investigate and address the issue
-before making any information public.
-
-## Reporting Non-SDK Related Security Issues
-
-If you encounter security issues that are not directly related to SDKs but pertain to the services
-or products provided by OpenAI, please follow the respective company's security reporting guidelines.
-
-### OpenAI Terms and Policies
-
-Our Security Policy can be found at [Security Policy URL](https://openai.com/policies/coordinated-vulnerability-disclosure-policy).
-
-Please contact disclosure@openai.com for any questions or concerns regarding the security of our services.
-
----
-
-Thank you for helping us keep the SDKs and systems they interact with secure.
+Please allow OpenAI a reasonable amount of time to investigate and address the
+issue before making information public. Thank you for helping us keep this SDK
+and the systems it interacts with secure.

SECURITY.md

@@ -1,4 +1,2 @@
-File generated from our OpenAPI spec by Stainless.
-
 This directory can be used to store example files demonstrating usage of this SDK.
-It is ignored by Stainless code generation and its content (other than this keep file) won't be touched.
+It is ignored by code generation and its content (other than this keep file) won't be touched.

examples/.keep

@@ -17,12 +17,7 @@ elif [[ -f .castiron.stats.yml && -f api_reference/openapi.transformed.yml ]]; t
     exit 1
   fi
 else
-  URL="$(grep 'openapi_spec_url' .stats.yml | cut -d' ' -f2)"
-fi
-
-# Check if the URL is empty
-if [ -z "$URL" ]; then
-  echo "Error: No OpenAPI spec path/url provided or found in .stats.yml"
+  echo "Error: No OpenAPI spec path/url provided or found in Castiron generation metadata" >&2
   exit 1
 fi
 

scripts/mock

@@ -1,5 +1,3 @@
-# File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
-
 import httpx2
 
 RAW_RESPONSE_HEADER = "X-Stainless-Raw-Response"

scripts/utils/upload-artifact.sh

@@ -1,5 +1,3 @@
-# File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
-
 from __future__ import annotations
 
 import threading