chore: prepare for release v0.21.0 (#1723)

Co-authored-by: Pouyanpi <Pouyanpi@users.noreply.github.com>
Co-authored-by: Pouyanpi <13303554+Pouyanpi@users.noreply.github.com>

Author: github-actions[bot]

CHANGELOG.md

@@ -9,6 +9,56 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 >
 > The changes related to the Colang language and runtime have moved to [CHANGELOG-Colang](./CHANGELOG-Colang.md) file.
 
+## [0.21.0] - 2026-03-12
+
+### 🚀 Features
+
+- *(library)* Update Trend Micro Vision One AI Guard official endpoint ([#1546](https://github.com/NVIDIA-NeMo/Guardrails/issues/1546))
+- *(llmrails)* Add check_async method for input/output rails validation ([#1605](https://github.com/NVIDIA-NeMo/Guardrails/issues/1605))
+- *(server)* Make guardrails server OpenAI compatible ([#1340](https://github.com/NVIDIA-NeMo/Guardrails/issues/1340))
+- New top-level scaffold ([#1613](https://github.com/NVIDIA-NeMo/Guardrails/issues/1613))
+- Add Async work queue ([#1620](https://github.com/NVIDIA-NeMo/Guardrails/issues/1620))
+- *(integration)* Add GuardrailsMiddleware for LangChain agent ([#1606](https://github.com/NVIDIA-NeMo/Guardrails/issues/1606))
+- *(library)* Update Fiddler Guardrails API to match new specification ([#1619](https://github.com/NVIDIA-NeMo/Guardrails/issues/1619))
+- *(library)* Add CrowdStrike AIDR community integration ([#1601](https://github.com/NVIDIA-NeMo/Guardrails/issues/1601))
+- *(iorails)* Introduce IORails optimized Input/Output rail engine. Supports non-streaming parallel nemoguard input/output rails (content-safety, topic-safety, jailbreak detection) ([#1638](https://github.com/NVIDIA-NeMo/Guardrails/issues/1638), [#1649](https://github.com/NVIDIA-NeMo/Guardrails/issues/1649), [#1654](https://github.com/NVIDIA-NeMo/Guardrails/issues/1654), [#1656](https://github.com/NVIDIA-NeMo/Guardrails/issues/1656), [#1658](https://github.com/NVIDIA-NeMo/Guardrails/issues/1658), [#1660](https://github.com/NVIDIA-NeMo/Guardrails/issues/1660), [#1661](https://github.com/NVIDIA-NeMo/Guardrails/issues/1661), [#1674](https://github.com/NVIDIA-NeMo/Guardrails/issues/1674))
+- *(server)* Add OpenAI compatible v1/models endpoint ([#1637](https://github.com/NVIDIA-NeMo/Guardrails/issues/1637))
+- *(benchmark)* Add Locust stress-test ([#1629](https://github.com/NVIDIA-NeMo/Guardrails/issues/1629))
+- *(jailbreak)* Validate Jailbreak Detection config at create-time ([#1675](https://github.com/NVIDIA-NeMo/Guardrails/issues/1675))
+- *(library)* Add PolicyAI Integration for Content Moderation ([#1576](https://github.com/NVIDIA-NeMo/Guardrails/issues/1576))
+
+### 🐛 Bug Fixes
+
+- *(server)* Make openai an optional server-only dependency ([#1623](https://github.com/NVIDIA-NeMo/Guardrails/issues/1623))
+- *(actions)* Rename generate_next_step to generate_next_steps for task-specific LLM support ([#1603](https://github.com/NVIDIA-NeMo/Guardrails/issues/1603))
+- *(library)* Add `valid` alias to action results in GuardrailsAI integration ([#1578](https://github.com/NVIDIA-NeMo/Guardrails/issues/1578)) ([#1611](https://github.com/NVIDIA-NeMo/Guardrails/issues/1611))
+- *(llm)* Filter stop parameter for OpenAI reasoning models ([#1653](https://github.com/NVIDIA-NeMo/Guardrails/issues/1653))
+- *(logging)* Show cache hits in Stats log and fix duplicate metadata restore ([#1666](https://github.com/NVIDIA-NeMo/Guardrails/issues/1666))
+- *(cache)* Make cache stats log visible in verbose mode ([#1667](https://github.com/NVIDIA-NeMo/Guardrails/issues/1667))
+- *(library)* Use bot refuse to respond in gliner PII detection flows ([#1671](https://github.com/NVIDIA-NeMo/Guardrails/issues/1671))
+- *(streaming)* Handle None stop tokens in streaming handler ([#1685](https://github.com/NVIDIA-NeMo/Guardrails/issues/1685))
+- *(streaming)* Handle dict chunks in RollingBuffer.format_chunks ([#1687](https://github.com/NVIDIA-NeMo/Guardrails/issues/1687))
+- *(middleware)* Handle MODIFIED status in GuardrailsMiddleware instead of silently dropping it ([#1714](https://github.com/NVIDIA-NeMo/Guardrails/issues/1714))
+
+### 🚜 Refactor
+
+- *(streaming)* Remove LangChain callback dependencies from StreamingHandler ([#1547](https://github.com/NVIDIA-NeMo/Guardrails/issues/1547))
+- *(streaming)* Remove ChatNVIDIA streaming patch ([#1607](https://github.com/NVIDIA-NeMo/Guardrails/issues/1607))
+- *(streaming)* [**breaking**] Remove stream_usage and fix streaming metadata capture ([#1624](https://github.com/NVIDIA-NeMo/Guardrails/issues/1624))
+
+### ⚡ Performance
+
+- *(actions)* Lazy initialization of embedding indexes ([#1572](https://github.com/NVIDIA-NeMo/Guardrails/issues/1572))
+
+### ⚙️ Miscellaneous Tasks
+
+- Update Pangea User-Agent repo URL ([#1595](https://github.com/NVIDIA-NeMo/Guardrails/issues/1595)) ([#1610](https://github.com/NVIDIA-NeMo/Guardrails/issues/1610))
+- *(jailbreak)* Update dependencies for jailbreak detection docker container. ([#1596](https://github.com/NVIDIA-NeMo/Guardrails/issues/1596))
+- Remove multi_kb example ([#1673](https://github.com/NVIDIA-NeMo/Guardrails/issues/1673))
+- *(iorails)* Increase work queue concurrency and depth ([#1674](https://github.com/NVIDIA-NeMo/Guardrails/issues/1674))
+- *(docs)* Remove AI Virtual Assistant Blueprint notebook ([#1682](https://github.com/NVIDIA-NeMo/Guardrails/issues/1682))
+- Update dependencies ahead of v0.21 release ([#1617](https://github.com/NVIDIA-NeMo/Guardrails/issues/1617))
+
 ## [0.20.0] - 2026-01-22
 
 ### 🚀 Features

README.md

@@ -13,7 +13,7 @@
 [![Downloads](https://static.pepy.tech/badge/nemoguardrails)](https://pepy.tech/project/nemoguardrails)
 [![Downloads](https://static.pepy.tech/badge/nemoguardrails/month)](https://pepy.tech/project/nemoguardrails)
 
-> **LATEST RELEASE / DEVELOPMENT VERSION**: The [main](https://github.com/NVIDIA-NeMo/Guardrails/tree/main) branch tracks the latest released beta version: [0.20.0](https://github.com/NVIDIA-NeMo/Guardrails/tree/v0.20.0). For the latest development version, checkout the [develop](https://github.com/NVIDIA-NeMo/Guardrails/tree/develop) branch.
+> **LATEST RELEASE / DEVELOPMENT VERSION**: The [main](https://github.com/NVIDIA-NeMo/Guardrails/tree/main) branch tracks the latest released beta version: [0.21.0](https://github.com/NVIDIA-NeMo/Guardrails/tree/v0.21.0). For the latest development version, checkout the [develop](https://github.com/NVIDIA-NeMo/Guardrails/tree/develop) branch.
 
 ✨✨✨
 

pyproject.toml

@@ -4,7 +4,7 @@ description = "NeMo Guardrails is an open-source toolkit for easily adding progr
 authors = ["NVIDIA <nemoguardrails@nvidia.com>"]
 license = "LICENSE.md"
 readme = "README.md"
-version = "0.20.0"
+version = "0.21.0"
 packages = [{ include = "nemoguardrails" }]