Add @typespec/pydantic emitter for generating Python pydantic models

.chronus/changes/add-pydantic-emitter-2026-02-13-02-26-11.md

@@ -0,0 +1,7 @@
+---
+changeKind: feature
+packages:
+  - "@typespec/pydantic"
+---
+
+Add new `@typespec/pydantic` emitter that generates Python pydantic model classes from TypeSpec definitions. Models are categorized by HTTP operation usage into separate modules (`input_types.py`, `output_types.py`, `roundtrip_types.py`). Includes support for constraints, enums, unions, inheritance, and configurable module names.

.chronus/config.yaml

@@ -67,6 +67,7 @@ versionPolicies:
     packages:
       - "@typespec/http-client-python"
       - "@typespec/http-client-java"
+      - "@typespec/pydantic"
 
 changelog: ["@chronus/github/changelog", { repo: "microsoft/typespec" }]
 

cspell.yaml

@@ -211,6 +211,7 @@ words:
   - pyimport
   - pylint
   - pylintrc
+  - pydantic
   - pyodide
   - pyproject
   - pyright

packages/pydantic/lib/main.tsp

@@ -0,0 +1 @@
+import "@typespec/http";

packages/pydantic/package.json

@@ -0,0 +1,68 @@
+{
+  "name": "@typespec/pydantic",
+  "version": "0.1.0",
+  "author": "Microsoft Corporation",
+  "description": "TypeSpec library for emitting Pydantic model classes",
+  "homepage": "https://github.com/microsoft/typespec",
+  "readme": "https://github.com/microsoft/typespec/blob/main/README.md",
+  "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/microsoft/typespec.git"
+  },
+  "bugs": {
+    "url": "https://github.com/microsoft/typespec/issues"
+  },
+  "keywords": [
+    "TypeSpec",
+    "pydantic",
+    "python"
+  ],
+  "type": "module",
+  "main": "dist/src/index.js",
+  "exports": {
+    ".": {
+      "typespec": "./lib/main.tsp",
+      "types": "./dist/src/index.d.ts",
+      "default": "./dist/src/index.js"
+    },
+    "./testing": {
+      "types": "./dist/src/testing/index.d.ts",
+      "default": "./dist/src/testing/index.js"
+    }
+  },
+  "tspMain": "lib/main.tsp",
+  "engines": {
+    "node": ">=20.0.0"
+  },
+  "scripts": {
+    "clean": "rimraf ./dist ./temp",
+    "build": "tsc -p tsconfig.build.json",
+    "watch": "tsc -p tsconfig.build.json --watch",
+    "test": "vitest run",
+    "test:ui": "vitest --ui",
+    "test:ci": "vitest run --coverage --reporter=junit --reporter=default",
+    "lint": "eslint . --max-warnings=0",
+    "lint:fix": "eslint . --fix"
+  },
+  "files": [
+    "lib/*.tsp",
+    "dist/**",
+    "!dist/test/**"
+  ],
+  "peerDependencies": {
+    "@typespec/compiler": "workspace:^",
+    "@typespec/http": "workspace:^"
+  },
+  "devDependencies": {
+    "@types/node": "~25.0.2",
+    "@typespec/compiler": "workspace:^",
+    "@typespec/http": "workspace:^",
+    "@typespec/rest": "workspace:^",
+    "@vitest/coverage-v8": "^4.0.15",
+    "@vitest/ui": "^4.0.15",
+    "rimraf": "~6.1.2",
+    "typescript": "~5.9.2",
+    "vitest": "^4.0.15"
+  }
+}