diff --git a/crud.py b/crud.py
new file mode 100644
index 00000000..969c93c9
--- /dev/null
+++ b/crud.py
@@ -0,0 +1,34 @@
+from sqlalchemy.orm import Session
+from schemas import AuthorCreate, BookCreate
+import models
+
+
+def get_author(db: Session, author_id: int):
+    return db.query(models.Author).filter(models.Author.id == author_id).first()
+
+
+def get_authors(db: Session, skip: int, limit: int):
+    return db.query(models.Author).offset(skip).limit(limit).all()
+
+
+def create_author(db: Session, author: AuthorCreate):
+    db_author = models.Author(**author.model_dump())
+    db.add(db_author)
+    db.commit()
+    db.refresh(db_author)
+    return db_author
+
+
+def get_books(db: Session, skip: int, limit: int, author_id: int = None):
+    query = db.query(models.Book)
+    if author_id:
+        query = query.filter(models.Book.author_id == author_id)
+    return query.offset(skip).limit(limit).all()
+
+
+def create_book(db: Session, book: BookCreate):
+    db_book = models.Book(**book.model_dump())
+    db.add(db_book)
+    db.commit()
+    db.refresh(db_book)
+    return db_book
\ No newline at end of file
diff --git a/database.py b/database.py
new file mode 100644
index 00000000..3682656f
--- /dev/null
+++ b/database.py
@@ -0,0 +1,12 @@
+from sqlalchemy import create_engine
+from sqlalchemy.orm import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+SQLALCHEMY_DATABASE_URL = "sqlite:///./library.db"
+
+engine = create_engine(
+    SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
+)
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+Base = declarative_base()
diff --git a/main.py b/main.py
new file mode 100644
index 00000000..3b80ad72
--- /dev/null
+++ b/main.py
@@ -0,0 +1,48 @@
+from sqlalchemy.orm import Session
+import crud
+from database import engine, SessionLocal
+from models import Base
+from schemas import AuthorCreate, AuthorResponse, BookResponse, BookCreate
+from fastapi import FastAPI, Depends, HTTPException
+from typing import List
+
+
+Base.metadata.create_all(bind=engine)
+
+app = FastAPI()
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()
+
+@app.post("/authors", response_model=AuthorResponse)
+def create_author(author: AuthorCreate, db: Session = Depends(get_db)):
+    return crud.create_author(db=db, author=author)
+
+
+@app.get("/authors", response_model=List[AuthorResponse])
+def read_authors(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
+    return crud.get_authors(db, skip=skip, limit=limit)
+
+
+@app.get("/authors/{author_id}", response_model=AuthorResponse)
+def read_author(author_id: int, db: Session = Depends(get_db)):
+    author = crud.get_author(db, author_id=author_id)
+    if not author:
+        raise HTTPException(status_code=404, detail="Author not found")
+    return author
+
+@app.post("/authors/{author_id}/books", response_model=BookResponse)
+def create_book(author_id: int, book: BookCreate, db: Session = Depends(get_db)):
+    author = crud.get_author(db, author_id=author_id)
+    if not author:
+        raise HTTPException(status_code=404, detail="Author not found")
+    return crud.create_book(db=db, book=book)
+
+
+@app.get("/books", response_model=List[BookResponse])
+def read_books(skip: int = 0, limit: int = 100, author_id: int = None, db: Session = Depends(get_db)):
+    return crud.get_books(db, skip=skip, limit=limit, author_id=author_id)
diff --git a/models.py b/models.py
new file mode 100644
index 00000000..84b35b97
--- /dev/null
+++ b/models.py
@@ -0,0 +1,24 @@
+from datetime import date
+from sqlalchemy import String, ForeignKey
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from database import Base
+
+
+class Author(Base):
+    __tablename__ = "author"
+
+    id: Mapped[int] = mapped_column(primary_key=True, index=True)
+    name: Mapped[str] = mapped_column(String(255), nullable=False, unique=True)
+    bio: Mapped[str] = mapped_column(String(511), nullable=False)
+    books: Mapped[list["Book"]] = relationship(back_populates="author")
+
+
+class Book(Base):
+    __tablename__ = "book"
+
+    id: Mapped[int] = mapped_column(primary_key=True, index=True)
+    title: Mapped[str] = mapped_column(String(255), nullable=False,)
+    summary: Mapped[str]
+    publication_date: Mapped[date]
+    author_id: Mapped[int] = mapped_column(ForeignKey("author.id"))
+    author : Mapped["Author"] = relationship(back_populates="books")
diff --git a/schemas.py b/schemas.py
new file mode 100644
index 00000000..7678fc66
--- /dev/null
+++ b/schemas.py
@@ -0,0 +1,33 @@
+from pydantic import BaseModel, ConfigDict
+from datetime import date
+
+
+class AuthorBase(BaseModel):
+    name: str
+    bio: str
+
+
+class AuthorCreate(AuthorBase):
+    pass
+
+
+class AuthorResponse(AuthorBase):
+    id: int
+    books: list["BookResponse"]
+    model_config = ConfigDict(from_attributes=True)
+
+
+class BookBase(BaseModel):
+    title: str
+    summary: str
+    publication_date: date
+    author_id: int
+
+
+class BookCreate(BookBase):
+    pass
+
+
+class BookResponse(BookBase):
+    id: int
+    model_config = ConfigDict(from_attributes=True)