# app/api/v1/routes/posts.py

from typing import List
from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session

from app.api.v1.models.posts import Posts
from app.api.v1.schemas.posts import PostsCreate, PostsResponse
from app.api.core.dependencies.dependencies import get_db

router = APIRouter()

@router.get("/postss", response_model=List[PostsResponse])
def get_postss(db: Session = Depends(get_db)):
    postss = db.query(Posts).all()
    return postss

@router.post("/postss", response_model=PostsResponse)
def create_posts(posts: PostsCreate, db: Session = Depends(get_db)):
    db_posts = Posts(**posts.dict())
    db.add(db_posts)
    db.commit()
    db.refresh(db_posts)
    return db_posts

@router.get("/postss/{id}", response_model=PostsResponse)
def get_posts(id: int, db: Session = Depends(get_db)):
    db_posts = db.query(Posts).filter(Posts.id == id).first()
    if not db_posts:
        raise HTTPException(status_code=404, detail="Posts not found")
    return db_posts
```

This code defines a FastAPI router with three endpoints:

1. `GET /postss`: Lists all posts from the database. It uses the `Posts` model from `app.api.v1.models.posts` and returns a list of `PostsResponse` schemas from `app.api.v1.schemas.posts`.

2. `POST /postss`: Creates a new post in the database. It accepts a `PostsCreate` schema from `app.api.v1.schemas.posts` as the request body, creates a new `Posts` model instance, adds it to the database, and returns the created `PostsResponse` schema.

3. `GET /postss/{id}`: Retrieves a specific post by ID from the database. It uses the `Posts` model from `app.api.v1.models.posts` and returns a `PostsResponse` schema from `app.api.v1.schemas.posts`. If the post with the given ID is not found, it raises an `HTTPException` with a 404 status code.

All the endpoints use the `get_db` dependency from `app.api.core.dependencies.dependencies` to obtain a database session.

Note: This code assumes that the `Posts` model, `PostsCreate` schema, and `PostsResponse` schema exist in the specified locations. You may need to create or modify these files based on your project's requirements.