diff --git a/docs/action.md b/docs/action.md
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+++ b/docs/action.md
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+# Action
+
+Runcobo use one action one file. 
+
+### Before Filter
+```crystal
+class BeforeExample < BaseAction
+  before required_login
+  def required_login
+    Runcobo::Log.info { "Required Login" }
+  end
+
+  get "/before_example"
+  call do
+    render_plain "Hello World!"
+  end
+end
+```
+
+### After Filter
+```crystal
+class BeforeExample < BaseAction
+  after log_params
+  def log_params
+    Runcobo::Log.info { "#{params}" }
+  end
+
+  get "/before_example"
+  call do
+    render_plain "Hello World!"
+  end
+end
+```
+
+### Skip Filter
+```crystal
+class BaseAction
+  before required_login
+  def required_login
+    Runcobo::Log.info { "Required Login" }
+  end
+end
+
+class SkipExample < BaseAction
+  skip required_login
+
+  get "/before_example"
+  call do
+    render_plain "Hello World!"
+  end
+end
+```
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diff --git a/docs/getting_started.md b/docs/getting_started.md
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+++ b/docs/getting_started.md
@@ -0,0 +1,40 @@
+# Getting Started
+
+1.Init a Crystal project.
+```shell
+crystal init app demo && cd demo
+```
+
+2.Add the dependency to your shard.yml and run `shards install`.
+```yaml
+dependencies:
+  runcobo:
+    github: runcobo/runcobo
+```
+
+3.Write down the following code in `src/demo.cr`.
+```crystal
+require "runcobo"
+
+class Api::V1::Add < BaseAction
+  get "/api/v1/add"
+  query NamedTuple(a: Int32, b: Int32)
+
+  call do
+    sum = params[:a] + params[:b]
+    render_plain sum.to_s
+  end
+end
+
+Runcobo.start
+```
+
+4.Run server.
+```shell
+crystal src/demo.cr
+```
+
+5.Send request.
+```shell
+curl "http://0.0.0.0:3000/api/v1/add?a=1&b=2"
+```
\ No newline at end of file
diff --git a/docs/html.md b/docs/html.md
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--- /dev/null
+++ b/docs/html.md
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+### Render HTML
+
+*src/controllers/books/index.cr*
+```crystal
+class Books::Index < BaseAction
+  get "/books"
+  call do
+    books = Book.all
+    render_water "books/index"
+  end
+end
+```
+
+*src/views/books/index.water*
+```crystal
+table %|class="table table-hover"| {
+  thead {
+    tr {
+      th "ID"
+      th "Author"
+      th "Name"
+      th "Published At"
+    } 
+  }
+  tbody {
+    books.each do |book|
+      tr {
+        td book.id
+        td book.author
+        td book.name
+        td book.published_at
+      }
+    end
+  }
+}
+```
+
+Then, output a HTML string.
+```json
+<table class="table table-hover">
+  <thead>
+    <tr>
+      <th>ID</th>
+      <th>Author</th>
+      <th>Name</th>
+      <th>Published At</th>
+    </tr>
+  </thead>
+  <tbody>
+    <tr>
+      <td>1</td>
+      <td>David</td>
+      <td>Crystal Programming</td>
+      <td>2020-08-02 14:07:41 +08:00</td>
+    </tr>
+  </tbody>
+</table>
+```
+
+### Render Partial
+
+*src/views/books/index.jbuilder*
+```crystal
+{{ read_file("src/views/books/table.water").id }}
+```
+
+*src/views/books/table.water*
+```crystal
+table %|class="table table-hover"| {
+  thead {
+    tr {
+      th "ID"
+      th "Author"
+      th "Name"
+      th "Published At"
+    } 
+  }
+  tbody {
+    books.each do |book|
+      tr {
+        td book.id
+        td book.author
+        td book.name
+        td book.published_at
+      }
+    end
+  }
+}
+``` 
diff --git a/docs/index.md b/docs/index.md
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--- /dev/null
+++ b/docs/index.md
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+# Introduction
+
+Runcobo is a general purpose framework built on Crystal.  
+
+### Commands
+
+```shell
+runcobo [<commands>...] [<arguments>...]
+
+  Commands:
+    routes                      - Print all routes of the app.
+    version                     - Print the current version of the runcobo.
+    help                        - Print usage synopsis.
+
+  Options:
+    -h, --help                       Print usage synopsis.
+    -v, --version                    Print the current version of the runcobo.
+```
+
+### Project Architecture
+
+    lib/                # Library
+    src/
+        main.cr         # Entry file
+        actions/        # Actions Directory
+            ...
+        assets/         # Assets Directory
+        views/          # Views Directory
+            layouts/    # Layouts directory
+            ...
+        models/         # Models Directory
+            ...
+    shards.yml          # The packages congfiuration file
+    shards.lock         # The lock file for packages congfiuration file
+
+### Design Architecture
+MVC (Model-View-Controller)
+
+### Design Principles
+
++ Simple Design must be simple, both in implementation and interface.
++ Intuitive Design must be intuitive.
++ Consistent Design must be consistent.
\ No newline at end of file
diff --git a/docs/installation.md b/docs/installation.md
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--- /dev/null
+++ b/docs/installation.md
@@ -0,0 +1,19 @@
+# Installation
+
+### Install Crystal
+Crystal is a language for humans and computers. 
+
+Crystal is a type safe, compiled language inspired by the simplicity of Ruby. Type safety means more errors are caught by the compiler during development, so you can be more confident about your code working in production.
+
+See [https://crystal-lang.org/install/](https://crystal-lang.org/install) to install Crystal.
+
+### Install Runcobo
+You can install Runcobo from sources. Other installations are working on.
+
+```shell
+curl -L https://github.com/runcobo/runcobo/archive/stable.zip --output runcobo.zip
+unzip runcobo.zip
+cd runcobo-stable/
+sudo make install
+runcobo -v
+```
\ No newline at end of file
diff --git a/docs/json.md b/docs/json.md
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--- /dev/null
+++ b/docs/json.md
@@ -0,0 +1,51 @@
+### Render JSON
+
+*src/controllers/books/index.cr*
+```crystal
+class Books::Index < BaseAction
+  get "/books"
+  call do
+    books = Book.all
+    render_jbuilder "books/index"
+  end
+end
+```
+
+*src/views/books/index.jbuilder*
+```crystal
+json.array! "books", books do |json, book|
+  json.book_id      book.id
+  json.author       book.author
+  json.name         book.name
+  json.published_at book.published_at
+end
+```
+
+Then, output a JSON string.
+```json
+{
+  "books": [{
+    "book_id": 1,
+    "author": "David",
+    "name": "Crystal Programming",
+    "published_at": "2020-08-08T20:00:00+00:00"
+  }]
+}
+```
+
+### Render Partial
+
+*src/views/books/index.jbuilder*
+```crystal
+json.array! "books", books do |json, book|
+  {{ read_file("src/views/books/_base_book.jbuilder").id }}
+end
+```
+
+*src/views/books/_base_book.jbuilder*
+```crystal
+json.book_id      book.id
+json.author       book.author
+json.name         book.name
+json.published_at book.published_at
+```
\ No newline at end of file
diff --git a/docs/model.md b/docs/model.md
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--- /dev/null
+++ b/docs/model.md
@@ -0,0 +1,15 @@
+# Model
+
+Here is a list of ORM from [awesome-crystal](https://github.com/veelenga/awesome-crystal#ormodm-extensions)
+
++ [avram](https://github.com/luckyframework/avram) - A database wrapper for reading, writing, and migrating Postgres databases. (Only Postgres)
++ [clear](https://github.com/anykeyh/clear) - ORM specialized to PostgreSQL only but with advanced features (Only Postgres)
++ [crecto](https://github.com/Crecto/crecto) - Database wrapper, based on Ecto
++ [granite](https://github.com/amberframework/granite) - ORM for Postgres, Mysql, Sqlite
++ [jennifer.cr](https://github.com/imdrasil/jennifer.cr) - Active Record pattern implementation with flexible query chainable builder and migration system
++ [ohm-crystal](https://github.com/soveran/ohm-crystal) - Object-hash mapping library for Redis (Only Redis)
++ [onyx-sql](https://github.com/onyxframework/sql) - DB-agnostic SQL ORM with beautiful DSL and type-safe Query builder
++ [rethinkdb-orm](https://github.com/spider-gazelle/rethinkdb-orm) - ORM for RethinkDB / RebirthDB (Only RethinkDB / RebirthDB)
++ [stal-crystal](https://github.com/soveran/stal-crystal) - Set algebra solver for Redis
+
+Runcobo prefers to use [jennifer.cr](https://github.com/imdrasil/jennifer.cr), you can check its [docs](https://imdrasil.github.io/jennifer.cr/docs/) and [api](https://imdrasil.github.io/jennifer.cr/latest/).
diff --git a/docs/params.md b/docs/params.md
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--- /dev/null
+++ b/docs/params.md
@@ -0,0 +1,73 @@
+# Params
+
+### Type-safe Params
+An old Chinese proverb says, "If something is important, then repeat it three times". So,
+
+**Params in Runcobo are type-safe.**
+
+**Params in Runcobo are type-safe.**
+
+**Params in Runcobo are type-safe.**
+
+### Three Steps To Use Params
+
++ First, declare what params you expect and what type you expect by following methods: `url`, `query`, `form` and `json`.
++ Next, Runcobo parses request and wraps params to a local variable called `params`.
++ Third, use `params` variable to get or set request params.
+
+### Url Params
+```crystal
+class UrlExample < BaseAction
+  get "/url_example/:a/:b"
+  url NamedTuple(a: Int32, b: Int32)
+
+  call do
+    sum = params[:a] + params[:b]
+    render_plain sum.to_s
+  end
+end
+```
+
+### Query Params
+```crystal
+class QueryExample < BaseAction
+  get "/query_example"
+  query NamedTuple(a: Int32, b: Int32)
+
+  call do
+    sum = params[:a] + params[:b]
+    render_plain sum.to_s
+  end
+end
+```
+
+### Form Params
+```crystal
+class FormExample < BaseAction
+  post "/form_example"
+  form NamedTuple(a: Int32, b: Int32)
+
+  call do
+    sum = params[:a] + params[:b]
+    render_plain sum.to_s
+  end
+end
+```
+
+### JSON Params
+```crystal
+class JsonExample < BaseAction
+  post "/json_example"
+  json NamedTuple(a: Int32, b: Int32)
+
+  call do
+    sum = params[:a] + params[:b]
+    render_plain sum.to_s
+  end
+end
+```
+
+### Params Merge Order
+You can declare various kinds of params in a action. If params are in same key, they will be merged in following order:
+
+`Query Params < Form Params < JSON Params < Url Params`
diff --git a/docs/render.md b/docs/render.md
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--- /dev/null
+++ b/docs/render.md
@@ -0,0 +1,41 @@
+# Render
+
+### Render HTML
+```crystal
+class WaterExample < BaseAction
+  get "/water_example"
+  call do
+    render_water "examples/index"
+  end
+end
+```
+
+### Render Plain
+```crystal
+class PlainExample < BaseAction
+  get "/plain_example"
+  call do
+    render_plain "Hello World!"
+  end
+end
+```
+
+### Render Body
+```crystal
+class BodyExample < BaseAction
+  get "/body_example"
+  call do
+    render_body "Hello World!"
+  end
+end
+```
+
+### Render JSON
+```crystal
+class JbuilderExample < BaseAction
+  get "/jbuilder_example"
+  call do
+    render_jbuilder "examples/index"
+  end
+end
+```
diff --git a/docs/route.md b/docs/route.md
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--- /dev/null
+++ b/docs/route.md
@@ -0,0 +1,61 @@
+# Route
+Runcobo declares routes in every Actions. If you access the route, it will run into related Action.
+
+In this way, you can know the routes of current Action quickly.
+
+You can declare RESTful routes as you want or not.
+
+> In my personal view, RESTful is too abstact when you were far way from a CRUD system like Backend Management System.
+
+> When writing API, I believe urls should be named like functions, not objects or resources.
+
+> When writing a Backend Management System, enjoy RESTful.
+
+### Routes Declaration
+Runcobo declares routes by following methods: `get`, `post`, `put`, `patch`, `delete`, `options`, `head`.
+An Action can bind to one or more routes.
+
+```crystal
+class Example < BaseAction
+  get "/books"
+  get "/books/:id"
+  post "/books"
+  put "/books/:id"
+  patch "/books/:id"
+  delete "/books/:id"
+  options "/books/:id"
+  head "/books/:id"
+
+  call do
+    render_plain "Hello World"
+  end
+end
+```
+
+### URL Params
+URL Params can be declared in the route like `/add/:apple_count/:banana_count`. And then you should use `url` method to declare the type of URL params.
+
+```crystal
+class Example < BaseAction
+  get "/add/:apple_count/:banana_count"
+  url NamedTuple(apple_count: Int32, banana_count: Int32)
+
+  call do
+    sum = params[:apple_count] + params[:banana_count]
+    render_plain sum.to_s
+  end
+end
+```
+
+### Custom HTTP method
+If you need a route with custom HTTP method, such as `LINK`, `UNLINK`, `FIND` or `PURGE`, then you can use `route` method to declare it.
+
+```crystal
+class Example < BaseAction
+  route "LINK", "/books/:id"
+
+  call do
+    render_plain "Hello World"
+  end
+end
+```
diff --git a/docs/view.md b/docs/view.md
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--- /dev/null
+++ b/docs/view.md
@@ -0,0 +1,39 @@
+# View
+
+Runcobo renders JSON by **Jbuilder**, renders HTML by **Water**.
+**Jbuilder** is a template engine designed for json using plain Crystal.
+**Water** is a template engine designed for html using plain Crystal.
+
+### Data transfer
+All methods or variables defined in the action are available in the views.
+This is because the views are compiled in the same scope as the action.
+
+### Layout
+
+You can override the default layout conventions in your actions by using the layout declaration. For example:
+```crystal
+class BaseAction
+  LAYOUT = "application.jbuilder"
+  #...
+end
+```
+
+### Partial
+
+Runcobo renders partial view by build-in `read_file` macro. There's no magic about partial view. 
+For example,
+
+*src/views/books/index.jbuilder*
+```crystal
+json.array! "books", books do |json, book|
+  {{ read_file("src/views/books/_base_book.jbuilder").id }}
+end
+```
+
+*src/views/books/_base_book.jbuilder*
+```crystal
+json.book_id      book.id
+json.author       book.author
+json.name         book.name
+json.published_at book.published_at
+```
\ No newline at end of file
diff --git a/mkdocs.yml b/mkdocs.yml
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--- /dev/null
+++ b/mkdocs.yml
@@ -0,0 +1,54 @@
+# Project Information
+site_name: Runcobo
+site_url: https://runcobo.github.io/
+site_author: Runcobo Community
+site_description: Runcobo documentation (web framework for Crystal).
+
+# Repository
+repo_name: Runcobo Github
+repo_url: https://github.com/runcobo/runcobo
+
+# Copyright
+copyright: "Copyright &copy; Runcobo Community"
+
+# Configuration
+theme:
+  name: material
+  language: en
+
+  palette:
+    primary: cyan
+
+  logo: assets/logo.png
+  favicon: assets/favicon.ico
+
+# Customization
+extra:
+  social:
+    - icon: fontawesome/brands/github
+      link: https://github.com/runcobo/runcobo
+
+markdown_extensions:
+  - admonition
+  - codehilite:
+      guess_lang: false
+  - footnotes
+  - meta
+  - toc:
+      permalink: true
+
+nav:
+  - Introduction: "index.md"
+  - Installation: "installation.md"
+  - Getting Started: "getting_started.md"
+  - Route: "route.md"
+  - Action: 
+    - Overview: "action.md"
+    - Params: "params.md"
+    - Render: "render.md"
+  - View:
+    - Overview: "view.md"
+    - JSON: "json.md"
+    - HTML: "html.md"
+  - Model:
+    - Overview: "model.md"