diff --git a/Sources/MongoKitten/CollectionHelpers/Collection+FindAndModify.swift b/Sources/MongoKitten/CollectionHelpers/Collection+FindAndModify.swift
new file mode 100644
index 00000000..7915dc93
--- /dev/null
+++ b/Sources/MongoKitten/CollectionHelpers/Collection+FindAndModify.swift
@@ -0,0 +1,169 @@
+import NIO
+import MongoClient
+import MongoKittenCore
+
+extension MongoCollection {
+    // MARK: - Builder Functions (Composable/Chained API)
+    
+    /// Modifies and returns a single document.
+    /// - Parameters:
+    ///   - query: The selection criteria for the modification.
+    ///   - update: If passed a document with update operator expressions, performs the specified modification. If passed a replacement document performs a replacement.
+    ///   - remove: Removes the document specified in the query field. Defaults to `false`
+    ///   - returnValue: Wether to return the `original` or `modified` document.
+    public func findAndModify(where query: Document,
+                              update document: Document = [:],
+                              remove: Bool = false,
+                              returnValue: FindAndModifyReturnValue = .original) -> FindAndModifyBuilder {
+        var command = FindAndModifyCommand(collection: self.name, query: query)
+        command.update = document
+        command.remove = remove
+        command.new = returnValue == .modified
+        return FindAndModifyBuilder(command: command, collection: self)
+    }
+    
+    /// Deletes a single document based on the query, returning the deleted document.
+    /// - Parameters:
+    ///   - query: The selection criteria for the deletion.
+    public func findOneAndDelete(where query: Document) -> FindAndModifyBuilder {
+        var command = FindAndModifyCommand(collection: self.name, query: query)
+        command.remove = true
+        return FindAndModifyBuilder(command: command, collection: self)
+    }
+    
+    /// Replaces a single document based on the specified query.
+    /// - Parameters:
+    ///   - query: The selection criteria for the upate.
+    ///   - replacement: The replacement document.
+    ///   - returnValue: Wether to return the `original` or `modified` document.
+    public func findOneAndReplace(where query: Document,
+                                  replacement document: Document,
+                                  returnValue: FindAndModifyReturnValue = .original) -> FindAndModifyBuilder {
+        var command = FindAndModifyCommand(collection: self.name, query: query)
+        command.new = returnValue == .modified
+        command.update = document
+        return FindAndModifyBuilder(command: command, collection: self)
+    }
+    
+    /// Updates a single document based on the specified query.
+    /// - Parameters:
+    ///   - query: The selection criteria for the upate.
+    ///   - document: The update document.
+    ///   - returnValue: Wether to return the `original` or `modified` document.
+    public func findOneAndUpdate(where query: Document,
+                                 to document: Document,
+                                 returnValue: FindAndModifyReturnValue = .original) -> FindAndModifyBuilder {
+        var command = FindAndModifyCommand(collection: self.name, query: query)
+        command.new = returnValue == .modified
+        command.update = document
+        return FindAndModifyBuilder(command: command, collection: self)
+    }
+    
+    /// Modifies and returns a single document.
+    /// - Parameters:
+    ///   - query: The selection criteria for the modification.
+    ///   - update: If passed a document with update operator expressions, performs the specified modification. If passed a replacement document performs a replacement.
+    ///   - remove: Removes the document specified in the query field. Defaults to `false`
+    ///   - returnValue: Wether to return the `original` or `modified` document.
+    public func findAndModify<Query: MongoKittenQuery>(where query: Query,
+                                                       update document: Document = [:],
+                                                       remove: Bool = false,
+                                                       returnValue: FindAndModifyReturnValue = .original) -> FindAndModifyBuilder {
+        var command = FindAndModifyCommand(collection: self.name, query: query.makeDocument())
+        command.update = document
+        command.remove = remove
+        command.new = returnValue == .modified
+        return FindAndModifyBuilder(command: command, collection: self)
+    }
+    
+    /// Deletes a single document based on the query, returning the deleted document.
+    /// - Parameters:
+    ///   - query: The selection criteria for the deletion.
+    public func findOneAndDelete<Query: MongoKittenQuery>(where query: Query) -> FindAndModifyBuilder {
+        var command = FindAndModifyCommand(collection: self.name, query: query.makeDocument())
+        command.remove = true
+        return FindAndModifyBuilder(command: command, collection: self)
+    }
+    
+    /// Replaces a single document based on the specified query.
+    /// - Parameters:
+    ///   - query: The selection criteria for the upate.
+    ///   - replacement: The replacement document.
+    ///   - returnValue: Wether to return the `original` or `modified` document.
+    public func findOneAndReplace<Query: MongoKittenQuery>(where query: Query,
+                                                           replacement document: Document,
+                                                           returnValue: FindAndModifyReturnValue = .original) -> FindAndModifyBuilder {
+        var command = FindAndModifyCommand(collection: self.name, query: query.makeDocument())
+        command.new = returnValue == .modified
+        command.update = document
+        return FindAndModifyBuilder(command: command, collection: self)
+    }
+    
+    /// Updates a single document based on the specified query.
+    /// - Parameters:
+    ///   - query: The selection criteria for the upate.
+    ///   - document: The update document.
+    ///   - returnValue: Wether to return the `original` or `modified` document.
+    public func findOneAndUpdate<Query: MongoKittenQuery>(where query: Query,
+                                                          to document: Document,
+                                                          returnValue: FindAndModifyReturnValue = .original) -> FindAndModifyBuilder {
+        var command = FindAndModifyCommand(collection: self.name, query: query.makeDocument())
+        command.new = returnValue == .modified
+        command.update = document
+        return FindAndModifyBuilder(command: command, collection: self)
+    }
+}
+
+public final class FindAndModifyBuilder {
+    /// The underlying command to be executed.
+    public var command: FindAndModifyCommand
+    private let collection: MongoCollection
+    
+    init(command: FindAndModifyCommand, collection: MongoCollection) {
+        self.command = command
+        self.collection = collection
+    }
+    
+    /// Executes the command
+    public func execute() -> EventLoopFuture<FindAndModifyReply> {
+        return collection.pool.next(for: .basic).flatMap { connection in
+            connection.executeCodable(self.command,
+                                      namespace: self.collection.database.commandNamespace,
+                                      in: self.collection.transaction,
+                                      sessionId: self.collection.sessionId ?? connection.implicitSessionId)
+            
+        }
+        .decode(FindAndModifyReply.self)
+        ._mongoHop(to: self.collection.hoppedEventLoop)
+    }
+    
+    public func sort(_ sort: Sort) -> FindAndModifyBuilder {
+        self.command.sort = sort.document
+        return self
+    }
+
+    public func sort(_ sort: Document) -> FindAndModifyBuilder {
+        self.command.sort = sort
+        return self
+    }
+    
+    public func project(_ projection: Projection) -> FindAndModifyBuilder {
+        self.command.fields = projection.document
+        return self
+    }
+
+    public func project(_ projection: Document) -> FindAndModifyBuilder {
+        self.command.fields = projection
+        return self
+    }
+    
+    public func writeConcern(_ concern: WriteConcern) -> FindAndModifyBuilder {
+        self.command.writeConcern = concern
+        return self
+    }
+    
+    public func collation(_ collation: Collation) -> FindAndModifyBuilder {
+        self.command.collation = collation
+        return self
+    }
+}
diff --git a/Sources/MongoKittenCore/Commands/FindAndModify.swift b/Sources/MongoKittenCore/Commands/FindAndModify.swift
index a00b1167..97e703f8 100644
--- a/Sources/MongoKittenCore/Commands/FindAndModify.swift
+++ b/Sources/MongoKittenCore/Commands/FindAndModify.swift
@@ -1,8 +1,115 @@
-//
-//  File.swift
-//  
-//
-//  Created by Joannis Orlandos on 21/06/2019.
-//
+import MongoCore
 
-import Foundation
+public struct FindAndModifyCommand: Codable {
+    /// The collection against which to run the command.
+    public private(set) var findAndModify: String
+    /// The selection criteria for the modification.
+    public var query: Document?
+    /// Determines which document the operation modifies if the query selects multiple documents. `findAndModify` modifies the first document in the sort order specified by this argument.
+    public var sort: Document?
+    /// Removes the document specified in the `query` field. Set this to `true` to remove the selected document . The default is `false`.
+    public var remove: Bool
+    /**
+     Performs an update of the selected document.
+     
+     * If passed a document with update operator expressions, `findAndModify` performs the specified modification.
+     * If passed a replacement document `{ <field1>: <value1>, ...}`, the `findAndModify` performs a replacement.
+     * Starting in MongoDB 4.2, if passed an aggregation pipeline `[ <stage1>, <stage2>, ... ]`, `findAndModify` modifies the document per the pipeline. The pipeline can consist of the following stages:
+        * `$addFields` and its alias `$set`
+        * `$project` and its alias `$unset`
+        * `$replaceRoot` and its alias `$replcaeWith`
+     */
+    public var update: Document = []
+    /// When true, returns the modified document rather than the original. The findAndModify method ignores the new option for remove operations.
+    public var new: Bool?
+    /// A subset of fields to return. The `fields` document specifies an inclusion of a field with `1`, as in: `fields: { <field1>: 1, <field2>: 1, ... }`. [See projection](https://docs.mongodb.com/manual/tutorial/project-fields-from-query-results/#read-operations-projection).
+    public var fields: Document?
+    /**
+     Used in conjuction with the update field.
+     
+     When true, `findAndModify()` either:
+     
+     * Creates a new document if no documents match the `query`. For more details see [upsert behavior](https://docs.mongodb.com/manual/reference/method/db.collection.update/#upsert-behavior).
+     * Updates a single document that matches `query`.
+    
+     To avoid multiple upserts, ensure that the query fields are uniquely indexed.
+     */
+    public var upsert: Bool?
+    /// Enables findAndModify to bypass document validation during the operation. This lets you update documents that do not meet the validation requirements.
+    public var bypassDocumentValidation: Bool?
+    /**
+     A document expressing the write concern. Omit to use the default write concern.
+        
+     Do not explicitly set the write concern for the operation if run in a transaction. To use write concern with transactions, see [Transactions and Write Concern](https://docs.mongodb.com/manual/core/transactions/#transactions-write-concern).
+     */
+    public var writeConcern: WriteConcern?
+    /// Specifies a time limit in milliseconds for processing the operation.
+    public var maxTimeMS: Int?
+    /// Specifies the collation to use for the operation.
+    public var collation: Collation?
+    /// An array of filter documents that determine which array elements to modify for an update operation on an array field.
+    public var arrayFilters: [Document]?
+    
+    public init(collection: String,
+                query: Document? = nil,
+                sort: Document? = nil,
+                remove: Bool = false,
+                update: Document = [],
+                new: Bool? = nil,
+                fields: Document? = nil,
+                upsert: Bool? = nil,
+                bypassDocumentValidation: Bool? = nil,
+                writeConcern: WriteConcern? = nil,
+                maxTimeMS: Int? = nil,
+                collation: Collation? = nil,
+                arrayFilters: [Document]? = nil) {
+        self.findAndModify = collection
+        self.query = query
+        self.sort = sort
+        self.remove = remove
+        self.update = update
+        self.new = new
+        self.fields = fields
+        self.upsert = upsert
+        self.bypassDocumentValidation = bypassDocumentValidation
+        self.writeConcern = writeConcern
+        self.maxTimeMS = maxTimeMS
+        self.collation = collation
+        self.arrayFilters = arrayFilters
+    }
+}
+
+public struct FindAndModifyReply: Codable, Error {
+    private enum CodingKeys: String, CodingKey {
+        case ok
+        case value
+        case lastErrorObject
+    }
+    
+    /// Contains the command’s execution status. `1` on success, or `0` if an error occurred.
+    public let ok: Int
+    /**
+     Contains the command’s returned value.
+     
+     For `remove` operations, `value` contains the removed document if the query matches a document. If the query does not match a document to remove, `value` contains `nil`.
+     For update operations, the value embedded document contains the following:
+     * If the `new` parameter is not set or is `false`:
+        * the pre-modification document if the query matches a document;
+        * otherwise, `nil`.
+     
+     * if `new` is `true`:
+        * the modified document if the query returns a match;
+        * the inserted document if `upsert: true` and no document matches the query;
+        * otherwise, `nil`.
+     */
+    public let value: Document?
+    /// Contains information about updated documents.
+    public let lastErrorObject: Document?
+}
+
+public enum FindAndModifyReturnValue: String, Codable {
+    /// Return the modified Document.
+    case modified
+    /// Return the original Document.
+    case original
+}