Feature: Implement modals (#2087)

* Implement Modals (#428)

* Socket Modal Support

* fix shareded client support

* Properly use `HasResponded` instead of `_hasResponded`

* `ModalBuilder` and `TextInputBuilder` validation.

* make orginisation more consistant.

* Rest Modals.

* Docs + add missing methods

* fix message signatures and missing abstract members

* modal changes

* um?????

* update modal docs

* update docs - again for some reason

* cleanup

* fix message signatures

* add modal commands support to interaction service

* Fix _hasResponded

* update to new unsupported standard.

* Sending modals with Interaction service.

* fix spelling in ComponentBuilder

* sending IModals when responding to interactions

* interaction service modals

* fix rest modals

* spelling and minor improvements.

* improve interaction service modal proformance

* use precompiled lambda for interaction service modals

* respect user compiled lambda choice

* changes to modals in the interaction service (more)

* support compiled lambdas in modal properties.

* modal interactions tweaks

* fix inline doc

* more modal docs

* configure responce to faild modal component

* init

* solve runtime errors

* solve build errors

* add default value parsing

* make modal info caching static

* make ModalUtils static

* add inline docs

* fix build errors

* code cleanup

* Introduce Required and Label properties as seperate attributes.

* replace internal dictionary of ModalInfo with a list

* change input building logic of modals

* update RespondWithModalAsync method

* add initial value parameter back to ModalTextInput and fix optional modal field

* add missing inline docs

* dispose the reference modal instance after building

* code cleanup on modalcommandbuilder

* Update docs/guides/int_basics/message-components/text-input.md

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update docs/guides/int_basics/message-components/text-input.md

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update docs/guides/int_basics/modals/intro.md

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update docs/guides/int_basics/modals/intro.md

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update docs/guides/int_basics/modals/intro.md

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update docs/guides/int_basics/modals/intro.md

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update docs/guides/int_basics/modals/intro.md

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update docs/guides/int_basics/modals/intro.md

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update docs/guides/int_basics/modals/intro.md

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update docs/guides/int_framework/intro.md

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update docs/guides/int_framework/intro.md

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update docs/guides/int_framework/samples/intro/modal.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update src/Discord.Net.Core/Entities/Interactions/MessageComponents/IComponentInteractionData.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update src/Discord.Net.Core/Entities/Interactions/MessageComponents/TextInputComponent.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update src/Discord.Net.Core/Entities/Interactions/Modals/IModalInteraction.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update src/Discord.Net.Core/Entities/Interactions/Modals/ModalBuilder.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update src/Discord.Net.Core/Entities/Interactions/Modals/ModalBuilder.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update src/Discord.Net.Core/Entities/Interactions/Modals/ModalBuilder.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update src/Discord.Net.Core/Entities/Interactions/Modals/ModalBuilder.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update src/Discord.Net.Core/Entities/Interactions/Modals/ModalBuilder.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update src/Discord.Net.Core/Entities/Interactions/Modals/ModalBuilder.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update src/Discord.Net.Interactions/Attributes/Commands/ModalInteractionAttribute.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update src/Discord.Net.Interactions/Attributes/Modals/RequiredInputAttribute.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update src/Discord.Net.Interactions/InteractionServiceConfig.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update src/Discord.Net.WebSocket/Entities/Interaction/MessageComponents/SocketMessageComponentData.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Update src/Discord.Net.WebSocket/Entities/Interaction/Modals/SocketModalData.cs

Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* update interaction service modal docs

* implements ExitOnMissingmModalField config option and adds Type field to modal info

* Add WithValue to text input builders

* Fix rare NRE on component enumeration

* Fix RequestOptions being required in some methods

* Use 'OfType' instead of 'Where'

* Remove android unsported warning

* Change publicity of properties in IInputComponeontBuilder.cs

Co-authored-by: Cenk Ergen <57065323+Cenngo@users.noreply.github.com>
Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

* Remove complex parameter ref

Co-authored-by: CottageDwellingCat <80918250+CottageDwellingCat@users.noreply.github.com>
Co-authored-by: Cenk Ergen <57065323+Cenngo@users.noreply.github.com>
Co-authored-by: Jared L <48422312+lhjt@users.noreply.github.com>

src/Discord.Net.Interactions/Attributes/Commands/ModalInteractionAttribute.cs

@@ -0,0 +1,44 @@
+using System;
+
+namespace Discord.Interactions
+{
+    /// <summary>
+    ///     Create a Modal interaction handler. CustomId represents
+    ///     the CustomId of the Modal that will be handled.
+    /// </summary>
+    /// <remarks>
+    ///     <see cref="GroupAttribute"/>s will add prefixes to this command if <see cref="IgnoreGroupNames"/> is set to <see langword="false"/>
+    ///     CustomID supports a Wild Card pattern where you can use the <see cref="InteractionServiceConfig.WildCardExpression"/> to match a set of CustomIDs.
+    /// </remarks>
+    [AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
+    public sealed class ModalInteractionAttribute : Attribute
+    {
+        /// <summary>
+        ///     Gets the string to compare the Modal CustomIDs with.
+        /// </summary>
+        public string CustomId { get; }
+        
+        /// <summary>
+        ///     Gets <see langword="true"/> if <see cref="GroupAttribute"/>s will be ignored while creating this command and this method will be treated as a top level command.
+        /// </summary>
+        public bool IgnoreGroupNames { get; }
+
+        /// <summary>
+        ///     Gets the run mode this command gets executed with.
+        /// </summary>
+        public RunMode RunMode { get; }
+
+        /// <summary>
+        ///     Create a command for modal interaction handling.
+        /// </summary>
+        /// <param name="customId">String to compare the modal CustomIDs with.</param>
+        /// <param name="ignoreGroupNames">If <see langword="true"/> <see cref="GroupAttribute"/>s will be ignored while creating this command and this method will be treated as a top level command.</param>
+        /// <param name="runMode">Set the run mode of the command.</param>
+        public ModalInteractionAttribute(string customId, bool ignoreGroupNames = false, RunMode runMode = RunMode.Default)
+        {
+            CustomId = customId;
+            IgnoreGroupNames = ignoreGroupNames;
+            RunMode = runMode;
+        }
+    }
+}

src/Discord.Net.Interactions/Attributes/Modals/InputLabelAttribute.cs

@@ -0,0 +1,25 @@
+using System;
+
+namespace Discord.Interactions
+{
+    /// <summary>
+    ///     Creates a custom label for an modal input.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
+    public class InputLabelAttribute : Attribute
+    {
+        /// <summary>
+        ///     Gets the label of the input.
+        /// </summary>
+        public string Label { get; }
+
+        /// <summary>
+        ///     Creates a custom label for an modal input.
+        /// </summary>
+        /// <param name="label">The label of the input.</param>
+        public InputLabelAttribute(string label)
+        {
+            Label = label;
+        }
+    }
+}

src/Discord.Net.Interactions/Attributes/Modals/ModalInputAttribute.cs

@@ -0,0 +1,32 @@
+using System;
+
+namespace Discord.Interactions
+{
+    /// <summary>
+    ///     Mark an <see cref="IModal"/> property as a modal input field.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
+    public abstract class ModalInputAttribute : Attribute
+    {
+        /// <summary>
+        ///     Gets the custom id of the text input.
+        /// </summary>
+        public string CustomId { get; }
+
+        /// <summary>
+        ///     Gets the type of the component.
+        /// </summary>
+        public abstract ComponentType ComponentType { get; }
+
+        /// <summary>
+        ///     Create a new <see cref="ModalInputAttribute"/>.
+        /// </summary>
+        /// <param name="label">The label of the input.</param>
+        /// <param name="customId">The custom id of the input.</param>
+        /// <param name="required">Whether the user is required to input a value.></param>
+        protected ModalInputAttribute(string customId)
+        {
+            CustomId = customId;
+        }
+    }
+}

src/Discord.Net.Interactions/Attributes/Modals/ModalTextInputAttribute.cs

@@ -0,0 +1,55 @@
+namespace Discord.Interactions
+{
+    /// <summary>
+    ///     Marks a <see cref="IModal"/> property as a text input.
+    /// </summary>
+    public sealed class ModalTextInputAttribute : ModalInputAttribute
+    {
+        /// <inheritdoc/>
+        public override ComponentType ComponentType => ComponentType.TextInput;
+
+        /// <summary>
+        ///     Gets the style of the text input.
+        /// </summary>
+        public TextInputStyle Style { get; }
+
+        /// <summary>
+        ///     Gets the placeholder of the text input.
+        /// </summary>
+        public string Placeholder { get; }
+
+        /// <summary>
+        ///     Gets the minimum length of the text input.
+        /// </summary>
+        public int MinLength { get; }
+
+        /// <summary>
+        ///     Gets the maximum length of the text input.
+        /// </summary>
+        public int MaxLength { get; }
+
+        /// <summary>
+        ///     Gets the initial value to be displayed by this input.
+        /// </summary>
+        public string InitialValue { get; }
+
+        /// <summary>
+        ///     Create a new <see cref="ModalTextInputAttribute"/>.
+        /// </summary>
+        /// <param name="customId"The custom id of the text input.></param>
+        /// <param name="style">The style of the text input.</param>
+        /// <param name="placeholder">The placeholder of the text input.</param>
+        /// <param name="minLength">The minimum length of the text input's content.</param>
+        /// <param name="maxLength">The maximum length of the text input's content.</param>
+        /// <param name="initValue">The initial value to be displayed by this input.</param>
+        public ModalTextInputAttribute(string customId, TextInputStyle style = TextInputStyle.Short, string placeholder = null, int minLength = 1, int maxLength = 4000, string initValue = null)
+            : base(customId)
+        {
+            Style = style;
+            Placeholder = placeholder;
+            MinLength = minLength;
+            MaxLength = maxLength;
+            InitialValue = initValue;
+        }
+    }
+}

src/Discord.Net.Interactions/Attributes/Modals/RequiredInputAttribute.cs

@@ -0,0 +1,25 @@
+using System;
+
+namespace Discord.Interactions
+{
+    /// <summary>
+    ///     Sets the input as required or optional.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
+    public class RequiredInputAttribute : Attribute
+    {
+        /// <summary>
+        ///     Gets whether or not user input is required for this input.
+        /// </summary>
+        public bool IsRequired { get; }
+
+        /// <summary>
+        ///     Sets the input as required or optinal.
+        /// </summary>
+        /// <param name="isRequired">Whether or not user input is required for this input.</param>
+        public RequiredInputAttribute(bool isRequired = true)
+        {
+            IsRequired = isRequired;
+        }
+    }
+}

src/Discord.Net.Interactions/Builders/Commands/ModalCommandBuilder.cs

@@ -0,0 +1,44 @@
+using System;
+
+namespace Discord.Interactions.Builders
+{
+    /// <summary>
+    ///     Represents a builder for creating a <see cref="ModalCommandInfo"/>.
+    /// </summary>
+    public class ModalCommandBuilder : CommandBuilder<ModalCommandInfo, ModalCommandBuilder, ModalCommandParameterBuilder>
+    {
+        protected override ModalCommandBuilder Instance => this;
+
+        /// <summary>
+        ///     Initializes a new <see cref="ModalCommandBuilder"/>.
+        /// </summary>
+        /// <param name="module">Parent module of this modal.</param>
+        public ModalCommandBuilder(ModuleBuilder module) : base(module) { }
+
+        /// <summary>
+        ///     Initializes a new <see cref="ModalCommandBuilder"/>.
+        /// </summary>
+        /// <param name="module">Parent module of this modal.</param>
+        /// <param name="name">Name of this modal.</param>
+        /// <param name="callback">Execution callback of this modal.</param>
+        public ModalCommandBuilder(ModuleBuilder module, string name, ExecuteCallback callback) : base(module, name, callback) { }
+
+        /// <summary>
+        ///     Adds a modal parameter to the parameters collection.
+        /// </summary>
+        /// <param name="configure"><see cref="ModalCommandParameterBuilder"/> factory.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public override ModalCommandBuilder AddParameter(Action<ModalCommandParameterBuilder> configure)
+        {
+            var parameter = new ModalCommandParameterBuilder(this);
+            configure(parameter);
+            AddParameters(parameter);
+            return this;
+        }
+
+        internal override ModalCommandInfo Build(ModuleInfo module, InteractionService commandService) =>
+            new(this, module, commandService);
+    }
+}

src/Discord.Net.Interactions/Builders/Modals/Inputs/IInputComponentBuilder.cs

@@ -0,0 +1,105 @@
+using System;
+using System.Collections.Generic;
+
+namespace Discord.Interactions.Builders
+{
+    /// <summary>
+    ///     Represent a builder for creating <see cref="InputComponentInfo"/>.
+    /// </summary>
+    public interface IInputComponentBuilder
+    {
+        /// <summary>
+        ///     Gets the parent modal of this input component.
+        /// </summary>
+        ModalBuilder Modal { get; }
+
+        /// <summary>
+        ///     Gets the custom id of this input component.
+        /// </summary>
+        string CustomId { get; }
+
+        /// <summary>
+        ///     Gets the label of this input component.
+        /// </summary>
+        string Label { get; }
+
+        /// <summary>
+        ///     Gets whether this input component is required.
+        /// </summary>
+        bool IsRequired { get; }
+
+        /// <summary>
+        ///     Gets the component type of this input component.
+        /// </summary>
+        ComponentType ComponentType { get; }
+
+        /// <summary>
+        ///     Get the reference type of this input component.
+        /// </summary>
+        Type Type { get; }
+
+        /// <summary>
+        ///     Gets the default value of this input component.
+        /// </summary>
+        object DefaultValue { get; }
+
+        /// <summary>
+        ///     Gets a collection of the attributes of this component.
+        /// </summary>
+        IReadOnlyCollection<Attribute> Attributes { get; }
+
+        /// <summary>
+        ///     Sets <see cref="CustomId"/>.
+        /// </summary>
+        /// <param name="customId">New value of the <see cref="CustomId"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        IInputComponentBuilder WithCustomId(string customId);
+
+        /// <summary>
+        ///     Sets <see cref="Label"/>.
+        /// </summary>
+        /// <param name="label">New value of the <see cref="Label"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        IInputComponentBuilder WithLabel(string label);
+
+        /// <summary>
+        ///     Sets <see cref="IsRequired"/>.
+        /// </summary>
+        /// <param name="isRequired">New value of the <see cref="IsRequired"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        IInputComponentBuilder SetIsRequired(bool isRequired);
+
+        /// <summary>
+        ///     Sets <see cref="Type"/>.
+        /// </summary>
+        /// <param name="type">New value of the <see cref="Type"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        IInputComponentBuilder WithType(Type type);
+
+        /// <summary>
+        ///     Sets <see cref="DefaultValue"/>.
+        /// </summary>
+        /// <param name="value">New value of the <see cref="DefaultValue"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        IInputComponentBuilder SetDefaultValue(object value);
+
+        /// <summary>
+        ///     Adds attributes to <see cref="Attributes"/>.
+        /// </summary>
+        /// <param name="attributes">New attributes to be added to <see cref="Attributes"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        IInputComponentBuilder WithAttributes(params Attribute[] attributes);
+    }
+}

src/Discord.Net.Interactions/Builders/Modals/Inputs/InputComponentBuilder.cs

@@ -0,0 +1,164 @@
+using System;
+using System.Collections.Generic;
+
+namespace Discord.Interactions.Builders
+{
+    /// <summary>
+    ///     Represents the base builder class for creating <see cref="InputComponentInfo"/>.
+    /// </summary>
+    /// <typeparam name="TInfo">The <see cref="InputComponentInfo"/> this builder yields when built.</typeparam>
+    /// <typeparam name="TBuilder">Inherited <see cref="InputComponentBuilder{TInfo, TBuilder}"/> type.</typeparam>
+    public abstract class InputComponentBuilder<TInfo, TBuilder> : IInputComponentBuilder
+        where TInfo : InputComponentInfo
+        where TBuilder : InputComponentBuilder<TInfo, TBuilder>
+    {
+        private readonly List<Attribute> _attributes;
+        protected abstract TBuilder Instance { get; }
+
+        /// <inheritdoc/>
+        public ModalBuilder Modal { get; }
+
+        /// <inheritdoc/>
+        public string CustomId { get; set; }
+
+        /// <inheritdoc/>
+        public string Label { get; set; }
+
+        /// <inheritdoc/>
+        public bool IsRequired { get; set; } = true;
+
+        /// <inheritdoc/>
+        public ComponentType ComponentType { get; internal set; }
+
+        /// <inheritdoc/>
+        public Type Type { get; private set; }
+
+        /// <inheritdoc/>
+        public object DefaultValue { get; set; }
+
+        /// <inheritdoc/>
+        public IReadOnlyCollection<Attribute> Attributes => _attributes;
+
+        /// <summary>
+        ///     Creates an instance of <see cref="InputComponentBuilder{TInfo, TBuilder}"/>
+        /// </summary>
+        /// <param name="modal">Parent modal of this input component.</param>
+        public InputComponentBuilder(ModalBuilder modal)
+        {
+            Modal = modal;
+            _attributes = new();
+        }
+
+        /// <summary>
+        ///     Sets <see cref="CustomId"/>.
+        /// </summary>
+        /// <param name="customId">New value of the <see cref="CustomId"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public TBuilder WithCustomId(string customId)
+        {
+            CustomId = customId;
+            return Instance;
+        }
+
+        /// <summary>
+        ///     Sets <see cref="Label"/>.
+        /// </summary>
+        /// <param name="label">New value of the <see cref="Label"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public TBuilder WithLabel(string label)
+        {
+            Label = label;
+            return Instance;
+        }
+
+        /// <summary>
+        ///     Sets <see cref="IsRequired"/>.
+        /// </summary>
+        /// <param name="isRequired">New value of the <see cref="IsRequired"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public TBuilder SetIsRequired(bool isRequired)
+        {
+            IsRequired = isRequired;
+            return Instance;
+        }
+
+        /// <summary>
+        ///     Sets <see cref="ComponentType"/>.
+        /// </summary>
+        /// <param name="componentType">New value of the <see cref="ComponentType"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public TBuilder WithComponentType(ComponentType componentType)
+        {
+            ComponentType = componentType;
+            return Instance;
+        }
+
+        /// <summary>
+        ///     Sets <see cref="Type"/>.
+        /// </summary>
+        /// <param name="type">New value of the <see cref="Type"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public TBuilder WithType(Type type)
+        {
+            Type = type;
+            return Instance;
+        }
+
+        /// <summary>
+        ///     Sets <see cref="DefaultValue"/>.
+        /// </summary>
+        /// <param name="value">New value of the <see cref="DefaultValue"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public TBuilder SetDefaultValue(object value)
+        {
+            DefaultValue = value;
+            return Instance;
+        }
+
+        /// <summary>
+        ///     Adds attributes to <see cref="Attributes"/>.
+        /// </summary>
+        /// <param name="attributes">New attributes to be added to <see cref="Attributes"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public TBuilder WithAttributes(params Attribute[] attributes)
+        {
+            _attributes.AddRange(attributes);
+            return Instance;
+        }
+
+        internal abstract TInfo Build(ModalInfo modal);
+
+        //IInputComponentBuilder
+        /// <inheritdoc/>
+        IInputComponentBuilder IInputComponentBuilder.WithCustomId(string customId) => WithCustomId(customId);
+
+        /// <inheritdoc/>
+        IInputComponentBuilder IInputComponentBuilder.WithLabel(string label) => WithCustomId(label);
+
+        /// <inheritdoc/>
+        IInputComponentBuilder IInputComponentBuilder.WithType(Type type) => WithType(type);
+
+        /// <inheritdoc/>
+        IInputComponentBuilder IInputComponentBuilder.SetDefaultValue(object value) => SetDefaultValue(value);
+
+        /// <inheritdoc/>
+        IInputComponentBuilder IInputComponentBuilder.WithAttributes(params Attribute[] attributes) => WithAttributes(attributes);
+
+        /// <inheritdoc/>
+        IInputComponentBuilder IInputComponentBuilder.SetIsRequired(bool isRequired) => SetIsRequired(isRequired);
+    }
+}

src/Discord.Net.Interactions/Builders/Modals/Inputs/TextInputComponentBuilder.cs

@@ -0,0 +1,109 @@
+namespace Discord.Interactions.Builders
+{
+    /// <summary>
+    ///     Represents a builder for creating <see cref="TextInputComponentInfo"/>.
+    /// </summary>
+    public class TextInputComponentBuilder : InputComponentBuilder<TextInputComponentInfo, TextInputComponentBuilder>
+    {
+        protected override TextInputComponentBuilder Instance => this;
+
+        /// <summary>
+        ///     Gets and sets the style of the text input.
+        /// </summary>
+        public TextInputStyle Style { get; set; }
+
+        /// <summary>
+        ///     Gets and sets the placeholder of the text input.
+        /// </summary>
+        public string Placeholder { get; set; }
+
+        /// <summary>
+        ///     Gets and sets the minimum length of the text input.
+        /// </summary>
+        public int MinLength { get; set; }
+
+        /// <summary>
+        ///     Gets and sets the maximum length of the text input.
+        /// </summary>
+        public int MaxLength { get; set; }
+
+        /// <summary>
+        ///     Gets and sets the initial value to be displayed by this input.
+        /// </summary>
+        public string InitialValue { get; set; }
+
+        /// <summary>
+        ///     Initializes a new <see cref="TextInputComponentBuilder"/>.
+        /// </summary>
+        /// <param name="modal">Parent modal of this component.</param>
+        public TextInputComponentBuilder(ModalBuilder modal) : base(modal) { }
+
+        /// <summary>
+        ///     Sets <see cref="Style"/>.
+        /// </summary>
+        /// <param name="style">New value of the <see cref="SetValue(string)"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public TextInputComponentBuilder WithStyle(TextInputStyle style)
+        {
+            Style = style;
+            return this;
+        }
+
+        /// <summary>
+        ///     Sets <see cref="Placeholder"/>.
+        /// </summary>
+        /// <param name="placeholder">New value of the <see cref="Placeholder"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public TextInputComponentBuilder WithPlaceholder(string placeholder)
+        {
+            Placeholder = placeholder;
+            return this;
+        }
+
+        /// <summary>
+        ///     Sets <see cref="MinLength"/>.
+        /// </summary>
+        /// <param name="minLenght">New value of the <see cref="MinLength"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public TextInputComponentBuilder WithMinLenght(int minLenght)
+        {
+            MinLength = minLenght;
+            return this;
+        }
+
+        /// <summary>
+        ///     Sets <see cref="MaxLength"/>.
+        /// </summary>
+        /// <param name="maxLenght">New value of the <see cref="MaxLength"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public TextInputComponentBuilder WithMaxLenght(int maxLenght)
+        {
+            MaxLength = maxLenght;
+            return this;
+        }
+
+        /// <summary>
+        ///     Sets <see cref="InitialValue"/>.
+        /// </summary>
+        /// <param name="value">New value of the <see cref="InitialValue"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public TextInputComponentBuilder WithInitialValue(string value)
+        {
+            InitialValue = value;
+            return this;
+        }
+
+        internal override TextInputComponentInfo Build(ModalInfo modal) =>
+            new(this, modal);
+    }
+}

src/Discord.Net.Interactions/Builders/Modals/ModalBuilder.cs

@@ -0,0 +1,81 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Discord.Interactions.Builders
+{
+    /// <summary>
+    ///     Represents a builder for creating <see cref="ModalInfo"/>.
+    /// </summary>
+    public class ModalBuilder
+    {
+        internal readonly List<IInputComponentBuilder> _components;
+
+        /// <summary>
+        ///     Gets the initialization delegate for this modal.
+        /// </summary>
+        public ModalInitializer ModalInitializer { get; internal set; }
+
+        /// <summary>
+        ///     Gets the title of this modal.
+        /// </summary>
+        public string Title { get; set; }
+
+        /// <summary>
+        ///     Gets the <see cref="IModal"/> implementation used to initialize this object.
+        /// </summary>
+        public Type Type { get; }
+
+        /// <summary>
+        ///     Gets a collection of the components of this modal.
+        /// </summary>
+        public IReadOnlyCollection<IInputComponentBuilder> Components => _components;
+
+        internal ModalBuilder(Type type)
+        {
+            if (!typeof(IModal).IsAssignableFrom(type))
+                throw new ArgumentException($"Must be an implementation of {nameof(IModal)}", nameof(type));
+
+            _components = new();
+        }
+
+        /// <summary>
+        ///     Initializes a new <see cref="ModalBuilder"/>
+        /// </summary>
+        /// <param name="modalInitializer">The initialization delegate for this modal.</param>
+        public ModalBuilder(Type type, ModalInitializer modalInitializer) : this(type)
+        {
+            ModalInitializer = modalInitializer;
+        }
+
+        /// <summary>
+        ///     Sets <see cref="Title"/>.
+        /// </summary>
+        /// <param name="title">New value of the <see cref="Title"/>.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public ModalBuilder WithTitle(string title)
+        {
+            Title = title;
+            return this;
+        }
+
+        /// <summary>
+        ///     Adds text components to <see cref="TextComponents"/>.
+        /// </summary>
+        /// <param name="configure">Text Component builder factory.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public ModalBuilder AddTextComponent(Action<TextInputComponentBuilder> configure)
+        {
+            var builder = new TextInputComponentBuilder(this);
+            configure(builder);
+            _components.Add(builder);
+            return this;
+        }
+
+        internal ModalInfo Build() => new(this);
+    }
+}

src/Discord.Net.Interactions/Builders/ModuleBuilder.cs

@@ -16,6 +16,7 @@ namespace Discord.Interactions.Builders
         private readonly List<ContextCommandBuilder> _contextCommands;
         private readonly List<ComponentCommandBuilder> _componentCommands;
         private readonly List<AutocompleteCommandBuilder> _autocompleteCommands;
+        private readonly List<ModalCommandBuilder> _modalCommands;
 
         /// <summary>
         ///     Gets the underlying Interaction Service.
@@ -92,6 +93,11 @@ namespace Discord.Interactions.Builders
         /// </summary>
         public IReadOnlyList<AutocompleteCommandBuilder> AutocompleteCommands => _autocompleteCommands;
 
+        /// <summary>
+        ///     Gets a collection of the Modal Commands of this module.
+        /// </summary>
+        public IReadOnlyList<ModalCommandBuilder> ModalCommands => _modalCommands;
+
         internal TypeInfo TypeInfo { get; set; }
 
         internal ModuleBuilder (InteractionService interactionService, ModuleBuilder parent = null)
@@ -105,6 +111,7 @@ namespace Discord.Interactions.Builders
             _contextCommands = new List<ContextCommandBuilder>();
             _componentCommands = new List<ComponentCommandBuilder>();
             _autocompleteCommands = new List<AutocompleteCommandBuilder>();
+            _modalCommands = new List<ModalCommandBuilder> ();
             _preconditions = new List<PreconditionAttribute>();
         }
 
@@ -152,7 +159,7 @@ namespace Discord.Interactions.Builders
         /// <returns>
         ///     The builder instance.
         /// </returns>
-        public ModuleBuilder WithDefaultPermision (bool permission)
+        public ModuleBuilder WithDefaultPermission (bool permission)
         {
             DefaultPermission = permission;
             return this;
@@ -310,6 +317,21 @@ namespace Discord.Interactions.Builders
             configure(command);
             _autocompleteCommands.Add(command);
             return this;
+
+        }
+        
+        ///     Adds a modal command builder to <see cref="ModalCommands"/>.
+        /// </summary>
+        /// <param name="configure"><see cref="ModalCommands"/> factory.</param>
+        /// <returns>
+        ///     The builder instance.
+        /// </returns>
+        public ModuleBuilder AddModalCommand(Action<ModalCommandBuilder> configure)
+        {
+            var command = new ModalCommandBuilder(this);
+            configure(command);
+            _modalCommands.Add(command);
+            return this;
         }
 
         /// <summary>

src/Discord.Net.Interactions/Builders/ModuleClassBuilder.cs

@@ -103,6 +103,7 @@ namespace Discord.Interactions.Builders
             var validContextCommands = methods.Where(IsValidContextCommandDefinition);
             var validInteractions = methods.Where(IsValidComponentCommandDefinition);
             var validAutocompleteCommands = methods.Where(IsValidAutocompleteCommandDefinition);
+            var validModalCommands = methods.Where(IsValidModalCommanDefinition);
 
             Func<IServiceProvider, IInteractionModuleBase> createInstance = commandService._useCompiledLambda ?
                 ReflectionUtils<IInteractionModuleBase>.CreateLambdaBuilder(typeInfo, commandService) : ReflectionUtils<IInteractionModuleBase>.CreateBuilder(typeInfo, commandService);
@@ -118,6 +119,9 @@ namespace Discord.Interactions.Builders
 
             foreach(var method in validAutocompleteCommands)
                 builder.AddAutocompleteCommand(x => BuildAutocompleteCommand(x, createInstance, method, commandService, services));
+
+            foreach(var method in validModalCommands)
+                builder.AddModalCommand(x => BuildModalCommand(x, createInstance, method, commandService, services));
         }
 
         private static void BuildSubModules (ModuleBuilder parent, IEnumerable<TypeInfo> subModules, IList<TypeInfo> builtTypes, InteractionService commandService,
@@ -298,6 +302,47 @@ namespace Discord.Interactions.Builders
             builder.Callback = CreateCallback(createInstance, methodInfo, commandService);
         }
 
+        private static void BuildModalCommand(ModalCommandBuilder builder, Func<IServiceProvider, IInteractionModuleBase> createInstance, MethodInfo methodInfo,
+            InteractionService commandService, IServiceProvider services)
+        {
+            var parameters = methodInfo.GetParameters();
+
+            if (parameters.Count(x => typeof(IModal).IsAssignableFrom(x.ParameterType)) > 1)
+                throw new InvalidOperationException($"A modal command can only have one {nameof(IModal)} parameter.");
+
+            if (!parameters.All(x => x.ParameterType == typeof(string) || typeof(IModal).IsAssignableFrom(x.ParameterType)))
+                throw new InvalidOperationException($"All parameters of a modal command must be either a string or an implementation of {nameof(IModal)}");
+
+            var attributes = methodInfo.GetCustomAttributes();
+
+            builder.MethodName = methodInfo.Name;
+
+            foreach (var attribute in attributes)
+            {
+                switch (attribute)
+                {
+                    case ModalInteractionAttribute modal:
+                        {
+                            builder.Name = modal.CustomId;
+                            builder.RunMode = modal.RunMode;
+                            builder.IgnoreGroupNames = modal.IgnoreGroupNames;
+                        }
+                        break;
+                    case PreconditionAttribute precondition:
+                        builder.WithPreconditions(precondition);
+                        break;
+                    default:
+                        builder.WithAttributes(attribute);
+                        break;
+                }
+            }
+
+            foreach (var parameter in parameters)
+                builder.AddParameter(x => BuildParameter(x, parameter));
+
+            builder.Callback = CreateCallback(createInstance, methodInfo, commandService);
+        }
+
         private static ExecuteCallback CreateCallback (Func<IServiceProvider, IInteractionModuleBase> createInstance,
             MethodInfo methodInfo, InteractionService commandService)
         {
@@ -400,7 +445,9 @@ namespace Discord.Interactions.Builders
             builder.Name = Regex.Replace(builder.Name, "(?<=[a-z])(?=[A-Z])", "-").ToLower();
         }
 
-        private static void BuildParameter (CommandParameterBuilder builder, ParameterInfo paramInfo)
+        private static void BuildParameter<TInfo, TBuilder> (ParameterBuilder<TInfo, TBuilder> builder, ParameterInfo paramInfo)
+            where TInfo : class, IParameterInfo
+            where TBuilder : ParameterBuilder<TInfo, TBuilder>
         {
             var attributes = paramInfo.GetCustomAttributes();
             var paramType = paramInfo.ParameterType;
@@ -428,6 +475,84 @@ namespace Discord.Interactions.Builders
         }
         #endregion
 
+        #region Modals
+        public static ModalInfo BuildModalInfo(Type modalType)
+        {
+            if (!typeof(IModal).IsAssignableFrom(modalType))
+                throw new InvalidOperationException($"{modalType.FullName} isn't an implementation of {typeof(IModal).FullName}");
+
+            var instance = Activator.CreateInstance(modalType, false) as IModal;
+
+            try
+            {
+                var builder = new ModalBuilder(modalType)
+                {
+                    Title = instance.Title
+                };
+
+                var inputs = modalType.GetProperties().Where(IsValidModalInputDefinition);
+
+                foreach (var prop in inputs)
+                {
+                    var componentType = prop.GetCustomAttribute<ModalInputAttribute>()?.ComponentType;
+
+                    switch (componentType)
+                    {
+                        case ComponentType.TextInput:
+                            builder.AddTextComponent(x => BuildTextInput(x, prop, prop.GetValue(instance)));
+                            break;
+                        case null:
+                            throw new InvalidOperationException($"{prop.Name} of {prop.DeclaringType.Name} isn't a valid modal input field.");
+                        default:
+                            throw new InvalidOperationException($"Component type {componentType} cannot be used in modals.");
+                    }
+                }
+
+                var memberInit = ReflectionUtils<IModal>.CreateLambdaMemberInit(modalType.GetTypeInfo(), modalType.GetConstructor(Type.EmptyTypes), x => x.IsDefined(typeof(ModalInputAttribute)));
+                builder.ModalInitializer = (args) => memberInit(Array.Empty<object>(), args);
+                return builder.Build();
+            }
+            finally
+            {
+                (instance as IDisposable)?.Dispose();
+            }
+        }
+
+        private static void BuildTextInput(TextInputComponentBuilder builder, PropertyInfo propertyInfo, object defaultValue)
+        {
+            var attributes = propertyInfo.GetCustomAttributes();
+
+            builder.Label = propertyInfo.Name;
+            builder.DefaultValue = defaultValue;
+            builder.WithType(propertyInfo.PropertyType);
+
+            foreach(var attribute in attributes)
+            {
+                switch (attribute)
+                {
+                    case ModalTextInputAttribute textInput:
+                        builder.CustomId = textInput.CustomId;
+                        builder.ComponentType = textInput.ComponentType;
+                        builder.Style = textInput.Style;
+                        builder.Placeholder = textInput.Placeholder;
+                        builder.MaxLength = textInput.MaxLength;
+                        builder.MinLength = textInput.MinLength;
+                        builder.InitialValue = textInput.InitialValue;
+                        break;
+                    case RequiredInputAttribute requiredInput:
+                        builder.IsRequired = requiredInput.IsRequired;
+                        break;
+                    case InputLabelAttribute inputLabel:
+                        builder.Label = inputLabel.Label;
+                        break;
+                    default:
+                        builder.WithAttributes(attribute);
+                        break;
+                }
+            }
+        }
+        #endregion
+
         internal static bool IsValidModuleDefinition (TypeInfo typeInfo)
         {
             return ModuleTypeInfo.IsAssignableFrom(typeInfo) &&
@@ -467,5 +592,21 @@ namespace Discord.Interactions.Builders
                 !methodInfo.IsGenericMethod &&
                 methodInfo.GetParameters().Length == 0;
         }
+
+        private static bool IsValidModalCommanDefinition(MethodInfo methodInfo)
+        {
+            return methodInfo.IsDefined(typeof(ModalInteractionAttribute)) &&
+                (methodInfo.ReturnType == typeof(Task) || methodInfo.ReturnType == typeof(Task<RuntimeResult>)) &&
+                !methodInfo.IsStatic &&
+                !methodInfo.IsGenericMethod &&
+                typeof(IModal).IsAssignableFrom(methodInfo.GetParameters().Last().ParameterType);
+        }
+
+        private static bool IsValidModalInputDefinition(PropertyInfo propertyInfo)
+        {
+            return propertyInfo.SetMethod?.IsPublic == true &&
+                propertyInfo.SetMethod?.IsStatic == false &&
+                propertyInfo.IsDefined(typeof(ModalInputAttribute));
+        }
     }
 }

src/Discord.Net.Interactions/Builders/Parameters/ModalCommandParameterBuilder.cs

@@ -0,0 +1,45 @@
+using System;
+
+namespace Discord.Interactions.Builders
+{
+
+    /// <summary>
+    ///     Represents a builder for creating <see cref="ModalCommandBuilder"/>.
+    /// </summary>
+    public class ModalCommandParameterBuilder : ParameterBuilder<ModalCommandParameterInfo, ModalCommandParameterBuilder>
+    {
+        protected override ModalCommandParameterBuilder Instance => this;
+
+        /// <summary>
+        ///     Gets the built <see cref="ModalInfo"/> class for this parameter, if <see cref="IsModalParameter"/> is <see langword="true"/>.
+        /// </summary>
+        public ModalInfo Modal { get; private set; }
+
+        /// <summary>
+        ///     Gets whether or not this parameter is an <see cref="IModal"/>.
+        /// </summary>
+        public bool IsModalParameter => Modal is not null;
+
+        internal ModalCommandParameterBuilder(ICommandBuilder command) : base(command) { }
+
+        /// <summary>
+        ///     Initializes a new <see cref="ModalCommandParameterBuilder"/>.
+        /// </summary>
+        /// <param name="command">Parent command of this parameter.</param>
+        /// <param name="name">Name of this command.</param>
+        /// <param name="type">Type of this parameter.</param>
+        public ModalCommandParameterBuilder(ICommandBuilder command, string name, Type type) : base(command, name, type) { }
+
+        /// <inheritdoc/>
+        public override ModalCommandParameterBuilder SetParameterType(Type type)
+        {
+            if (typeof(IModal).IsAssignableFrom(type))
+                Modal = ModalUtils.GetOrAdd(type);
+
+            return base.SetParameterType(type);
+        }
+
+        internal override ModalCommandParameterInfo Build(ICommandInfo command) =>
+            new(this, command);
+    }
+}

src/Discord.Net.Interactions/Entities/IModal.cs

@@ -0,0 +1,13 @@
+namespace Discord.Interactions
+{
+    /// <summary>
+    ///     Represents a generic <see cref="Modal"/> for use with the interaction service.
+    /// </summary>
+    public interface IModal
+    {
+        /// <summary>
+        ///     Gets the modal's title.
+        /// </summary>
+        string Title { get; }
+    }
+}

src/Discord.Net.Interactions/Extensions/IDiscordInteractionExtensions.cs

@@ -0,0 +1,37 @@
+using System;
+using System.Threading.Tasks;
+
+namespace Discord.Interactions
+{
+    public static class IDiscordInteractionExtentions
+    {
+        /// <summary>
+        ///     Respond to an interaction with a <see cref="IModal"/>.
+        /// </summary>
+        /// <typeparam name="T">Type of the <see cref="IModal"/> implementation.</typeparam>
+        /// <param name="interaction">The interaction to respond to.</param>
+        /// <param name="options">The request options for this <see langword="async"/> request.</param>
+        /// <returns>A task that represents the asynchronous operation of responding to the interaction.</returns>
+        public static async Task RespondWithModalAsync<T>(this IDiscordInteraction interaction, string customId, RequestOptions options = null)
+            where T : class, IModal
+        {
+            if (!ModalUtils.TryGet<T>(out var modalInfo))
+                throw new ArgumentException($"{typeof(T).FullName} isn't referenced by any registered Modal Interaction Command and doesn't have a cached {typeof(ModalInfo)}");
+
+            var builder = new ModalBuilder(modalInfo.Title, customId);
+
+            foreach(var input in modalInfo.Components)
+                switch (input)
+                {
+                    case TextInputComponentInfo textComponent:
+                        builder.AddTextInput(textComponent.Label, textComponent.CustomId, textComponent.Style, textComponent.Placeholder, textComponent.IsRequired ? textComponent.MinLength : null,
+                            textComponent.MaxLength, textComponent.IsRequired, textComponent.InitialValue);
+                        break;
+                    default:
+                        throw new InvalidOperationException($"{input.GetType().FullName} isn't a valid component info class");
+                }
+
+            await interaction.RespondWithModalAsync(builder.Build(), options).ConfigureAwait(false);
+        }
+    }
+}

src/Discord.Net.Interactions/Info/Commands/ComponentCommandInfo.cs

@@ -35,7 +35,7 @@ namespace Discord.Interactions
         /// <param name="services">Services that will be used while initializing the <see cref="InteractionModuleBase{T}"/>.</param>
         /// <param name="additionalArgs">Provide additional string parameters to the method along with the auto generated parameters.</param>
         /// <returns>
-        ///     A task representing the asyncronous command execution process.
+        ///     A task representing the asynchronous command execution process.
         /// </returns>
         public async Task<IResult> ExecuteAsync(IInteractionContext context, IServiceProvider services, params string[] additionalArgs)
         {

src/Discord.Net.Interactions/Info/Commands/ModalCommandInfo.cs

@@ -0,0 +1,81 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Threading.Tasks;
+namespace Discord.Interactions
+{
+    /// <summary>
+    ///     Represents the info class of an attribute based method for handling Modal Interaction events.
+    /// </summary>
+    public class ModalCommandInfo : CommandInfo<ModalCommandParameterInfo>
+    {
+        /// <summary>
+        ///     Gets the <see cref="ModalInfo"/> class for this commands <see cref="IModal"/> parameter.
+        /// </summary>
+        public ModalInfo Modal { get; }
+
+        /// <inheritdoc/>
+        public override bool SupportsWildCards => true;
+
+        /// <inheritdoc/>
+        public override IReadOnlyCollection<ModalCommandParameterInfo> Parameters { get; }
+
+        internal ModalCommandInfo(Builders.ModalCommandBuilder builder, ModuleInfo module, InteractionService commandService) : base(builder, module, commandService)
+        {
+            Parameters = builder.Parameters.Select(x => x.Build(this)).ToImmutableArray();
+            Modal = Parameters.Last().Modal;
+        }
+
+        /// <inheritdoc/>
+        public override async Task<IResult> ExecuteAsync(IInteractionContext context, IServiceProvider services)
+            => await ExecuteAsync(context, services, null).ConfigureAwait(false);
+
+        /// <summary>
+        ///     Execute this command using dependency injection.
+        /// </summary>
+        /// <param name="context">Context that will be injected to the <see cref="InteractionModuleBase{T}"/>.</param>
+        /// <param name="services">Services that will be used while initializing the <see cref="InteractionModuleBase{T}"/>.</param>
+        /// <param name="additionalArgs">Provide additional string parameters to the method along with the auto generated parameters.</param>
+        /// <returns>
+        ///     A task representing the asynchronous command execution process.
+        /// </returns>
+        public async Task<IResult> ExecuteAsync(IInteractionContext context, IServiceProvider services, params string[] additionalArgs)
+        {
+            if (context.Interaction is not IModalInteraction modalInteraction)
+                return ExecuteResult.FromError(InteractionCommandError.ParseFailed, $"Provided {nameof(IInteractionContext)} doesn't belong to a Modal Interaction.");
+
+            try
+            {
+                var args = new List<object>();
+
+                if (additionalArgs is not null)
+                    args.AddRange(additionalArgs);
+
+                var modal = Modal.CreateModal(modalInteraction, Module.CommandService._exitOnMissingModalField);
+                args.Add(modal);
+
+                return await RunAsync(context, args.ToArray(), services);
+            }
+            catch (Exception ex)
+            {
+                var result = ExecuteResult.FromError(ex);
+                await InvokeModuleEvent(context, result).ConfigureAwait(false);
+                return result;
+            }
+        }
+
+        /// <inheritdoc/>
+        protected override Task InvokeModuleEvent(IInteractionContext context, IResult result)
+            => CommandService._modalCommandExecutedEvent.InvokeAsync(this, context, result);
+
+        /// <inheritdoc/>
+        protected override string GetLogString(IInteractionContext context)
+        {
+            if (context.Guild != null)
+                return $"Modal Command: \"{base.ToString()}\" for {context.User} in {context.Guild}/{context.Channel}";
+            else
+                return $"Modal Command: \"{base.ToString()}\" for {context.User} in {context.Channel}";
+        }
+    }
+}

src/Discord.Net.Interactions/Info/InputComponents/InputComponentInfo.cs

@@ -0,0 +1,64 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+
+namespace Discord.Interactions
+{
+    /// <summary>
+    ///     Represents the base info class for <see cref="IModal"/> input components.
+    /// </summary>
+    public abstract class InputComponentInfo
+    {
+        /// <summary>
+        ///     Gets the parent modal of this component.
+        /// </summary>
+        public ModalInfo Modal { get; }
+
+        /// <summary>
+        ///     Gets the custom id of this component.
+        /// </summary>
+        public string CustomId { get; }
+
+        /// <summary>
+        ///     Gets the label of this component.
+        /// </summary>
+        public string Label { get; }
+
+        /// <summary>
+        ///     Gets whether or not this component requires a user input.
+        /// </summary>
+        public bool IsRequired { get; }
+
+        /// <summary>
+        ///     Gets the type of this component.
+        /// </summary>
+        public ComponentType ComponentType { get; }
+
+        /// <summary>
+        ///     Gets the reference type of this component.
+        /// </summary>
+        public Type Type { get; }
+
+        /// <summary>
+        ///     Gets the default value of this component.
+        /// </summary>
+        public object DefaultValue { get; }
+
+        /// <summary>
+        ///     Gets a collection of the attributes of this command.
+        /// </summary>
+        public IReadOnlyCollection<Attribute> Attributes { get; }
+
+        protected InputComponentInfo(Builders.IInputComponentBuilder builder, ModalInfo modal)
+        {
+            Modal = modal;
+            CustomId = builder.CustomId;
+            Label = builder.Label;
+            IsRequired = builder.IsRequired;
+            ComponentType = builder.ComponentType;
+            Type = builder.Type;
+            DefaultValue = builder.DefaultValue;
+            Attributes = builder.Attributes.ToImmutableArray();
+        }
+    }
+}

src/Discord.Net.Interactions/Info/InputComponents/TextInputComponentInfo.cs

@@ -0,0 +1,42 @@
+namespace Discord.Interactions
+{
+    /// <summary>
+    ///     Represents the <see cref="InputComponentInfo"/> class for <see cref="ComponentType.TextInput"/> type.
+    /// </summary>
+    public class TextInputComponentInfo : InputComponentInfo
+    {
+        /// <summary>
+        ///     Gets the style of the text input.
+        /// </summary>
+        public TextInputStyle Style { get; }
+
+        /// <summary>
+        ///     Gets the placeholder of the text input.
+        /// </summary>
+        public string Placeholder { get; }
+
+        /// <summary>
+        ///     Gets the minimum length of the text input.
+        /// </summary>
+        public int MinLength { get; }
+
+        /// <summary>
+        ///     Gets the maximum length of the text input.
+        /// </summary>
+        public int MaxLength { get; }
+
+        /// <summary>
+        ///     Gets the initial value to be displayed by this input.
+        /// </summary>
+        public string InitialValue { get; }
+
+        internal TextInputComponentInfo(Builders.TextInputComponentBuilder builder, ModalInfo modal) : base(builder, modal)
+        {
+            Style = builder.Style;
+            Placeholder = builder.Placeholder;
+            MinLength = builder.MinLength;
+            MaxLength = builder.MaxLength;
+            InitialValue = builder.InitialValue;
+        }
+    }
+}

src/Discord.Net.Interactions/Info/ModalInfo.cs

@@ -0,0 +1,90 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+
+namespace Discord.Interactions
+{
+    /// <summary>
+    ///     Represents a cached object initialization delegate.
+    /// </summary>
+    /// <param name="args">Property arguments array.</param>
+    /// <returns>
+    ///     Returns the constructed object.
+    /// </returns>
+    public delegate IModal ModalInitializer(object[] args);
+
+    /// <summary>
+    ///     Represents the info class of an <see cref="IModal"/> form.
+    /// </summary>
+    public class ModalInfo
+    {
+        internal readonly ModalInitializer _initializer;
+
+        /// <summary>
+        ///     Gets the title of this modal.
+        /// </summary>
+        public string Title { get; }
+
+        /// <summary>
+        ///     Gets the <see cref="IModal"/> implementation used to initialize this object.
+        /// </summary>
+        public Type Type { get; }
+
+        /// <summary>
+        ///     Gets a collection of the components of this modal.
+        /// </summary>
+        public IReadOnlyCollection<InputComponentInfo> Components { get; }
+
+        /// <summary>
+        ///     Gets a collection of the text components of this modal.
+        /// </summary>
+        public IReadOnlyCollection<TextInputComponentInfo> TextComponents { get; }
+
+        internal ModalInfo(Builders.ModalBuilder builder)
+        {
+            Title = builder.Title;
+            Type = builder.Type;
+            Components = builder.Components.Select(x => x switch
+            {
+                Builders.TextInputComponentBuilder textComponent => textComponent.Build(this),
+                _ => throw new InvalidOperationException($"{x.GetType().FullName} isn't a supported modal input component builder type.")
+            }).ToImmutableArray();
+
+            TextComponents = Components.OfType<TextInputComponentInfo>().ToImmutableArray();
+
+            _initializer = builder.ModalInitializer;
+        }
+
+        /// <summary>
+        ///     Creates an <see cref="IModal"/> and fills it with provided message components.
+        /// </summary>
+        /// <param name="components"><see cref="IModalInteraction"/> that will be injected into the modal.</param>
+        /// <returns>
+        ///     A <see cref="IModal"/> filled with the provided components.
+        /// </returns>
+        public IModal CreateModal(IModalInteraction modalInteraction, bool throwOnMissingField = false)
+        {
+            var args = new object[Components.Count];
+            var components = modalInteraction.Data.Components.ToList();
+
+            for (var i = 0; i < Components.Count; i++)
+            {
+                var input = Components.ElementAt(i);
+                var component = components.Find(x => x.CustomId == input.CustomId);
+
+                if (component is null)
+                {
+                    if (!throwOnMissingField)
+                        args[i] = input.DefaultValue;
+                    else
+                        throw new InvalidOperationException($"Modal interaction is missing the required field: {input.CustomId}");
+                }
+                else
+                    args[i] = component.Value;
+            }
+
+            return _initializer(args);
+        }
+    }
+}

src/Discord.Net.Interactions/Info/ModuleInfo.cs

@@ -68,6 +68,8 @@ namespace Discord.Interactions
         /// </summary>
         public IReadOnlyCollection<AutocompleteCommandInfo> AutocompleteCommands { get; }
 
+        public IReadOnlyCollection<ModalCommandInfo> ModalCommands { get; }
+
         /// <summary>
         ///     Gets the declaring type of this module, if <see cref="IsSubModule"/> is <see langword="true"/>.
         /// </summary>
@@ -112,6 +114,7 @@ namespace Discord.Interactions
             ContextCommands = BuildContextCommands(builder).ToImmutableArray();
             ComponentCommands = BuildComponentCommands(builder).ToImmutableArray();
             AutocompleteCommands = BuildAutocompleteCommands(builder).ToImmutableArray();
+            ModalCommands = BuildModalCommands(builder).ToImmutableArray();
             SubModules = BuildSubModules(builder, commandService, services).ToImmutableArray();
             Attributes = BuildAttributes(builder).ToImmutableArray();
             Preconditions = BuildPreconditions(builder).ToImmutableArray();
@@ -171,6 +174,16 @@ namespace Discord.Interactions
             return result;
         }
 
+        private IEnumerable<ModalCommandInfo> BuildModalCommands(ModuleBuilder builder)
+        {
+            var result = new List<ModalCommandInfo>();
+
+            foreach (var commandBuilder in builder.ModalCommands)
+                result.Add(commandBuilder.Build(this, CommandService));
+
+            return result;
+        }
+
         private IEnumerable<Attribute> BuildAttributes (ModuleBuilder builder)
         {
             var result = new List<Attribute>();

src/Discord.Net.Interactions/Info/Parameters/ModalCommandParameterInfo.cs

@@ -0,0 +1,28 @@
+using Discord.Interactions.Builders;
+
+namespace Discord.Interactions
+{
+    /// <summary>
+    ///     Represents the base parameter info class for <see cref="InteractionService"/> modals.
+    /// </summary>
+    public class ModalCommandParameterInfo : CommandParameterInfo
+    {
+        /// <summary>
+        ///     Gets the <see cref="ModalInfo"/> class for this parameter if <see cref="IsModalParameter"/> is true.
+        /// </summary>
+        public ModalInfo Modal { get; private set; }
+
+        /// <summary>
+        ///     Gets whether this parameter is an <see cref="IModal"/>
+        /// </summary>
+        public bool IsModalParameter => Modal is not null;
+
+        /// <inheritdoc/>
+        public new ModalCommandInfo Command => base.Command as ModalCommandInfo;
+
+        internal ModalCommandParameterInfo(ModalCommandParameterBuilder builder, ICommandInfo command) : base(builder, command)
+        {
+            Modal = builder.Modal;
+        }
+    }
+}

src/Discord.Net.Interactions/InteractionModuleBase.cs

@@ -114,6 +114,13 @@ namespace Discord.Interactions
             var response = await Context.Interaction.GetOriginalResponseAsync().ConfigureAwait(false);
             await response.DeleteAsync().ConfigureAwait(false);
         }
+        
+        /// <inheritdoc cref="IDiscordInteraction.RespondWithModalAsync(Modal, RequestOptions)"/>
+        protected virtual async Task RespondWithModalAsync(Modal modal, RequestOptions options = null) => await Context.Interaction.RespondWithModalAsync(modal);
+        
+        /// <inheritdoc cref="IDiscordInteractionExtentions.RespondWithModalAsync(IDiscordInteraction, IModal, RequestOptions)"/>
+        protected virtual async Task RespondWithModalAsync<T>(string customId, RequestOptions options = null) where T : class, IModal
+            => await Context.Interaction.RespondWithModalAsync<T>(customId, options);
 
         //IInteractionModuleBase
 

src/Discord.Net.Interactions/InteractionService.cs

@@ -53,21 +53,29 @@ namespace Discord.Interactions
         public event Func<IAutocompleteHandler, IInteractionContext, IResult, Task> AutocompleteHandlerExecuted { add { _autocompleteHandlerExecutedEvent.Add(value); } remove { _autocompleteHandlerExecutedEvent.Remove(value); } }
         internal readonly AsyncEvent<Func<IAutocompleteHandler, IInteractionContext, IResult, Task>> _autocompleteHandlerExecutedEvent = new();
 
+        /// <summary>
+        ///     Occurs when a Modal command is executed.
+        /// </summary>
+        public event Func<ModalCommandInfo, IInteractionContext, IResult, Task> ModalCommandExecuted { add { _modalCommandExecutedEvent.Add(value); } remove { _modalCommandExecutedEvent.Remove(value); } }
+        internal readonly AsyncEvent<Func<ModalCommandInfo, IInteractionContext, IResult, Task>> _modalCommandExecutedEvent = new();
+
         private readonly ConcurrentDictionary<Type, ModuleInfo> _typedModuleDefs;
         private readonly CommandMap<SlashCommandInfo> _slashCommandMap;
         private readonly ConcurrentDictionary<ApplicationCommandType, CommandMap<ContextCommandInfo>> _contextCommandMaps;
         private readonly CommandMap<ComponentCommandInfo> _componentCommandMap;
         private readonly CommandMap<AutocompleteCommandInfo> _autocompleteCommandMap;
+        private readonly CommandMap<ModalCommandInfo> _modalCommandMap;
         private readonly HashSet<ModuleInfo> _moduleDefs;
         private readonly ConcurrentDictionary<Type, TypeConverter> _typeConverters;
         private readonly ConcurrentDictionary<Type, Type> _genericTypeConverters;
         private readonly ConcurrentDictionary<Type, IAutocompleteHandler> _autocompleteHandlers = new();
+        private readonly ConcurrentDictionary<Type, ModalInfo> _modalInfos = new();
         private readonly SemaphoreSlim _lock;
         internal readonly Logger _cmdLogger;
         internal readonly LogManager _logManager;
         internal readonly Func<DiscordRestClient> _getRestClient;
 
-        internal readonly bool _throwOnError, _useCompiledLambda, _enableAutocompleteHandlers, _autoServiceScopes;
+        internal readonly bool _throwOnError, _useCompiledLambda, _enableAutocompleteHandlers, _autoServiceScopes, _exitOnMissingModalField;
         internal readonly string _wildCardExp;
         internal readonly RunMode _runMode;
         internal readonly RestResponseCallback _restResponseCallback;
@@ -97,6 +105,16 @@ namespace Discord.Interactions
         /// </summary>
         public IReadOnlyCollection<ComponentCommandInfo> ComponentCommands => _moduleDefs.SelectMany(x => x.ComponentCommands).ToList();
 
+        /// <summary>
+        ///     Represents all Modal Commands loaded within <see cref="InteractionService"/>.
+        /// </summary>
+        public IReadOnlyCollection<ModalCommandInfo> ModalCommands => _moduleDefs.SelectMany(x => x.ModalCommands).ToList();
+
+        /// <summary>
+        ///     Gets a collection of the cached <see cref="ModalInfo"/> classes that are referenced in registered <see cref="ModalCommandInfo"/>s.
+        /// </summary>
+        public IReadOnlyCollection<ModalInfo> Modals => ModalUtils.Modals;
+
         /// <summary>
         ///     Initialize a <see cref="InteractionService"/> with provided configurations.
         /// </summary>
@@ -145,6 +163,7 @@ namespace Discord.Interactions
             _contextCommandMaps = new ConcurrentDictionary<ApplicationCommandType, CommandMap<ContextCommandInfo>>();
             _componentCommandMap = new CommandMap<ComponentCommandInfo>(this, config.InteractionCustomIdDelimiters);
             _autocompleteCommandMap = new CommandMap<AutocompleteCommandInfo>(this);
+            _modalCommandMap = new CommandMap<ModalCommandInfo>(this, config.InteractionCustomIdDelimiters);
 
             _getRestClient = getRestClient;
 
@@ -155,6 +174,7 @@ namespace Discord.Interactions
             _throwOnError = config.ThrowOnError;
             _wildCardExp = config.WildCardExpression;
             _useCompiledLambda = config.UseCompiledLambda;
+            _exitOnMissingModalField = config.ExitOnMissingModalField;
             _enableAutocompleteHandlers = config.EnableAutocompleteHandlers;
             _autoServiceScopes = config.AutoServiceScopes;
             _restResponseCallback = config.RestResponseCallback;
@@ -509,6 +529,9 @@ namespace Discord.Interactions
             foreach (var command in module.AutocompleteCommands)
                 _autocompleteCommandMap.AddCommand(command.GetCommandKeywords(), command);
 
+            foreach (var command in module.ModalCommands)
+                _modalCommandMap.AddCommand(command, command.IgnoreGroupNames);
+
             foreach (var subModule in module.SubModules)
                 LoadModuleInternal(subModule);
         }
@@ -654,7 +677,7 @@ namespace Discord.Interactions
         public async Task<IResult> ExecuteCommandAsync (IInteractionContext context, IServiceProvider services)
         {
             var interaction = context.Interaction;
-
+            
             return interaction switch
             {
                 ISlashCommandInteraction slashCommand => await ExecuteSlashCommandAsync(context, slashCommand, services).ConfigureAwait(false),
@@ -662,6 +685,7 @@ namespace Discord.Interactions
                 IUserCommandInteraction userCommand => await ExecuteContextCommandAsync(context, userCommand.Data.Name, ApplicationCommandType.User, services).ConfigureAwait(false),
                 IMessageCommandInteraction messageCommand => await ExecuteContextCommandAsync(context, messageCommand.Data.Name, ApplicationCommandType.Message, services).ConfigureAwait(false),
                 IAutocompleteInteraction autocomplete => await ExecuteAutocompleteAsync(context, autocomplete, services).ConfigureAwait(false),
+                IModalInteraction modalCommand => await ExecuteModalCommandAsync(context, modalCommand.Data.CustomId, services).ConfigureAwait(false),
                 _ => throw new InvalidOperationException($"{interaction.Type} interaction type cannot be executed by the Interaction service"),
             };
         }
@@ -745,6 +769,20 @@ namespace Discord.Interactions
             return await commandResult.Command.ExecuteAsync(context, services).ConfigureAwait(false);
         }
 
+        private async Task<IResult> ExecuteModalCommandAsync(IInteractionContext context, string input, IServiceProvider services)
+        {
+            var result = _modalCommandMap.GetCommand(input);
+
+            if (!result.IsSuccess)
+            {
+                await _cmdLogger.DebugAsync($"Unknown custom interaction id, skipping execution ({input.ToUpper()})");
+
+                await _componentCommandExecutedEvent.InvokeAsync(null, context, result).ConfigureAwait(false);
+                return result;
+            }
+            return await result.Command.ExecuteAsync(context, services, result.RegexCaptureGroups).ConfigureAwait(false);
+        }
+
         internal TypeConverter GetTypeConverter (Type type, IServiceProvider services = null)
         {
             if (_typeConverters.TryGetValue(type, out var specific))
@@ -819,6 +857,24 @@ namespace Discord.Interactions
             _genericTypeConverters[targetType] = converterType;
         }
 
+        /// <summary>
+        ///     Loads and caches an <see cref="ModalInfo"/> for the provided <see cref="IModal"/>.
+        /// </summary>
+        /// <typeparam name="T">Type of <see cref="IModal"/> to be loaded.</typeparam>
+        /// <returns>
+        ///     The built <see cref="ModalInfo"/> instance.
+        /// </returns>
+        /// <exception cref="InvalidOperationException"></exception>
+        public ModalInfo AddModalInfo<T>() where T : class, IModal
+        {
+            var type = typeof(T);
+
+            if (_modalInfos.ContainsKey(type))
+                throw new InvalidOperationException($"Modal type {type.FullName} already exists.");
+
+            return ModalUtils.GetOrAdd(type);
+        }
+
         internal IAutocompleteHandler GetAutocompleteHandler(Type autocompleteHandlerType, IServiceProvider services = null)
         {
             services ??= EmptyServiceProvider.Instance;

src/Discord.Net.Interactions/InteractionServiceConfig.cs

@@ -36,6 +36,9 @@ namespace Discord.Interactions
         /// <summary>
         ///     Gets or sets the option to use compiled lambda expressions to create module instances and execute commands. This method improves performance at the cost of memory.
         /// </summary>
+        /// <remarks>
+        ///     For performance reasons, if you frequently use <see cref="Modal"/>s with the service, it is highly recommended that you enable compiled lambdas.
+        /// </remarks>
         public bool UseCompiledLambda { get; set; } = false;
 
         /// <summary>
@@ -56,6 +59,11 @@ namespace Discord.Interactions
         ///     Gets or sets delegate to be used by the <see cref="InteractionService"/> when responding to a Rest based interaction.
         /// </summary>
         public RestResponseCallback RestResponseCallback { get; set; } = (ctx, str) => Task.CompletedTask;
+
+        /// <summary>
+        ///     Gets or sets whether a command execution should exit when a modal command encounters a missing modal component value.
+        /// </summary>
+        public bool ExitOnMissingModalField { get; set; } = false;
     }
 
     /// <summary>

src/Discord.Net.Interactions/Utilities/ModalUtils.cs

@@ -0,0 +1,51 @@
+using Discord.Interactions.Builders;
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+
+namespace Discord.Interactions
+{
+    internal static class ModalUtils
+    {
+        private static ConcurrentDictionary<Type, ModalInfo> _modalInfos = new();
+
+        public static IReadOnlyCollection<ModalInfo> Modals => _modalInfos.Values.ToReadOnlyCollection();
+
+        public static ModalInfo GetOrAdd(Type type)
+        {
+            if (!typeof(IModal).IsAssignableFrom(type))
+                throw new ArgumentException($"Must be an implementation of {nameof(IModal)}", nameof(type));
+
+            return _modalInfos.GetOrAdd(type, ModuleClassBuilder.BuildModalInfo(type));
+        }
+
+        public static ModalInfo GetOrAdd<T>() where T : class, IModal
+            => GetOrAdd(typeof(T));
+
+        public static bool TryGet(Type type, out ModalInfo modalInfo)
+        {
+            if (!typeof(IModal).IsAssignableFrom(type))
+                throw new ArgumentException($"Must be an implementation of {nameof(IModal)}", nameof(type));
+
+            return _modalInfos.TryGetValue(type, out modalInfo);
+        }
+
+        public static bool TryGet<T>(out ModalInfo modalInfo) where T : class, IModal
+            => TryGet(typeof(T), out modalInfo);
+
+        public static bool TryRemove(Type type, out ModalInfo modalInfo)
+        {
+            if (!typeof(IModal).IsAssignableFrom(type))
+                throw new ArgumentException($"Must be an implementation of {nameof(IModal)}", nameof(type));
+
+            return _modalInfos.TryRemove(type, out modalInfo);
+        }
+
+        public static bool TryRemove<T>(out ModalInfo modalInfo) where T : class, IModal
+            => TryRemove(typeof(T), out modalInfo);
+
+        public static void Clear() => _modalInfos.Clear();
+
+        public static int Count() => _modalInfos.Count;
+    }
+}

src/Discord.Net.Interactions/Utilities/ReflectionUtils.cs

@@ -112,6 +112,67 @@ namespace Discord.Interactions
             var parameters = constructor.GetParameters();
             var properties = GetProperties(typeInfo);
 
+            var lambda = CreateLambdaMemberInit(typeInfo, constructor);
+
+            return (services) =>
+            {
+                var args = new object[parameters.Length];
+                var props = new object[properties.Length];
+
+                for (int i = 0; i < parameters.Length; i++)
+                    args[i] = GetMember(commandService, services, parameters[i].ParameterType, typeInfo);
+
+                for (int i = 0; i < properties.Length; i++)
+                    props[i] = GetMember(commandService, services, properties[i].PropertyType, typeInfo);
+
+                var instance = lambda(args, props);
+
+                return instance;
+            };
+        }
+
+        internal static Func<object[], T> CreateLambdaConstructorInvoker(TypeInfo typeInfo)
+        {
+            var constructor = GetConstructor(typeInfo);
+            var parameters = constructor.GetParameters();
+
+            var argsExp = Expression.Parameter(typeof(object[]), "args");
+
+            var parameterExps = new Expression[parameters.Length];
+
+            for (var i = 0; i < parameters.Length; i++)
+            {
+                var indexExp = Expression.Constant(i);
+                var accessExp = Expression.ArrayIndex(argsExp, indexExp);
+                parameterExps[i] = Expression.Convert(accessExp, parameters[i].ParameterType);
+            }
+
+            var newExp = Expression.New(constructor, parameterExps);
+
+            return Expression.Lambda<Func<object[], T>>(newExp, argsExp).Compile();
+        }
+
+        /// <summary>
+        ///     Create a compiled lambda property setter.
+        /// </summary>
+        internal static Action<T, object> CreateLambdaPropertySetter(PropertyInfo propertyInfo)
+        {
+            var instanceParam = Expression.Parameter(typeof(T), "instance");
+            var valueParam = Expression.Parameter(typeof(object), "value");
+
+            var prop = Expression.Property(instanceParam, propertyInfo);
+            var assign = Expression.Assign(prop, Expression.Convert(valueParam, propertyInfo.PropertyType));
+
+            return Expression.Lambda<Action<T, object>>(assign, instanceParam, valueParam).Compile();
+        }
+
+        internal static Func<object[], object[], T> CreateLambdaMemberInit(TypeInfo typeInfo, ConstructorInfo constructor, Predicate<PropertyInfo> propertySelect = null)
+        {
+            propertySelect ??= x => true;
+
+            var parameters = constructor.GetParameters();
+            var properties = GetProperties(typeInfo).Where(x => propertySelect(x)).ToArray();
+
             var argsExp = Expression.Parameter(typeof(object[]), "args");
             var propsExp = Expression.Parameter(typeof(object[]), "props");
 
@@ -137,17 +198,8 @@ namespace Discord.Interactions
             var memberInit = Expression.MemberInit(newExp, memberExps);
             var lambda = Expression.Lambda<Func<object[], object[], T>>(memberInit, argsExp, propsExp).Compile();
 
-            return (services) =>
+            return (args, props) =>
             {
-                var args = new object[parameters.Length];
-                var props = new object[properties.Length];
-
-                for (int i = 0; i < parameters.Length; i++)
-                    args[i] = GetMember(commandService, services, parameters[i].ParameterType, typeInfo);
-
-                for (int i = 0; i < properties.Length; i++)
-                    props[i] = GetMember(commandService, services, properties[i].PropertyType, typeInfo);
-
                 var instance = lambda(args, props);
 
                 return instance;