diff --git a/code/__DEFINES/tgs.dm b/code/__DEFINES/tgs.dm
index 51bf6e66f7c..42f2d5fc31f 100644
--- a/code/__DEFINES/tgs.dm
+++ b/code/__DEFINES/tgs.dm
@@ -1,19 +1,20 @@
 // tgstation-server DMAPI
+// The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in IETF RFC 2119.
 
-#define TGS_DMAPI_VERSION "6.0.5"
+#define TGS_DMAPI_VERSION "7.3.0"
 
 // All functions and datums outside this document are subject to change with any version and should not be relied on.
 
 // CONFIGURATION
 
-/// Create this define if you want to do TGS configuration outside of this file.
+/// Consumers SHOULD create this define if you want to do TGS configuration outside of this file.
 #ifndef TGS_EXTERNAL_CONFIGURATION
 
-// Comment this out once you've filled in the below.
+// Consumers MUST comment this out once you've filled in the below and are not using [TGS_EXTERNAL_CONFIGURATION].
 #error TGS API unconfigured
 
-// Uncomment this if you wish to allow the game to interact with TGS 3.
-// This will raise the minimum required security level of your game to TGS_SECURITY_TRUSTED due to it utilizing call()()
+// Consumers MUST uncomment this if you wish to allow the game to interact with TGS version 3.
+// This will raise the minimum required security level of your game to TGS_SECURITY_TRUSTED due to it utilizing call()().
 //#define TGS_V3_API
 
 // Required interfaces (fill in with your codebase equivalent):
@@ -50,46 +51,55 @@
 
 #endif
 
+#ifndef TGS_FILE2TEXT_NATIVE
+#ifdef file2text
+#error Your codebase is re-defining the BYOND proc file2text. The DMAPI requires the native version to read the result of world.Export(). You SHOULD fix this by adding "#define TGS_FILE2TEXT_NATIVE file2text" before your override of file2text to allow the DMAPI to use the native version. This will only be used for world.Export(), not regular file accesses
+#endif
+#define TGS_FILE2TEXT_NATIVE file2text
+#endif
+
 // EVENT CODES
 
-/// Before a reboot mode change, extras parameters are the current and new reboot mode enums
+/// Before a reboot mode change, extras parameters are the current and new reboot mode enums.
 #define TGS_EVENT_REBOOT_MODE_CHANGE -1
-/// Before a port change is about to happen, extra parameters is new port
+/// Before a port change is about to happen, extra parameters is new port.
 #define TGS_EVENT_PORT_SWAP -2
-/// Before the instance is renamed, extra parameter is the new name
+/// Before the instance is renamed, extra parameter is the new name.
 #define TGS_EVENT_INSTANCE_RENAMED -3
-/// After the watchdog reattaches to DD, extra parameter is the new [/datum/tgs_version] of the server
+/// After the watchdog reattaches to DD, extra parameter is the new [/datum/tgs_version] of the server.
 #define TGS_EVENT_WATCHDOG_REATTACH -4
+/// When the watchdog sends a health check to DD. No parameters.
+#define TGS_EVENT_HEALTH_CHECK -5
 
-/// When the repository is reset to its origin reference. Parameters: Reference name, Commit SHA
+/// When the repository is reset to its origin reference. Parameters: Reference name, Commit SHA.
 #define TGS_EVENT_REPO_RESET_ORIGIN 0
-/// When the repository performs a checkout. Parameters: Checkout git object
+/// When the repository performs a checkout. Parameters: Checkout git object.
 #define TGS_EVENT_REPO_CHECKOUT 1
-/// When the repository performs a fetch operation. No parameters
+/// When the repository performs a fetch operation. No parameters.
 #define TGS_EVENT_REPO_FETCH 2
-/// When the repository test merges. Parameters: PR Number, PR Sha, (Nullable) Comment made by TGS user
+/// When the repository test merges. Parameters: PR Number, PR Sha, (Nullable) Comment made by TGS user.
 #define TGS_EVENT_REPO_MERGE_PULL_REQUEST 3
-/// Before the repository makes a sychronize operation. Parameters: Absolute repostiory path
+/// Before the repository makes a sychronize operation. Parameters: Absolute repostiory path.
 #define TGS_EVENT_REPO_PRE_SYNCHRONIZE 4
-/// Before a BYOND install operation begins. Parameters: [/datum/tgs_version] of the installing BYOND
-#define TGS_EVENT_BYOND_INSTALL_START 5
-/// When a BYOND install operation fails. Parameters: Error message
-#define TGS_EVENT_BYOND_INSTALL_FAIL 6
-/// When the active BYOND version changes.  Parameters: (Nullable) [/datum/tgs_version] of the current BYOND, [/datum/tgs_version] of the new BYOND
-#define TGS_EVENT_BYOND_ACTIVE_VERSION_CHANGE 7
-/// When the compiler starts running. Parameters: Game directory path, origin commit SHA
+/// Before a engine install operation begins. Parameters: Version string of the installing engine.
+#define TGS_EVENT_ENGINE_INSTALL_START 5
+/// When a engine install operation fails. Parameters: Error message
+#define TGS_EVENT_ENGINE_INSTALL_FAIL 6
+/// When the active engine version changes. Parameters: (Nullable) Version string of the current engine, version string of the new engine.
+#define TGS_EVENT_ENGINE_ACTIVE_VERSION_CHANGE 7
+/// When the compiler starts running. Parameters: Game directory path, origin commit SHA.
 #define TGS_EVENT_COMPILE_START 8
-/// When a compile is cancelled. No parameters
+/// When a compile is cancelled. No parameters.
 #define TGS_EVENT_COMPILE_CANCELLED 9
-/// When a compile fails. Parameters: Game directory path, [TRUE]/[FALSE] based on if the cause for failure was DMAPI validation
+/// When a compile fails. Parameters: Game directory path, [TRUE]/[FALSE] based on if the cause for failure was DMAPI validation.
 #define TGS_EVENT_COMPILE_FAILURE 10
-/// When a compile operation completes. Note, this event fires before the new .dmb is loaded into the watchdog. Consider using the [TGS_EVENT_DEPLOYMENT_COMPLETE] instead. Parameters: Game directory path
+/// When a compile operation completes. Note, this event fires before the new .dmb is loaded into the watchdog. Consider using the [TGS_EVENT_DEPLOYMENT_COMPLETE] instead. Parameters: Game directory path.
 #define TGS_EVENT_COMPILE_COMPLETE 11
-/// When an automatic update for the current instance begins. No parameters
+/// When an automatic update for the current instance begins. No parameters.
 #define TGS_EVENT_INSTANCE_AUTO_UPDATE_START 12
-/// When the repository encounters a merge conflict: Parameters: Base SHA, target SHA, base reference, target reference
+/// When the repository encounters a merge conflict: Parameters: Base SHA, target SHA, base reference, target reference.
 #define TGS_EVENT_REPO_MERGE_CONFLICT 13
-/// When a deployment completes. No Parameters
+/// When a deployment completes. No Parameters.
 #define TGS_EVENT_DEPLOYMENT_COMPLETE 14
 /// Before the watchdog shuts down. Not sent for graceful shutdowns. No parameters.
 #define TGS_EVENT_WATCHDOG_SHUTDOWN 15
@@ -104,6 +114,12 @@
 #define TGS_EVENT_WORLD_PRIME 21
 // DMAPI also doesnt implement this
 // #define TGS_EVENT_DREAM_DAEMON_LAUNCH 22
+/// After a single submodule update is performed. Parameters: Updated submodule name.
+#define TGS_EVENT_REPO_SUBMODULE_UPDATE 23
+/// After CodeModifications are applied, before DreamMaker is run. Parameters: Game directory path, origin commit sha, version string of the used engine.
+#define TGS_EVENT_PRE_DREAM_MAKER 24
+/// Whenever a deployment folder is deleted from disk. Parameters: Game directory path.
+#define TGS_EVENT_DEPLOYMENT_CLEANUP 25
 
 // OTHER ENUMS
 
@@ -114,6 +130,7 @@
 /// The watchdog will restart on reboot.
 #define TGS_REBOOT_MODE_RESTART 2
 
+// Note that security levels are currently meaningless in OpenDream
 /// DreamDaemon Trusted security level.
 #define TGS_SECURITY_TRUSTED 0
 /// DreamDaemon Safe security level.
@@ -121,19 +138,32 @@
 /// DreamDaemon Ultrasafe security level.
 #define TGS_SECURITY_ULTRASAFE 2
 
+/// DreamDaemon public visibility level.
+#define TGS_VISIBILITY_PUBLIC 0
+/// DreamDaemon private visibility level.
+#define TGS_VISIBILITY_PRIVATE 1
+/// DreamDaemon invisible visibility level.
+#define TGS_VISIBILITY_INVISIBLE 2
+
+/// The Build Your Own Net Dream engine.
+#define TGS_ENGINE_TYPE_BYOND 0
+/// The OpenDream engine.
+#define TGS_ENGINE_TYPE_OPENDREAM 1
+
 //REQUIRED HOOKS
 
 /**
- * Call this somewhere in [/world/proc/New] that is always run. This function may sleep!
+ * Consumers MUST call this somewhere in [/world/proc/New] that is always run. This function may sleep!
  *
  * * event_handler - Optional user defined [/datum/tgs_event_handler].
  * * minimum_required_security_level: The minimum required security level to run the game in which the DMAPI is integrated. Can be one of [TGS_SECURITY_ULTRASAFE], [TGS_SECURITY_SAFE], or [TGS_SECURITY_TRUSTED].
+ * * http_handler - Optional user defined [/datum/tgs_http_handler].
  */
-/world/proc/TgsNew(datum/tgs_event_handler/event_handler, minimum_required_security_level = TGS_SECURITY_ULTRASAFE)
+/world/proc/TgsNew(datum/tgs_event_handler/event_handler, minimum_required_security_level = TGS_SECURITY_ULTRASAFE, datum/tgs_http_handler/http_handler)
 	return
 
 /**
- * Call this when your initializations are complete and your game is ready to play before any player interactions happen.
+ * Consumers MUST call this when world initializations are complete and the game is ready to play before any player interactions happen.
  *
  * This may use [/world/var/sleep_offline] to make this happen so ensure no changes are made to it while this call is running.
  * Afterwards, consider explicitly setting it to what you want to avoid this BYOND bug: http://www.byond.com/forum/post/2575184
@@ -142,12 +172,10 @@
 /world/proc/TgsInitializationComplete()
 	return
 
-/// Put this at the start of [/world/proc/Topic].
+/// Consumers MUST run this macro at the start of [/world/proc/Topic].
 #define TGS_TOPIC var/tgs_topic_return = TgsTopic(args[1]); if(tgs_topic_return) return tgs_topic_return
 
-/**
- * Call this as late as possible in [world/proc/Reboot].
- */
+/// Consumers MUST call this as late as possible in [world/proc/Reboot] (BEFORE ..()).
 /world/proc/TgsReboot()
 	return
 
@@ -158,28 +186,28 @@
 /datum/tgs_revision_information
 	/// Full SHA of the commit.
 	var/commit
-	/// ISO 8601 timestamp of when the commit was created
+	/// ISO 8601 timestamp of when the commit was created.
 	var/timestamp
 	/// Full sha of last known remote commit. This may be null if the TGS repository is not currently tracking a remote branch.
 	var/origin_commit
 
 /// Represents a version.
 /datum/tgs_version
-	/// The suite/major version number
+	/// The suite/major version number.
 	var/suite
 
-	// This group of variables can be null to represent a wild card
-	/// The minor version number. null for wildcards
+	// This group of variables can be null to represent a wild card.
+	/// The minor version number. null for wildcards.
 	var/minor
-	/// The patch version number. null for wildcards
+	/// The patch version number. null for wildcards.
 	var/patch
 
-	/// Legacy version number. Generally null
+	/// Legacy version number. Generally null.
 	var/deprecated_patch
 
-	/// Unparsed string value
+	/// Unparsed string value.
 	var/raw_parameter
-	/// String value minus prefix
+	/// String value minus prefix.
 	var/deprefixed_parameter
 
 /**
@@ -225,47 +253,208 @@
 	var/is_admin_channel
 	/// [TRUE]/[FALSE] if the channel is a private message channel for a [/datum/tgs_chat_user].
 	var/is_private_channel
-	/// Tag string associated with the channel in TGS
+	/// Tag string associated with the channel in TGS.
 	var/custom_tag
+	/// [TRUE]/[FALSE] if the channel supports embeds.
+	var/embeds_supported
 
 // Represents a chat user
 /datum/tgs_chat_user
 	/// TGS internal user ID.
 	var/id
-	// The user's display name.
+	/// The user's display name.
 	var/friendly_name
-	// The string to use to ping this user in a message.
+	/// The string to use to ping this user in a message.
 	var/mention
-	/// The [/datum/tgs_chat_channel] the user was from
+	/// The [/datum/tgs_chat_channel] the user was from.
 	var/datum/tgs_chat_channel/channel
 
+/// User definable handler for TGS events This abstract version SHOULD be overridden to be used.
+/datum/tgs_event_handler
+	/// If the handler receieves [TGS_EVENT_HEALTH_CHECK] events.
+	var/receive_health_checks = FALSE
+
 /**
  * User definable callback for handling TGS events.
  *
- * event_code - One of the TGS_EVENT_ defines. Extra parameters will be documented in each
+ * event_code - One of the TGS_EVENT_ defines. Extra parameters will be documented in each.
  */
 /datum/tgs_event_handler/proc/HandleEvent(event_code, ...)
 	set waitfor = FALSE
 	return
 
-/// User definable chat command
+/// User definable handler for HTTP calls. This abstract version MUST be overridden to be used.
+/datum/tgs_http_handler
+
+/**
+ * User definable callback for executing HTTP GET requests.
+ * MUST perform BYOND sleeps while the request is in flight.
+ * MUST return a [/datum/tgs_http_result].
+ * SHOULD log its own errors
+ *
+ * url - The full URL to execute the GET request for including query parameters.
+ */
+/datum/tgs_http_handler/proc/PerformGet(url)
+	CRASH("[type]/PerformGet not implemented!")
+
+/// Result of a [/datum/tgs_http_handler] call. MUST NOT be overridden.
+/datum/tgs_http_result
+	/// HTTP response as text
+	var/response_text
+	/// Boolean request success flag. Set for any 2XX response code.
+	var/success
+
+/**
+ * Create a [/datum/tgs_http_result].
+ *
+ * * response_text - HTTP response as text. Must be provided in New().
+ * * success - Boolean request success flag. Set for any 2XX response code. Must be provided in New().
+ */
+/datum/tgs_http_result/New(response_text, success)
+	if(response_text && !istext(response_text))
+		CRASH("response_text was not text!")
+
+	src.response_text = response_text
+	src.success = success
+
+/// User definable chat command. This abstract version MUST be overridden to be used.
 /datum/tgs_chat_command
-	/// The string to trigger this command on a chat bot. e.g `@bot name ...` or `!tgs name ...`
+	/// The string to trigger this command on a chat bot. e.g `@bot name ...` or `!tgs name ...`.
 	var/name = ""
-	/// The help text displayed for this command
+	/// The help text displayed for this command.
 	var/help_text = ""
-	/// If this command should be available to game administrators only
+	/// If this command should be available to game administrators only.
 	var/admin_only = FALSE
+	/// A subtype of [/datum/tgs_chat_command] that is ignored when enumerating available commands. Use this to create shared base /datums for commands.
+	var/ignore_type
 
 /**
- * Process command activation. Should return a string to respond to the issuer with.
+ * Process command activation. Should return a [/datum/tgs_message_content] to respond to the issuer with.
+ * MUST be implemented
  *
- * sender - The [/datum/tgs_chat_user] who issued the command.
- * params - The trimmed string following the command `/datum/tgs_chat_command/var/name].
+ * * sender - The [/datum/tgs_chat_user] who issued the command.
+ * * params - The trimmed string following the command `/datum/tgs_chat_command/var/name].
  */
 /datum/tgs_chat_command/proc/Run(datum/tgs_chat_user/sender, params)
 	CRASH("[type] has no implementation for Run()")
 
+/// User definable chat message. MUST NOT be overridden.
+/datum/tgs_message_content
+	/// The string content of the message. Must be provided in New().
+	var/text
+
+	/// The [/datum/tgs_chat_embed] to embed in the message. Not supported on all chat providers.
+	var/datum/tgs_chat_embed/structure/embed
+
+/**
+ * Create a [/datum/tgs_message_content].
+ *
+ * * text - The string content of the message.
+ */
+/datum/tgs_message_content/New(text)
+	..()
+	if(!istext(text))
+		TGS_ERROR_LOG("[/datum/tgs_message_content] created with no text!")
+		text = null
+
+	src.text = text
+
+/// User definable chat embed. Currently mirrors Discord chat embeds. See https://discord.com/developers/docs/resources/message#embed-object for details.
+/datum/tgs_chat_embed/structure
+	var/title
+	var/description
+	var/url
+
+	/// Timestamp must be encoded as: time2text(world.timeofday, "YYYY-MM-DD hh:mm:ss"). Use the active timezone.
+	var/timestamp
+
+	/// Colour must be #AARRGGBB or #RRGGBB hex string.
+	var/colour
+
+	/// See https://discord.com/developers/docs/resources/message#embed-object-embed-image-structure for details.
+	var/datum/tgs_chat_embed/media/image
+
+	/// See https://discord.com/developers/docs/resources/message#embed-object-embed-thumbnail-structure for details.
+	var/datum/tgs_chat_embed/media/thumbnail
+
+	/// See https://discord.com/developers/docs/resources/message#embed-object-embed-video-structure for details.
+	var/datum/tgs_chat_embed/media/video
+
+	var/datum/tgs_chat_embed/footer/footer
+	var/datum/tgs_chat_embed/provider/provider
+	var/datum/tgs_chat_embed/provider/author/author
+
+	var/list/datum/tgs_chat_embed/field/fields
+
+/// Common datum for similar Discord embed medias.
+/datum/tgs_chat_embed/media
+	/// Must be set in New().
+	var/url
+	var/width
+	var/height
+	var/proxy_url
+
+/// Create a [/datum/tgs_chat_embed].
+/datum/tgs_chat_embed/media/New(url)
+	..()
+	if(!istext(url))
+		CRASH("[/datum/tgs_chat_embed/media] created with no url!")
+
+	src.url = url
+
+/// See https://discord.com/developers/docs/resources/message#embed-object-embed-footer-structure for details.
+/datum/tgs_chat_embed/footer
+	/// Must be set in New().
+	var/text
+	var/icon_url
+	var/proxy_icon_url
+
+/// Create a [/datum/tgs_chat_embed/footer].
+/datum/tgs_chat_embed/footer/New(text)
+	..()
+	if(!istext(text))
+		CRASH("[/datum/tgs_chat_embed/footer] created with no text!")
+
+	src.text = text
+
+/// See https://discord.com/developers/docs/resources/message#embed-object-embed-provider-structure for details.
+/datum/tgs_chat_embed/provider
+	var/name
+	var/url
+
+/// See https://discord.com/developers/docs/resources/message#embed-object-embed-author-structure for details. Must have name set in New().
+/datum/tgs_chat_embed/provider/author
+	var/icon_url
+	var/proxy_icon_url
+
+/// Create a [/datum/tgs_chat_embed/footer].
+/datum/tgs_chat_embed/provider/author/New(name)
+	..()
+	if(!istext(name))
+		CRASH("[/datum/tgs_chat_embed/provider/author] created with no name!")
+
+	src.name = name
+
+/// See https://discord.com/developers/docs/resources/message#embed-object-embed-field-structure for details.
+/datum/tgs_chat_embed/field
+	/// Must be set in New().
+	var/name
+	/// Must be set in New().
+	var/value
+	var/is_inline
+
+/// Create a [/datum/tgs_chat_embed/field].
+/datum/tgs_chat_embed/field/New(name, value)
+	..()
+	if(!istext(name))
+		CRASH("[/datum/tgs_chat_embed/field] created with no name!")
+
+	if(!istext(value))
+		CRASH("[/datum/tgs_chat_embed/field] created with no value!")
+
+	src.name = name
+	src.value = value
+
 // API FUNCTIONS
 
 /// Returns the maximum supported [/datum/tgs_version] of the DMAPI.
@@ -285,75 +474,94 @@
 // No function below this succeeds if it TgsAvailable() returns FALSE or if TgsNew() has yet to be called.
 
 /**
- * Forces a hard reboot of DreamDaemon by ending the process.
+ * Forces a hard reboot of DreamDaemon by ending the process. This function may sleep!
  *
  * Unlike del(world) clients will try to reconnect.
- * If TGS has not requested a [TGS_REBOOT_MODE_SHUTDOWN] DreamDaemon will be launched again
+ * If TGS has not requested a [TGS_REBOOT_MODE_SHUTDOWN] DreamDaemon will be launched again.
  */
 /world/proc/TgsEndProcess()
 	return
 
 /**
- * Send a message to connected chats.
+ * Send a message to connected chats. This function may sleep!
+ * If TGS is offline when called, the message may be placed in a queue to be sent and this function will return immediately. Your message will be sent when TGS reconnects to the game.
  *
- * message - The string to send.
+ * message - The [/datum/tgs_message_content] to send.
  * admin_only: If [TRUE], message will be sent to admin connected chats. Vice-versa applies.
  */
-/world/proc/TgsTargetedChatBroadcast(message, admin_only = FALSE)
+/world/proc/TgsTargetedChatBroadcast(datum/tgs_message_content/message, admin_only = FALSE)
 	return
 
 /**
- * Send a private message to a specific user.
+ * Send a private message to a specific user. This function may sleep!
+ * If TGS is offline when called, the message may be placed in a queue to be sent and this function will return immediately. Your message will be sent when TGS reconnects to the game.
  *
- * message - The string to send.
+ * message - The [/datum/tgs_message_content] to send.
  * user: The [/datum/tgs_chat_user] to PM.
  */
-/world/proc/TgsChatPrivateMessage(message, datum/tgs_chat_user/user)
+/world/proc/TgsChatPrivateMessage(datum/tgs_message_content/message, datum/tgs_chat_user/user)
 	return
 
-// The following functions will sleep if a call to TgsNew() is sleeping
-
 /**
- * Send a message to connected chats that are flagged as game-related in TGS.
+ * Send a message to connected chats that are flagged as game-related in TGS. This function may sleep!
+ * If TGS is offline when called, the message may be placed in a queue to be sent and this function will return immediately. Your message will be sent when TGS reconnects to the game.
  *
- * message - The string to send.
+ * message - The [/datum/tgs_message_content] to send.
  * channels - Optional list of [/datum/tgs_chat_channel]s to restrict the message to.
  */
-/world/proc/TgsChatBroadcast(message, list/channels = null)
+/world/proc/TgsChatBroadcast(datum/tgs_message_content/message, list/channels = null)
 	return
 
-/// Returns the current [/datum/tgs_version] of TGS if it is running the server, null otherwise.
+/// Returns the current [/datum/tgs_version] of TGS if it is running the server, null otherwise. This function may sleep if the call to [/world/proc/TgsNew] is sleeping!
 /world/proc/TgsVersion()
 	return
 
-/// Returns the current [/datum/tgs_version] of the DMAPI being used if it was activated, null otherwise.
+/// Returns the running engine type
+/world/proc/TgsEngine()
+	return
+
+/// Returns the current [/datum/tgs_version] of the DMAPI being used if it was activated, null otherwise. This function may sleep if the call to [/world/proc/TgsNew] is sleeping!
 /world/proc/TgsApiVersion()
 	return
 
-/// Returns the name of the TGS instance running the game if TGS is present, null otherwise.
+/// Returns the name of the TGS instance running the game if TGS is present, null otherwise. This function may sleep if the call to [/world/proc/TgsNew] is sleeping!
 /world/proc/TgsInstanceName()
 	return
 
-/// Return the current [/datum/tgs_revision_information] of the running server if TGS is present, null otherwise.
+/// Return the current [/datum/tgs_revision_information] of the running server if TGS is present, null otherwise. This function may sleep if the call to [/world/proc/TgsNew] is sleeping!
 /world/proc/TgsRevision()
 	return
 
-/// Returns the current BYOND security level as a TGS_SECURITY_ define if TGS is present, null otherwise.
+/// Returns the current BYOND security level as a TGS_SECURITY_ define if TGS is present, null otherwise. This function may sleep if the call to [/world/proc/TgsNew] is sleeping!
 /world/proc/TgsSecurityLevel()
 	return
 
-/// Returns a list of active [/datum/tgs_revision_information/test_merge]s if TGS is present, null otherwise.
+/// Returns the current BYOND visibility level as a TGS_VISIBILITY_ define if TGS is present, null otherwise. Requires TGS to be using interop API version 5 or higher otherwise the string "___unimplemented" wil be returned. This function may sleep if the call to [/world/proc/TgsNew] is sleeping!
+/world/proc/TgsVisibility()
+	return
+
+/// Returns a list of active [/datum/tgs_revision_information/test_merge]s if TGS is present, null otherwise. This function may sleep if the call to [/world/proc/TgsNew] is sleeping!
 /world/proc/TgsTestMerges()
 	return
 
-/// Returns a list of connected [/datum/tgs_chat_channel]s if TGS is present, null otherwise.
+/// Returns a list of connected [/datum/tgs_chat_channel]s if TGS is present, null otherwise. This function may sleep if the call to [/world/proc/TgsNew] is sleeping!
 /world/proc/TgsChatChannelInfo()
 	return
 
+/**
+ * Trigger an event in TGS. Requires TGS version >= 6.3.0. Returns [TRUE] if the event was triggered successfully, [FALSE] otherwise. This function may sleep!
+ *
+ * event_name - The name of the event to trigger
+ * parameters - Optional list of string parameters to pass as arguments to the event script. The first parameter passed to a script will always be the running game's directory followed by these parameters.
+ * wait_for_completion - If set, this function will not return until the event has run to completion.
+ */
+/world/proc/TgsTriggerEvent(event_name, list/parameters, wait_for_completion = FALSE)
+	return
+
 /*
 The MIT License
 
-Copyright (c) 2017 Jordan Brown
+Copyright (c) 2017-2024 Jordan Brown
 
 Permission is hereby granted, free of charge,
 to any person obtaining a copy of this software and
diff --git a/code/modules/tgs/LICENSE b/code/modules/tgs/LICENSE
index 221f9e1deb2..324c48e993e 100644
--- a/code/modules/tgs/LICENSE
+++ b/code/modules/tgs/LICENSE
@@ -1,6 +1,6 @@
 The MIT License
 
-Copyright (c) 2017 Jordan Brown
+Copyright (c) 2017-2024 Jordan Brown
 
 Permission is hereby granted, free of charge,
 to any person obtaining a copy of this software and
diff --git a/code/modules/tgs/README.md b/code/modules/tgs/README.md
index 6319028d810..35ca73d7e9a 100644
--- a/code/modules/tgs/README.md
+++ b/code/modules/tgs/README.md
@@ -1,6 +1,6 @@
 # DMAPI Internals
 
-This folder should be placed on it's own inside a codebase that wishes to use the TGS DMAPI. Warranty void if modified.
+This folder should be placed on its own inside a codebase that wishes to use the TGS DMAPI. Warranty void if modified.
 
 - [includes.dm](./includes.dm) is the file that should be included by DM code, it handles including the rest.
 - The [core](./core) folder includes all code not directly part of any API version.
diff --git a/code/modules/tgs/core/README.md b/code/modules/tgs/core/README.md
index aa3c7a9c9db..965e21b549a 100644
--- a/code/modules/tgs/core/README.md
+++ b/code/modules/tgs/core/README.md
@@ -3,6 +3,7 @@
 This folder contains all DMAPI code not directly involved in an API.
 
 - [_definitions.dm](./definitions.dm) contains defines needed across DMAPI internals.
+- [byond_world_export.dm](./byond_world_export.dm) contains the default `/datum/tgs_http_handler` implementation which uses `world.Export()`.
 - [core.dm](./core.dm) contains the implementations of the `/world/proc/TgsXXX()` procs. Many map directly to the `/datum/tgs_api` functions. It also contains the /datum selection and setup code.
 - [datum.dm](./datum.dm) contains the `/datum/tgs_api` declarations that all APIs must implement.
-- [tgs_version.dm](./tgs_version.dm) contains the `/datum/tgs_version` definition
\ No newline at end of file
+- [tgs_version.dm](./tgs_version.dm) contains the `/datum/tgs_version` definition
diff --git a/code/modules/tgs/core/_definitions.dm b/code/modules/tgs/core/_definitions.dm
index ebf6d17c2a0..fd98034eb71 100644
--- a/code/modules/tgs/core/_definitions.dm
+++ b/code/modules/tgs/core/_definitions.dm
@@ -1,2 +1,10 @@
+#if DM_VERSION < 510
+#error The TGS DMAPI does not support BYOND versions < 510!
+#endif
+
 #define TGS_UNIMPLEMENTED "___unimplemented"
 #define TGS_VERSION_PARAMETER "server_service_version"
+
+#ifndef TGS_DEBUG_LOG
+#define TGS_DEBUG_LOG(message)
+#endif
diff --git a/code/modules/tgs/core/byond_world_export.dm b/code/modules/tgs/core/byond_world_export.dm
new file mode 100644
index 00000000000..6ef8d841b8f
--- /dev/null
+++ b/code/modules/tgs/core/byond_world_export.dm
@@ -0,0 +1,22 @@
+/datum/tgs_http_handler/byond_world_export
+
+/datum/tgs_http_handler/byond_world_export/PerformGet(url)
+	// This is an infinite sleep until we get a response
+	var/export_response = world.Export(url)
+	TGS_DEBUG_LOG("byond_world_export: Export complete")
+
+	if(!export_response)
+		TGS_ERROR_LOG("byond_world_export: Failed request: [url]")
+		return new /datum/tgs_http_result(null, FALSE)
+
+	var/content = export_response["CONTENT"]
+	if(!content)
+		TGS_ERROR_LOG("byond_world_export: Failed request, missing content!")
+		return new /datum/tgs_http_result(null, FALSE)
+
+	var/response_json = TGS_FILE2TEXT_NATIVE(content)
+	if(!response_json)
+		TGS_ERROR_LOG("byond_world_export: Failed request, failed to load content!")
+		return new /datum/tgs_http_result(null, FALSE)
+
+	return new /datum/tgs_http_result(response_json, TRUE)
diff --git a/code/modules/tgs/core/core.dm b/code/modules/tgs/core/core.dm
index 41a04733945..63cb5a2c351 100644
--- a/code/modules/tgs/core/core.dm
+++ b/code/modules/tgs/core/core.dm
@@ -1,4 +1,4 @@
-/world/TgsNew(datum/tgs_event_handler/event_handler, minimum_required_security_level = TGS_SECURITY_ULTRASAFE)
+/world/TgsNew(datum/tgs_event_handler/event_handler, minimum_required_security_level = TGS_SECURITY_ULTRASAFE, datum/tgs_http_handler/http_handler = null)
 	var/current_api = TGS_READ_GLOBAL(tgs)
 	if(current_api)
 		TGS_ERROR_LOG("API datum already set (\ref[current_api] ([current_api]))! Was TgsNew() called more than once?")
@@ -42,11 +42,11 @@
 
 	var/datum/tgs_version/max_api_version = TgsMaximumApiVersion();
 	if(version.suite != null && version.minor != null && version.patch != null && version.deprecated_patch != null && version.deprefixed_parameter > max_api_version.deprefixed_parameter)
-		TGS_ERROR_LOG("Detected unknown API version! Defaulting to latest. Update the DMAPI to fix this problem.")
+		TGS_ERROR_LOG("Detected unknown Interop API version! Defaulting to latest. Update the DMAPI to fix this problem.")
 		api_datum = /datum/tgs_api/latest
 
 	if(!api_datum)
-		TGS_ERROR_LOG("Found unsupported API version: [raw_parameter]. If this is a valid version please report this, backporting is done on demand.")
+		TGS_ERROR_LOG("Found unsupported Interop API version: [raw_parameter]. If this is a valid version please report this, backporting is done on demand.")
 		return
 
 	TGS_INFO_LOG("Activating API for version [version.deprefixed_parameter]")
@@ -55,7 +55,10 @@
 		TGS_ERROR_LOG("Invalid parameter for event_handler: [event_handler]")
 		event_handler = null
 
-	var/datum/tgs_api/new_api = new api_datum(event_handler, version)
+	if(!http_handler)
+		http_handler = new /datum/tgs_http_handler/byond_world_export
+
+	var/datum/tgs_api/new_api = new api_datum(event_handler, version, http_handler)
 
 	TGS_WRITE_GLOBAL(tgs, new_api)
 
@@ -107,6 +110,13 @@
 	if(api)
 		return api.ApiVersion()
 
+/world/TgsEngine()
+#ifdef OPENDREAM
+	return TGS_ENGINE_TYPE_OPENDREAM
+#else
+	return TGS_ENGINE_TYPE_BYOND
+#endif
+
 /world/TgsInstanceName()
 	var/datum/tgs_api/api = TGS_READ_GLOBAL(tgs)
 	if(api)
@@ -153,4 +163,17 @@
 /world/TgsSecurityLevel()
 	var/datum/tgs_api/api = TGS_READ_GLOBAL(tgs)
 	if(api)
-		api.SecurityLevel()
+		return api.SecurityLevel()
+
+/world/TgsVisibility()
+	var/datum/tgs_api/api = TGS_READ_GLOBAL(tgs)
+	if(api)
+		return api.Visibility()
+
+/world/TgsTriggerEvent(event_name, list/parameters, wait_for_completion = FALSE)
+	var/datum/tgs_api/api = TGS_READ_GLOBAL(tgs)
+	if(api)
+		if(!istype(parameters, /list))
+			parameters = list()
+
+		return api.TriggerEvent(event_name, parameters, wait_for_completion)
diff --git a/code/modules/tgs/core/datum.dm b/code/modules/tgs/core/datum.dm
index 4d37ed662d1..3ca53e9bf7c 100644
--- a/code/modules/tgs/core/datum.dm
+++ b/code/modules/tgs/core/datum.dm
@@ -4,11 +4,22 @@ TGS_DEFINE_AND_SET_GLOBAL(tgs, null)
 	var/datum/tgs_version/version
 	var/datum/tgs_event_handler/event_handler
 
-/datum/tgs_api/New(datum/tgs_event_handler/event_handler, datum/tgs_version/version)
-	. = ..()
+	var/list/warned_deprecated_command_runs
+
+/datum/tgs_api/New(datum/tgs_event_handler/event_handler, datum/tgs_version/version, datum/tgs_http_handler/http_handler)
+	..()
 	src.event_handler = event_handler
 	src.version = version
 
+/datum/tgs_api/proc/TerminateWorld()
+	while(TRUE)
+		TGS_DEBUG_LOG("About to terminate world. Tick: [world.time], sleep_offline: [world.sleep_offline]")
+		world.sleep_offline = FALSE // https://www.byond.com/forum/post/2894866
+		del(world)
+		world.sleep_offline = FALSE // just in case, this is BYOND after all...
+		sleep(world.tick_lag)
+		TGS_DEBUG_LOG("BYOND DIDN'T TERMINATE THE WORLD!!! TICK IS: [world.time], sleep_offline: [world.sleep_offline]")
+
 /datum/tgs_api/latest
 	parent_type = /datum/tgs_api/v5
 
@@ -55,3 +66,9 @@ TGS_PROTECT_DATUM(/datum/tgs_api)
 
 /datum/tgs_api/proc/SecurityLevel()
 	return TGS_UNIMPLEMENTED
+
+/datum/tgs_api/proc/Visibility()
+	return TGS_UNIMPLEMENTED
+
+/datum/tgs_api/proc/TriggerEvent(event_name, list/parameters, wait_for_completion)
+	return FALSE
diff --git a/code/modules/tgs/core/tgs_version.dm b/code/modules/tgs/core/tgs_version.dm
index a5dae1241a3..bc561e67487 100644
--- a/code/modules/tgs/core/tgs_version.dm
+++ b/code/modules/tgs/core/tgs_version.dm
@@ -1,4 +1,5 @@
 /datum/tgs_version/New(raw_parameter)
+	..()
 	src.raw_parameter = raw_parameter
 	deprefixed_parameter = replacetext(raw_parameter, "/tg/station 13 Server v", "")
 	var/list/version_bits = splittext(deprefixed_parameter, ".")
diff --git a/code/modules/tgs/includes.dm b/code/modules/tgs/includes.dm
index 4018074f4e3..f5118ed55a3 100644
--- a/code/modules/tgs/includes.dm
+++ b/code/modules/tgs/includes.dm
@@ -1,4 +1,5 @@
 #include "core\_definitions.dm"
+#include "core\byond_world_export.dm"
 #include "core\core.dm"
 #include "core\datum.dm"
 #include "core\tgs_version.dm"
@@ -13,5 +14,9 @@
 
 #include "v5\_defines.dm"
 #include "v5\api.dm"
+#include "v5\bridge.dm"
+#include "v5\chunking.dm"
 #include "v5\commands.dm"
+#include "v5\serializers.dm"
+#include "v5\topic.dm"
 #include "v5\undefs.dm"
diff --git a/code/modules/tgs/v3210/api.dm b/code/modules/tgs/v3210/api.dm
index 9bcc8018971..666201a3225 100644
--- a/code/modules/tgs/v3210/api.dm
+++ b/code/modules/tgs/v3210/api.dm
@@ -99,7 +99,11 @@
 	if(skip_compat_check && !fexists(SERVICE_INTERFACE_DLL))
 		TGS_ERROR_LOG("Service parameter present but no interface DLL detected. This is symptomatic of running a service less than version 3.1! Please upgrade.")
 		return
+	#if DM_VERSION >= 515
+	call_ext(SERVICE_INTERFACE_DLL, SERVICE_INTERFACE_FUNCTION)(instance_name, command) //trust no retval
+	#else
 	call(SERVICE_INTERFACE_DLL, SERVICE_INTERFACE_FUNCTION)(instance_name, command) //trust no retval
+	#endif
 	return TRUE
 
 /datum/tgs_api/v3210/OnTopic(T)
@@ -175,7 +179,7 @@
 /datum/tgs_api/v3210/Revision()
 	if(!warned_revison)
 		var/datum/tgs_version/api_version = ApiVersion()
-		TGS_ERROR_LOG("Use of TgsRevision on [api_version.deprefixed_parameter] origin_commit only points to master!")
+		TGS_WARNING_LOG("Use of TgsRevision on [api_version.deprefixed_parameter] origin_commit only points to master!")
 		warned_revison = TRUE
 	var/datum/tgs_revision_information/ri = new
 	ri.commit = commit
@@ -189,16 +193,19 @@
 /datum/tgs_api/v3210/ChatChannelInfo()
 	return list() // :omegalul:
 
-/datum/tgs_api/v3210/ChatBroadcast(message, list/channels)
+/datum/tgs_api/v3210/ChatBroadcast(datum/tgs_message_content/message, list/channels)
 	if(channels)
 		return TGS_UNIMPLEMENTED
+	message = UpgradeDeprecatedChatMessage(message)
 	ChatTargetedBroadcast(message, TRUE)
 	ChatTargetedBroadcast(message, FALSE)
 
-/datum/tgs_api/v3210/ChatTargetedBroadcast(message, admin_only)
-	ExportService("[admin_only ? SERVICE_REQUEST_IRC_ADMIN_CHANNEL_MESSAGE : SERVICE_REQUEST_IRC_BROADCAST] [message]")
+/datum/tgs_api/v3210/ChatTargetedBroadcast(datum/tgs_message_content/message, admin_only)
+	message = UpgradeDeprecatedChatMessage(message)
+	ExportService("[admin_only ? SERVICE_REQUEST_IRC_ADMIN_CHANNEL_MESSAGE : SERVICE_REQUEST_IRC_BROADCAST] [message.text]")
 
 /datum/tgs_api/v3210/ChatPrivateMessage(message, datum/tgs_chat_user/user)
+	UpgradeDeprecatedChatMessage(message)
 	return TGS_UNIMPLEMENTED
 
 /datum/tgs_api/v3210/SecurityLevel()
diff --git a/code/modules/tgs/v3210/commands.dm b/code/modules/tgs/v3210/commands.dm
index 4ccfc1a8a60..e65c816320d 100644
--- a/code/modules/tgs/v3210/commands.dm
+++ b/code/modules/tgs/v3210/commands.dm
@@ -10,9 +10,12 @@
 	var/warned_about_the_dangers_of_robutussin = !warnings_only
 	for(var/I in typesof(/datum/tgs_chat_command) - /datum/tgs_chat_command)
 		if(!warned_about_the_dangers_of_robutussin)
-			TGS_ERROR_LOG("Custom chat commands in [ApiVersion()] lacks the /datum/tgs_chat_user/sender.channel field!")
+			TGS_WARNING_LOG("Custom chat commands in [ApiVersion()] lacks the /datum/tgs_chat_user/sender.channel field!")
 			warned_about_the_dangers_of_robutussin = TRUE
 		var/datum/tgs_chat_command/stc = I
+		if(stc.ignore_type == I)
+			continue
+
 		var/command_name = initial(stc.name)
 		if(!command_name || findtext(command_name, " ") || findtext(command_name, "'") || findtext(command_name, "\""))
 			if(warnings_only && !warned_command_names[command_name])
@@ -44,9 +47,12 @@
 	user.friendly_name = sender
 
 	// Discord hack, fix the mention if it's only numbers (fuck you IRC trolls)
-	var/regex/discord_id_regex = regex(@"^[0-9]+$")
+	var/regex/discord_id_regex = regex("^\[0-9\]+$")
 	if(findtext(sender, discord_id_regex))
 		sender = "<@[sender]>"
 
 	user.mention = sender
-	return stc.Run(user, params) || TRUE
+	var/datum/tgs_message_content/result = stc.Run(user, params)
+	result = UpgradeDeprecatedCommandResponse(result, command)
+
+	return result ? result.text : TRUE
diff --git a/code/modules/tgs/v4/api.dm b/code/modules/tgs/v4/api.dm
index 0e37a7aa24c..7c87922750b 100644
--- a/code/modules/tgs/v4/api.dm
+++ b/code/modules/tgs/v4/api.dm
@@ -73,7 +73,7 @@
 	if(cached_json["apiValidateOnly"])
 		TGS_INFO_LOG("Validating API and exiting...")
 		Export(TGS4_COMM_VALIDATE, list(TGS4_PARAMETER_DATA = "[minimum_required_security_level]"))
-		del(world)
+		TerminateWorld()
 
 	security_level = cached_json["securityLevel"]
 	chat_channels_json_path = cached_json["chatChannelsJson"]
@@ -181,14 +181,14 @@
 	var/json = json_encode(data)
 
 	while(requesting_new_port && !override_requesting_new_port)
-		sleep(1)
+		sleep(world.tick_lag)
 
 	//we need some port open at this point to facilitate return communication
 	if(!world.port)
 		requesting_new_port = TRUE
 		if(!world.OpenPort(0)) //open any port
 			TGS_ERROR_LOG("Unable to open random port to retrieve new port![TGS4_PORT_CRITFAIL_MESSAGE]")
-			del(world)
+			TerminateWorld()
 
 		//request a new port
 		export_lock = FALSE
@@ -196,20 +196,20 @@
 
 		if(!new_port_json)
 			TGS_ERROR_LOG("No new port response from server![TGS4_PORT_CRITFAIL_MESSAGE]")
-			del(world)
+			TerminateWorld()
 
 		var/new_port = new_port_json[TGS4_PARAMETER_DATA]
 		if(!isnum(new_port) || new_port <= 0)
 			TGS_ERROR_LOG("Malformed new port json ([json_encode(new_port_json)])![TGS4_PORT_CRITFAIL_MESSAGE]")
-			del(world)
+			TerminateWorld()
 
 		if(new_port != world.port && !world.OpenPort(new_port))
 			TGS_ERROR_LOG("Unable to open port [new_port]![TGS4_PORT_CRITFAIL_MESSAGE]")
-			del(world)
+			TerminateWorld()
 		requesting_new_port = FALSE
 
 	while(export_lock)
-		sleep(1)
+		sleep(world.tick_lag)
 	export_lock = TRUE
 
 	last_interop_response = null
@@ -217,7 +217,7 @@
 	text2file(json, server_commands_json_path)
 
 	for(var/I = 0; I < EXPORT_TIMEOUT_DS && !last_interop_response; ++I)
-		sleep(1)
+		sleep(world.tick_lag)
 
 	if(!last_interop_response)
 		TGS_ERROR_LOG("Failed to get export result for: [json]")
@@ -256,33 +256,46 @@
 /datum/tgs_api/v4/Revision()
 	return cached_revision
 
-/datum/tgs_api/v4/ChatBroadcast(message, list/channels)
+/datum/tgs_api/v4/ChatBroadcast(datum/tgs_message_content/message, list/channels)
 	var/list/ids
 	if(length(channels))
 		ids = list()
 		for(var/I in channels)
 			var/datum/tgs_chat_channel/channel = I
 			ids += channel.id
-	message = list("message" = message, "channelIds" = ids)
+
+	message = UpgradeDeprecatedChatMessage(message)
+
+	if (!length(channels))
+		return
+
+	message = list("message" = message.text, "channelIds" = ids)
 	if(intercepted_message_queue)
 		intercepted_message_queue += list(message)
 	else
 		Export(TGS4_COMM_CHAT, message)
 
-/datum/tgs_api/v4/ChatTargetedBroadcast(message, admin_only)
+/datum/tgs_api/v4/ChatTargetedBroadcast(datum/tgs_message_content/message, admin_only)
 	var/list/channels = list()
 	for(var/I in ChatChannelInfo())
 		var/datum/tgs_chat_channel/channel = I
 		if (!channel.is_private_channel && ((channel.is_admin_channel && admin_only) || (!channel.is_admin_channel && !admin_only)))
 			channels += channel.id
-	message = list("message" = message, "channelIds" = channels)
+
+	message = UpgradeDeprecatedChatMessage(message)
+
+	if (!length(channels))
+		return
+
+	message = list("message" = message.text, "channelIds" = channels)
 	if(intercepted_message_queue)
 		intercepted_message_queue += list(message)
 	else
 		Export(TGS4_COMM_CHAT, message)
 
-/datum/tgs_api/v4/ChatPrivateMessage(message, datum/tgs_chat_user/user)
-	message = list("message" = message, "channelIds" = list(user.channel.id))
+/datum/tgs_api/v4/ChatPrivateMessage(datum/tgs_message_content/message, datum/tgs_chat_user/user)
+	message = UpgradeDeprecatedChatMessage(message)
+	message = list("message" = message.text, "channelIds" = list(user.channel.id))
 	if(intercepted_message_queue)
 		intercepted_message_queue += list(message)
 	else
diff --git a/code/modules/tgs/v4/commands.dm b/code/modules/tgs/v4/commands.dm
index 4ca1500167b..25dd6740e3a 100644
--- a/code/modules/tgs/v4/commands.dm
+++ b/code/modules/tgs/v4/commands.dm
@@ -3,6 +3,9 @@
 	custom_commands = list()
 	for(var/I in typesof(/datum/tgs_chat_command) - /datum/tgs_chat_command)
 		var/datum/tgs_chat_command/stc = new I
+		if(stc.ignore_type == I)
+			continue
+
 		var/command_name = stc.name
 		if(!command_name || findtext(command_name, " ") || findtext(command_name, "'") || findtext(command_name, "\""))
 			TGS_ERROR_LOG("Custom command [command_name] ([I]) can't be used as it is empty or contains illegal characters!")
@@ -34,8 +37,8 @@
 
 	var/datum/tgs_chat_command/sc = custom_commands[command]
 	if(sc)
-		var/result = sc.Run(u, params)
-		if(result == null)
-			result = ""
-		return result
+		var/datum/tgs_message_content/result = sc.Run(u, params)
+		result = UpgradeDeprecatedCommandResponse(result, command)
+
+		return result ? result.text : TRUE
 	return "Unknown command: [command]!"
diff --git a/code/modules/tgs/v5/README.md b/code/modules/tgs/v5/README.md
index 5b48d57a1f0..a8a0c748e7b 100644
--- a/code/modules/tgs/v5/README.md
+++ b/code/modules/tgs/v5/README.md
@@ -2,7 +2,12 @@
 
 This DMAPI implements bridge requests using HTTP GET requests to TGS. It has no security restrictions.
 
+- [__interop_version.dm](./__interop_version.dm) contains the version of the API used between the DMAPI and TGS.
 - [_defines.dm](./_defines.dm) contains constant definitions.
 - [api.dm](./api.dm) contains the bulk of the API code.
+- [bridge.dm](./bridge.dm) contains functions related to making bridge requests.
+- [chunking.dm](./chunking.dm) contains common function for splitting large raw data sets into chunks BYOND can natively process.
 - [commands.dm](./commands.dm) contains functions relating to `/datum/tgs_chat_command`s.
+- [serializers.dm](./serializers.dm) contains function to help convert interop `/datum`s into a JSON encodable `list()` format.
+- [topic.dm](./topic.dm) contains functions related to processing topic requests.
 - [undefs.dm](./undefs.dm) Undoes the work of `_defines.dm`.
diff --git a/code/modules/tgs/v5/__interop_version.dm b/code/modules/tgs/v5/__interop_version.dm
new file mode 100644
index 00000000000..29ea239ad84
--- /dev/null
+++ b/code/modules/tgs/v5/__interop_version.dm
@@ -0,0 +1 @@
+"5.10.0"
diff --git a/code/modules/tgs/v5/_defines.dm b/code/modules/tgs/v5/_defines.dm
index 10bc4cbe406..a47bfd78000 100644
--- a/code/modules/tgs/v5/_defines.dm
+++ b/code/modules/tgs/v5/_defines.dm
@@ -4,15 +4,29 @@
 #define DMAPI5_BRIDGE_DATA "data"
 #define DMAPI5_TOPIC_DATA "tgs_data"
 
-#define DMAPI5_BRIDGE_COMMAND_PORT_UPDATE 0
+#define DMAPI5_BRIDGE_REQUEST_LIMIT 8198
+#define DMAPI5_TOPIC_REQUEST_LIMIT 65528
+#define DMAPI5_TOPIC_RESPONSE_LIMIT 65529
+
 #define DMAPI5_BRIDGE_COMMAND_STARTUP 1
 #define DMAPI5_BRIDGE_COMMAND_PRIME 2
 #define DMAPI5_BRIDGE_COMMAND_REBOOT 3
 #define DMAPI5_BRIDGE_COMMAND_KILL 4
 #define DMAPI5_BRIDGE_COMMAND_CHAT_SEND 5
+#define DMAPI5_BRIDGE_COMMAND_CHUNK 6
+#define DMAPI5_BRIDGE_COMMAND_EVENT 7
 
 #define DMAPI5_PARAMETER_ACCESS_IDENTIFIER "accessIdentifier"
 #define DMAPI5_PARAMETER_CUSTOM_COMMANDS "customCommands"
+#define DMAPI5_PARAMETER_TOPIC_PORT "topicPort"
+
+#define DMAPI5_CHUNK "chunk"
+#define DMAPI5_CHUNK_PAYLOAD "payload"
+#define DMAPI5_CHUNK_TOTAL "totalChunks"
+#define DMAPI5_CHUNK_SEQUENCE_ID "sequenceId"
+#define DMAPI5_CHUNK_PAYLOAD_ID "payloadId"
+
+#define DMAPI5_MISSING_CHUNKS "missingChunks"
 
 #define DMAPI5_RESPONSE_ERROR_MESSAGE "errorMessage"
 
@@ -21,11 +35,11 @@
 #define DMAPI5_BRIDGE_PARAMETER_VERSION "version"
 #define DMAPI5_BRIDGE_PARAMETER_CHAT_MESSAGE "chatMessage"
 #define DMAPI5_BRIDGE_PARAMETER_MINIMUM_SECURITY_LEVEL "minimumSecurityLevel"
+#define DMAPI5_BRIDGE_PARAMETER_EVENT_INVOCATION "eventInvocation"
 
 #define DMAPI5_BRIDGE_RESPONSE_NEW_PORT "newPort"
 #define DMAPI5_BRIDGE_RESPONSE_RUNTIME_INFORMATION "runtimeInformation"
 
-#define DMAPI5_CHAT_MESSAGE_TEXT "text"
 #define DMAPI5_CHAT_MESSAGE_CHANNEL_IDS "channelIds"
 
 #define DMAPI5_RUNTIME_INFORMATION_ACCESS_IDENTIFIER "accessIdentifier"
@@ -36,6 +50,7 @@
 #define DMAPI5_RUNTIME_INFORMATION_REVISION "revision"
 #define DMAPI5_RUNTIME_INFORMATION_TEST_MERGES "testMerges"
 #define DMAPI5_RUNTIME_INFORMATION_SECURITY_LEVEL "securityLevel"
+#define DMAPI5_RUNTIME_INFORMATION_VISIBILITY "visibility"
 
 #define DMAPI5_CHAT_UPDATE_CHANNELS "channels"
 
@@ -63,8 +78,12 @@
 #define DMAPI5_TOPIC_COMMAND_INSTANCE_RENAMED 4
 #define DMAPI5_TOPIC_COMMAND_CHAT_CHANNELS_UPDATE 5
 #define DMAPI5_TOPIC_COMMAND_SERVER_PORT_UPDATE 6
-#define DMAPI5_TOPIC_COMMAND_HEARTBEAT 7
+#define DMAPI5_TOPIC_COMMAND_HEALTHCHECK 7
 #define DMAPI5_TOPIC_COMMAND_WATCHDOG_REATTACH 8
+#define DMAPI5_TOPIC_COMMAND_SEND_CHUNK 9
+#define DMAPI5_TOPIC_COMMAND_RECEIVE_CHUNK 10
+#define DMAPI5_TOPIC_COMMAND_RECEIVE_BROADCAST 11
+#define DMAPI5_TOPIC_COMMAND_COMPLETE_EVENT 12
 
 #define DMAPI5_TOPIC_PARAMETER_COMMAND_TYPE "commandType"
 #define DMAPI5_TOPIC_PARAMETER_CHAT_COMMAND "chatCommand"
@@ -74,7 +93,10 @@
 #define DMAPI5_TOPIC_PARAMETER_NEW_INSTANCE_NAME "newInstanceName"
 #define DMAPI5_TOPIC_PARAMETER_CHAT_UPDATE "chatUpdate"
 #define DMAPI5_TOPIC_PARAMETER_NEW_SERVER_VERSION "newServerVersion"
+#define DMAPI5_TOPIC_PARAMETER_BROADCAST_MESSAGE "broadcastMessage"
 
+#define DMAPI5_TOPIC_RESPONSE_CLIENT_COUNT "clientCount"
+#define DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE "commandResponse"
 #define DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE_MESSAGE "commandResponseMessage"
 #define DMAPI5_TOPIC_RESPONSE_CHAT_RESPONSES "chatResponses"
 
@@ -93,7 +115,14 @@
 #define DMAPI5_CHAT_CHANNEL_IS_ADMIN_CHANNEL "isAdminChannel"
 #define DMAPI5_CHAT_CHANNEL_IS_PRIVATE_CHANNEL "isPrivateChannel"
 #define DMAPI5_CHAT_CHANNEL_TAG "tag"
+#define DMAPI5_CHAT_CHANNEL_EMBEDS_SUPPORTED "embedsSupported"
 
 #define DMAPI5_CUSTOM_CHAT_COMMAND_NAME "name"
 #define DMAPI5_CUSTOM_CHAT_COMMAND_HELP_TEXT "helpText"
 #define DMAPI5_CUSTOM_CHAT_COMMAND_ADMIN_ONLY "adminOnly"
+
+#define DMAPI5_EVENT_ID "eventId"
+
+#define DMAPI5_EVENT_INVOCATION_NAME "eventName"
+#define DMAPI5_EVENT_INVOCATION_PARAMETERS "parameters"
+#define DMAPI5_EVENT_INVOCATION_NOTIFY_COMPLETION "notifyCompletion"
diff --git a/code/modules/tgs/v5/api.dm b/code/modules/tgs/v5/api.dm
index 572944ed401..3e328fc7c27 100644
--- a/code/modules/tgs/v5/api.dm
+++ b/code/modules/tgs/v5/api.dm
@@ -4,11 +4,16 @@
 
 	var/instance_name
 	var/security_level
+	var/visibility
 
 	var/reboot_mode = TGS_REBOOT_MODE_NORMAL
 
+	/// List of chat messages list()s that attempted to be sent during a topic call. To be bundled in the result of the call
 	var/list/intercepted_message_queue
 
+	/// List of chat messages list()s that attempted to be sent during a topic call. To be bundled in the result of the call
+	var/list/offline_message_queue
+
 	var/list/custom_commands
 
 	var/list/test_merges
@@ -16,19 +21,43 @@
 	var/list/chat_channels
 
 	var/initialized = FALSE
+	var/initial_bridge_request_received = FALSE
+	var/datum/tgs_version/interop_version
+
+	var/chunked_requests = 0
+	var/list/chunked_topics = list()
+
+	var/list/pending_events = list()
+
+	var/detached = FALSE
+
+	var/datum/tgs_http_handler/http_handler
+
+/datum/tgs_api/v5/New(datum/tgs_event_handler/event_handler, datum/tgs_version/version, datum/tgs_http_handler/http_handler)
+	. = ..()
+	interop_version = version
+	src.http_handler = http_handler
+	TGS_DEBUG_LOG("V5 API created: [json_encode(args)]")
 
 /datum/tgs_api/v5/ApiVersion()
 	return new /datum/tgs_version(
-		#include "interop_version.dm"
+		#include "__interop_version.dm"
 	)
 
 /datum/tgs_api/v5/OnWorldNew(minimum_required_security_level)
+	TGS_DEBUG_LOG("OnWorldNew()")
 	server_port = world.params[DMAPI5_PARAM_SERVER_PORT]
 	access_identifier = world.params[DMAPI5_PARAM_ACCESS_IDENTIFIER]
 
 	var/datum/tgs_version/api_version = ApiVersion()
-	version = null
-	var/list/bridge_response = Bridge(DMAPI5_BRIDGE_COMMAND_STARTUP, list(DMAPI5_BRIDGE_PARAMETER_MINIMUM_SECURITY_LEVEL = minimum_required_security_level, DMAPI5_BRIDGE_PARAMETER_VERSION = api_version.raw_parameter, DMAPI5_PARAMETER_CUSTOM_COMMANDS = ListCustomCommands()))
+	version = null // we want this to be the TGS version, not the interop version
+
+	// sleep once to prevent an issue where world.Export on the first tick can hang indefinitely
+	TGS_DEBUG_LOG("Starting Export bug prevention sleep tick. time:[world.time] sleep_offline:[world.sleep_offline]")
+	sleep(world.tick_lag)
+	TGS_DEBUG_LOG("Export bug prevention sleep complete")
+
+	var/list/bridge_response = Bridge(DMAPI5_BRIDGE_COMMAND_STARTUP, list(DMAPI5_BRIDGE_PARAMETER_MINIMUM_SECURITY_LEVEL = minimum_required_security_level, DMAPI5_BRIDGE_PARAMETER_VERSION = api_version.raw_parameter, DMAPI5_PARAMETER_CUSTOM_COMMANDS = ListCustomCommands(), DMAPI5_PARAMETER_TOPIC_PORT = GetTopicPort()))
 	if(!istype(bridge_response))
 		TGS_ERROR_LOG("Failed initial bridge request!")
 		return FALSE
@@ -40,10 +69,12 @@
 
 	if(runtime_information[DMAPI5_RUNTIME_INFORMATION_API_VALIDATE_ONLY])
 		TGS_INFO_LOG("DMAPI validation, exiting...")
-		del(world)
+		TerminateWorld()
 
-	version = new /datum/tgs_version(runtime_information[DMAPI5_RUNTIME_INFORMATION_SERVER_VERSION])
+	initial_bridge_request_received = TRUE
+	version = new /datum/tgs_version(runtime_information[DMAPI5_RUNTIME_INFORMATION_SERVER_VERSION]) // reassigning this because it can change if TGS updates
 	security_level = runtime_information[DMAPI5_RUNTIME_INFORMATION_SECURITY_LEVEL]
+	visibility = runtime_information[DMAPI5_RUNTIME_INFORMATION_VISIBILITY]
 	instance_name = runtime_information[DMAPI5_RUNTIME_INFORMATION_INSTANCE_NAME]
 
 	var/list/revisionData = runtime_information[DMAPI5_RUNTIME_INFORMATION_REVISION]
@@ -90,179 +121,43 @@
 	initialized = TRUE
 	return TRUE
 
+/datum/tgs_api/v5/proc/GetTopicPort()
+#if defined(OPENDREAM) && defined(OPENDREAM_TOPIC_PORT_EXISTS)
+	return "[world.opendream_topic_port]"
+#else
+	return null
+#endif
+
 /datum/tgs_api/v5/proc/RequireInitialBridgeResponse()
-	while(!version)
-		sleep(1)
+	TGS_DEBUG_LOG("RequireInitialBridgeResponse()")
+	var/logged = FALSE
+	while(!initial_bridge_request_received)
+		if(!logged)
+			TGS_DEBUG_LOG("RequireInitialBridgeResponse: Starting sleep")
+			logged = TRUE
 
-/datum/tgs_api/v5/OnInitializationComplete()
-	Bridge(DMAPI5_BRIDGE_COMMAND_PRIME)
+		sleep(world.tick_lag)
 
-/datum/tgs_api/v5/proc/TopicResponse(error_message = null)
-	var/list/response = list()
-	response[DMAPI5_RESPONSE_ERROR_MESSAGE] = error_message
+	TGS_DEBUG_LOG("RequireInitialBridgeResponse: Passed")
 
-	return json_encode(response)
+/datum/tgs_api/v5/OnInitializationComplete()
+	Bridge(DMAPI5_BRIDGE_COMMAND_PRIME)
 
 /datum/tgs_api/v5/OnTopic(T)
+	TGS_DEBUG_LOG("OnTopic()")
+	RequireInitialBridgeResponse()
+	TGS_DEBUG_LOG("OnTopic passed bridge request gate")
 	var/list/params = params2list(T)
 	var/json = params[DMAPI5_TOPIC_DATA]
 	if(!json)
+		TGS_DEBUG_LOG("No \"[DMAPI5_TOPIC_DATA]\" entry found, ignoring...")
 		return FALSE // continue to /world/Topic
 
-	var/list/topic_parameters = json_decode(json)
-	if(!topic_parameters)
-		return TopicResponse("Invalid topic parameters json!");
-
 	if(!initialized)
-		TGS_WARNING_LOG("Missed topic due to not being initialized: [T]")
+		TGS_WARNING_LOG("Missed topic due to not being initialized: [json]")
 		return TRUE // too early to handle, but it's still our responsibility
 
-	var/their_sCK = topic_parameters[DMAPI5_PARAMETER_ACCESS_IDENTIFIER]
-	if(their_sCK != access_identifier)
-		return TopicResponse("Failed to decode [DMAPI5_PARAMETER_ACCESS_IDENTIFIER] from: [json]!");
-
-	var/command = topic_parameters[DMAPI5_TOPIC_PARAMETER_COMMAND_TYPE]
-	if(!isnum(command))
-		return TopicResponse("Failed to decode [DMAPI5_TOPIC_PARAMETER_COMMAND_TYPE] from: [json]!")
-
-	switch(command)
-		if(DMAPI5_TOPIC_COMMAND_CHAT_COMMAND)
-			var/result = HandleCustomCommand(topic_parameters[DMAPI5_TOPIC_PARAMETER_CHAT_COMMAND])
-			if(!result)
-				result = TopicResponse("Error running chat command!")
-			return result
-		if(DMAPI5_TOPIC_COMMAND_EVENT_NOTIFICATION)
-			intercepted_message_queue = list()
-			var/list/event_notification = topic_parameters[DMAPI5_TOPIC_PARAMETER_EVENT_NOTIFICATION]
-			if(!istype(event_notification))
-				return TopicResponse("Invalid [DMAPI5_TOPIC_PARAMETER_EVENT_NOTIFICATION]!")
-
-			var/event_type = event_notification[DMAPI5_EVENT_NOTIFICATION_TYPE]
-			if(!isnum(event_type))
-				return TopicResponse("Invalid or missing [DMAPI5_EVENT_NOTIFICATION_TYPE]!")
-
-			var/list/event_parameters = event_notification[DMAPI5_EVENT_NOTIFICATION_PARAMETERS]
-			if(event_parameters && !istype(event_parameters))
-				return TopicResponse("Invalid or missing [DMAPI5_EVENT_NOTIFICATION_PARAMETERS]!")
-
-			var/list/event_call = list(event_type)
-			if(event_parameters)
-				event_call += event_parameters
-
-			if(event_handler != null)
-				event_handler.HandleEvent(arglist(event_call))
-
-			var/list/response = list()
-			response[DMAPI5_TOPIC_RESPONSE_CHAT_RESPONSES] = intercepted_message_queue
-			intercepted_message_queue = null
-			return json_encode(response)
-		if(DMAPI5_TOPIC_COMMAND_CHANGE_PORT)
-			var/new_port = topic_parameters[DMAPI5_TOPIC_PARAMETER_NEW_PORT]
-			if (!isnum(new_port) || !(new_port > 0))
-				return TopicResponse("Invalid or missing [DMAPI5_TOPIC_PARAMETER_NEW_PORT]]")
-
-			if(event_handler != null)
-				event_handler.HandleEvent(TGS_EVENT_PORT_SWAP, new_port)
-
-			//the topic still completes, miraculously
-			//I honestly didn't believe byond could do it without exploding
-			if(!world.OpenPort(new_port))
-				return TopicResponse("Port change failed!")
-
-			return TopicResponse()
-		if(DMAPI5_TOPIC_COMMAND_CHANGE_REBOOT_STATE)
-			var/new_reboot_mode = topic_parameters[DMAPI5_TOPIC_PARAMETER_NEW_REBOOT_STATE]
-			if(!isnum(new_reboot_mode))
-				return TopicResponse("Invalid or missing [DMAPI5_TOPIC_PARAMETER_NEW_REBOOT_STATE]!")
-
-			if(event_handler != null)
-				event_handler.HandleEvent(TGS_EVENT_REBOOT_MODE_CHANGE, reboot_mode, new_reboot_mode)
-
-			reboot_mode = new_reboot_mode
-			return TopicResponse()
-		if(DMAPI5_TOPIC_COMMAND_INSTANCE_RENAMED)
-			var/new_instance_name = topic_parameters[DMAPI5_TOPIC_PARAMETER_NEW_INSTANCE_NAME]
-			if(!istext(new_instance_name))
-				return TopicResponse("Invalid or missing [DMAPI5_TOPIC_PARAMETER_NEW_INSTANCE_NAME]!")
-
-			if(event_handler != null)
-				event_handler.HandleEvent(TGS_EVENT_INSTANCE_RENAMED, new_instance_name)
-
-			instance_name = new_instance_name
-			return TopicResponse()
-		if(DMAPI5_TOPIC_COMMAND_CHAT_CHANNELS_UPDATE)
-			var/list/chat_update_json = topic_parameters[DMAPI5_TOPIC_PARAMETER_CHAT_UPDATE]
-			if(!istype(chat_update_json))
-				return TopicResponse("Invalid or missing [DMAPI5_TOPIC_PARAMETER_CHAT_UPDATE]!")
-
-			DecodeChannels(chat_update_json)
-			return TopicResponse()
-		if(DMAPI5_TOPIC_COMMAND_SERVER_PORT_UPDATE)
-			var/new_port = topic_parameters[DMAPI5_TOPIC_PARAMETER_NEW_PORT]
-			if (!isnum(new_port) || !(new_port > 0))
-				return TopicResponse("Invalid or missing [DMAPI5_TOPIC_PARAMETER_NEW_PORT]]")
-
-			server_port = new_port
-			return TopicResponse()
-		if(DMAPI5_TOPIC_COMMAND_HEARTBEAT)
-			return TopicResponse()
-		if(DMAPI5_TOPIC_COMMAND_WATCHDOG_REATTACH)
-			var/new_port = topic_parameters[DMAPI5_TOPIC_PARAMETER_NEW_PORT]
-			var/error_message = null
-			if (new_port != null)
-				if (!isnum(new_port) || !(new_port > 0))
-					error_message = "Invalid [DMAPI5_TOPIC_PARAMETER_NEW_PORT]]"
-				else
-					server_port = new_port
-
-			var/new_version_string = topic_parameters[DMAPI5_TOPIC_PARAMETER_NEW_SERVER_VERSION]
-			if (!istext(new_version_string))
-				if(error_message != null)
-					error_message += ", "
-				error_message += "Invalid or missing [DMAPI5_TOPIC_PARAMETER_NEW_SERVER_VERSION]]"
-			else
-				var/datum/tgs_version/new_version = new(new_version_string)
-				if (event_handler)
-					event_handler.HandleEvent(TGS_EVENT_WATCHDOG_REATTACH, new_version)
-
-				version = new_version
-
-			return json_encode(list(DMAPI5_RESPONSE_ERROR_MESSAGE = error_message, DMAPI5_PARAMETER_CUSTOM_COMMANDS = ListCustomCommands()))
-
-	return TopicResponse("Unknown command: [command]")
-
-/datum/tgs_api/v5/proc/Bridge(command, list/data)
-	if(!data)
-		data = list()
-
-	data[DMAPI5_BRIDGE_PARAMETER_COMMAND_TYPE] = command
-	data[DMAPI5_PARAMETER_ACCESS_IDENTIFIER] = access_identifier
-
-	var/json = json_encode(data)
-	var/encoded_json = url_encode(json)
-
-	// This is an infinite sleep until we get a response
-	var/export_response = world.Export("http://127.0.0.1:[server_port]/Bridge?[DMAPI5_BRIDGE_DATA]=[encoded_json]")
-	if(!export_response)
-		TGS_ERROR_LOG("Failed export request: [json]")
-		return
-
-	var/response_json = file2text(export_response["CONTENT"])
-	if(!response_json)
-		TGS_ERROR_LOG("Failed export request, missing content!")
-		return
-
-	var/list/bridge_response = json_decode(response_json)
-	if(!bridge_response)
-		TGS_ERROR_LOG("Failed export request, bad json: [response_json]")
-		return
-
-	var/error = bridge_response[DMAPI5_RESPONSE_ERROR_MESSAGE]
-	if(error)
-		TGS_ERROR_LOG("Failed export request, bad request: [error]")
-		return
-
-	return bridge_response
+	return ProcessTopicJson(json, TRUE)
 
 /datum/tgs_api/v5/OnReboot()
 	var/list/result = Bridge(DMAPI5_BRIDGE_COMMAND_REBOOT)
@@ -297,7 +192,15 @@
 	RequireInitialBridgeResponse()
 	return revision
 
-/datum/tgs_api/v5/ChatBroadcast(message, list/channels)
+// Common proc b/c it's used by the V3/V4 APIs
+/datum/tgs_api/proc/UpgradeDeprecatedChatMessage(datum/tgs_message_content/message)
+	if(!istext(message))
+		return message
+
+	TGS_WARNING_LOG("Received legacy string when a [/datum/tgs_message_content] was expected. Please audit all calls to TgsChatBroadcast, TgsChatTargetedBroadcast, and TgsChatPrivateMessage to ensure they use the new /datum.")
+	return new /datum/tgs_message_content(message)
+
+/datum/tgs_api/v5/ChatBroadcast(datum/tgs_message_content/message2, list/channels)
 	if(!length(channels))
 		channels = ChatChannelInfo()
 
@@ -306,36 +209,93 @@
 		var/datum/tgs_chat_channel/channel = I
 		ids += channel.id
 
-	message = list(DMAPI5_CHAT_MESSAGE_TEXT = message, DMAPI5_CHAT_MESSAGE_CHANNEL_IDS = ids)
-	if(intercepted_message_queue)
-		intercepted_message_queue += list(message)
-	else
-		Bridge(DMAPI5_BRIDGE_COMMAND_CHAT_SEND, list(DMAPI5_BRIDGE_PARAMETER_CHAT_MESSAGE = message))
+	SendChatMessageRaw(message2, ids)
 
-/datum/tgs_api/v5/ChatTargetedBroadcast(message, admin_only)
+/datum/tgs_api/v5/ChatTargetedBroadcast(datum/tgs_message_content/message2, admin_only)
 	var/list/channels = list()
 	for(var/I in ChatChannelInfo())
 		var/datum/tgs_chat_channel/channel = I
 		if (!channel.is_private_channel && ((channel.is_admin_channel && admin_only) || (!channel.is_admin_channel && !admin_only)))
 			channels += channel.id
-	message = list(DMAPI5_CHAT_MESSAGE_TEXT = message, DMAPI5_CHAT_MESSAGE_CHANNEL_IDS = channels)
-	if(intercepted_message_queue)
-		intercepted_message_queue += list(message)
-	else
-		Bridge(DMAPI5_BRIDGE_COMMAND_CHAT_SEND, list(DMAPI5_BRIDGE_PARAMETER_CHAT_MESSAGE = message))
 
-/datum/tgs_api/v5/ChatPrivateMessage(message, datum/tgs_chat_user/user)
-	message = list(DMAPI5_CHAT_MESSAGE_TEXT = message, DMAPI5_CHAT_MESSAGE_CHANNEL_IDS = list(user.channel.id))
+	SendChatMessageRaw(message2, channels)
+
+/datum/tgs_api/v5/ChatPrivateMessage(datum/tgs_message_content/message2, datum/tgs_chat_user/user)
+	SendChatMessageRaw(message2, list(user.channel.id))
+
+/datum/tgs_api/v5/proc/SendChatMessageRaw(datum/tgs_message_content/message2, list/channel_ids)
+	message2 = UpgradeDeprecatedChatMessage(message2)
+
+	if (!length(channel_ids))
+		return
+
+	var/list/data = message2._interop_serialize()
+	data[DMAPI5_CHAT_MESSAGE_CHANNEL_IDS] = channel_ids
 	if(intercepted_message_queue)
-		intercepted_message_queue += list(message)
+		intercepted_message_queue += list(data)
+		return
+
+	if(offline_message_queue)
+		offline_message_queue += list(data)
+		return
+
+	if(detached)
+		offline_message_queue = list(data)
+
+		WaitForReattach(FALSE)
+
+		data = offline_message_queue
+		offline_message_queue = null
+
+		for(var/queued_message in data)
+			SendChatDataRaw(queued_message)
 	else
-		Bridge(DMAPI5_BRIDGE_COMMAND_CHAT_SEND, list(DMAPI5_BRIDGE_PARAMETER_CHAT_MESSAGE = message))
+		SendChatDataRaw(data)
+
+/datum/tgs_api/v5/proc/SendChatDataRaw(list/data)
+	Bridge(DMAPI5_BRIDGE_COMMAND_CHAT_SEND, list(DMAPI5_BRIDGE_PARAMETER_CHAT_MESSAGE = data))
 
 /datum/tgs_api/v5/ChatChannelInfo()
 	RequireInitialBridgeResponse()
+	WaitForReattach(TRUE)
 	return chat_channels.Copy()
 
+/datum/tgs_api/v5/TriggerEvent(event_name, list/parameters, wait_for_completion)
+	RequireInitialBridgeResponse()
+	WaitForReattach(TRUE)
+
+	if(interop_version.minor < 9)
+		TGS_WARNING_LOG("Interop version too low for custom events!")
+		return FALSE
+
+	var/str_parameters = list()
+	for(var/i in parameters)
+		str_parameters += "[i]"
+
+	var/list/response = Bridge(DMAPI5_BRIDGE_COMMAND_EVENT, list(DMAPI5_BRIDGE_PARAMETER_EVENT_INVOCATION = list(DMAPI5_EVENT_INVOCATION_NAME = event_name, DMAPI5_EVENT_INVOCATION_PARAMETERS = str_parameters, DMAPI5_EVENT_INVOCATION_NOTIFY_COMPLETION = wait_for_completion)))
+	if(!response)
+		return FALSE
+
+	var/event_id = response[DMAPI5_EVENT_ID]
+	if(!event_id)
+		return FALSE
+
+	TGS_DEBUG_LOG("Created event ID: [event_id]")
+	if(!wait_for_completion)
+		return TRUE
+
+	TGS_DEBUG_LOG("Waiting for completion of event ID: [event_id]")
+
+	while(!pending_events[event_id])
+		sleep(world.tick_lag)
+
+	TGS_DEBUG_LOG("Completed wait on event ID: [event_id]")
+	pending_events -= event_id
+
+	return TRUE
+
 /datum/tgs_api/v5/proc/DecodeChannels(chat_update_json)
+	TGS_DEBUG_LOG("DecodeChannels()")
 	var/list/chat_channels_json = chat_update_json[DMAPI5_CHAT_UPDATE_CHANNELS]
 	if(istype(chat_channels_json))
 		chat_channels.Cut()
@@ -354,8 +314,13 @@
 	channel.is_admin_channel = channel_json[DMAPI5_CHAT_CHANNEL_IS_ADMIN_CHANNEL]
 	channel.is_private_channel = channel_json[DMAPI5_CHAT_CHANNEL_IS_PRIVATE_CHANNEL]
 	channel.custom_tag = channel_json[DMAPI5_CHAT_CHANNEL_TAG]
+	channel.embeds_supported = channel_json[DMAPI5_CHAT_CHANNEL_EMBEDS_SUPPORTED]
 	return channel
 
 /datum/tgs_api/v5/SecurityLevel()
 	RequireInitialBridgeResponse()
 	return security_level
+
+/datum/tgs_api/v5/Visibility()
+	RequireInitialBridgeResponse()
+	return visibility
diff --git a/code/modules/tgs/v5/bridge.dm b/code/modules/tgs/v5/bridge.dm
new file mode 100644
index 00000000000..62201fcc9e5
--- /dev/null
+++ b/code/modules/tgs/v5/bridge.dm
@@ -0,0 +1,106 @@
+/datum/tgs_api/v5/proc/Bridge(command, list/data)
+	if(!data)
+		data = list()
+
+	var/single_bridge_request = CreateBridgeRequest(command, data)
+	if(length(single_bridge_request) <= DMAPI5_BRIDGE_REQUEST_LIMIT)
+		return PerformBridgeRequest(single_bridge_request)
+
+	// chunking required
+	var/payload_id = ++chunked_requests
+
+	var/raw_data = CreateBridgeData(command, data, FALSE)
+
+	var/list/chunk_requests = GenerateChunks(raw_data, TRUE)
+
+	var/list/response
+	for(var/bridge_request in chunk_requests)
+		response = PerformBridgeRequest(bridge_request)
+		if(!response)
+			// Abort
+			return
+
+	var/list/missing_sequence_ids = response[DMAPI5_MISSING_CHUNKS]
+	if(length(missing_sequence_ids))
+		do
+			TGS_WARNING_LOG("Server is still missing some chunks of bridge P[payload_id]! Sending missing chunks...")
+			if(!istype(missing_sequence_ids))
+				TGS_ERROR_LOG("Did not receive a list() for [DMAPI5_MISSING_CHUNKS]!")
+				return
+
+			for(var/missing_sequence_id in missing_sequence_ids)
+				if(!isnum(missing_sequence_id))
+					TGS_ERROR_LOG("Did not receive a num in [DMAPI5_MISSING_CHUNKS]!")
+					return
+
+				var/missing_chunk_request = chunk_requests[missing_sequence_id + 1]
+				response = PerformBridgeRequest(missing_chunk_request)
+				if(!response)
+					// Abort
+					return
+
+			missing_sequence_ids = response[DMAPI5_MISSING_CHUNKS]
+		while(length(missing_sequence_ids))
+
+	return response
+
+/datum/tgs_api/v5/proc/CreateBridgeRequest(command, list/data)
+	var/json = CreateBridgeData(command, data, TRUE)
+	var/encoded_json = url_encode(json)
+
+	var/api_prefix = interop_version.minor >= 8 ? "api/" : ""
+
+	var/url = "http://127.0.0.1:[server_port]/[api_prefix]Bridge?[DMAPI5_BRIDGE_DATA]=[encoded_json]"
+	return url
+
+/datum/tgs_api/v5/proc/CreateBridgeData(command, list/data, needs_auth)
+	data[DMAPI5_BRIDGE_PARAMETER_COMMAND_TYPE] = command
+	if(needs_auth)
+		data[DMAPI5_PARAMETER_ACCESS_IDENTIFIER] = access_identifier
+
+	var/json = json_encode(data)
+	return json
+
+/datum/tgs_api/v5/proc/WaitForReattach(require_channels = FALSE)
+	if(detached)
+		// Wait up to one minute
+		for(var/i in 1 to 600)
+			sleep(world.tick_lag)
+			if(!detached && (!require_channels || length(chat_channels)))
+				break
+
+			// dad went out for milk and cigarettes 20 years ago...
+			// yes, this affects all other waiters, intentional
+			if(i == 600)
+				detached = FALSE
+
+/datum/tgs_api/v5/proc/PerformBridgeRequest(bridge_request)
+	WaitForReattach(FALSE)
+
+	TGS_DEBUG_LOG("Bridge request start")
+	var/datum/tgs_http_result/result = http_handler.PerformGet(bridge_request)
+	TGS_DEBUG_LOG("Bridge request complete")
+
+	if(isnull(result))
+		TGS_ERROR_LOG("Failed bridge request, handler returned null!")
+		return
+
+	if(!istype(result) || result.type != /datum/tgs_http_result)
+		TGS_ERROR_LOG("Failed bridge request, handler returned non-[/datum/tgs_http_result]!")
+		return
+
+	if(!result.success)
+		TGS_DEBUG_LOG("Failed bridge request, HTTP request failed!")
+		return
+
+	var/list/bridge_response = json_decode(result.response_text)
+	if(!bridge_response)
+		TGS_ERROR_LOG("Failed bridge request, bad json: [result.response_text]")
+		return
+
+	var/error = bridge_response[DMAPI5_RESPONSE_ERROR_MESSAGE]
+	if(error)
+		TGS_ERROR_LOG("Failed bridge request, bad request: [error]")
+		return
+
+	return bridge_response
diff --git a/code/modules/tgs/v5/chunking.dm b/code/modules/tgs/v5/chunking.dm
new file mode 100644
index 00000000000..cd5944d34fb
--- /dev/null
+++ b/code/modules/tgs/v5/chunking.dm
@@ -0,0 +1,43 @@
+/datum/tgs_api/v5/proc/GenerateChunks(payload, bridge)
+	var/limit = bridge ? DMAPI5_BRIDGE_REQUEST_LIMIT : DMAPI5_TOPIC_RESPONSE_LIMIT
+
+	var/payload_id = ++chunked_requests
+	var/data_length = length(payload)
+
+	var/chunk_count
+	var/list/chunk_requests
+	for(chunk_count = 2; !chunk_requests; ++chunk_count)
+		var/max_chunk_size = -round(-(data_length / chunk_count))
+		if(max_chunk_size > limit)
+			continue
+
+		chunk_requests = list()
+		for(var/i in 1 to chunk_count)
+			var/start_index = 1 + ((i - 1) * max_chunk_size)
+			if (start_index > data_length)
+				break
+
+			var/end_index = min(1 + (i * max_chunk_size), data_length + 1)
+
+			var/chunk_payload = copytext(payload, start_index, end_index)
+
+			// sequence IDs in interop chunking are always zero indexed
+			var/list/chunk = list(DMAPI5_CHUNK_PAYLOAD_ID = payload_id, DMAPI5_CHUNK_SEQUENCE_ID = (i - 1), DMAPI5_CHUNK_TOTAL = chunk_count, DMAPI5_CHUNK_PAYLOAD = chunk_payload)
+
+			var/chunk_request = list(DMAPI5_CHUNK = chunk)
+			var/chunk_length
+			if(bridge)
+				chunk_request = CreateBridgeRequest(DMAPI5_BRIDGE_COMMAND_CHUNK, chunk_request)
+				chunk_length = length(chunk_request)
+			else
+				chunk_request = list(chunk_request) // wrap for adding to list
+				chunk_length = length(json_encode(chunk_request))
+
+			if(chunk_length > limit)
+				// Screwed by encoding, no way to preempt it though
+				chunk_requests = null
+				break
+
+			chunk_requests += chunk_request
+
+	return chunk_requests
diff --git a/code/modules/tgs/v5/commands.dm b/code/modules/tgs/v5/commands.dm
index 6d31dd3422d..9557f8a08ed 100644
--- a/code/modules/tgs/v5/commands.dm
+++ b/code/modules/tgs/v5/commands.dm
@@ -3,14 +3,17 @@
 	custom_commands = list()
 	for(var/I in typesof(/datum/tgs_chat_command) - /datum/tgs_chat_command)
 		var/datum/tgs_chat_command/stc = new I
+		if(stc.ignore_type == I)
+			continue
+
 		var/command_name = stc.name
 		if(!command_name || findtext(command_name, " ") || findtext(command_name, "'") || findtext(command_name, "\""))
-			TGS_WARNING_LOG("Custom command [command_name] ([I]) can't be used as it is empty or contains illegal characters!")
+			TGS_ERROR_LOG("Custom command [command_name] ([I]) can't be used as it is empty or contains illegal characters!")
 			continue
 
 		if(results[command_name])
 			var/datum/other = custom_commands[command_name]
-			TGS_WARNING_LOG("Custom commands [other.type] and [I] have the same name (\"[command_name]\"), only [other.type] will be available!")
+			TGS_ERROR_LOG("Custom commands [other.type] and [I] have the same name (\"[command_name]\"), only [other.type] will be available!")
 			continue
 		results += list(list(DMAPI5_CUSTOM_CHAT_COMMAND_NAME = command_name, DMAPI5_CUSTOM_CHAT_COMMAND_HELP_TEXT = stc.help_text, DMAPI5_CUSTOM_CHAT_COMMAND_ADMIN_ONLY = stc.admin_only))
 		custom_commands[command_name] = stc
@@ -30,11 +33,28 @@
 
 	var/datum/tgs_chat_command/sc = custom_commands[command]
 	if(sc)
-		var/text_response = sc.Run(u, params)
-		var/list/topic_response = list()
-		if(!istext(text_response))
-			TGS_ERROR_LOG("Custom command [command] should return a string! Got: \"[text_response]\"")
-			text_response = null
-		topic_response[DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE_MESSAGE] = text_response
-		return json_encode(topic_response)
+		var/datum/tgs_message_content/response = sc.Run(u, params)
+		response = UpgradeDeprecatedCommandResponse(response, command)
+
+		var/list/topic_response = TopicResponse()
+		topic_response[DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE_MESSAGE] = response ? response.text : null
+		topic_response[DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE] = response ? response._interop_serialize() : null
+		return topic_response
 	return TopicResponse("Unknown custom chat command: [command]!")
+
+// Common proc b/c it's used by the V3/V4 APIs
+/datum/tgs_api/proc/UpgradeDeprecatedCommandResponse(datum/tgs_message_content/response, command)
+	// Backwards compatibility, used to return a string
+	if(istext(response))
+		warned_deprecated_command_runs = warned_deprecated_command_runs || list()
+		if(!warned_deprecated_command_runs[command])
+			TGS_WARNING_LOG("Custom chat command \"[command]\" is still returning a string. This behaviour is deprecated, please upgrade it to return a [/datum/tgs_message_content].")
+			warned_deprecated_command_runs[command] = TRUE
+
+		return new /datum/tgs_message_content(response)
+
+	if(!istype(response))
+		TGS_ERROR_LOG("Custom chat command \"[command]\" should return a [/datum/tgs_message_content]! Got: \"[response]\"")
+		return null
+
+	return response
diff --git a/code/modules/tgs/v5/interop_version.dm b/code/modules/tgs/v5/interop_version.dm
deleted file mode 100644
index c7bf62ecae3..00000000000
--- a/code/modules/tgs/v5/interop_version.dm
+++ /dev/null
@@ -1 +0,0 @@
-"5.3.0"
diff --git a/code/modules/tgs/v5/serializers.dm b/code/modules/tgs/v5/serializers.dm
new file mode 100644
index 00000000000..3a32848ad51
--- /dev/null
+++ b/code/modules/tgs/v5/serializers.dm
@@ -0,0 +1,59 @@
+/datum/tgs_message_content/proc/_interop_serialize()
+	return list("text" = text, "embed" = embed ? embed._interop_serialize() : null)
+
+/datum/tgs_chat_embed/proc/_interop_serialize()
+	CRASH("Base /proc/interop_serialize called on [type]!")
+
+/datum/tgs_chat_embed/structure/_interop_serialize()
+	var/list/serialized_fields
+	if(istype(fields, /list))
+		serialized_fields = list()
+		for(var/datum/tgs_chat_embed/field/field as anything in fields)
+			serialized_fields += list(field._interop_serialize())
+	return list(
+		"title" = title,
+		"description" = description,
+		"url" = url,
+		"timestamp" = timestamp,
+		"colour" = colour,
+		"image" = src.image ? src.image._interop_serialize() : null,
+		"thumbnail" = thumbnail ? thumbnail._interop_serialize() : null,
+		"video" = video ? video._interop_serialize() : null,
+		"footer" = footer ? footer._interop_serialize() : null,
+		"provider" = provider ? provider._interop_serialize() : null,
+		"author" = author ? author._interop_serialize() : null,
+		"fields" = serialized_fields
+	)
+
+/datum/tgs_chat_embed/media/_interop_serialize()
+	return list(
+		"url" = url,
+		"width" = width,
+		"height" = height,
+		"proxyUrl" = proxy_url
+	)
+
+/datum/tgs_chat_embed/provider/_interop_serialize()
+	return list(
+		"url" = url,
+		"name" = name
+	)
+
+/datum/tgs_chat_embed/provider/author/_interop_serialize()
+	. = ..()
+	.["iconUrl"] = icon_url
+	.["proxyIconUrl"] = proxy_icon_url
+
+/datum/tgs_chat_embed/footer/_interop_serialize()
+	return list(
+		"text" = text,
+		"iconUrl" = icon_url,
+		"proxyIconUrl" = proxy_icon_url
+	)
+
+/datum/tgs_chat_embed/field/_interop_serialize()
+	return list(
+		"name" = name,
+		"value" = value,
+		"isInline" = is_inline
+	)
diff --git a/code/modules/tgs/v5/topic.dm b/code/modules/tgs/v5/topic.dm
new file mode 100644
index 00000000000..59e5e63e5cd
--- /dev/null
+++ b/code/modules/tgs/v5/topic.dm
@@ -0,0 +1,298 @@
+/datum/tgs_api/v5/proc/TopicResponse(error_message = null)
+	var/list/response = list()
+	if(error_message)
+		response[DMAPI5_RESPONSE_ERROR_MESSAGE] = error_message
+	return response
+
+/datum/tgs_api/v5/proc/ProcessTopicJson(json, check_access_identifier)
+	TGS_DEBUG_LOG("ProcessTopicJson(..., [check_access_identifier])")
+	var/list/result = ProcessRawTopic(json, check_access_identifier)
+	if(!result)
+		result = TopicResponse("Runtime error!")
+	else if(!length(result))
+		return "{}" // quirk of json_encode is an empty list returns "[]"
+
+	var/response_json = json_encode(result)
+	if(length(response_json) > DMAPI5_TOPIC_RESPONSE_LIMIT)
+		// cache response chunks and send the first
+		var/list/chunks = GenerateChunks(response_json, FALSE)
+		var/payload_id = chunks[1][DMAPI5_CHUNK][DMAPI5_CHUNK_PAYLOAD_ID]
+		var/cache_key = ResponseTopicChunkCacheKey(payload_id)
+
+		chunked_topics[cache_key] = chunks
+
+		response_json = json_encode(chunks[1])
+
+	return response_json
+
+/datum/tgs_api/v5/proc/ProcessRawTopic(json, check_access_identifier)
+	TGS_DEBUG_LOG("ProcessRawTopic(..., [check_access_identifier])")
+	var/list/topic_parameters = json_decode(json)
+	if(!topic_parameters)
+		TGS_DEBUG_LOG("ProcessRawTopic: json_decode failed")
+		return TopicResponse("Invalid topic parameters json: [json]!");
+
+	var/their_sCK = topic_parameters[DMAPI5_PARAMETER_ACCESS_IDENTIFIER]
+	if(check_access_identifier && their_sCK != access_identifier)
+		TGS_DEBUG_LOG("ProcessRawTopic: access identifier check failed")
+		return TopicResponse("Failed to decode [DMAPI5_PARAMETER_ACCESS_IDENTIFIER] or it does not match!")
+
+	var/command = topic_parameters[DMAPI5_TOPIC_PARAMETER_COMMAND_TYPE]
+	if(!isnum(command))
+		TGS_DEBUG_LOG("ProcessRawTopic: command type check failed")
+		return TopicResponse("Failed to decode [DMAPI5_TOPIC_PARAMETER_COMMAND_TYPE]!")
+
+	return ProcessTopicCommand(command, topic_parameters)
+
+/datum/tgs_api/v5/proc/ResponseTopicChunkCacheKey(payload_id)
+	return "response[payload_id]"
+
+/datum/tgs_api/v5/proc/ProcessTopicCommand(command, list/topic_parameters)
+	TGS_DEBUG_LOG("ProcessTopicCommand([command], ...)")
+	switch(command)
+
+		if(DMAPI5_TOPIC_COMMAND_CHAT_COMMAND)
+			intercepted_message_queue = list()
+			var/list/result = HandleCustomCommand(topic_parameters[DMAPI5_TOPIC_PARAMETER_CHAT_COMMAND])
+			if(!result)
+				result = TopicResponse("Error running chat command!")
+			result[DMAPI5_TOPIC_RESPONSE_CHAT_RESPONSES] = intercepted_message_queue
+			intercepted_message_queue = null
+			return result
+
+		if(DMAPI5_TOPIC_COMMAND_EVENT_NOTIFICATION)
+			var/list/event_notification = topic_parameters[DMAPI5_TOPIC_PARAMETER_EVENT_NOTIFICATION]
+			if(!istype(event_notification))
+				return TopicResponse("Invalid [DMAPI5_TOPIC_PARAMETER_EVENT_NOTIFICATION]!")
+
+			var/event_type = event_notification[DMAPI5_EVENT_NOTIFICATION_TYPE]
+			if(!isnum(event_type))
+				return TopicResponse("Invalid or missing [DMAPI5_EVENT_NOTIFICATION_TYPE]!")
+
+			var/list/event_parameters = event_notification[DMAPI5_EVENT_NOTIFICATION_PARAMETERS]
+			if(event_parameters && !istype(event_parameters))
+				. = TopicResponse("Invalid or missing [DMAPI5_EVENT_NOTIFICATION_PARAMETERS]!")
+			else
+				var/list/response = TopicResponse()
+				. = response
+				if(event_handler != null)
+					var/list/event_call = list(event_type)
+					if(event_parameters)
+						event_call += event_parameters
+
+					intercepted_message_queue = list()
+					event_handler.HandleEvent(arglist(event_call))
+					response[DMAPI5_TOPIC_RESPONSE_CHAT_RESPONSES] = intercepted_message_queue
+					intercepted_message_queue = null
+
+			if (event_type == TGS_EVENT_WATCHDOG_DETACH)
+				detached = TRUE
+				chat_channels.Cut() // https://github.com/tgstation/tgstation-server/issues/1490
+
+			return
+
+		if(DMAPI5_TOPIC_COMMAND_CHANGE_PORT)
+			var/new_port = topic_parameters[DMAPI5_TOPIC_PARAMETER_NEW_PORT]
+			if (!isnum(new_port) || !(new_port > 0))
+				return TopicResponse("Invalid or missing [DMAPI5_TOPIC_PARAMETER_NEW_PORT]")
+
+			if(event_handler != null)
+				event_handler.HandleEvent(TGS_EVENT_PORT_SWAP, new_port)
+
+			//the topic still completes, miraculously
+			//I honestly didn't believe byond could do it without exploding
+			if(!world.OpenPort(new_port))
+				return TopicResponse("Port change failed!")
+
+			return TopicResponse()
+
+		if(DMAPI5_TOPIC_COMMAND_CHANGE_REBOOT_STATE)
+			var/new_reboot_mode = topic_parameters[DMAPI5_TOPIC_PARAMETER_NEW_REBOOT_STATE]
+			if(!isnum(new_reboot_mode))
+				return TopicResponse("Invalid or missing [DMAPI5_TOPIC_PARAMETER_NEW_REBOOT_STATE]!")
+
+			if(event_handler != null)
+				event_handler.HandleEvent(TGS_EVENT_REBOOT_MODE_CHANGE, reboot_mode, new_reboot_mode)
+
+			reboot_mode = new_reboot_mode
+			return TopicResponse()
+
+		if(DMAPI5_TOPIC_COMMAND_INSTANCE_RENAMED)
+			var/new_instance_name = topic_parameters[DMAPI5_TOPIC_PARAMETER_NEW_INSTANCE_NAME]
+			if(!istext(new_instance_name))
+				return TopicResponse("Invalid or missing [DMAPI5_TOPIC_PARAMETER_NEW_INSTANCE_NAME]!")
+
+			if(event_handler != null)
+				event_handler.HandleEvent(TGS_EVENT_INSTANCE_RENAMED, new_instance_name)
+
+			instance_name = new_instance_name
+			return TopicResponse()
+
+		if(DMAPI5_TOPIC_COMMAND_CHAT_CHANNELS_UPDATE)
+			TGS_DEBUG_LOG("ProcessTopicCommand: It's a chat update")
+			var/list/chat_update_json = topic_parameters[DMAPI5_TOPIC_PARAMETER_CHAT_UPDATE]
+			if(!istype(chat_update_json))
+				TGS_DEBUG_LOG("ProcessTopicCommand: failed \"[DMAPI5_TOPIC_PARAMETER_CHAT_UPDATE]\" check")
+				return TopicResponse("Invalid or missing [DMAPI5_TOPIC_PARAMETER_CHAT_UPDATE]!")
+
+			DecodeChannels(chat_update_json)
+			return TopicResponse()
+
+		if(DMAPI5_TOPIC_COMMAND_SERVER_PORT_UPDATE)
+			var/new_port = topic_parameters[DMAPI5_TOPIC_PARAMETER_NEW_PORT]
+			if (!isnum(new_port) || !(new_port > 0))
+				return TopicResponse("Invalid or missing [DMAPI5_TOPIC_PARAMETER_NEW_PORT]")
+
+			server_port = new_port
+			return TopicResponse()
+
+		if(DMAPI5_TOPIC_COMMAND_HEALTHCHECK)
+			if(event_handler && event_handler.receive_health_checks)
+				event_handler.HandleEvent(TGS_EVENT_HEALTH_CHECK)
+			var/list/health_check_response = TopicResponse()
+			health_check_response[DMAPI5_TOPIC_RESPONSE_CLIENT_COUNT] = TGS_CLIENT_COUNT
+			return health_check_response;
+
+		if(DMAPI5_TOPIC_COMMAND_WATCHDOG_REATTACH)
+			detached = FALSE
+			var/new_port = topic_parameters[DMAPI5_TOPIC_PARAMETER_NEW_PORT]
+			var/error_message = null
+			if (new_port != null)
+				if (!isnum(new_port) || !(new_port > 0))
+					error_message = "Invalid [DMAPI5_TOPIC_PARAMETER_NEW_PORT]"
+				else
+					server_port = new_port
+
+			var/new_version_string = topic_parameters[DMAPI5_TOPIC_PARAMETER_NEW_SERVER_VERSION]
+			if (!istext(new_version_string))
+				if(error_message != null)
+					error_message += ", "
+				error_message += "Invalid or missing [DMAPI5_TOPIC_PARAMETER_NEW_SERVER_VERSION]"
+			else
+				var/datum/tgs_version/new_version = new(new_version_string)
+				if (event_handler)
+					event_handler.HandleEvent(TGS_EVENT_WATCHDOG_REATTACH, new_version)
+
+				version = new_version
+
+			var/list/reattach_response = TopicResponse(error_message)
+			reattach_response[DMAPI5_PARAMETER_CUSTOM_COMMANDS] = ListCustomCommands()
+			reattach_response[DMAPI5_PARAMETER_TOPIC_PORT] = GetTopicPort()
+
+			for(var/eventId in pending_events)
+				pending_events[eventId] = TRUE
+
+			return reattach_response
+
+		if(DMAPI5_TOPIC_COMMAND_SEND_CHUNK)
+			var/list/chunk = topic_parameters[DMAPI5_CHUNK]
+			if(!istype(chunk))
+				return TopicResponse("Invalid [DMAPI5_CHUNK]!")
+
+			var/payload_id = chunk[DMAPI5_CHUNK_PAYLOAD_ID]
+			if(!isnum(payload_id))
+				return TopicResponse("[DMAPI5_CHUNK_PAYLOAD_ID] is not a number!")
+
+			// Always updated the highest known payload ID
+			chunked_requests = max(chunked_requests, payload_id)
+
+			var/sequence_id = chunk[DMAPI5_CHUNK_SEQUENCE_ID]
+			if(!isnum(sequence_id))
+				return TopicResponse("[DMAPI5_CHUNK_SEQUENCE_ID] is not a number!")
+
+			var/total_chunks = chunk[DMAPI5_CHUNK_TOTAL]
+			if(!isnum(total_chunks))
+				return TopicResponse("[DMAPI5_CHUNK_TOTAL] is not a number!")
+
+			if(total_chunks == 0)
+				return TopicResponse("[DMAPI5_CHUNK_TOTAL] is zero!")
+
+			var/payload = chunk[DMAPI5_CHUNK_PAYLOAD]
+			if(!istext(payload))
+				return TopicResponse("[DMAPI5_CHUNK_PAYLOAD] is not text!")
+
+			var/cache_key = "request[payload_id]"
+			var/payloads = chunked_topics[cache_key]
+
+			if(!payloads)
+				payloads = new /list(total_chunks)
+				chunked_topics[cache_key] = payloads
+
+			if(total_chunks != length(payloads))
+				chunked_topics -= cache_key
+				return TopicResponse("Received differing total chunks for same [DMAPI5_CHUNK_PAYLOAD_ID]! Invalidating [DMAPI5_CHUNK_PAYLOAD_ID]!")
+
+			var/pre_existing_chunk = payloads[sequence_id + 1]
+			if(pre_existing_chunk && pre_existing_chunk != payload)
+				chunked_topics -= cache_key
+				return TopicResponse("Received differing payload for same [DMAPI5_CHUNK_SEQUENCE_ID]! Invalidating [DMAPI5_CHUNK_PAYLOAD_ID]!")
+
+			payloads[sequence_id + 1] = payload
+
+			var/list/missing_sequence_ids = list()
+			for(var/i in 1 to total_chunks)
+				if(!payloads[i])
+					missing_sequence_ids += i - 1
+
+			if(length(missing_sequence_ids))
+				return list(DMAPI5_MISSING_CHUNKS = missing_sequence_ids)
+
+			chunked_topics -= cache_key
+			var/full_json = jointext(payloads, "")
+
+			return ProcessRawTopic(full_json, FALSE)
+
+		if(DMAPI5_TOPIC_COMMAND_RECEIVE_CHUNK)
+			var/payload_id = topic_parameters[DMAPI5_CHUNK_PAYLOAD_ID]
+			if(!isnum(payload_id))
+				return TopicResponse("[DMAPI5_CHUNK_PAYLOAD_ID] is not a number!")
+
+			// Always updated the highest known payload ID
+			chunked_requests = max(chunked_requests, payload_id)
+
+			var/list/missing_chunks = topic_parameters[DMAPI5_MISSING_CHUNKS]
+			if(!istype(missing_chunks) || !length(missing_chunks))
+				return TopicResponse("Missing or empty [DMAPI5_MISSING_CHUNKS]!")
+
+			var/sequence_id_to_send = missing_chunks[1]
+			if(!isnum(sequence_id_to_send))
+				return TopicResponse("[DMAPI5_MISSING_CHUNKS] contained a non-number!")
+
+			var/cache_key = ResponseTopicChunkCacheKey(payload_id)
+			var/list/chunks = chunked_topics[cache_key]
+			if(!chunks)
+				return TopicResponse("Unknown response chunk set: P[payload_id]!")
+
+			// sequence IDs in interop chunking are always zero indexed
+			var/chunk_to_send = chunks[sequence_id_to_send + 1]
+			if(!chunk_to_send)
+				return TopicResponse("Sequence ID [sequence_id_to_send] is not present in response chunk P[payload_id]!")
+
+			if(length(missing_chunks) == 1)
+				// sending last chunk, purge the cache
+				chunked_topics -= cache_key
+
+			return chunk_to_send
+
+		if(DMAPI5_TOPIC_COMMAND_RECEIVE_BROADCAST)
+			var/message = topic_parameters[DMAPI5_TOPIC_PARAMETER_BROADCAST_MESSAGE]
+			if (!istext(message))
+				return TopicResponse("Invalid or missing [DMAPI5_TOPIC_PARAMETER_BROADCAST_MESSAGE]")
+
+			TGS_WORLD_ANNOUNCE(message)
+			return TopicResponse()
+
+		if(DMAPI5_TOPIC_COMMAND_COMPLETE_EVENT)
+			var/event_id = topic_parameters[DMAPI5_EVENT_ID]
+			if (!istext(event_id))
+				return TopicResponse("Invalid or missing [DMAPI5_EVENT_ID]")
+
+			TGS_DEBUG_LOG("Completing event ID [event_id]...")
+			pending_events[event_id] = TRUE
+			return TopicResponse()
+
+	return TopicResponse("Unknown command: [command]")
+
+/datum/tgs_api/v5/proc/WorldBroadcast(message)
+	set waitfor = FALSE
+	TGS_WORLD_ANNOUNCE(message)
diff --git a/code/modules/tgs/v5/undefs.dm b/code/modules/tgs/v5/undefs.dm
index 5885a60e75c..acd19dfa641 100644
--- a/code/modules/tgs/v5/undefs.dm
+++ b/code/modules/tgs/v5/undefs.dm
@@ -4,16 +4,29 @@
 #undef DMAPI5_BRIDGE_DATA
 #undef DMAPI5_TOPIC_DATA
 
-#undef DMAPI5_BRIDGE_COMMAND_PORT_UPDATE
+#undef DMAPI5_BRIDGE_REQUEST_LIMIT
+#undef DMAPI5_TOPIC_REQUEST_LIMIT
+#undef DMAPI5_TOPIC_RESPONSE_LIMIT
+
 #undef DMAPI5_BRIDGE_COMMAND_STARTUP
 #undef DMAPI5_BRIDGE_COMMAND_PRIME
 #undef DMAPI5_BRIDGE_COMMAND_REBOOT
 #undef DMAPI5_BRIDGE_COMMAND_KILL
 #undef DMAPI5_BRIDGE_COMMAND_CHAT_SEND
+#undef DMAPI5_BRIDGE_COMMAND_CHUNK
+#undef DMAPI5_BRIDGE_COMMAND_EVENT
 
 #undef DMAPI5_PARAMETER_ACCESS_IDENTIFIER
 #undef DMAPI5_PARAMETER_CUSTOM_COMMANDS
 
+#undef DMAPI5_CHUNK
+#undef DMAPI5_CHUNK_PAYLOAD
+#undef DMAPI5_CHUNK_TOTAL
+#undef DMAPI5_CHUNK_SEQUENCE_ID
+#undef DMAPI5_CHUNK_PAYLOAD_ID
+
+#undef DMAPI5_MISSING_CHUNKS
+
 #undef DMAPI5_RESPONSE_ERROR_MESSAGE
 
 #undef DMAPI5_BRIDGE_PARAMETER_COMMAND_TYPE
@@ -21,11 +34,11 @@
 #undef DMAPI5_BRIDGE_PARAMETER_VERSION
 #undef DMAPI5_BRIDGE_PARAMETER_CHAT_MESSAGE
 #undef DMAPI5_BRIDGE_PARAMETER_MINIMUM_SECURITY_LEVEL
+#undef DMAPI5_BRIDGE_PARAMETER_EVENT_INVOCATION
 
 #undef DMAPI5_BRIDGE_RESPONSE_NEW_PORT
 #undef DMAPI5_BRIDGE_RESPONSE_RUNTIME_INFORMATION
 
-#undef DMAPI5_CHAT_MESSAGE_TEXT
 #undef DMAPI5_CHAT_MESSAGE_CHANNEL_IDS
 
 #undef DMAPI5_RUNTIME_INFORMATION_ACCESS_IDENTIFIER
@@ -36,6 +49,7 @@
 #undef DMAPI5_RUNTIME_INFORMATION_REVISION
 #undef DMAPI5_RUNTIME_INFORMATION_TEST_MERGES
 #undef DMAPI5_RUNTIME_INFORMATION_SECURITY_LEVEL
+#undef DMAPI5_RUNTIME_INFORMATION_VISIBILITY
 
 #undef DMAPI5_CHAT_UPDATE_CHANNELS
 
@@ -63,8 +77,12 @@
 #undef DMAPI5_TOPIC_COMMAND_INSTANCE_RENAMED
 #undef DMAPI5_TOPIC_COMMAND_CHAT_CHANNELS_UPDATE
 #undef DMAPI5_TOPIC_COMMAND_SERVER_PORT_UPDATE
-#undef DMAPI5_TOPIC_COMMAND_HEARTBEAT
+#undef DMAPI5_TOPIC_COMMAND_HEALTHCHECK
 #undef DMAPI5_TOPIC_COMMAND_WATCHDOG_REATTACH
+#undef DMAPI5_TOPIC_COMMAND_SEND_CHUNK
+#undef DMAPI5_TOPIC_COMMAND_RECEIVE_CHUNK
+#undef DMAPI5_TOPIC_COMMAND_RECEIVE_BROADCAST
+#undef DMAPI5_TOPIC_COMMAND_COMPLETE_EVENT
 
 #undef DMAPI5_TOPIC_PARAMETER_COMMAND_TYPE
 #undef DMAPI5_TOPIC_PARAMETER_CHAT_COMMAND
@@ -74,7 +92,10 @@
 #undef DMAPI5_TOPIC_PARAMETER_NEW_INSTANCE_NAME
 #undef DMAPI5_TOPIC_PARAMETER_CHAT_UPDATE
 #undef DMAPI5_TOPIC_PARAMETER_NEW_SERVER_VERSION
+#undef DMAPI5_TOPIC_PARAMETER_BROADCAST_MESSAGE
 
+#undef DMAPI5_TOPIC_RESPONSE_CLIENT_COUNT
+#undef DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE
 #undef DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE_MESSAGE
 #undef DMAPI5_TOPIC_RESPONSE_CHAT_RESPONSES
 
@@ -93,7 +114,14 @@
 #undef DMAPI5_CHAT_CHANNEL_IS_ADMIN_CHANNEL
 #undef DMAPI5_CHAT_CHANNEL_IS_PRIVATE_CHANNEL
 #undef DMAPI5_CHAT_CHANNEL_TAG
+#undef DMAPI5_CHAT_CHANNEL_EMBEDS_SUPPORTED
 
 #undef DMAPI5_CUSTOM_CHAT_COMMAND_NAME
 #undef DMAPI5_CUSTOM_CHAT_COMMAND_HELP_TEXT
 #undef DMAPI5_CUSTOM_CHAT_COMMAND_ADMIN_ONLY
+
+#undef DMAPI5_EVENT_ID
+
+#undef DMAPI5_EVENT_INVOCATION_NAME
+#undef DMAPI5_EVENT_INVOCATION_PARAMETERS
+#undef DMAPI5_EVENT_INVOCATION_NOTIFY_COMPLETION