From 9ccb9bddc4efd91f99c31a5242e860d19f931c86 Mon Sep 17 00:00:00 2001
From: AffectedArc07 <25063394+AffectedArc07@users.noreply.github.com>
Date: Sat, 17 Jun 2023 11:00:01 +0100
Subject: [PATCH] 2-way server heartbeats (plus bonus DMAPI update) (#21101)

* 2-way server heartbeats

* Upgrades people, upgrades

* DMAPI bump again

* How did this compile

* BALLS
---
 code/__DEFINES/tgs.dm                     | 236 ++++++++++++++-----
 code/controllers/subsystem/SSheartbeat.dm |  20 ++
 code/datums/tgs_event_handler.dm          |   3 +
 code/modules/tgs/LICENSE                  |   2 +-
 code/modules/tgs/core/tgs_datum.dm        |   2 +
 code/modules/tgs/includes.dm              |   4 +
 code/modules/tgs/v3210/README.md          |   4 +-
 code/modules/tgs/v4/README.md             |   4 +-
 code/modules/tgs/v4/v4_api.dm             |  25 ++-
 code/modules/tgs/v4/v4_commands.dm        |  11 +-
 code/modules/tgs/v5/README.md             |  13 +-
 code/modules/tgs/v5/_v5_defines.dm        |  20 +-
 code/modules/tgs/v5/v5_api.dm             | 202 ++++-------------
 code/modules/tgs/v5/v5_bridge.dm          |  99 ++++++++
 code/modules/tgs/v5/v5_chunking.dm        |  43 ++++
 code/modules/tgs/v5/v5_commands.dm        |  38 +++-
 code/modules/tgs/v5/v5_interop_version.dm |   2 +-
 code/modules/tgs/v5/v5_serializers.dm     |  59 +++++
 code/modules/tgs/v5/v5_topic.dm           | 261 ++++++++++++++++++++++
 code/modules/tgs/v5/v5_undefs.dm          |  18 +-
 paradise.dme                              |   1 +
 21 files changed, 811 insertions(+), 256 deletions(-)
 create mode 100644 code/controllers/subsystem/SSheartbeat.dm
 create mode 100644 code/modules/tgs/v5/v5_bridge.dm
 create mode 100644 code/modules/tgs/v5/v5_chunking.dm
 create mode 100644 code/modules/tgs/v5/v5_serializers.dm
 create mode 100644 code/modules/tgs/v5/v5_topic.dm

diff --git a/code/__DEFINES/tgs.dm b/code/__DEFINES/tgs.dm
index 83e06658c57..89976c49842 100644
--- a/code/__DEFINES/tgs.dm
+++ b/code/__DEFINES/tgs.dm
@@ -1,6 +1,6 @@
 // tgstation-server DMAPI
 
-#define TGS_DMAPI_VERSION "6.0.6"
+#define TGS_DMAPI_VERSION "6.5.0"
 
 // All functions and datums outside this document are subject to change with any version and should not be relied on.
 
@@ -12,8 +12,8 @@
 // Comment this out once you've filled in the below.
 #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()()
+// 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()().
 //#define TGS_V3_API
 
 // Required interfaces (fill in with your codebase equivalent):
@@ -52,44 +52,46 @@
 
 // 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
+/// 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
+/// 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
+/// 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 +106,12 @@
 #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, byond version.
+#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
 
@@ -158,28 +166,28 @@
 /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
 
 /**
@@ -225,40 +233,49 @@
 	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.
+/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 chat command.
 /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.
  *
  * sender - The [/datum/tgs_chat_user] who issued the command.
  * params - The trimmed string following the command `/datum/tgs_chat_command/var/name].
@@ -266,6 +283,107 @@
 /datum/tgs_chat_command/proc/Run(datum/tgs_chat_user/sender, params)
 	CRASH("[type] has no implementation for Run()")
 
+/// User definable chat message.
+/datum/tgs_message_content
+	/// The tring 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
+
+/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/channel#embed-object-embed-structure 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/channel#embed-object-embed-image-structure for details.
+	var/datum/tgs_chat_embed/media/image
+
+	/// See https://discord.com/developers/docs/resources/channel#embed-object-embed-thumbnail-structure for details.
+	var/datum/tgs_chat_embed/media/thumbnail
+
+	/// See https://discord.com/developers/docs/resources/channel#embed-object-embed-image-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
+
+/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/channel#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
+
+/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/channel#embed-object-embed-provider-structure for details.
+/datum/tgs_chat_embed/provider
+	var/name
+	var/url
+
+/// See https://discord.com/developers/docs/resources/channel#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
+
+/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/channel#embed-object-embed-field-structure for details. Must have name and value set in New().
+/datum/tgs_chat_embed/field
+	var/name
+	var/value
+	var/is_inline
+
+/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 +403,73 @@
 // 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!
  *
- * 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!
  *
- * 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!
  *
- * 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 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 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
 
 /*
 The MIT License
 
-Copyright (c) 2017 Jordan Brown
+Copyright (c) 2017-2023 Jordan Brown
 
 Permission is hereby granted, free of charge,
 to any person obtaining a copy of this software and
diff --git a/code/controllers/subsystem/SSheartbeat.dm b/code/controllers/subsystem/SSheartbeat.dm
new file mode 100644
index 00000000000..83a2aa6419a
--- /dev/null
+++ b/code/controllers/subsystem/SSheartbeat.dm
@@ -0,0 +1,20 @@
+SUBSYSTEM_DEF(heartbeat)
+	name = "Heartbeat"
+	flags = SS_KEEP_TIMING
+	wait = 30 SECONDS
+	runlevels = RUNLEVEL_INIT | RUNLEVEL_LOBBY | RUNLEVEL_SETUP | RUNLEVEL_GAME | RUNLEVEL_POSTGAME // ALL THE THINGS
+	/// Last time we got a heartbeat from TGS
+	var/last_heartbeat = 0
+	/// Has a warning been sent this round?
+	var/warning_tripped = FALSE
+
+/datum/controller/subsystem/heartbeat/Initialize()
+	// Disable if we arent running on TGS
+	if(!world.TgsAvailable())
+		flags |= SS_NO_FIRE
+
+/datum/controller/subsystem/heartbeat/fire(resumed)
+	// If the last heartbeat is 0, we never got one this round
+	if(last_heartbeat != 0 && (last_heartbeat + 2 MINUTES < REALTIMEOFDAY) && !warning_tripped)
+		to_chat(GLOB.admins, "<hr><center><span class='userdanger'><big>--- CRITICAL ---</big></span><br>The server hasn't received an uptime check from the server daemon for over 2 minutes. Inform AA ASAP.</center><hr>")
+		warning_tripped = TRUE
diff --git a/code/datums/tgs_event_handler.dm b/code/datums/tgs_event_handler.dm
index 584c932c951..0918a8ba9f2 100644
--- a/code/datums/tgs_event_handler.dm
+++ b/code/datums/tgs_event_handler.dm
@@ -10,6 +10,7 @@ GLOBAL_VAR_INIT(slower_restart, FALSE)
 /datum/tgs_event_handler/impl
 	var/datum/timedevent/reattach_timer
 
+	receive_health_checks = TRUE
 
 /datum/tgs_event_handler/impl/HandleEvent(event_code, ...)
 	switch(event_code)
@@ -48,6 +49,8 @@ GLOBAL_VAR_INIT(slower_restart, FALSE)
 			if(reattach_timer)
 				deltimer(reattach_timer)
 				reattach_timer = null
+		if(TGS_EVENT_HEALTH_CHECK)
+			SSheartbeat.last_heartbeat = REALTIMEOFDAY
 
 /datum/tgs_event_handler/impl/proc/LateOnReattach()
 	server_announce_adminonly("\[Warning] TGS hasn't notified us of it coming back for a full minute! Is there a problem?")
diff --git a/code/modules/tgs/LICENSE b/code/modules/tgs/LICENSE
index 221f9e1deb2..2bedf9a63aa 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) 2017-2023 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/core/tgs_datum.dm b/code/modules/tgs/core/tgs_datum.dm
index 4d37ed662d1..68b0330fe86 100644
--- a/code/modules/tgs/core/tgs_datum.dm
+++ b/code/modules/tgs/core/tgs_datum.dm
@@ -4,6 +4,8 @@ TGS_DEFINE_AND_SET_GLOBAL(tgs, null)
 	var/datum/tgs_version/version
 	var/datum/tgs_event_handler/event_handler
 
+	var/list/warned_deprecated_command_runs
+
 /datum/tgs_api/New(datum/tgs_event_handler/event_handler, datum/tgs_version/version)
 	. = ..()
 	src.event_handler = event_handler
diff --git a/code/modules/tgs/includes.dm b/code/modules/tgs/includes.dm
index 70f10c7ff76..29ee5886ac2 100644
--- a/code/modules/tgs/includes.dm
+++ b/code/modules/tgs/includes.dm
@@ -13,5 +13,9 @@
 
 #include "v5\_v5_defines.dm"
 #include "v5\v5_api.dm"
+#include "v5\v5_bridge.dm"
+#include "v5\v5_chunking.dm"
 #include "v5\v5_commands.dm"
+#include "v5\v5_serializers.dm"
+#include "v5\v5_topic.dm"
 #include "v5\v5_undefs.dm"
diff --git a/code/modules/tgs/v3210/README.md b/code/modules/tgs/v3210/README.md
index f96e7cf3b31..01ef44767ad 100644
--- a/code/modules/tgs/v3210/README.md
+++ b/code/modules/tgs/v3210/README.md
@@ -2,5 +2,5 @@
 
 This DMAPI implements bridge using file output which TGS monitors for.
 
-- [api.dm](./api.dm) contains the bulk of the API code.
-- [commands.dm](./commands.dm) contains functions relating to `/datum/tgs_chat_command`s.
+- [api.dm](./v3_api.dm) contains the bulk of the API code.
+- [commands.dm](./v3_commands.dm) contains functions relating to `/datum/tgs_chat_command`s.
diff --git a/code/modules/tgs/v4/README.md b/code/modules/tgs/v4/README.md
index 78191447b27..c14d7d38872 100644
--- a/code/modules/tgs/v4/README.md
+++ b/code/modules/tgs/v4/README.md
@@ -2,5 +2,5 @@
 
 This DMAPI implements bridge requests using file output which TGS monitors for. It has a safe mode restriction.
 
-- [api.dm](./api.dm) contains the bulk of the API code.
-- [commands.dm](./commands.dm) contains functions relating to `/datum/tgs_chat_command`s.
+- [api.dm](./v4_api.dm) contains the bulk of the API code.
+- [commands.dm](./v4_commands.dm) contains functions relating to `/datum/tgs_chat_command`s.
diff --git a/code/modules/tgs/v4/v4_api.dm b/code/modules/tgs/v4/v4_api.dm
index 0e37a7aa24c..b9a75c4abb4 100644
--- a/code/modules/tgs/v4/v4_api.dm
+++ b/code/modules/tgs/v4/v4_api.dm
@@ -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/v4_commands.dm b/code/modules/tgs/v4/v4_commands.dm
index 4ca1500167b..d6d3d718d47 100644
--- a/code/modules/tgs/v4/v4_commands.dm
+++ b/code/modules/tgs/v4/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?.text
 	return "Unknown command: [command]!"
diff --git a/code/modules/tgs/v5/README.md b/code/modules/tgs/v5/README.md
index 5b48d57a1f0..dd8da3bea43 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.
 
-- [_defines.dm](./_defines.dm) contains constant definitions.
-- [api.dm](./api.dm) contains the bulk of the API code.
-- [commands.dm](./commands.dm) contains functions relating to `/datum/tgs_chat_command`s.
-- [undefs.dm](./undefs.dm) Undoes the work of `_defines.dm`.
+- [v5_interop_version.dm](./v5_interop_version.dm) contains the version of the API used between the DMAPI and TGS.
+- [_v5_defines.dm](./_v5_defines.dm) contains constant definitions.
+- [v5_api.dm](./v5_api.dm) contains the bulk of the API code.
+- [v5_bridge.dm](./v5_bridge.dm) contains functions related to making bridge requests.
+- [v5_chunking.dm](./v5_chunking.dm) contains common function for splitting large raw data sets into chunks BYOND can natively process.
+- [v5_commands.dm](./v5_commands.dm) contains functions relating to `/datum/tgs_chat_command`s.
+- [v5_serializers.dm](./v5_serializers.dm) contains function to help convert interop `/datum`s into a JSON encodable `list()` format.
+- [v5_topic.dm](./v5_topic.dm) contains functions related to processing topic requests.
+- [v5_undefs.dm](./v5_undefs.dm) Undoes the work of `_v5_defines.dm`.
diff --git a/code/modules/tgs/v5/_v5_defines.dm b/code/modules/tgs/v5/_v5_defines.dm
index 10bc4cbe406..c7213cc2469 100644
--- a/code/modules/tgs/v5/_v5_defines.dm
+++ b/code/modules/tgs/v5/_v5_defines.dm
@@ -4,16 +4,29 @@
 #define DMAPI5_BRIDGE_DATA "data"
 #define DMAPI5_TOPIC_DATA "tgs_data"
 
+#define DMAPI5_BRIDGE_REQUEST_LIMIT 8198
+#define DMAPI5_TOPIC_REQUEST_LIMIT 65529
+#define DMAPI5_TOPIC_RESPONSE_LIMIT 65528
+
 #define DMAPI5_BRIDGE_COMMAND_PORT_UPDATE 0
 #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_PARAMETER_ACCESS_IDENTIFIER "accessIdentifier"
 #define DMAPI5_PARAMETER_CUSTOM_COMMANDS "customCommands"
 
+#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"
 
 #define DMAPI5_BRIDGE_PARAMETER_COMMAND_TYPE "commandType"
@@ -25,7 +38,6 @@
 #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"
@@ -63,8 +75,10 @@
 #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_PARAMETER_COMMAND_TYPE "commandType"
 #define DMAPI5_TOPIC_PARAMETER_CHAT_COMMAND "chatCommand"
@@ -75,6 +89,7 @@
 #define DMAPI5_TOPIC_PARAMETER_CHAT_UPDATE "chatUpdate"
 #define DMAPI5_TOPIC_PARAMETER_NEW_SERVER_VERSION "newServerVersion"
 
+#define DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE "commandResponse"
 #define DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE_MESSAGE "commandResponseMessage"
 #define DMAPI5_TOPIC_RESPONSE_CHAT_RESPONSES "chatResponses"
 
@@ -93,6 +108,7 @@
 #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"
diff --git a/code/modules/tgs/v5/v5_api.dm b/code/modules/tgs/v5/v5_api.dm
index 9e040d22754..60f1c00bdaf 100644
--- a/code/modules/tgs/v5/v5_api.dm
+++ b/code/modules/tgs/v5/v5_api.dm
@@ -17,6 +17,11 @@
 
 	var/initialized = FALSE
 
+	var/chunked_requests = 0
+	var/list/chunked_topics = list()
+
+	var/detached = FALSE
+
 /datum/tgs_api/v5/ApiVersion()
 	return new /datum/tgs_version(
 		#include "v5_interop_version.dm"
@@ -97,172 +102,18 @@
 /datum/tgs_api/v5/OnInitializationComplete()
 	Bridge(DMAPI5_BRIDGE_COMMAND_PRIME)
 
-/datum/tgs_api/v5/proc/TopicResponse(error_message = null)
-	var/list/response = list()
-	response[DMAPI5_RESPONSE_ERROR_MESSAGE] = error_message
-
-	return json_encode(response)
-
 /datum/tgs_api/v5/OnTopic(T)
+	RequireInitialBridgeResponse()
 	var/list/params = params2list(T)
 	var/json = params[DMAPI5_TOPIC_DATA]
 	if(!json)
 		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 +148,15 @@
 	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/message, list/channels)
 	if(!length(channels))
 		channels = ChatChannelInfo()
 
@@ -306,26 +165,41 @@
 		var/datum/tgs_chat_channel/channel = I
 		ids += channel.id
 
-	message = list(DMAPI5_CHAT_MESSAGE_TEXT = message, DMAPI5_CHAT_MESSAGE_CHANNEL_IDS = ids)
+	message = UpgradeDeprecatedChatMessage(message)
+
+	if (!length(channels))
+		return
+
+	message = message._interop_serialize()
+	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))
 
-/datum/tgs_api/v5/ChatTargetedBroadcast(message, admin_only)
+/datum/tgs_api/v5/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(DMAPI5_CHAT_MESSAGE_TEXT = message, DMAPI5_CHAT_MESSAGE_CHANNEL_IDS = channels)
+
+	message = UpgradeDeprecatedChatMessage(message)
+
+	if (!length(channels))
+		return
+
+	message = message._interop_serialize()
+	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))
+/datum/tgs_api/v5/ChatPrivateMessage(datum/tgs_message_content/message, datum/tgs_chat_user/user)
+	message = UpgradeDeprecatedChatMessage(message)
+	message = message._interop_serialize()
+	message[DMAPI5_CHAT_MESSAGE_CHANNEL_IDS] = list(user.channel.id)
 	if(intercepted_message_queue)
 		intercepted_message_queue += list(message)
 	else
@@ -333,6 +207,7 @@
 
 /datum/tgs_api/v5/ChatChannelInfo()
 	RequireInitialBridgeResponse()
+	WaitForReattach(TRUE)
 	return chat_channels.Copy()
 
 /datum/tgs_api/v5/proc/DecodeChannels(chat_update_json)
@@ -354,6 +229,7 @@
 	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()
diff --git a/code/modules/tgs/v5/v5_bridge.dm b/code/modules/tgs/v5/v5_bridge.dm
new file mode 100644
index 00000000000..37f58bcdf63
--- /dev/null
+++ b/code/modules/tgs/v5/v5_bridge.dm
@@ -0,0 +1,99 @@
+/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/url = "http://127.0.0.1:[server_port]/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(1)
+			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)
+
+	// This is an infinite sleep until we get a response
+	var/export_response = world.Export(bridge_request)
+	if(!export_response)
+		TGS_ERROR_LOG("Failed bridge request: [bridge_request]")
+		return
+
+	var/response_json = file2text(export_response["CONTENT"])
+	if(!response_json)
+		TGS_ERROR_LOG("Failed bridge request, missing content!")
+		return
+
+	var/list/bridge_response = json_decode(response_json)
+	if(!bridge_response)
+		TGS_ERROR_LOG("Failed bridge request, bad json: [response_json]")
+		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/v5_chunking.dm b/code/modules/tgs/v5/v5_chunking.dm
new file mode 100644
index 00000000000..cd5944d34fb
--- /dev/null
+++ b/code/modules/tgs/v5/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/v5_commands.dm b/code/modules/tgs/v5/v5_commands.dm
index 6d31dd3422d..c8f538db593 100644
--- a/code/modules/tgs/v5/v5_commands.dm
+++ b/code/modules/tgs/v5/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?.text
+		topic_response[DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE] = response?._interop_serialize()
+		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/v5_interop_version.dm b/code/modules/tgs/v5/v5_interop_version.dm
index c7bf62ecae3..5d3d491a736 100644
--- a/code/modules/tgs/v5/v5_interop_version.dm
+++ b/code/modules/tgs/v5/v5_interop_version.dm
@@ -1 +1 @@
-"5.3.0"
+"5.6.1"
diff --git a/code/modules/tgs/v5/v5_serializers.dm b/code/modules/tgs/v5/v5_serializers.dm
new file mode 100644
index 00000000000..3a6fbe6be34
--- /dev/null
+++ b/code/modules/tgs/v5/v5_serializers.dm
@@ -0,0 +1,59 @@
+/datum/tgs_message_content/proc/_interop_serialize()
+	return list("text" = text, "embed" = embed?._interop_serialize())
+
+/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(islist(fields))
+		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" = image?._interop_serialize(),
+		"thumbnail" = thumbnail?._interop_serialize(),
+		"video" = video?._interop_serialize(),
+		"footer" = footer?._interop_serialize(),
+		"provider" = provider?._interop_serialize(),
+		"author" = author?._interop_serialize(),
+		"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/v5_topic.dm b/code/modules/tgs/v5/v5_topic.dm
new file mode 100644
index 00000000000..56c1824fd97
--- /dev/null
+++ b/code/modules/tgs/v5/v5_topic.dm
@@ -0,0 +1,261 @@
+/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)
+	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)
+	var/list/topic_parameters = json_decode(json)
+	if(!topic_parameters)
+		return TopicResponse("Invalid topic parameters json: [json]!");
+
+	var/their_sCK = topic_parameters[DMAPI5_PARAMETER_ACCESS_IDENTIFIER]
+	if(check_access_identifier && their_sCK != access_identifier)
+		return TopicResponse("Failed to decode [DMAPI5_PARAMETER_ACCESS_IDENTIFIER]!")
+
+	var/command = topic_parameters[DMAPI5_TOPIC_PARAMETER_COMMAND_TYPE]
+	if(!isnum(command))
+		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)
+	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)
+			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_type == TGS_EVENT_WATCHDOG_DETACH)
+				detached = TRUE
+				chat_channels.Cut() // https://github.com/tgstation/tgstation-server/issues/1490
+
+			if(event_parameters)
+				event_call += event_parameters
+
+			if(event_handler != null)
+				event_handler.HandleEvent(arglist(event_call))
+
+			var/list/response = TopicResponse()
+			response[DMAPI5_TOPIC_RESPONSE_CHAT_RESPONSES] = intercepted_message_queue
+			intercepted_message_queue = null
+			return 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_HEALTHCHECK)
+			if(event_handler?.receive_health_checks)
+				event_handler.HandleEvent(TGS_EVENT_HEALTH_CHECK)
+			return TopicResponse()
+
+		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()
+			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
+
+	return TopicResponse("Unknown command: [command]")
diff --git a/code/modules/tgs/v5/v5_undefs.dm b/code/modules/tgs/v5/v5_undefs.dm
index 5885a60e75c..c679737dfc4 100644
--- a/code/modules/tgs/v5/v5_undefs.dm
+++ b/code/modules/tgs/v5/v5_undefs.dm
@@ -4,16 +4,29 @@
 #undef DMAPI5_BRIDGE_DATA
 #undef DMAPI5_TOPIC_DATA
 
+#undef DMAPI5_BRIDGE_REQUEST_LIMIT
+#undef DMAPI5_TOPIC_REQUEST_LIMIT
+#undef DMAPI5_TOPIC_RESPONSE_LIMIT
+
 #undef DMAPI5_BRIDGE_COMMAND_PORT_UPDATE
 #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_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
@@ -25,7 +38,6 @@
 #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
@@ -63,7 +75,7 @@
 #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_PARAMETER_COMMAND_TYPE
@@ -75,6 +87,7 @@
 #undef DMAPI5_TOPIC_PARAMETER_CHAT_UPDATE
 #undef DMAPI5_TOPIC_PARAMETER_NEW_SERVER_VERSION
 
+#undef DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE
 #undef DMAPI5_TOPIC_RESPONSE_COMMAND_RESPONSE_MESSAGE
 #undef DMAPI5_TOPIC_RESPONSE_CHAT_RESPONSES
 
@@ -93,6 +106,7 @@
 #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
diff --git a/paradise.dme b/paradise.dme
index 5d6210011b7..f71ab7dac2b 100644
--- a/paradise.dme
+++ b/paradise.dme
@@ -251,6 +251,7 @@
 #include "code\controllers\subsystem\SSfires.dm"
 #include "code\controllers\subsystem\SSgarbage.dm"
 #include "code\controllers\subsystem\SSghost_spawns.dm"
+#include "code\controllers\subsystem\SSheartbeat.dm"
 #include "code\controllers\subsystem\SShttp.dm"
 #include "code\controllers\subsystem\SSicon_smooth.dm"
 #include "code\controllers\subsystem\SSidlenpcpool.dm"