Client hooks
Every hook Sunrise installs in the game client, what it does, and what retires it.
A client hook is a change Sunrise makes to the game’s code at run time. Sunrise keeps these to a minimum. The tables below list every hook Sunrise installs. They follow the install calls in the code. A hook that is never installed is not listed.
The rule
A hook may do four things: redirect traffic, serve the Sunrise tools and menu, draw, or log.
A hook that changes game behavior is a stand-in for server behavior not yet understood. The live game needed no such hook, so a correct server needs none. When the server behavior lands, the hook is deleted in the same change.
The Activity Host never reads the client to make up events or state. It works only from the activity messages.
Every hook finds its target by byte pattern, export name or a probe object, never by a fixed address. It fails cleanly when the target is missing. Every hook except the egress guard can detach.
These behaviors come from the server. No hook is needed for them:
behavior
how the server delivers it
hold the spawn until the fade
the message 5 roster holds the client’s own spawn gate
fix the solo fireteam check
the matchmaking config carries the fireteam threshold
skip the profile setup screens
the account object publishes a completion marker
drop an empty queue update
the subscribe answer carries the family snapshot
force the join state
the host waits for the client’s join
Install order
Hooks use Microsoft Detours (src/client/hooking/detour.cpp). A group attaches in one transaction: all or none.
when
where
what
DLL load, Steam init
src/dllmain.cpp, src/steam/runtime/steam_lifecycle.cpp
egress guard, package trust, boot textures
Steam networking loads
src/client/runtime/client_platform_hook_activation.cpp
two Steam networking hooks
first frame
src/client/runtime/client_hook_activation.cpp
DXGI, cursor, keys
game image scanned
src/client/runtime/client_hook_activation.cpp
network group, all game hooks; noclip and infinite ammo only when client.cheats is on
Studio link starts
src/client/diagnostics/studio/
pose and CUI observers, only when core.studio_attach is on
on a trigger
src/client/hooks/retail_log/, src/steam/runtime/callbacks/callback_dispatch.cpp
two data fixes, one feature flag
In the tables below, “detour” hooks a function found by byte pattern or through a probe object, “export” hooks a Windows export by name, and “data” writes a game value that is restored on detach. A number is how many hooks.
Transport
hook
what it does
kind
egress guard
sockets and DNS: blocks outbound traffic, sends connects to Sunrise, answers the discovery query
export (31)
HTTP executor
answers HTTP in process; unserved requests get 503
detour
transport kind
uses direct sockets instead of the Steam relay
detour
Steam certificate
reports a local certificate as valid; in steamnetworkingsockets.dll
detour (2)
content config
answers the content manifest request; skips its signature check
detour (2), data
config URL and token
supply the values the content fetch asks for
detour (2)
external server
external-server mode only: turns off TLS peer checks and points every request URL at that server
detour
The egress guard never detaches. The certificate and manifest hooks stay until Sunrise can sign these itself.
Tools and menu
Most of these attach at start, so a tool can be turned on without a restart. The noclip step and the ammo setters attach only when client.cheats is on at startup.
hook
what it does
kind
game windows
take mouse and keys while the menu is open
window subclass (2)
SetCursorPos, ClipCursor
free the pointer while the menu is open
export (2)
GetKeyState, GetAsyncKeyState
hide keys from the game; hold the teleport key
export (2)
camera and physics sync
teleport; also ticks fly, sword skate and the Sunrise Studio link
detour (2)
physics step
noclip and fly
detour
ammo setters
infinite ammo
detour (3)
inactivity timeouts
anti-AFK
data
placed-object create, destroy
feed the world-object browser and the Studio link; read only
detour (7)
skinned pose producer
copies finished bone palettes for the Studio link; read only; only with core.studio_attach
detour
UI frame
copies the open CUI screens for the Studio link; read only; only with core.studio_attach
detour
mission launcher
starts an activity through the game’s own entry points
call
Rendering
hook
what it does
kind
Present, ResizeBuffers, SetFullscreenState
draw the menu on the game’s swap chain, only when the menu is on
detour (3)
boot texture dispatcher
swap a few boot-screen textures for ones built into Sunrise
detour
Hooks that change game behavior
hook
what it does
kind
retired by
bubble authority
lets message 5 set authority on every bubble
detour (2)
nothing yet; no server field reaches the gate
package trust
loads installed packages the trust check refuses
detour, patch (2)
unknown; the refusal is not understood
mod package path
opens the package files a mod serves from the Sunrise folder: the path builder and the file opener; attached only when a mod serves a file
detour (2)
nothing; the game only opens packages from packages (Mods)
async I/O guard
stops a native reload from racing a teardown
patch
a fix for the native race
lore books
clears display gates on lore books; on by default
data
a data fix for the gates
Arrivals leg mods
moves four leg mods into the leg plug set; off by default
data
removal; the retail game has the same gap
ownerless channel
sets one client feature flag; off by default
call
server behavior that keeps the channel owned
Diagnostics
These only read and log, with two exceptions: the assert handler, and the retail log’s verbosity setting.
hook
what it logs
kind
retail log
the game’s own log, into the Sunrise log; with the client channel at debug, it also sets the game’s 26 log categories to full verbosity every 2 seconds
detour
assert handler
the assert; the game keeps running unless the device was lost
handler swap
hitch watchdog
the watchdog snapshot and the stuck thread’s stack
detour
stall watcher
every thread’s stack when the frame pump stops
thread
cinematic readiness
the readiness stages of boot cinematics
detour (16)
lifetime gate
the spawn gate inputs and each message 5 roster apply
detour (2)
network tick
one byte of the network guard, each frame
call
entity create, purge, policy
entity ids and purge masks; 3 of the 7 object hooks above
detour