diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,17 @@
 and this project adheres to the
 [Haskell Package Versioning Policy](https://pvp.haskell.org/).
 
+## 0.1.2.0 - 2025-11-01
+
+- Fixed byte order in IsLabel Color instance.
+- Move library dependencies under a flag.
+  The package takes extra effort to remove traces of itself unless enabled.
+- Added a safety net around zones.
+  Controlled with flags: zones_pedantic (disable to silently skip) and zones_unsafe (enable to remove the check).
+- Added `withSrcLoc` which avoids CPP.
+- Renamed `withSrcLoc_` to `withSrcLocImpl`, don't use.
+- `Added System.Tracy.Memory` wrappers (sans the callback variants).
+
 ## 0.1.1.0 - 2025-10-30
 
 - Fixes for copypasta in `#ifndef TRACE_ENABLE` sections.
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -9,13 +9,25 @@
 You can install the prebuilt package from your distribution if it has one:
 
 ```sh
-sudo apt install libtracy-dev tracy-capture
+sudo apt install libtracy-dev tracy-capture tracy-profiler
 ```
 
 Or you can [download] and build one yourself and point your project to it:
 
 [download]: https://github.com/wolfpld/tracy/
 
+```sh
+mkdir -p upstream
+cd upstream && git clone --recursive https://github.com/wolfpld/tracy
+cmake -B upstream/tracy/build -S upstream/tracy \
+  -DCMAKE_POSITION_INDEPENDENT_CODE=ON \
+  -DTRACY_ONLY_LOCALHOST=ON \
+  -DTRACY_ENABLE=ON \
+  -DTRACY_MANUAL_LIFETIME=ON \
+  -DTRACY_DELAYED_INIT=ON
+cmake --build upstream/tracy/build --config Release
+```
+
 ```yaml
 extra-lib-dirs:
 - upstream/tracy/build
@@ -26,7 +38,7 @@
 This way you can customize configuration.
 Make sure you update package flags to match.
 
-Either way, you have to ensure that `tracy-capture` is built with the same version.
+Either way, you have to ensure that `tracy-capture`/`tracy-profiler` is built with the same version.
 Otherwise it will connect and immediately refuse to record anything.
 
 ### Flags
@@ -64,11 +76,12 @@
 main :: IO ()
 main = Tracy.withProfiler $ do
   Tracy.waitConnected_       -- wait for the tracy-capture to connect
-  Tracy.messageL "hi there"# -- static strings require no copying to be logged
-  mapM_ runFrame [0..600]
+  Tracy.withSrcLoc "main.nowhereInParticular" #f0fa do
+    Tracy.messageL "hi there"# -- static strings require no copying to be logged
+    mapM_ runFrame [0..600]
 
 runFrame :: Int -> IO ()
-runFrame ix = Tracy.withSrcLoc_ __LINE__ __FILE__ "runFrame" #fcc do
+runFrame ix = Tracy.withSrcLoc "runFrame" #fcc do
   Tracy.frameMark_
   let factorial = product [1 .. toInteger ix]
   let !digits = length (show factorial)
diff --git a/src/System/Tracy.hs b/src/System/Tracy.hs
--- a/src/System/Tracy.hs
+++ b/src/System/Tracy.hs
@@ -10,7 +10,7 @@
   , setThreadName
   , appInfo
 
-  , Zone.withSrcLoc_
+  , Zone.withSrcLoc
 
   , frameMark
   , frameMark_
diff --git a/src/System/Tracy/FFI.hs b/src/System/Tracy/FFI.hs
--- a/src/System/Tracy/FFI.hs
+++ b/src/System/Tracy/FFI.hs
@@ -153,16 +153,65 @@
 
 ----------------------------------------------------------------
 
-{-
-TRACY_API void ___tracy_emit_memory_alloc( const void* ptr, size_t size, int secure );
-TRACY_API void ___tracy_emit_memory_alloc_callstack( const void* ptr, size_t size, int depth, int secure );
-TRACY_API void ___tracy_emit_memory_free( const void* ptr, int secure );
-TRACY_API void ___tracy_emit_memory_free_callstack( const void* ptr, int depth, int secure );
-TRACY_API void ___tracy_emit_memory_alloc_named( const void* ptr, size_t size, int secure, const char* name );
-TRACY_API void ___tracy_emit_memory_alloc_callstack_named( const void* ptr, size_t size, int depth, int secure, const char* name );
-TRACY_API void ___tracy_emit_memory_free_named( const void* ptr, int secure, const char* name );
-TRACY_API void ___tracy_emit_memory_free_callstack_named( const void* ptr, int depth, int secure, const char* name );
--}
+foreign import ccall unsafe "___tracy_emit_memory_alloc"
+  emitMemoryAlloc
+    :: ConstPtr () -- ^ ptr
+    -> CSize       -- ^ size
+    -> CInt        -- ^ secure
+    -> IO ()
+
+foreign import ccall unsafe "___tracy_emit_memory_alloc_callstack"
+  emitMemoryAllocCallstack
+    :: ConstPtr () -- ^ ptr
+    -> CSize       -- ^ size
+    -> CInt        -- ^ depth
+    -> CInt        -- ^ secure
+    -> IO ()
+
+foreign import ccall unsafe "___tracy_emit_memory_free"
+  emitMemoryFree
+    :: ConstPtr () -- ^ ptr
+    -> CInt        -- ^ secure
+    -> IO ()
+
+foreign import ccall unsafe "___tracy_emit_memory_free_callstack"
+  emitMemoryFreeCallstack
+    :: ConstPtr () -- ^ ptr
+    -> CInt        -- ^ depth
+    -> CInt        -- ^ secure
+    -> IO ()
+
+foreign import ccall unsafe "___tracy_emit_memory_alloc_named"
+  emitMemoryAllocNamed
+    :: ConstPtr ()    -- ^ ptr
+    -> CSize          -- ^ size
+    -> CInt           -- ^ secure
+    -> ConstPtr CChar -- ^ name
+    -> IO ()
+
+foreign import ccall unsafe "___tracy_emit_memory_alloc_callstack_named"
+  emitMemoryAllocCallstackNamed
+    :: ConstPtr ()    -- ^ ptr
+    -> CSize          -- ^ size
+    -> CInt           -- ^ depth
+    -> CInt           -- ^ secure
+    -> ConstPtr CChar -- ^ name
+    -> IO ()
+
+foreign import ccall unsafe "___tracy_emit_memory_free_named"
+  emitMemoryFreeNamed
+    :: ConstPtr ()    -- ^ ptr
+    -> CInt           -- ^ secure
+    -> ConstPtr CChar -- ^ name
+    -> IO ()
+
+foreign import ccall unsafe "___tracy_emit_memory_free_callstack_named"
+  emitMemoryFreeCallstackNamed
+    :: ConstPtr ()    -- ^ ptr
+    -> CInt           -- ^ depth
+    -> CInt           -- ^ secure
+    -> ConstPtr CChar -- ^ name
+    -> IO ()
 
 ----------------------------------------------------------------
 
diff --git a/src/System/Tracy/FFI/Types.hsc b/src/System/Tracy/FFI/Types.hsc
--- a/src/System/Tracy/FFI/Types.hsc
+++ b/src/System/Tracy/FFI/Types.hsc
@@ -10,6 +10,11 @@
 #define TRACY_ENABLE
 #include <tracy/TracyC.h>
 
+{- | Packed 32-bit color
+
+Hex literals can be used as @0xRRGGBB@.
+Alternatively, "webcolors" notation is supported via labels: @#rgb@, @#rrggbb@, even some @#red@.
+-}
 newtype Color = Color Word32
   deriving (Show)
   deriving newtype (Eq, Ord, Storable, Num)
@@ -18,9 +23,9 @@
   fromLabel = webColorAlpha @s \r g b a ->
     Color $
       shiftL (fromIntegral a) 24 .|.
-      shiftL (fromIntegral b) 16 .|.
+      shiftL (fromIntegral r) 16 .|.
       shiftL (fromIntegral g)  8 .|.
-      fromIntegral r
+      fromIntegral b
 
 newtype SrcLoc = SrcLoc Word64
   deriving (Show)
@@ -31,7 +36,7 @@
   , function :: Ptr CChar
   , file     :: Ptr CChar
   , line     :: Word32
-  , color    :: Word32
+  , color    :: Color
   }
 
 instance Storable SourceLocationData where
diff --git a/src/System/Tracy/Memory.hs b/src/System/Tracy/Memory.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Tracy/Memory.hs
@@ -0,0 +1,84 @@
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE MagicHash #-}
+
+{-| Tracing memory allocations
+
+https://github.com/wolfpld/tracy/blob/master/manual/tracy.md#memory-profiling-memoryprofiling
+-}
+
+module System.Tracy.Memory
+  ( -- * Generic allocation tracing
+    alloc
+  , free
+    -- * Memory pools
+  , allocNamed
+  , freeNamed
+  ) where
+
+import Control.Monad.IO.Class (MonadIO(..))
+import Foreign.Ptr (Ptr)
+import GHC.Exts (Addr#)
+
+#ifdef TRACY_ENABLE
+import GHC.Exts (Ptr(..))
+import Foreign.Ptr (castPtr)
+import Foreign.C.ConstPtr (ConstPtr(..))
+
+import System.Tracy.FFI qualified as FFI
+#endif
+
+{-# INLINE alloc #-}
+alloc
+  :: MonadIO m
+  => Bool  -- ^ secure
+  -> Ptr a -- ^ address to register
+  -> Int   -- ^ size
+  -> m ()
+#ifdef TRACY_ENABLE
+alloc secure ptr size =
+  liftIO $ FFI.emitMemoryAlloc (ConstPtr $ castPtr ptr) (fromIntegral size) (fromIntegral $ fromEnum secure)
+#else
+alloc _secure _ptr _size = pure ()
+#endif
+
+{-# INLINE free #-}
+free
+  :: MonadIO m
+  => Bool  -- ^ secure
+  -> Ptr a -- ^ address that was registered
+  -> m ()
+#ifdef TRACY_ENABLE
+free secure ptr =
+  liftIO $ FFI.emitMemoryFree (ConstPtr $ castPtr ptr) (fromIntegral $ fromEnum secure)
+#else
+free _secure _ptr = pure ()
+#endif
+
+{-# INLINE allocNamed #-}
+allocNamed
+  :: MonadIO m
+  => Bool  -- ^ secure
+  -> Ptr a -- ^ address to register
+  -> Int   -- ^ size
+  -> Addr# -- ^ memory pool name
+  -> m ()
+#ifdef TRACY_ENABLE
+allocNamed secure ptr size name =
+  liftIO $ FFI.emitMemoryAllocNamed (ConstPtr $ castPtr ptr) (fromIntegral size) (fromIntegral $ fromEnum secure) (ConstPtr $ Ptr name)
+#else
+allocNamed _secure _ptr _size _name = pure ()
+#endif
+
+{-# INLINE freeNamed #-}
+freeNamed
+  :: MonadIO m
+  => Bool  -- ^ secure
+  -> Ptr a -- ^ address that was registered
+  -> Addr# -- ^ memory pool name
+  -> m ()
+#ifdef TRACY_ENABLE
+freeNamed secure ptr name =
+  liftIO $ FFI.emitMemoryFreeNamed (ConstPtr $ castPtr ptr) (fromIntegral $ fromEnum secure) (ConstPtr $ Ptr name)
+#else
+freeNamed _secure _ptr _name = pure ()
+#endif
diff --git a/src/System/Tracy/Zone.hs b/src/System/Tracy/Zone.hs
--- a/src/System/Tracy/Zone.hs
+++ b/src/System/Tracy/Zone.hs
@@ -3,7 +3,7 @@
 
 module System.Tracy.Zone
   ( -- * Declare zones
-    withSrcLoc_
+    withSrcLoc
 
     -- * Update zone context
   , text
@@ -12,6 +12,7 @@
   , value
 
     -- * Internals
+  , withSrcLocImpl
   , allocSrcloc
   ) where
 
@@ -26,7 +27,20 @@
 #ifdef TRACY_ENABLE
 import Control.Exception (bracket)
 import Control.Monad.IO.Unlift (MonadUnliftIO, withRunInIO)
+import Data.ByteString.Char8 qualified as ByteString
+import GHC.Stack
+import GHC.Stack.Types qualified as GHC
+
+#ifndef ZONES_UNSAFE
+import Control.Concurrent (isCurrentThreadBound)
+#ifdef ZONES_PEDANTIC
+import System.Exit (die)
+-- pedantic
 #endif
+-- !unsafe
+#endif
+-- enable
+#endif
 
 import System.Tracy.FFI qualified as FFI
 import System.Tracy.FFI.Types qualified as FFI
@@ -36,38 +50,96 @@
 It will produce a @?zoneCtx@ implicit for the zone functions to work.
 
 @
-{-# LANGUAGE CPP #-}
+{-# LANGUAGE OverloadedLabels #-} -- for colors
+{-# LANGUAGE OverloadedStrings #-} -- for names
 
 import System.Tracy.Zone qualified as Zone
 
-rendering = Zone.withSrcLoc_ \_\_LINE\_\_ \_\_FILE\_\_ "rendering" #yellow do
+rendering = Zone.withSrcLoc "rendering" #yellow do
   -- ...
 @
+
+NB: Zones can only be used on a bound thread.
+Main thread is safe, but the rest should use one of forkOn/asyncBound/runInBoundThread.
 -}
-{-# INLINE withSrcLoc_ #-}
-withSrcLoc_ ::
+{-# INLINE withSrcLoc #-}
+withSrcLoc
+#ifdef TRACY_ENABLE
+  :: ( HasCallStack
+     , MonadUnliftIO m
+     )
+#else
+  :: ()
+#endif
+  => ByteString -- ^ Function name (if used as a top-level wrapper) or section name (in a middle of a @do@ block).
+  -> FFI.Color
+  -> ((?zoneCtx :: FFI.TracyCZoneCtx) => m a)
+  -> m a
 #ifndef TRACY_ENABLE
-  ()
+withSrcLoc _function _col action = let ?zoneCtx = FFI.nullTracyCZoneCtx in action
 #else
-  (MonadUnliftIO m)
+withSrcLoc function col action = withRunInIO \inIO -> do
+  -- XXX: breaking into non-public API from GHC.Stack.Types to short-circuit `srcLocFile` stringification
+  case callStack of
+    GHC.PushCallStack _myself GHC.SrcLoc{srcLocStartLine, srcLocFile} _next ->
+      withSrcLocImpl
+        (fromIntegral srcLocStartLine)
+        (ByteString.pack srcLocFile) -- XXX: srcLocFile is originally an Addr#. So pack should be optimized down to FinalPtr too.
+        function -- XXX: IsString instance has an unsafePackLiteral rule for string literals
+        col
+        inIO
+        action
+    _EmptyOrFreeze ->
+      error "withSrcLoc ought to have HasCallStack in context"
 #endif
-  => Word32
+
+{- | Allocate SrcLoc and run a Zone with it.
+
+This will copy the strings into a one-time temporary buffer and feed it into emitZoneBeginAlloc.
+You'd better have those bytestrings come from static literals to avoid even more intermediate allocations.
+-}
+{-# INLINE withSrcLocImpl #-}
+withSrcLocImpl
+  :: Word32
   -> ByteString
   -> ByteString
   -> FFI.Color
+  -> (m a -> IO a)
   -> ((?zoneCtx :: FFI.TracyCZoneCtx) => m a)
-  -> m a
+  -> IO a
 #ifndef TRACY_ENABLE
-withSrcLoc_ _line _file _function _col action =
-  let ?zoneCtx = FFI.nullTracyCZoneCtx
-  in action
+withSrcLocImpl _line _file _function _col inIO action =
+  inIO $ let ?zoneCtx = FFI.nullTracyCZoneCtx in action
 #else
-withSrcLoc_ line file function col action = withRunInIO \run -> do
-  srcloc <- allocSrcloc line file function Nothing col
-  bracket
-    (FFI.emitZoneBeginAlloc srcloc 1)
-    FFI.emitZoneEnd
-    (\ctx -> run $ let ?zoneCtx = ctx in action)
+withSrcLocImpl line file function col inIO action = do
+#ifdef ZONES_UNSAFE
+  runZone
+#else
+  bound <- isCurrentThreadBound
+  if bound then
+    runZone
+  else
+#ifdef ZONES_PEDANTIC
+    {-
+      XXX: Will not actually crash the whole program, only the thread.
+      But at least there would be a console notice when this happens.
+    -}
+    die $ ByteString.unpack file <> ":" <> show line <> " Starting a zone on unbound thread"
+#else
+    inIO $ let ?zoneCtx = FFI.nullTracyCZoneCtx in action
+#endif
+
+-- ZONES_UNSAFE
+#endif
+  where
+    {-# INLINE runZone #-}
+    runZone = do
+      srcloc <- allocSrcloc line file function Nothing col
+      bracket
+        (FFI.emitZoneBeginAlloc srcloc 1)
+        FFI.emitZoneEnd
+        (\ctx -> inIO $ let ?zoneCtx = ctx in action)
+-- TRACY_ENABLE
 #endif
 
 {- | Prepare a single-use location identifier
diff --git a/test/Readme.hs b/test/Readme.hs
--- a/test/Readme.hs
+++ b/test/Readme.hs
@@ -11,11 +11,12 @@
 main :: IO ()
 main = Tracy.withProfiler $ do
   Tracy.waitConnected_       -- wait for the tracy-capture to connect
-  Tracy.messageL "hi there"# -- static strings require no copying to be logged
-  mapM_ runFrame [0..600]
+  Tracy.withSrcLoc "main.nowhereInParticular" #f0fa do
+    Tracy.messageL "hi there"# -- static strings require no copying to be logged
+    mapM_ runFrame [0..600]
 
 runFrame :: Int -> IO ()
-runFrame ix = Tracy.withSrcLoc_ __LINE__ __FILE__ "runFrame" #fcc do
+runFrame ix = Tracy.withSrcLoc "runFrame" #fcc do
   Tracy.frameMark_
   let factorial = product [1 .. toInteger ix]
   let !digits = length (show factorial)
diff --git a/tracy-profiler.cabal b/tracy-profiler.cabal
--- a/tracy-profiler.cabal
+++ b/tracy-profiler.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           tracy-profiler
-version:        0.1.1.0
+version:        0.1.2.0
 synopsis:       Haskell bindings for Tracy frame profiler
 category:       Profiling
 homepage:       https://github.com/haskell-game/tracy-profiler#readme
@@ -45,11 +45,27 @@
   manual: True
   default: False
 
+flag on_demand
+  description: Don't generate and keep events if there's no connection. Enable if your libtracyclient has this enabled.
+  manual: True
+  default: False
+
+flag zones_pedantic
+  description: Crash when a zone is starting on an unbound thread.
+  manual: True
+  default: True
+
+flag zones_unsafe
+  description: Skip the bound-thread check for zones. This may crash the profile server with "zone ended twice" error.
+  manual: True
+  default: False
+
 library
   exposed-modules:
       System.Tracy
       System.Tracy.FFI
       System.Tracy.FFI.Types
+      System.Tracy.Memory
       System.Tracy.Zone
   other-modules:
       Paths_tracy_profiler
@@ -69,9 +85,7 @@
       RecordWildCards
       StrictData
       ImplicitParams
-  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints
-  extra-libraries:
-      TracyClient
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints -O2
   build-depends:
       base >=4.16 && <5
     , bytestring
@@ -79,14 +93,23 @@
     , unliftio-core
     , webcolor-labels
   default-language: GHC2021
-  if flag(manual_lifetime)
-    cpp-options: -DTRACY_MANUAL_LIFETIME
   if flag(enable)
     cpp-options: -DTRACY_ENABLE
+    extra-libraries:
+        TracyClient
+        stdc++
+  if flag(manual_lifetime)
+    cpp-options: -DTRACY_MANUAL_LIFETIME
+  if flag(on_demand)
+    cpp-options: -DTRACY_ON_DEMAND
   if flag(fibers)
     cpp-options: -DTRACY_FIBERS
   if flag(has_callstack)
     cpp-options: -DTRACY_HAS_CALLSTACK
+  if flag(zones_pedantic)
+    cpp-options: -DZONES_PEDANTIC
+  if flag(zones_unsafe)
+    cpp-options: -DZONES_UNSAFE
 
 test-suite tracy-profiler-test
   type: exitcode-stdio-1.0