diff --git a/toolkit/Makefile b/toolkit/Makefile
index cd8c4063132..bca63079332 100644
--- a/toolkit/Makefile
+++ b/toolkit/Makefile
@@ -143,30 +143,8 @@ include $(SCRIPTS_DIR)/utils.mk
 
 ######## REMAINING BUILD FLAGS ########
 
-ifneq ($(DAILY_BUILD_ID),)
-   $(warning Using Daily Build $(DAILY_BUILD_ID))
-   # Ensure build_arch is set
-   ifeq ($(build_arch),)
-      $(error build_arch must be set when using DAILY_BUILD_ID)
-   endif
-   # build_arch cannot be directly used because Azure storage do not support container names with '_' char
-   ifeq ($(build_arch),x86_64)
-      # The actual repo is found at <URL>/, while a duplicate copy of all the rpms can be found at <URL>/built_rpms_all/
-      # Include both so that the tools that expect a valid repo work, while the tools that expect a basic URL also work.
-      override PACKAGE_URL_LIST   := https://mariner3dailydevrepo.blob.core.windows.net/daily-repo-$(DAILY_BUILD_ID)-x86-64/built_rpms_all \
-                                       https://mariner3dailydevrepo.blob.core.windows.net/daily-repo-$(DAILY_BUILD_ID)-x86-64
-      override SRPM_URL_LIST      := https://mariner3dailydevrepo.blob.core.windows.net/daily-repo-$(DAILY_BUILD_ID)-x86-64/SRPMS
-   else
-      override PACKAGE_URL_LIST   := https://mariner3dailydevrepo.blob.core.windows.net/daily-repo-$(DAILY_BUILD_ID)-aarch64/built_rpms_all \
-                                       https://mariner3dailydevrepo.blob.core.windows.net/daily-repo-$(DAILY_BUILD_ID)-aarch64
-      override SRPM_URL_LIST      := https://mariner3dailydevrepo.blob.core.windows.net/daily-repo-$(DAILY_BUILD_ID)-aarch64/SRPMS
-   endif
-else
-   ifeq ($(USE_PREVIEW_REPO),y)
-      # Configure the preview repo
-      include $(SCRIPTS_DIR)/preview.mk
-   endif
-endif
+# Daily build ID and repo configuration
+include $(SCRIPTS_DIR)/daily_build.mk
 
 CA_CERT     ?=
 TLS_CERT    ?=
@@ -207,6 +185,12 @@ include $(SCRIPTS_DIR)/build_tag_imagecustomizer.mk
 #   go-tools, clean-go-tools, go-tidy-all (tidy go utilities before committing) go-test-coverage
 include $(SCRIPTS_DIR)/tools.mk
 
+# Based on daily build configuration, configure testing repos
+include $(SCRIPTS_DIR)/preview.mk
+
+# Dynamically update toolchain and chroot manifests for some flows with:
+include $(SCRIPTS_DIR)/manifests.mk
+
 # Bootstrap the toolchain's compilers and other tools with:
 #   toolchain, raw-toolchain, clean-toolchain, check-manifests, check-x86_64-manifests, check-aarch64-manifests
 include $(SCRIPTS_DIR)/toolchain.mk
diff --git a/toolkit/docs/building/building.md b/toolkit/docs/building/building.md
index 77c4ccf8dd9..bf3b8aab6ab 100644
--- a/toolkit/docs/building/building.md
+++ b/toolkit/docs/building/building.md
@@ -353,6 +353,8 @@ The `REPO_LIST` variable supports multiple repo files, and they are prioritized
 The Azure Linux base repo is implicitly provided and an optional preview repo is available by setting `USE_PREVIEW_REPO=y`.
 If `DISABLE_UPSTREAM_REPOS=y` is set, any repo that is accessed through the network is disabled.
 
+Daily build packages are available via `DAILY_BUILD_ID`. Use `DAILY_BUILD_ID=lkg`, or `DAILY_BUILD_ID=V-v-YYYYMMDD`.
+
 ### Authentication
 
 If supplying custom endpoints for source/SRPM/package servers, accessing these resources may require keys and certificates. The keys and certificates can be set using:
@@ -464,7 +466,8 @@ If that is not desired all remote sources can be disabled by clearing the follow
 
 #### `PACKAGE_URL_LIST=...`
 
-> Space separated list of URLs to download toolchain RPM packages from, used to populate the toolchain packages if `$(REBUILD_TOOLCHAIN)` is set to `n`. Defaults to the standard distro repos. Overriding this will clear all the default values. May be augmented by passing `USE_PREVIEW_REPO=y` which will uncondinally append the distro's preview repos to what ever set of URLs is being used.
+> Space separated list of URLs to download toolchain RPM packages from, used to populate the toolchain packages if `$(REBUILD_TOOLCHAIN)` is set to `n`. Defaults to the standard distro repos. Overriding this will clear all the default values. May be augmented by passing `USE_PREVIEW_REPO=y` which will unconditionally append the distro's preview repos to what ever set of URLs is being used. `DAILY_BUILD_ID=...` will
+also augment the URL list.
 
 #### `SRPM_URL_LIST=...`
 
@@ -479,6 +482,8 @@ If that is not desired all remote sources can be disabled by clearing the follow
 > - `mariner-ms-non-oss.repo` and `mariner-ms-non-oss-preview.repo` - Azure Linux repository containing Microsoft non open Source RPMs with sources not viewable to the public. The preview version serves the same purpose as the official preview repo.
 >
 
+`DAILY_BUILD_ID` and `DAILY_BUILD_REPO` will automatically augment the `REPO_LIST`.
+
 #### Build Enable/Disable Flags
 
 #### `REBUILD_TOOLCHAIN=...`
@@ -561,6 +566,16 @@ If that is not desired all remote sources can be disabled by clearing the follow
 
 > Pull missing packages from the upstream preview repository in addition to the base repository. This will uncondinally append the preview repo sources to `PACKAGE_URL_LIST`, `SRPM_URL_LIST`, and `REPO_LIST`.
 
+#### `DAILY_BUILD_ID=...`
+
+##### `DAILY_BUILD_ID=`**`""`** *(default)*
+
+> Disable daily build sources.
+
+##### `DAILY_BUILD_ID=`**`lkg` | `V-v-YYYYMMDD`**
+
+> Use the daily build sources for the given date. `lkg` will use the last known good build.
+
 #### `DISABLE_UPSTREAM_REPOS=...`
 
 ##### `DISABLE_UPSTREAM_REPOS=`**`n`** *(default)*
@@ -665,6 +680,8 @@ sudo make hydrate-rpms PACKAGE_ARCHIVE=./rpms.tar.gz
 
 ## All Build Targets
 
+**Help is available via `make help`**
+
 These are the useful build targets:
 | Target                           | Description
 |:---------------------------------|:---
@@ -784,6 +801,7 @@ To reproduce an ISO build, run the same make invocation as before, but set:
 | PACKAGE_ARCHIVE               |                                                                                                        | Use with `make hydrate-rpms` to populate a set of rpms from an archive.
 | DOWNLOAD_SRPMS                | n                                                                                                      | Pack SRPMs from local SPECs or download published ones?
 | USE_PREVIEW_REPO              | n                                                                                                      | Pull missing packages from the upstream preview repository in addition to the base repository?
+| DAILY_BUILD_ID                |                                                                                                        | `lkg` or `V-v-YYYYMMDD` to use the daily build resources for the given date.
 | DISABLE_UPSTREAM_REPOS        | n                                                                                                      | Only pull missing packages from local repositories? This does not affect hydrating the toolchain from `$(PACKAGE_URL_LIST)`.
 | DISABLE_DEFAULT_REPOS         | n                                                                                                      | Disable pulling packages from PMC. Use this option with `REPO_LIST` if you want to use your own repository exclusively.
 | CACHED_PACKAGES_ARCHIVE       |                                                                                                        | Use with `make hydrate-cached-rpms` to populate the external RPMs cache from an archive.
diff --git a/toolkit/resources/manifests/package/daily_build_repo.repo.template b/toolkit/resources/manifests/package/daily_build_repo.repo.template
new file mode 100644
index 00000000000..78bae9ed399
--- /dev/null
+++ b/toolkit/resources/manifests/package/daily_build_repo.repo.template
@@ -0,0 +1,10 @@
+[daily-build-repo]
+name=Azure Linux {{.DAILY_REPO_NAME}}
+baseurl=https://mariner3dailydevrepo.blob.core.windows.net/{{.DAILY_REPO_NAME}}
+gpgkey=file:///etc/pki/rpm-gpg/MICROSOFT-RPM-GPG-KEY
+gpgcheck=0
+repo_gpgcheck=0
+enabled=1
+skip_if_unavailable=True
+sslverify=0
+priority=10
diff --git a/toolkit/scripts/chroot.mk b/toolkit/scripts/chroot.mk
index 08af968dcad..ec461909ee4 100644
--- a/toolkit/scripts/chroot.mk
+++ b/toolkit/scripts/chroot.mk
@@ -21,22 +21,18 @@ clean-chroot-tools:
 	rm -rf $(BUILD_DIR)/worker && \
 	rm -rf $(BUILD_DIR)/validatechroot
 
-# Worker chroot manifest is a file corresponding to the TOOLCHAIN_MANIFEST name.
-toolchain_config_name=$(notdir $(TOOLCHAIN_MANIFEST))
-worker_manifest_name=$(shell echo "$(toolchain_config_name)" | sed -E 's:^toolchain:pkggen_core:' )
-worker_chroot_manifest = $(TOOLCHAIN_MANIFESTS_DIR)/$(worker_manifest_name)
 #$(TOOLCHAIN_MANIFESTS_DIR)/pkggen_core_$(build_arch).txt
 # Find the *.rpm corresponding to each of the entries in the manifest
 # regex operation: (.*\.([^\.]+)\.rpm) extracts *.(<arch>).rpm" to determine
 # the exact path of the required rpm
 # Outputs: $(TOOLCHAIN_RPMS_DIR)/<arch>/<name>.<arch>.rpm
 sed_regex_full_path = 's`(.*\.([^\.]+)\.rpm)`$(TOOLCHAIN_RPMS_DIR)/\2/\1`p'
-worker_chroot_rpm_paths := $(shell sed -nr $(sed_regex_full_path) < $(worker_chroot_manifest))
+worker_chroot_rpm_paths := $(shell sed -nr $(sed_regex_full_path) < $(WORKER_CHROOT_MANIFEST))
 
 # The worker chroot depends on specific toolchain RPMs, the $(toolchain_rpms): target in toolchain.mk knows how
 # to update these RPMs if required.
 worker_chroot_deps := \
-	$(worker_chroot_manifest) \
+	$(WORKER_CHROOT_MANIFEST) \
 	$(worker_chroot_rpm_paths) \
 	$(PKGGEN_DIR)/worker/create_worker_chroot.sh
 
@@ -45,14 +41,14 @@ $(chroot_worker): $(worker_chroot_deps) $(depend_REBUILD_TOOLCHAIN) $(depend_TOO
 else
 $(chroot_worker):
 endif
-	$(PKGGEN_DIR)/worker/create_worker_chroot.sh $(BUILD_DIR)/worker $(worker_chroot_manifest) $(TOOLCHAIN_RPMS_DIR) $(LOGS_DIR)
+	$(PKGGEN_DIR)/worker/create_worker_chroot.sh $(BUILD_DIR)/worker $(WORKER_CHROOT_MANIFEST) $(TOOLCHAIN_RPMS_DIR) $(LOGS_DIR)
 
 validate-chroot: $(go-validatechroot) $(chroot_worker)
 	$(go-validatechroot) \
 	--rpm-dir="$(TOOLCHAIN_RPMS_DIR)" \
 	--tmp-dir="$(BUILD_DIR)/validatechroot" \
 	--worker-chroot="$(chroot_worker)" \
-	--worker-manifest="$(worker_chroot_manifest)" \
+	--worker-manifest="$(WORKER_CHROOT_MANIFEST)" \
 	--log-file="$(LOGS_DIR)/worker/validate.log" \
 	--log-level="$(LOG_LEVEL)" \
 	--log-color="$(LOG_COLOR)"
diff --git a/toolkit/scripts/daily_build.mk b/toolkit/scripts/daily_build.mk
new file mode 100644
index 00000000000..d990a6ca09c
--- /dev/null
+++ b/toolkit/scripts/daily_build.mk
@@ -0,0 +1,89 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+# Contains:
+#	- Configuration for getting daily build packages
+
+# DAILY_BUILD_ID and DAILY_BUILD_REPO while similar are mutually exclusive.
+#
+# DAILY_BUILD_ID is points the build tools to the latest daily built
+# packages as part of a tight local workflow.  The DAILY_BUILD_ID argument
+# takes the form: V-v-YYYYMMDD where V-v is the Major-Minor branch or
+# may be 'lkg' which will auto-detect the latest valid build.
+#
+# DAILY_BUILD_REPO also points to the latest daily built packages.  However
+# this is intended for internal teams to access the packages at build time and
+# runtime.  The argument takes the form of a repo file supplied by the
+# Azure Linux Team's daily artifact feed.  The repo file may be provisioned
+# in a downstream image so that it has access to the repo at runtime.  The
+# DAILY_BUILD_REPO argument takes a path to the daily-mariner.repo file.
+
+##help:var:DAILY_BUILD_ID:{'lkg',<build_id>}='lkg' will auto select latest daily build repo. An explicit ID of the form 'V-v-YYYYMMDD' where V-v is the Major-Minor branch is also supported.
+DAILY_BUILD_ID ?=
+##help:var:DAILY_BUILD_ID_UPDATE_MANIFESTS={y,n}=Update the toolchain manifests when using DAILY_BUILD_ID to match the daily build repo.
+DAILY_BUILD_ID_UPDATE_MANIFESTS ?= y
+##help:var:DAILY_BUILD_REPO={path to daily.repo}=Path to the daily build repo file to use.
+DAILY_BUILD_REPO ?=
+
+daily_lkg_workdir = $(BUILD_DIR)/daily_build_id
+
+ifneq ($(DAILY_BUILD_ID),)
+   ifneq ($(DAILY_BUILD_REPO),)
+      $(error DAILY_BUILD_ID and DAILY_BUILD_REPO are mutually exclusive.)
+   endif
+endif
+
+ifneq ($(DAILY_BUILD_ID),)
+    ifeq ($(DAILY_BUILD_ID),lkg)
+        $(call create_folder,$(daily_lkg_workdir))
+
+        override DAILY_BUILD_ID := $(shell $(SCRIPTS_DIR)/get_lkg_id.sh $(daily_lkg_workdir))
+        ifneq ($(.SHELLSTATUS),0)
+            $(error Failed to auto detect DAILY_BUILD_ID)
+        endif
+    endif
+
+    $(warning Using Daily Build $(DAILY_BUILD_ID))
+    # Ensure build_arch is set
+    ifeq ($(build_arch),)
+       $(error build_arch must be set when using DAILY_BUILD_ID)
+    endif
+    # build_arch cannot be directly used because Azure storage do not support container names with '_' char
+    daily_build_repo_name := $(subst _,-,daily-repo-$(DAILY_BUILD_ID)-$(build_arch))
+    # The actual repo is found at <URL>/, while a duplicate copy of all the rpms can be found at <URL>/built_rpms_all/
+    # Include both so that the tools that expect a valid repo work, while the tools that expect a basic URL also work.
+    # The ordering is important, we want to always take the daily build versions of packages first since they are NOT
+    # the same files as the official packages and will fail checksum validation.
+    override PACKAGE_URL_LIST := https://mariner3dailydevrepo.blob.core.windows.net/$(daily_build_repo_name)/built_rpms_all \
+                                    https://mariner3dailydevrepo.blob.core.windows.net/$(daily_build_repo_name) \
+                                    $(PACKAGE_URL_LIST)
+    override SRPM_URL_LIST    := https://mariner3dailydevrepo.blob.core.windows.net/$(daily_build_repo_name)/SRPMS \
+                                    $(SRPM_URL_LIST)
+endif
+
+ifneq ($(DAILY_BUILD_REPO),)
+   PACKAGE_ROOT := $(shell grep -m 1 "baseurl" $(DAILY_BUILD_REPO) | sed 's|baseurl=||g')
+   $(warning )
+   $(warning ######################### WARNING #########################)
+   $(warning Using a Daily Build Repo at following location:)
+   $(warning $(PACKAGE_ROOT))
+   $(warning ######################### WARNING #########################)
+   $(warning )
+   override PACKAGE_URL_LIST  += $(PACKAGE_ROOT)/built_rpms_all
+   override SRPM_URL_LIST     += $(PACKAGE_ROOT)/SRPMS
+   override REPO_LIST         += $(DAILY_BUILD_REPO)
+endif
+
+# This does not use $(depend_DAILY_BUILD_ID) because that mechanism will not detect the conversion of "lkg" to a
+# specific daily build ID since utils.mk runs before daily_build.mk.
+.PHONY: daily_build_id_always_run_phony
+$(STATUS_FLAGS_DIR)/daily_build_id.flag: daily_build_id_always_run_phony
+	@if [ ! -f $@ ]; then \
+		echo "Initializing daily build ID sanitization"; \
+		touch $@; \
+	fi && \
+	if [ "$$(cat $@)" = "$(DAILY_BUILD_ID)" ]; then \
+		exit 0; \
+	fi && \
+	echo "#### Daily build ID changed ('$$(cat $@)' -> '$(DAILY_BUILD_ID)') ####" && \
+	echo $(DAILY_BUILD_ID) > $@
diff --git a/toolkit/scripts/get_lkg_id.sh b/toolkit/scripts/get_lkg_id.sh
new file mode 100755
index 00000000000..12a6732bff6
--- /dev/null
+++ b/toolkit/scripts/get_lkg_id.sh
@@ -0,0 +1,39 @@
+#!/bin/bash
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+# Prints to stdout the daily build id from the LKG file
+
+set -e
+
+if [ "$#" -ne 1 ]; then
+    echo "Usage: $0 <temp_dir>" >&2
+    exit 1
+fi
+
+temp_dir="$1"
+
+LKG_FILENAME="lkg-3.0-dev.json"
+LKG_TEMP_FILENAME="$(mktemp -p "$temp_dir" "${LKG_FILENAME}.XXXXXX" )"
+
+# shellcheck disable=SC2317
+cleanup() {
+    rm -f "$LKG_TEMP_FILENAME"
+}
+trap cleanup EXIT
+
+get_lkg() {
+    wget -O "$LKG_TEMP_FILENAME" -nv "https://mariner3dailydevrepo.blob.core.windows.net/lkg/$LKG_FILENAME"
+    DAILY_BUILD_ID=$(jq -r .dailybuildid "$LKG_TEMP_FILENAME" | tr . -)
+}
+
+get_lkg
+
+if [ -z "$DAILY_BUILD_ID" ]; then
+    echo "Failed to get DAILY_BUILD_ID from https://mariner3dailydevrepo.blob.core.windows.net/lkg/$LKG_FILENAME" >&2
+    exit 1
+fi
+
+echo "$DAILY_BUILD_ID"
+
+exit 0
diff --git a/toolkit/scripts/manifests.mk b/toolkit/scripts/manifests.mk
new file mode 100644
index 00000000000..e2b92d2bab6
--- /dev/null
+++ b/toolkit/scripts/manifests.mk
@@ -0,0 +1,27 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+# Contains:
+#   - Optional mechanisms for regenerating the toolchain manifests
+
+TOOLCHAIN_MANIFEST           ?= $(TOOLCHAIN_MANIFESTS_DIR)/toolchain_$(build_arch).txt
+WORKER_CHROOT_MANIFEST       ?= $(TOOLCHAIN_MANIFESTS_DIR)/pkggen_core_$(build_arch).txt
+
+# We use the contents of the manifests to derive some makefile recipes so we need to ensure they are up to date. It
+# is not sufficient to add a recipe to update the manifests, they must be updated prior to the makefile being parsed
+# sicne we use them as input to create recipes. A shell command is used to update the manifests if they are out of date.
+ifeq ($(DAILY_BUILD_ID_UPDATE_MANIFESTS),y)
+    ifneq ($(DAILY_BUILD_ID),)
+        $(call create_folder,$(daily_lkg_workdir))
+
+        manifest_exit_status := $(call shell_real_build_only, $(SCRIPTS_DIR)/update_manifest.sh $(TOOLCHAIN_MANIFEST) $(build_arch) $(daily_lkg_workdir) $(DAILY_BUILD_ID) 1>&2 ; echo $$?)
+        ifneq ($(manifest_exit_status),0)
+            $(error Failed to auto update manifest '$(TOOLCHAIN_MANIFEST)' with DAILY_BUILD_ID '$(DAILY_BUILD_ID)')
+        endif
+
+        manifest_exit_status := $(call shell_real_build_only, $(SCRIPTS_DIR)/update_manifest.sh $(WORKER_CHROOT_MANIFEST) $(build_arch) $(daily_lkg_workdir) $(DAILY_BUILD_ID) 1>&2 ; echo $$?)
+        ifneq ($(manifest_exit_status),0)
+            $(error Failed to auto update manifest '$(WORKER_CHROOT_MANIFEST) with DAILY_BUILD_ID '$(DAILY_BUILD_ID)')
+        endif
+    endif
+endif
diff --git a/toolkit/scripts/pkggen.mk b/toolkit/scripts/pkggen.mk
index b7d986835ad..00843eb09ef 100644
--- a/toolkit/scripts/pkggen.mk
+++ b/toolkit/scripts/pkggen.mk
@@ -65,6 +65,7 @@ clean-cache-worker:
 clean-cache: clean-cache-worker
 	rm -rf $(CACHED_RPMS_DIR)
 	rm -f $(validate-pkggen-config)
+	rm -f $(cached_file)
 	@echo Verifying no mountpoints present in $(cache_working_dir)
 clean-spec-parse:
 	@echo Verifying no mountpoints present in $(parse_working_dir)
diff --git a/toolkit/scripts/preview.mk b/toolkit/scripts/preview.mk
index e2e5f8081c4..20242caef2d 100644
--- a/toolkit/scripts/preview.mk
+++ b/toolkit/scripts/preview.mk
@@ -4,43 +4,67 @@
 # Contains:
 #	- Create a preview repo file
 #	- Configuration for getting preview packages
-
-# Ensure USE_PREVIEW_REPO is set to 'y', else this file is not needed.
-ifneq ($(USE_PREVIEW_REPO),y)
-$(error USE_PREVIEW_REPO is not set to 'y' but preview.mk is included)
-endif
+#	- Create a daily build repo file
 
 ######## REPO FILE MANAGEMENT/CREATION ########
 
-preview_repo        := $(toolkit_root)/repos/azurelinux-official-preview.repo
-# Intentionally not using $(SPECS) here to avoid issues with custom SPECS directories
-preview_repo_source := $(PROJECT_ROOT)/SPECS/azurelinux-repos/azurelinux-official-preview.repo
-
-# Stop immediately if the preview repo file is missing and cannot be created.
-ifeq ($(wildcard $(preview_repo_source))$(wildcard $(preview_repo)),)
-    $(warning )
-    $(warning ######################### ERROR #########################)
-    $(warning 'USE_PREVIEW_REPO=y' is set but all of the following failed:)
-    $(warning - packaged default '$(preview_repo)' is missing)
-    $(warning - backup source    '$(preview_repo_source)' is missing)
-    $(warning ######################### ERROR #########################)
-    $(error )
-endif
+# Handle creating the preview repo file if it is missing
+
+ifeq ($(USE_PREVIEW_REPO),y)
+    preview_repo        := $(toolkit_root)/repos/azurelinux-official-preview.repo
+    # Intentionally not using $(SPECS) here to avoid issues with custom SPECS directories
+    preview_repo_source := $(PROJECT_ROOT)/SPECS/azurelinux-repos/azurelinux-official-preview.repo
+
+    # Stop immediately if the preview repo file is missing and cannot be created.
+    ifeq ($(wildcard $(preview_repo_source))$(wildcard $(preview_repo)),)
+        $(warning )
+        $(warning ######################### ERROR #########################)
+        $(warning 'USE_PREVIEW_REPO=y' is set but all of the following failed:)
+        $(warning - packaged default '$(preview_repo)' is missing)
+        $(warning - backup source    '$(preview_repo_source)' is missing)
+        $(warning ######################### ERROR #########################)
+        $(error )
+    endif
+
+    # Copy the preview repo file to the expected repo location, but only if we  have a target to copy from.
+    ifeq ($(wildcard $(preview_repo_source)),)
 
-# Copy the preview repo file to the expected repo location, but only if we  have a target to copy from.
-ifeq ($(wildcard $(preview_repo_source)),)
 $(preview_repo): ;
-else
+
+    else
+
 $(preview_repo): $(preview_repo_source)
 	@echo "Regenerating preview repo file from '$<' to '$@'"
 	mkdir -p $(dir $@)
 	cp $< $@
+
+    endif
+
+    ######## VARIABLE CONFIGURATION ########
+
+    override PACKAGE_URL_LIST   += https://packages.microsoft.com/azurelinux/$(RELEASE_MAJOR_ID)/preview/base/$(build_arch)
+    override PACKAGE_URL_LIST   += https://packages.microsoft.com/azurelinux/$(RELEASE_MAJOR_ID)/preview/base/debuginfo/$(build_arch)
+    override PACKAGE_URL_LIST   += https://packages.microsoft.com/azurelinux/$(RELEASE_MAJOR_ID)/preview/ms-oss/$(build_arch)
+    override SRPM_URL_LIST      += https://packages.microsoft.com/azurelinux/$(RELEASE_MAJOR_ID)/preview/base/srpms
+    override REPO_LIST += $(preview_repo)
 endif
 
-######## VARIABLE CONFIGURATION ########
+# Generate the daily build repo file if DAILY_BUILD_ID is set
+
+ifneq ($(DAILY_BUILD_ID),)
+# The repo file for daily builds is generated from a template file as needed
+daily_build_repo_source := $(MANIFESTS_DIR)/package/daily_build_repo.repo.template
+daily_build_repo := $(daily_lkg_workdir)/daily_build.repo
+override REPO_LIST += $(daily_build_repo)
 
-override PACKAGE_URL_LIST   += https://packages.microsoft.com/azurelinux/$(RELEASE_MAJOR_ID)/preview/base/$(build_arch)
-override PACKAGE_URL_LIST   += https://packages.microsoft.com/azurelinux/$(RELEASE_MAJOR_ID)/preview/base/debuginfo/$(build_arch)
-override PACKAGE_URL_LIST   += https://packages.microsoft.com/azurelinux/$(RELEASE_MAJOR_ID)/preview/ms-oss/$(build_arch)
-override SRPM_URL_LIST      += https://packages.microsoft.com/azurelinux/$(RELEASE_MAJOR_ID)/preview/base/srpms
-override REPO_LIST += $(preview_repo)
+# Ensure daily_build_repo_name was generated correctly
+ifeq ($(daily_build_repo_name),)
+    $(error daily_build_repo_name must be non-empty when using DAILY_BUILD_ID)
+endif
+
+# Copy the daily build repo file and replace the placeholder with the actual daily build ID
+$(daily_build_repo): $(daily_build_repo_source) $(STATUS_FLAGS_DIR)/daily_build_id.flag
+	@echo "Regenerating daily build repo file from '$<' to '$@'"
+	mkdir -p $(dir $@)
+	sed 's|{{.DAILY_REPO_NAME}}|$(daily_build_repo_name)|g' $< > $@
+endif
diff --git a/toolkit/scripts/toolchain.mk b/toolkit/scripts/toolchain.mk
index e85fb75d365..8d2f562abb3 100644
--- a/toolkit/scripts/toolchain.mk
+++ b/toolkit/scripts/toolchain.mk
@@ -28,7 +28,6 @@ toolchain_files = \
 	$(call shell_real_build_only, find $(SCRIPTS_DIR)/toolchain -name '*.sh') \
 	$(SCRIPTS_DIR)/toolchain/container/Dockerfile
 toolchain_spec_list := $(call shell_real_build_only, $(SCRIPTS_DIR)/toolchain/list_toolchain_specs.sh $(SCRIPTS_DIR)/toolchain/build_official_toolchain_rpms.sh)
-TOOLCHAIN_MANIFEST ?= $(TOOLCHAIN_MANIFESTS_DIR)/toolchain_$(build_arch).txt
 # Find the *.rpm corresponding to each of the entries in the manifest
 # regex operation: (.*\.([^\.]+)\.rpm) extracts *.(<arch>).rpm" to determine
 # the exact path of the required rpm
@@ -66,6 +65,7 @@ clean-toolchain: clean-toolchain-rpms
 	rm -rf $(toolchain_logs_dir)
 	rm -rf $(toolchain_from_repos)
 	rm -rf $(STATUS_FLAGS_DIR)/toolchain_local_temp.flag
+	rm -rf $(STATUS_FLAGS_DIR)/daily_build_auto_cleanup.flag
 	rm -f $(SCRIPTS_DIR)/toolchain/container/toolchain-local-wget-list
 	rm -f $(SCRIPTS_DIR)/toolchain/container/texinfo-perl-fix.patch
 	rm -f $(SCRIPTS_DIR)/toolchain/container/Awt_build_headless_only.patch
@@ -86,6 +86,13 @@ clean-toolchain-rpms:
 	@for f in $(toolchain_out_rpms); do rm -vf $$f; done
 	rm -rvf $(TOOLCHAIN_RPMS_DIR)
 
+# We need to clear the toolchain if we are using a daily build. The filenames will all be the same, but the actual
+# .rpm files may be fundamentally different.
+$(STATUS_FLAGS_DIR)/daily_build_auto_cleanup.flag: $(STATUS_FLAGS_DIR)/daily_build_id.flag
+	@echo "Daily build ID changed, sanitizing toolchain"
+	rm -rf $(TOOLCHAIN_RPMS_DIR)
+	touch $@
+
 copy-toolchain-rpms:
 	for f in $(toolchain_rpms_buildarch); do cp -vf $(TOOLCHAIN_RPMS_DIR)/$(build_arch)/$$f $(RPMS_DIR)/$(build_arch); done
 	for f in $(toolchain_rpms_noarch); do cp -vf $(TOOLCHAIN_RPMS_DIR)/noarch/$$f $(RPMS_DIR)/noarch; done
@@ -274,7 +281,7 @@ $(STATUS_FLAGS_DIR)/toolchain_local_temp.flag: $(selected_toolchain_archive) $(t
 #	The .rpm doesn't exist
 #	The .rpm is older than the archive we are extracting it from
 #	The toolchain configuration has been changed (depend_TOOLCHAIN_ARCHIVE and depend_REBUILD_TOOLCHAIN)
-$(toolchain_rpms): $(TOOLCHAIN_MANIFEST) $(STATUS_FLAGS_DIR)/toolchain_local_temp.flag $(depend_TOOLCHAIN_ARCHIVE) $(depend_REBUILD_TOOLCHAIN)
+$(toolchain_rpms): $(TOOLCHAIN_MANIFEST) $(STATUS_FLAGS_DIR)/toolchain_local_temp.flag $(STATUS_FLAGS_DIR)/daily_build_auto_cleanup.flag $(depend_TOOLCHAIN_ARCHIVE) $(depend_REBUILD_TOOLCHAIN)
 	tempFile=$(toolchain_local_temp)/$(notdir $@) && \
 	if [ ! -f $@ \
 			-o $(selected_toolchain_archive) -nt $@ \
@@ -289,7 +296,7 @@ $(toolchain_rpms): $(TOOLCHAIN_MANIFEST) $(STATUS_FLAGS_DIR)/toolchain_local_tem
 
 # No archive was selected, so download from online package server instead. All packages must be available for this step to succeed.
 else
-$(toolchain_rpms): $(TOOLCHAIN_MANIFEST) $(depend_REBUILD_TOOLCHAIN) $(go-downloader)
+$(toolchain_rpms): $(TOOLCHAIN_MANIFEST) $(STATUS_FLAGS_DIR)/daily_build_auto_cleanup.flag $(depend_REBUILD_TOOLCHAIN) $(go-downloader)
 	@rpm_filename="$(notdir $@)" && \
 	rpm_dir="$(dir $@)" && \
 	log_file="$(toolchain_downloads_logs_dir)/$$rpm_filename.log" && \
diff --git a/toolkit/scripts/update_manifest.sh b/toolkit/scripts/update_manifest.sh
new file mode 100755
index 00000000000..5eb98baae80
--- /dev/null
+++ b/toolkit/scripts/update_manifest.sh
@@ -0,0 +1,113 @@
+#!/bin/bash
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+# Updates the requested manifest file based on the contents of the LKG json.
+
+set -e
+
+if [ "$#" -ne 4 ]; then
+    echo "Usage: $0 <manifest_file> <arch> <temp_dir> <build_id>" >&2
+    exit 1
+fi
+
+manifest_file="$1"
+arch="$2"
+temp_dir="$3"
+build_id="$4"
+
+# Get SUDO_USER if set, USER otherwise
+CALLING_USER=${SUDO_USER:-$USER}
+echo "Running update_manifest.sh as $CALLING_USER"
+
+# Convert build_id to the associated filename on the LKG blob
+# "3-0-YYYYMMDD" -> "YYYY-MM-DD-3.0-dev"
+convert_id() {
+    branch=$(echo "$1" | cut -d- -f1-2)
+    date=$(echo "$1" | cut -d- -f3)
+
+    # Ensure the parts are in the correct format
+    if [[ ! "$branch" =~ ^[0-9]+-[0-9]+$ ]]; then
+        echo "Invalid branch format: $branch" >&2
+        echo "Expected ID format: lkg | <major>-<minor>-<YYYYMMDD>" >&2
+        exit 1
+    fi
+    if [[ ! "$date" =~ ^[0-9]{8}$ ]]; then
+        echo "Invalid date format: $date" >&2
+        echo "Expected DAILY_BUILD_ID format: lkg | <major>-<minor>-<YYYYMMDD>" >&2
+        exit 1
+    fi
+    # Check we can parse the date
+    date -d "$date" >/dev/null 2>&1 || {
+        echo "Invalid date: $date" >&2
+        echo "Expected DAILY_BUILD_ID format: lkg | <major>-<minor>-<YYYYMMDD>" >&2
+        exit 1
+    }
+
+    branch=$(echo "$branch" | tr - .)-dev
+    date=$(date -d "$date" +%Y-%m-%d)
+
+    echo "${date}-${branch}"
+}
+
+BUILD_FILENAME="$(convert_id "$build_id").json"
+BUILD_TEMP_FILENAME="$(mktemp -p "$temp_dir" "${BUILD_FILENAME}.XXXXXX" )"
+BUILD_TEMP_MANIFEST_FILENAME="$(mktemp -p "$temp_dir" "$(basename "$manifest_file").XXXXXX" )"
+
+# shellcheck disable=SC2317
+cleanup() {
+    rm -f "$BUILD_TEMP_FILENAME"
+    rm -f "$BUILD_TEMP_MANIFEST_FILENAME"
+}
+trap cleanup EXIT
+
+get_commit_info() {
+    wget -O "$BUILD_TEMP_FILENAME" -nv "https://mariner3dailydevrepo.blob.core.windows.net/lkg/$BUILD_FILENAME"
+    GIT_COMMIT=$(jq -r .commit "$BUILD_TEMP_FILENAME")
+}
+
+# Check if the current manifest have been changed by the user
+check_for_modified_manifests() {
+    if git status --porcelain | grep -qP "$(basename "$manifest_file")"; then
+        echo "    #### Local modifications to '$manifest_file' detected."
+        echo "           Revert changes to '$manifest_file' before proceeding. ####" >&2
+        exit 1
+    fi
+}
+
+# We don't want to update the timestamps unless we actually change the file, so download to a temp file and then move it over
+# if the files are different. Refuse to overwrite possible user changes to the manifest files.
+# $1 - filename (e.g. toolchain_aarch64.txt)
+update_manifest() {
+    local filepath
+    local arch
+    local url
+    filepath="$1"
+    arch="$2"
+    basename=$(basename "$filepath")
+
+    url="https://raw.githubusercontent.com/microsoft/CBL-Mariner/$GIT_COMMIT/toolkit/resources/manifests/package/${basename}"
+
+    echo "Checking for updates to $basename manifest from $url"
+
+    wget -nv "${url}" -O "${BUILD_TEMP_MANIFEST_FILENAME}"
+    # only update if the files are different
+    if ! cmp -s "${BUILD_TEMP_MANIFEST_FILENAME}" "${filepath}"; then
+
+        # Refuse to overwrite possible user changes to the manifest files. This will fail if LKG changes the manifests
+        # day-to-day but is better than silently overwriting user changes.
+        check_for_modified_manifests
+
+        echo "Manifests are different, updating ${basename}"
+        mv "${BUILD_TEMP_MANIFEST_FILENAME}" "${filepath}"
+        chown "$CALLING_USER:$CALLING_USER" "${filepath}"
+    else
+        echo "Manifests are the same, not updating ${basename}"
+    fi
+}
+
+get_commit_info
+
+update_manifest "${manifest_file}" "${arch}"
+
+exit 0