diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..1431c7e
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "sys-asm"]
+	path = sys-asm
+	url = https://github.com/wemeetagain/sys-asm.git
diff --git a/Makefile b/Makefile
index 81e806a..bfa3f40 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,5 @@
-.PHONY: build build-gpu build-metal build-cuda-lib build-cuda clean test list-gpus help
+.PHONY: build build-gpu build-metal build-cuda-lib build-cuda clean test list-gpus help \
+        initcode initcode-deposit initcode-exit mine-deposit .sys-asm-ref
 
 BINARY_NAME=nick
 GOBUILD=go build
@@ -73,6 +74,84 @@ clean:
 	rm -f $(BINARY_NAME)
 	rm -f miner/kernel/*.o miner/kernel/*.a
 
+# ---------------------------------------------------------------------------
+# Contract init code (assembled from the sys-asm submodule)
+#
+# The predeploy contracts are geas assembly in the `sys-asm` submodule.
+# Assembling ctor.eas yields `ctor ++ runtime` = the deployment init code,
+# whose bytes determine the vanity address. These targets emit it 0x-prefixed,
+# ready for `./nick search --initcode`.
+#
+# REF selects the sys-asm revision (a SHA is used from the local clone; a
+# branch is fetched at runtime). Default = the pinned commit below.
+#   make initcode-deposit              # pinned default (offline)
+#   make initcode-deposit REF=<sha>    # any commit
+#   make initcode-deposit REF=<branch> # latest branch tip (fetches)
+# TODO: when the contracts land on sys-asm main, point
+#       SYS_ASM_REMOTE=https://github.com/ethereum/sys-asm.git and REF=main.
+# ---------------------------------------------------------------------------
+GEAS           ?= $(shell command -v geas 2>/dev/null || echo "$$(go env GOPATH)/bin/geas")
+SYS_ASM_DIR    ?= sys-asm
+SYS_ASM_REMOTE ?= https://github.com/wemeetagain/sys-asm.git
+REF            ?= 537b9c17d14705e77bc3f512e17dd253ad69b020
+DEPOSIT_CTOR   := $(SYS_ASM_DIR)/src/builder_deposits/ctor.eas
+EXIT_CTOR      := $(SYS_ASM_DIR)/src/builder_exits/ctor.eas
+
+# Vanity search parameters (override on the command line). The target address
+# is 0x0000-leading with a 00<eip> suffix; sig-r spells the EIP number too.
+# EIP has no default -- set it, or pass SUFFIX/SIG_R explicitly.
+#   make mine-deposit EIP=<num>                    # suffix 0x00<num>, sig-r 0x<num>
+#   make mine-deposit SUFFIX=0xdead SIG_R=0xdead   # override directly
+EIP         ?=
+PREFIX      ?= 0x0000
+SUFFIX      ?= $(if $(EIP),0x00$(EIP))
+SIG_R       ?= $(if $(EIP),0x$(EIP))
+SCORE       ?= 10
+GPU_BACKEND ?= cuda
+GPU_DEVICES ?= all
+BATCH       ?= 67108864
+
+# Ensure the sys-asm submodule is present, checked out at $(REF), and that geas
+# is available. Run as a prerequisite of the init code / mining targets.
+.sys-asm-ref:
+	@test -e $(DEPOSIT_CTOR) || git submodule update --init $(SYS_ASM_DIR) >/dev/null 2>&1 || { \
+		echo "ERROR: sys-asm submodule missing; run: git submodule update --init $(SYS_ASM_DIR)"; exit 1; }
+	@if echo "$(REF)" | grep -qE '^[0-9a-fA-F]{7,40}$$'; then \
+		git -C $(SYS_ASM_DIR) checkout -q $(REF) 2>/dev/null || { \
+			git -C $(SYS_ASM_DIR) fetch -q $(SYS_ASM_REMOTE) $(REF) && \
+			git -C $(SYS_ASM_DIR) checkout -q FETCH_HEAD; }; \
+	else \
+		git -C $(SYS_ASM_DIR) fetch -q $(SYS_ASM_REMOTE) $(REF) && \
+		git -C $(SYS_ASM_DIR) checkout -q FETCH_HEAD; \
+	fi
+	@command -v $(GEAS) >/dev/null 2>&1 || test -x $(GEAS) || { \
+		echo "ERROR: geas not found; run: go install github.com/fjl/geas/cmd/geas@latest"; exit 1; }
+
+## initcode-deposit: Print 0x-prefixed builder-deposit init code (pipeable)
+initcode-deposit: .sys-asm-ref
+	@printf '0x%s\n' "$$($(GEAS) $(DEPOSIT_CTOR))"
+
+## initcode-exit: Print 0x-prefixed builder-exit init code (pipeable)
+initcode-exit: .sys-asm-ref
+	@printf '0x%s\n' "$$($(GEAS) $(EXIT_CTOR))"
+
+## initcode: Show both init codes with byte sizes and the assembled sys-asm commit
+initcode: .sys-asm-ref
+	@echo "sys-asm @ $$(git -C $(SYS_ASM_DIR) rev-parse --short HEAD) (REF=$(REF))"
+	@dep=$$($(GEAS) $(DEPOSIT_CTOR)); echo "deposit ($$(( $${#dep}/2 )) bytes): 0x$$dep"
+	@ext=$$($(GEAS) $(EXIT_CTOR));    echo "exit    ($$(( $${#ext}/2 )) bytes): 0x$$ext"
+
+## mine-deposit: Assemble the deposit init code and run the GPU vanity search
+mine-deposit: .sys-asm-ref
+	@test -n "$(SUFFIX)" -a -n "$(SIG_R)" || { \
+		echo "ERROR: which EIP do you want to mine for? Set EIP=<num>, e.g.:"; \
+		echo "         make mine-deposit EIP=<num>"; \
+		echo "       (or override SUFFIX=0x... SIG_R=0x... directly)"; exit 1; }
+	@test -x ./$(BINARY_NAME) || { echo "ERROR: ./$(BINARY_NAME) not built; run: make build-cuda"; exit 1; }
+	./$(BINARY_NAME) search --gpu --gpu-backend $(GPU_BACKEND) --gpu-devices $(GPU_DEVICES) \
+		--batch-size $(BATCH) --initcode 0x$$($(GEAS) $(DEPOSIT_CTOR)) \
+		--prefix $(PREFIX) --suffix $(SUFFIX) --sig-r $(SIG_R) --score $(SCORE)
+
 ## help: Show this help
 help:
 	@echo "Usage: make [target]"
diff --git a/sys-asm b/sys-asm
new file mode 160000
index 0000000..537b9c1
--- /dev/null
+++ b/sys-asm
@@ -0,0 +1 @@
+Subproject commit 537b9c17d14705e77bc3f512e17dd253ad69b020