diff --git a/AGENTS.md b/AGENTS.md
index cd1f567..10eb8a3 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -207,6 +207,18 @@ the tool is not installed, with a one-line install hint. CI runs them
 unconditionally. Any failure means the ticket is not done. Fix it, do not
 bypass.
 
+### Vendored assets
+
+A few workspace-root files (`schemas/v1.json`, `schemas/pipe/v0.json`,
+`pricing.yaml`, the agent-skill markdown) are embedded into publishable crates
+with `include_str!`, and `cargo publish` only packages files inside a crate
+directory, so each is vendored as a byte-identical in-crate copy (for example
+`schemas/v1.json` has copies under both `crates/mcptest-config/` and
+`crates/mcptest/`). After editing one of these canonical files, run **`make
+sync-vendored`** to propagate it to every vendored copy in one step, then commit
+the copies alongside the source. `make vendored-check` (also part of the check
+gate) fails on any drift; the pair list lives in `scripts/check-vendored-assets.sh`.
+
 ### cargo-nextest
 
 The test step uses `cargo-nextest` when it is installed (`cargo install
diff --git a/Makefile b/Makefile
index e51b5b0..22d92a9 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@
 # the two cannot drift. Run `make` or `make help` to list targets.
 
 .DEFAULT_GOAL := help
-.PHONY: help check fmt fmt-check lint doc build test module-size stats clean
+.PHONY: help check fmt fmt-check lint doc build test module-size sync-vendored vendored-check stats clean
 
 help: ## List the available targets
 	@grep -E '^[a-zA-Z_-]+:.*## ' $(MAKEFILE_LIST) | sort \
@@ -36,6 +36,12 @@ test: ## Run the workspace test suite
 module-size: ## Enforce the production module-size guard
 	./scripts/check-module-size.sh
 
+sync-vendored: ## Copy each canonical asset (schemas, pricing, skill) over its vendored crate copies
+	./scripts/check-vendored-assets.sh --fix
+
+vendored-check: ## Fail if a vendored in-crate copy drifted from its canonical source (CI gate)
+	./scripts/check-vendored-assets.sh
+
 stats: ## Report adoption from public registries (no in-binary telemetry)
 	./scripts/usage-stats.sh
 
diff --git a/scripts/check-vendored-assets.sh b/scripts/check-vendored-assets.sh
index f98ea60..e7792a7 100755
--- a/scripts/check-vendored-assets.sh
+++ b/scripts/check-vendored-assets.sh
@@ -4,17 +4,34 @@
 # Some publishable crates embed workspace-root files (the JSON Schemas and the
 # pricing table) with `include_str!`. `cargo publish` only packages files that
 # live inside the crate directory, so each of those files is vendored as an
-# in-crate copy. This check fails if a vendored copy drifts from its canonical
-# source, so the embedded copy and the source of truth never diverge.
+# in-crate copy. This script keeps the embedded copies byte-identical to their
+# canonical source so the two never diverge.
 #
-# Canonical source -> vendored copy pairs are listed in PAIRS below. When you
-# edit a canonical file, copy it over its vendored sibling(s) in the same
-# commit (or run this script to find the drift).
+# Two modes, one PAIRS list (the single source of truth for what mirrors what):
+#
+#   check-vendored-assets.sh          # CHECK: fail if any vendored copy drifted
+#                                     #        (the CI gate; the default)
+#   check-vendored-assets.sh --fix    # SYNC:  copy each canonical file over its
+#                                     #        vendored sibling(s)
+#
+# Workflow: edit a canonical file, then run `make sync-vendored` (or this script
+# with `--fix`) to propagate it to every vendored copy in one step. The no-arg
+# check then gates the commit and CI against any remaining drift.
 set -euo pipefail
 
 ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 cd "$ROOT"
 
+FIX=0
+case "${1:-}" in
+    --fix) FIX=1 ;;
+    "") ;;
+    *)
+        printf "usage: %s [--fix]\n" "$(basename "$0")" >&2
+        exit 2
+        ;;
+esac
+
 # "canonical|vendored" pairs.
 PAIRS=(
     "schemas/v1.json|crates/mcptest-config/schemas/v1.json"
@@ -26,6 +43,7 @@ PAIRS=(
 )
 
 drift=0
+synced=0
 for pair in "${PAIRS[@]}"; do
     canonical="${pair%%|*}"
     vendored="${pair##*|}"
@@ -34,18 +52,34 @@ for pair in "${PAIRS[@]}"; do
         drift=1
         continue
     fi
-    if [[ ! -f "$vendored" ]]; then
-        printf "error: vendored copy missing: %s (copy %s there)\n" "$vendored" "$canonical" >&2
-        drift=1
+    if [[ -f "$vendored" ]] && cmp -s "$canonical" "$vendored"; then
         continue
     fi
-    if ! cmp -s "$canonical" "$vendored"; then
-        printf "error: vendored asset out of sync:\n  %s\n  differs from %s\n  fix: cp %s %s\n" \
-            "$vendored" "$canonical" "$canonical" "$vendored" >&2
-        drift=1
+    if [[ "$FIX" -eq 1 ]]; then
+        mkdir -p "$(dirname "$vendored")"
+        cp "$canonical" "$vendored"
+        printf "synced %s -> %s\n" "$canonical" "$vendored"
+        synced=$((synced + 1))
+        continue
+    fi
+    if [[ ! -f "$vendored" ]]; then
+        printf "error: vendored copy missing: %s (run \`make sync-vendored\`)\n" "$vendored" >&2
+    else
+        printf "error: vendored asset out of sync:\n  %s\n  differs from %s\n  fix: run \`make sync-vendored\`\n" \
+            "$vendored" "$canonical" >&2
     fi
+    drift=1
 done
 
+if [[ "$FIX" -eq 1 ]]; then
+    if [[ "$synced" -eq 0 ]]; then
+        printf "vendored assets already in sync; nothing to do.\n"
+    else
+        printf "synced %d vendored asset(s); review and commit the copies.\n" "$synced"
+    fi
+    exit 0
+fi
+
 if [[ "$drift" -ne 0 ]]; then
     exit 1
 fi