diff --git a/.golangci.yml b/.golangci.yml
index b2dcc35..148b747 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -17,6 +17,19 @@ linters:
         # deferred response-body closes
         - (io.ReadCloser).Close
 
+# Formatting is a gate, not a convention. Nothing enforced gofmt before this,
+# so six files had drifted unnoticed (#329) — `golangci-lint run` now reports a
+# diff as an issue, which fails both `make lint` and the CI lint job.
+# Run `make fmt` (golangci-lint fmt) to apply the fixes.
+formatters:
+  enable:
+    - gofmt
+  exclusions:
+    # internal/api/gen/generated.go is written by genqlient; a formatting
+    # complaint there is not actionable by hand, since `make generate`
+    # rewrites it.
+    generated: strict
+
 issues:
   max-issues-per-linter: 0
   max-same-issues: 0
diff --git a/CLAUDE.md b/CLAUDE.md
index 44bedca..bb51496 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -32,7 +32,8 @@ don't batch to end-of-session.
 ```sh
 make build      # version-stamped binary at bin/hadron (ldflags from `git describe`)
 make test       # go test ./...
-make lint       # golangci-lint run
+make lint       # golangci-lint run (gofmt is gated here — a diff fails the build)
+make fmt        # golangci-lint fmt — apply the formatting `make lint` gates on
 make generate   # regenerate genqlient code from the committed schema snapshot
 make schema     # re-export the schema from ../hadron-server, then generate
 make schema-check  # fail if the committed snapshot is stale vs ../hadron-server (drift detector)
diff --git a/Makefile b/Makefile
index d08832b..1eae3f0 100644
--- a/Makefile
+++ b/Makefile
@@ -15,7 +15,7 @@ HADRON_SERVER_DIR ?= ../hadron-server
 # (typeDefs.ts is a self-contained SDL string, so those are the only deps).
 SDL_EXPORT ?= pnpm -s tsx scripts/export-graphql-sdl.mjs
 
-.PHONY: build test lint generate schema schema-check tools-manifest tools-manifest-check clean
+.PHONY: build test lint fmt generate schema schema-check tools-manifest tools-manifest-check clean
 
 build:
 	go build -ldflags "$(LDFLAGS)" -o $(BIN) ./cmd/hadron
@@ -26,6 +26,10 @@ test:
 lint:
 	golangci-lint run
 
+# Apply the formatting `make lint` gates on (gofmt, per .golangci.yml).
+fmt:
+	golangci-lint fmt
+
 # Regenerate genqlient code from the committed schema snapshot.
 generate:
 	go tool genqlient