diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..bad6abd
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,3 @@
+.PHONY: test
+test:
+	@bash tests/test_profiles.sh
diff --git a/tests/test_profiles.sh b/tests/test_profiles.sh
new file mode 100755
index 0000000..f824f6a
--- /dev/null
+++ b/tests/test_profiles.sh
@@ -0,0 +1,222 @@
+#!/usr/bin/env bash
+#
+# Tests for claude-launcher-profiles (profile logic + installer).
+#
+# Design:
+#   - A stub `claude` captures the ANTHROPIC_* env vars the launcher exports,
+#     so we can assert on them without a real Claude Code or network.
+#   - launch_profile calls `exec claude`, so every invocation runs inside a
+#     subshell — the exec then only ends the subshell, not the test runner.
+#   - Installer tests run with HOME pointed at a temp dir and a throwaway repo
+#     clone, so they never touch the real repo working tree.
+#
+# Run:  bash tests/test_profiles.sh
+#   or:  make test
+
+set -u
+
+REPO_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+
+TESTS_RUN=0
+TESTS_FAIL=0
+FAILED_CASES=()
+
+# ---- assert helpers --------------------------------------------------------
+
+assert_eq() {
+  # assert_eq <label> <expected> <actual>
+  local label="$1" expected="$2" actual="$3"
+  TESTS_RUN=$((TESTS_RUN + 1))
+  if [[ "$expected" == "$actual" ]]; then
+    printf '    ok   %s\n' "$label"
+  else
+    printf '    FAIL %s\n     expected: <%s>\n     actual:   <%s>\n' \
+      "$label" "$expected" "$actual" >&2
+    TESTS_FAIL=$((TESTS_FAIL + 1))
+    FAILED_CASES+=("$label")
+  fi
+}
+
+assert_true() {
+  # assert_true <label> <condition-as-string>; runs the condition in a subshell
+  local label="$1"; shift
+  TESTS_RUN=$((TESTS_RUN + 1))
+  if ( "$@" ); then
+    printf '    ok   %s\n' "$label"
+  else
+    printf '    FAIL %s (condition false)\n' "$label" >&2
+    TESTS_FAIL=$((TESTS_FAIL + 1))
+    FAILED_CASES+=("$label")
+  fi
+}
+
+assert_exit() {
+  # assert_exit <label> <expected_code> -- <cmd...>
+  local label="$1" expected="$2"; shift 2
+  [[ "$1" == "--" ]] && shift
+  local actual
+  "$@" >/dev/null 2>&1
+  actual=$?
+  TESTS_RUN=$((TESTS_RUN + 1))
+  if [[ "$expected" == "$actual" ]]; then
+    printf '    ok   %s (exit %s)\n' "$label" "$actual"
+  else
+    printf '    FAIL %s: expected exit %s, got %s\n' "$label" "$expected" "$actual" >&2
+    TESTS_FAIL=$((TESTS_FAIL + 1))
+    FAILED_CASES+=("$label (exit $expected != $actual)")
+  fi
+}
+
+# ---- stub claude on PATH ----------------------------------------------------
+
+STUB_DIR="$(mktemp -d)"
+trap 'rm -rf "$STUB_DIR" "$REAL_CLONE" "$CAPTURE" "$H"' EXIT
+export PATH="$STUB_DIR:$PATH"
+
+cat > "$STUB_DIR/claude" <<'STUB'
+#!/usr/bin/env bash
+# If CLAUDE_ENV_CAPTURE is set, snapshot the exported ANTHROP_* vars into it.
+if [[ -n "${CLAUDE_ENV_CAPTURE:-}" ]]; then
+  {
+    printf 'BASE_URL=%s\n' "${ANTHROPIC_BASE_URL:-}"
+    printf 'AUTH_TOKEN=%s\n' "${ANTHROPIC_AUTH_TOKEN:-}"
+    printf 'API_KEY=%s\n' "${ANTHROPIC_API_KEY:-}"
+    printf 'MODEL=%s\n' "${ANTHROPIC_MODEL:-}"
+  } > "$CLAUDE_ENV_CAPTURE"
+fi
+echo "stub-claude-invoked"
+STUB
+chmod +x "$STUB_DIR/claude"
+
+# ---- throwaway repo clone with a test config -------------------------------
+
+REAL_CLONE="$(mktemp -d)"
+cp -r "$REPO_DIR"/. "$REAL_CLONE"/
+chmod +x "$REAL_CLONE/bin/"* "$REAL_CLONE/lib/profiles.sh" 2>/dev/null || true
+
+cat > "$REAL_CLONE/config/profiles.yml" <<'YML'
+defaults:
+  claude_cmd: "claude"
+  openrouter_base_url: "https://openrouter.ai/api"
+profiles:
+  pro:
+    mode: "pro"
+  glm:
+    mode: "openrouter"
+    model: "z-ai/glm-5.2"
+  free:
+    mode: "openrouter"
+    model: "openrouter/free"
+  badmode:
+    mode: "bogus"
+YML
+
+CAPTURE="$(mktemp)"
+
+# Run a profile in a subshell (launch_profile execs claude -> ends subshell
+# only). Env capture written into $CAPTURE.
+run_profile() {
+  CLAUDE_ENV_CAPTURE="$CAPTURE" bash -c '
+    set -euo pipefail
+    source "$0/lib/profiles.sh"
+    launch_profile "$1"
+  ' "$REAL_CLONE" "$1" >/dev/null 2>&1
+}
+
+field() { sed -n "s/^$1=//p" "$CAPTURE" 2>/dev/null; }
+
+# ===========================================================================
+echo "## Profile logic"
+# ---------------------------------------------------------------------------
+
+echo "-- pro profile clears ANTHROPIC env and launches claude"
+export ANTHROPIC_BASE_URL="stale" ANTHROPIC_AUTH_TOKEN="stale" ANTHROPIC_MODEL="stale"
+run_profile pro
+assert_eq "pro: BASE_URL cleared"   "" "$(field BASE_URL)"
+assert_eq "pro: AUTH_TOKEN cleared"  "" "$(field AUTH_TOKEN)"
+assert_eq "pro: MODEL cleared"       "" "$(field MODEL)"
+
+echo "-- glm profile exports OpenRouter env"
+export OPENROUTER_API_KEY="sk-or-v1-TEST123"
+run_profile glm
+assert_eq "glm: BASE_URL"     "https://openrouter.ai/api" "$(field BASE_URL)"
+assert_eq "glm: AUTH_TOKEN"    "sk-or-v1-TEST123"          "$(field AUTH_TOKEN)"
+assert_eq "glm: API_KEY empty" ""                          "$(field API_KEY)"
+assert_eq "glm: MODEL"         "z-ai/glm-5.2"               "$(field MODEL)"
+
+echo "-- free profile exports configured model slug"
+run_profile free
+assert_eq "free: MODEL"       "openrouter/free"             "$(field MODEL)"
+
+echo "-- error: missing OPENROUTER_API_KEY"
+assert_exit "missing key exits 1" 1 -- env -u OPENROUTER_API_KEY bash -c '
+  set -euo pipefail
+  source "$0/lib/profiles.sh"
+  launch_profile glm
+' "$REAL_CLONE"
+
+echo "-- error: unknown profile"
+assert_exit "unknown profile exits 1" 1 -- bash -c '
+  set -euo pipefail
+  source "$0/lib/profiles.sh"
+  launch_profile does-not-exist
+' "$REAL_CLONE"
+
+echo "-- error: unsupported mode"
+assert_exit "bad mode exits 1" 1 -- bash -c '
+  set -euo pipefail
+  source "$0/lib/profiles.sh"
+  launch_profile badmode
+' "$REAL_CLONE"
+
+# ===========================================================================
+echo "## Installer symlink logic"
+# ---------------------------------------------------------------------------
+# Run install-claude-profiles with HOME pointed at a temp dir, so the real
+# repo working tree is never touched.
+
+target_points_to_clone() {
+  local t="$1/src/claude-launcher-profiles"
+  [[ -L "$t" ]] && [[ "$(readlink "$t")" == "$REAL_CLONE" ]]
+}
+
+echo "-- S1: broken (dangling) symlink is repointed, not fatal"
+H="$(mktemp -d)"; mkdir -p "$H/src"
+ln -sfn /does/not/exist "$H/src/claude-launcher-profiles"
+HOME="$H" bash "$REAL_CLONE/bin/install-claude-profiles" >/dev/null 2>&1
+assert_true "S1 broken link repointed to clone" target_points_to_clone "$H"
+rm -rf "$H"
+
+echo "-- S2: real directory at target -> warning, left in place"
+H="$(mktemp -d)"; mkdir -p "$H/src/claude-launcher-profiles"
+OUT="$(HOME="$H" bash "$REAL_CLONE/bin/install-claude-profiles" 2>&1 >/dev/null)"
+if [[ "$OUT" == *"exists and is not a symlink"* ]] && [[ -d "$H/src/claude-launcher-profiles" ]] && [[ ! -L "$H/src/claude-launcher-profiles" ]]; then
+  assert_eq "S2 real dir warned and preserved" "ok" "ok"
+else
+  assert_eq "S2 real dir warned and preserved" "ok" "FAIL ($OUT)"
+fi
+rm -rf "$H"
+
+echo "-- S3: free path -> new symlink created"
+H="$(mktemp -d)"; mkdir -p "$H/src"
+HOME="$H" bash "$REAL_CLONE/bin/install-claude-profiles" >/dev/null 2>&1
+assert_true "S3 free path got a new symlink" target_points_to_clone "$H"
+rm -rf "$H"
+
+echo "-- S4: existing valid symlink -> repointed"
+H="$(mktemp -d)"; mkdir -p "$H/src"
+ln -sfn /some/other/old "$H/src/claude-launcher-profiles"
+HOME="$H" bash "$REAL_CLONE/bin/install-claude-profiles" >/dev/null 2>&1
+assert_true "S4 existing symlink repointed" target_points_to_clone "$H"
+rm -rf "$H"
+
+# ===========================================================================
+echo
+echo "------------------------------------------------------------"
+printf 'tests: %d run, %d failed\n' "$TESTS_RUN" "$TESTS_FAIL"
+if (( TESTS_FAIL > 0 )); then
+  printf 'FAILED cases:\n'
+  printf '  - %s\n' "${FAILED_CASES[@]}"
+  exit 1
+fi
+echo "all tests passed."