fix(platform): fall back to USERPROFILE when HOME is unset

src/cli/cli.c

@@ -6,6 +6,7 @@
  */
 #include "cli/cli.h"
 #include "foundation/compat.h"
+#include "foundation/platform.h"
 
 // the correct standard headers are included below but clang-tidy doesn't map them.
 #include <ctype.h>
@@ -1613,7 +1614,7 @@ unsigned char *cbm_extract_binary_from_targz(const unsigned char *data, int data
 static const char *get_cache_dir(const char *home_dir) {
     static char buf[1024];
     if (!home_dir) {
-        home_dir = getenv("HOME");
+        home_dir = cbm_get_home_dir();
     }
     if (!home_dir) {
         return NULL;
@@ -1837,10 +1838,9 @@ int cbm_cmd_config(int argc, char **argv) {
         return 0;
     }
 
-    // NOLINTNEXTLINE(concurrency-mt-unsafe)
-    const char *home = getenv("HOME");
+    const char *home = cbm_get_home_dir();
     if (!home) {
-        fprintf(stderr, "error: HOME not set\n");
+        fprintf(stderr, "error: HOME not set (use USERPROFILE on Windows)\n");
         return 1;
     }
 
@@ -1968,9 +1968,9 @@ int cbm_cmd_install(int argc, char **argv) {
         }
     }
 
-    const char *home = getenv("HOME");
+    const char *home = cbm_get_home_dir();
     if (!home) {
-        fprintf(stderr, "error: HOME not set\n");
+        fprintf(stderr, "error: HOME not set (use USERPROFILE on Windows)\n");
         return 1;
     }
 
@@ -2232,9 +2232,9 @@ int cbm_cmd_uninstall(int argc, char **argv) {
         }
     }
 
-    const char *home = getenv("HOME");
+    const char *home = cbm_get_home_dir();
     if (!home) {
-        fprintf(stderr, "error: HOME not set\n");
+        fprintf(stderr, "error: HOME not set (use USERPROFILE on Windows)\n");
         return 1;
     }
 
@@ -2425,9 +2425,9 @@ int cbm_cmd_uninstall(int argc, char **argv) {
 int cbm_cmd_update(int argc, char **argv) {
     parse_auto_answer(argc, argv);
 
-    const char *home = getenv("HOME");
+    const char *home = cbm_get_home_dir();
     if (!home) {
-        fprintf(stderr, "error: HOME not set\n");
+        fprintf(stderr, "error: HOME not set (use USERPROFILE on Windows)\n");
         return 1;
     }
 

src/foundation/platform.c

@@ -6,7 +6,8 @@
 #include "platform.h"
 #include "compat.h"
 
-#include <stdint.h> // uint64_t, int64_t
+#include <stdint.h>  // uint64_t, int64_t
+#include <stdlib.h>  // getenv
 
 #ifdef _WIN32
 
@@ -216,3 +217,19 @@ int64_t cbm_file_size(const char *path) {
 }
 
 #endif /* _WIN32 */
+
+/* ── Home directory (cross-platform) ──────────────────────────── */
+
+const char *cbm_get_home_dir(void) {
+    // NOLINTNEXTLINE(concurrency-mt-unsafe)
+    const char *h = getenv("HOME");
+    if (h && h[0]) {
+        return h;
+    }
+    // NOLINTNEXTLINE(concurrency-mt-unsafe)
+    h = getenv("USERPROFILE");
+    if (h && h[0]) {
+        return h;
+    }
+    return NULL;
+}

src/foundation/platform.h

@@ -64,6 +64,12 @@ cbm_system_info_t cbm_system_info(void);
  * initial=false: max(1, perf_cores-1) (leave headroom for user apps) */
 int cbm_default_worker_count(bool initial);
 
+/* ── Home directory ─────────────────────────────────────────────── */
+
+/* Cross-platform home directory: tries HOME first, then USERPROFILE (Windows).
+ * Returns NULL when neither is set. */
+const char *cbm_get_home_dir(void);
+
 /* ── File system ───────────────────────────────────────────────── */
 
 /* Check if a path exists. */

src/main.c

@@ -19,6 +19,7 @@
 #include "store/store.h"
 #include "cli/cli.h"
 #include "foundation/log.h"
+#include "foundation/platform.h"
 #include "foundation/compat_thread.h"
 #include "foundation/mem.h"
 #include "ui/config.h"
@@ -221,7 +222,7 @@ int main(int argc, char **argv) {
 
     /* Open config store for runtime settings */
     char config_dir[1024];
-    const char *cfg_home = getenv("HOME");
+    const char *cfg_home = cbm_get_home_dir();
     cbm_config_t *runtime_config = NULL;
     if (cfg_home) {
         snprintf(config_dir, sizeof(config_dir), "%s/.cache/codebase-memory-mcp", cfg_home);

src/mcp/mcp.c

@@ -564,10 +564,9 @@ bool cbm_mcp_server_has_cached_store(cbm_mcp_server_t *srv) {
 /* Returns the platform cache directory: ~/.cache/codebase-memory-mcp
  * Writes to buf, returns buf for convenience. */
 static const char *cache_dir(char *buf, size_t bufsz) {
-    // NOLINTNEXTLINE(concurrency-mt-unsafe)
-    const char *home = getenv("HOME");
+    const char *home = cbm_get_home_dir();
     if (!home) {
-        home = "/tmp";
+        home = cbm_tmpdir();
     }
     snprintf(buf, bufsz, "%s/.cache/codebase-memory-mcp", home);
     return buf;
@@ -1995,8 +1994,7 @@ static void detect_session(cbm_mcp_server_t *srv) {
     /* 1. Try CWD */
     char cwd[1024];
     if (getcwd(cwd, sizeof(cwd)) != NULL) {
-        // NOLINTNEXTLINE(concurrency-mt-unsafe)
-        const char *home = getenv("HOME");
+        const char *home = cbm_get_home_dir();
         /* Skip useless roots: / and $HOME */
         if (strcmp(cwd, "/") != 0 && (home == NULL || strcmp(cwd, home) != 0)) {
             snprintf(srv->session_root, sizeof(srv->session_root), "%s", cwd);
@@ -2067,8 +2065,7 @@ static void maybe_auto_index(cbm_mcp_server_t *srv) {
     }
 
     /* Check if project already has a DB */
-    // NOLINTNEXTLINE(concurrency-mt-unsafe)
-    const char *home = getenv("HOME");
+    const char *home = cbm_get_home_dir();
     if (home) {
         char db_check[1024];
         snprintf(db_check, sizeof(db_check), "%s/.cache/codebase-memory-mcp/%s.db", home,

src/pipeline/pipeline.c

@@ -127,10 +127,9 @@ static char *resolve_db_path(const cbm_pipeline_t *p) {
     if (p->db_path) {
         snprintf(path, 1024, "%s", p->db_path);
     } else {
-        // NOLINTNEXTLINE(concurrency-mt-unsafe)
-        const char *home = getenv("HOME");
+        const char *home = cbm_get_home_dir();
         if (!home) {
-            home = "/tmp";
+            home = cbm_tmpdir();
         }
         snprintf(path, 1024, "%s/.cache/codebase-memory-mcp/%s.db", home, p->project_name);
     }
@@ -680,14 +679,13 @@ int cbm_pipeline_run(cbm_pipeline_t *p) {
     if (!check_cancel(p)) {
         cbm_clock_gettime(CLOCK_MONOTONIC, &t);
 
-        // NOLINTNEXTLINE(concurrency-mt-unsafe) — called once during single-threaded dump
-        const char *home = getenv("HOME");
+        const char *home = cbm_get_home_dir();
         char db_path[1024];
         if (p->db_path) {
             snprintf(db_path, sizeof(db_path), "%s", p->db_path);
         } else {
             if (!home) {
-                home = "/tmp";
+                home = cbm_tmpdir();
             }
             snprintf(db_path, sizeof(db_path), "%s/.cache/codebase-memory-mcp/%s.db", home,
                      p->project_name);

src/store/store.c

@@ -348,10 +348,9 @@ cbm_store_t *cbm_store_open(const char *project) {
         return NULL;
     }
     /* Build path: ~/.cache/codebase-memory-mcp/<project>.db */
-    const char *home = getenv("HOME"); // NOLINT(concurrency-mt-unsafe) — called once during
-                                       // single-threaded store open, never concurrently
+    const char *home = cbm_get_home_dir();
     if (!home) {
-        home = "/tmp";
+        home = cbm_tmpdir();
     }
     char path[1024];
     snprintf(path, sizeof(path), "%s/.cache/codebase-memory-mcp/%s.db", home, project);

src/ui/config.c

@@ -6,7 +6,9 @@
  */
 #include "ui/config.h"
 #include "foundation/log.h"
+#include "foundation/platform.h"
 #include "foundation/compat_fs.h"
+#include "foundation/compat.h"
 
 #include <yyjson/yyjson.h>
 
@@ -17,9 +19,9 @@
 /* ── Path ────────────────────────────────────────────────────── */
 
 void cbm_ui_config_path(char *buf, int bufsz) {
-    const char *home = getenv("HOME"); // NOLINT(concurrency-mt-unsafe)
+    const char *home = cbm_get_home_dir();
     if (!home) {
-        home = "/tmp";
+        home = cbm_tmpdir();
     }
     snprintf(buf, (size_t)bufsz, "%s/.cache/codebase-memory-mcp/config.json", home);
 }

src/ui/http_server.c

@@ -315,7 +315,7 @@ static void handle_browse(struct mg_connection *c, struct mg_http_message *hm) {
     char path[1024] = {0};
     if (!get_query_param(hm->query, "path", path, (int)sizeof(path)) || path[0] == '\0') {
         /* Default to home directory */
-        const char *home = getenv("HOME");
+        const char *home = cbm_get_home_dir();
         if (home)
             snprintf(path, sizeof(path), "%s", home);
         else
@@ -387,9 +387,9 @@ static void handle_adr_get(struct mg_connection *c, struct mg_http_message *hm)
         return;
     }
 
-    const char *home = getenv("HOME");
+    const char *home = cbm_get_home_dir();
     if (!home)
-        home = "/tmp";
+        home = cbm_tmpdir();
     char db_path[1024];
     snprintf(db_path, sizeof(db_path), "%s/.cache/codebase-memory-mcp/%s.db", home, name);
 
@@ -480,9 +480,9 @@ static void handle_adr_save(struct mg_connection *c, struct mg_http_message *hm)
     const char *proj = yyjson_get_str(v_proj);
     const char *content = yyjson_get_str(v_content);
 
-    const char *home = getenv("HOME");
+    const char *home = cbm_get_home_dir();
     if (!home)
-        home = "/tmp";
+        home = cbm_tmpdir();
     char db_path[1024];
     snprintf(db_path, sizeof(db_path), "%s/.cache/codebase-memory-mcp/%s.db", home, proj);
 
@@ -777,9 +777,9 @@ static void handle_delete_project(struct mg_connection *c, struct mg_http_messag
         return;
     }
 
-    const char *home = getenv("HOME"); // NOLINT(concurrency-mt-unsafe)
+    const char *home = cbm_get_home_dir();
     if (!home)
-        home = "/tmp";
+        home = cbm_tmpdir();
     char db_path[1024];
     snprintf(db_path, sizeof(db_path), "%s/.cache/codebase-memory-mcp/%s.db", home, name);
 
@@ -815,9 +815,9 @@ static void handle_project_health(struct mg_connection *c, struct mg_http_messag
         return;
     }
 
-    const char *home = getenv("HOME"); // NOLINT(concurrency-mt-unsafe)
+    const char *home = cbm_get_home_dir();
     if (!home)
-        home = "/tmp";
+        home = cbm_tmpdir();
     char db_path[1024];
     snprintf(db_path, sizeof(db_path), "%s/.cache/codebase-memory-mcp/%s.db", home, name);
 
@@ -873,9 +873,9 @@ static void handle_layout(struct mg_connection *c, struct mg_http_message *hm) {
     }
 
     /* Open a read-only store for this project */
-    const char *home = getenv("HOME"); // NOLINT(concurrency-mt-unsafe)
+    const char *home = cbm_get_home_dir();
     if (!home)
-        home = "/tmp";
+        home = cbm_tmpdir();
     char db_path[1024];
     snprintf(db_path, sizeof(db_path), "%s/.cache/codebase-memory-mcp/%s.db", home, project);
 

tests/test_integration.c

@@ -13,6 +13,7 @@
 #include <store/store.h>
 #include <pipeline/pipeline.h>
 #include <foundation/log.h>
+#include <foundation/platform.h>
 
 #include <string.h>
 #include <stdlib.h>
@@ -105,9 +106,9 @@ static int integration_setup(void) {
         return -1;
 
     /* Build db path for direct store queries (pipeline writes here) */
-    const char *home = getenv("HOME");
+    const char *home = cbm_get_home_dir();
     if (!home)
-        home = "/tmp";
+        home = cbm_tmpdir();
     snprintf(g_dbpath, sizeof(g_dbpath), "%s/.cache/codebase-memory-mcp/%s.db", home, g_project);
 
     /* Ensure cache dir exists */