diff --git a/src/discover/discover.c b/src/discover/discover.c
index a43b44be3..96b66144d 100644
--- a/src/discover/discover.c
+++ b/src/discover/discover.c
@@ -245,7 +245,7 @@ static bool expand_git_path(const char *path, char *out, size_t out_sz) {
 }
 
 static bool read_core_excludes_file(const char *config_path, char *out, size_t out_sz) {
-    FILE *f = fopen(config_path, "r");
+    FILE *f = cbm_fopen(config_path, "r");
     if (!f) {
         return false;
     }
diff --git a/src/discover/gitignore.c b/src/discover/gitignore.c
index 57b1e1581..d390c637f 100644
--- a/src/discover/gitignore.c
+++ b/src/discover/gitignore.c
@@ -12,6 +12,7 @@
  *   - patterns with / are rooted (anchored to base)
  */
 #include "foundation/constants.h"
+#include "foundation/compat_fs.h"
 
 enum { GI_INIT_CAP = 16, GI_CHAR_IDX1 = 1, GI_CHAR_IDX2 = 2, GI_SKIP3 = 3 };
 #include "discover/discover.h"
@@ -287,7 +288,7 @@ cbm_gitignore_t *cbm_gitignore_load(const char *path) {
         return NULL;
     }
 
-    FILE *f = fopen(path, "r");
+    FILE *f = cbm_fopen(path, "r");
     if (!f) {
         return NULL;
     }
diff --git a/src/discover/language.c b/src/discover/language.c
index a0254306c..917651d13 100644
--- a/src/discover/language.c
+++ b/src/discover/language.c
@@ -11,6 +11,7 @@
 #include "cbm.h" // CBMLanguage, CBM_LANG_*
 
 #include "foundation/constants.h"
+#include "foundation/compat_fs.h"
 
 enum { LANG_SCAN_PASSES = 2 };
 #define SLEN(s) (sizeof(s) - 1)
@@ -998,7 +999,7 @@ CBMLanguage cbm_disambiguate_m(const char *path) {
         return CBM_LANG_MATLAB;
     }
 
-    FILE *f = fopen(path, "r");
+    FILE *f = cbm_fopen(path, "r");
     if (!f) {
         return CBM_LANG_MATLAB;
     }
diff --git a/src/discover/userconfig.c b/src/discover/userconfig.c
index 63ba4885c..7c606f912 100644
--- a/src/discover/userconfig.c
+++ b/src/discover/userconfig.c
@@ -13,6 +13,7 @@
 #include "cbm.h" /* CBMLanguage, CBM_LANG_* */
 #include "foundation/constants.h"
 #include "foundation/platform.h" /* cbm_safe_getenv */
+#include "foundation/compat_fs.h"
 
 enum { MAX_CONFIG_SIZE = 65536 };
 #include "foundation/log.h"
@@ -231,7 +232,7 @@ static int parse_extra_extensions(yyjson_val *root, cbm_userext_t **entries, int
  * Returns 0 on success (or absent file), -1 on alloc failure.
  */
 static int load_config_file(const char *path, cbm_userext_t **entries, int *count) {
-    FILE *f = fopen(path, "rb");
+    FILE *f = cbm_fopen(path, "rb");
     if (!f) {
         return 0; /* file absent — silently ignore */
     }
diff --git a/src/foundation/compat_fs.c b/src/foundation/compat_fs.c
index f77ad9a89..886f5c459 100644
--- a/src/foundation/compat_fs.c
+++ b/src/foundation/compat_fs.c
@@ -130,6 +130,22 @@ int cbm_pclose(FILE *f) {
     return _pclose(f);
 }
 
+FILE *cbm_fopen(const char *path, const char *mode) {
+    wchar_t *wpath = cbm_utf8_to_wide(path);
+    if (!wpath) {
+        return NULL;
+    }
+    wchar_t *wmode = cbm_utf8_to_wide(mode);
+    if (!wmode) {
+        free(wpath);
+        return NULL;
+    }
+    FILE *f = _wfopen(wpath, wmode);
+    free(wpath);
+    free(wmode);
+    return f;
+}
+
 bool cbm_mkdir_p(const char *path, int mode) {
     (void)mode;
     wchar_t *wpath = cbm_utf8_to_wide(path);
@@ -262,6 +278,10 @@ int cbm_pclose(FILE *f) {
     return pclose(f);
 }
 
+FILE *cbm_fopen(const char *path, const char *mode) {
+    return fopen(path, mode);
+}
+
 bool cbm_mkdir_p(const char *path, int mode) {
     /* Try direct mkdir first */
     if (mkdir(path, (mode_t)mode) == 0) {
diff --git a/src/foundation/compat_fs.h b/src/foundation/compat_fs.h
index 285ad555b..224e2b9a4 100644
--- a/src/foundation/compat_fs.h
+++ b/src/foundation/compat_fs.h
@@ -50,10 +50,16 @@ int cbm_unlink(const char *path);
 /* Delete an empty directory. Returns 0 on success. */
 int cbm_rmdir(const char *path);
 
+/* Open a file by UTF-8 path.
+ * On Windows, converts to wide-char and calls _wfopen so paths with
+ * non-ASCII characters (accents, CJK, etc.) are handled correctly.
+ * On POSIX, delegates to fopen. mode must be an ASCII string. */
+FILE *cbm_fopen(const char *path, const char *mode);
+
 /* Execute a command without shell interpretation.
  * argv is a NULL-terminated array: {"cmd", "arg1", "arg2", NULL}.
  * Returns the process exit code, or -1 on fork/exec failure.
- * POSIX: fork() + execvp(). Windows: _spawnvp(). */
+ * POSIX: fork() + execvp(). Windows: CreateProcess with proper quoting. */
 int cbm_exec_no_shell(const char *const *argv);
 
 #endif /* CBM_COMPAT_FS_H */
diff --git a/src/mcp/mcp.c b/src/mcp/mcp.c
index 5235aaab5..84bc08492 100644
--- a/src/mcp/mcp.c
+++ b/src/mcp/mcp.c
@@ -2782,7 +2782,7 @@ static void free_node_contents(cbm_node_t *n) {
 /* ── Helper: read lines [start, end] from a file ─────────────── */
 
 static char *read_file_lines(const char *path, int start, int end) {
-    FILE *fp = fopen(path, "r");
+    FILE *fp = cbm_fopen(path, "r");
     if (!fp) {
         return NULL;
     }
@@ -4639,7 +4639,7 @@ static char *adr_read_legacy_file(const char *root_path) {
     }
     char adr_path[CBM_SZ_4K];
     snprintf(adr_path, sizeof(adr_path), "%s/.codebase-memory/adr.md", root_path);
-    FILE *fp = fopen(adr_path, "r");
+    FILE *fp = cbm_fopen(adr_path, "r");
     if (!fp) {
         return NULL;
     }
diff --git a/src/pipeline/artifact.c b/src/pipeline/artifact.c
index 720c9d237..014f32b23 100644
--- a/src/pipeline/artifact.c
+++ b/src/pipeline/artifact.c
@@ -122,7 +122,7 @@ static bool artifact_path(char *buf, size_t bufsz, const char *repo_path, const
 
 /* Read entire file into malloc'd buffer. Sets *out_len. Returns NULL on error. */
 static char *read_file_alloc(const char *path, size_t *out_len) {
-    FILE *fp = fopen(path, "rb");
+    FILE *fp = cbm_fopen(path, "rb");
     if (!fp) {
         return NULL;
     }
diff --git a/src/pipeline/pass_calls.c b/src/pipeline/pass_calls.c
index 2e27adc18..5c0f978e3 100644
--- a/src/pipeline/pass_calls.c
+++ b/src/pipeline/pass_calls.c
@@ -22,6 +22,7 @@ enum { PC_RING = 4, PC_RING_MASK = 3, PC_SIG_SCAN = 15, PC_REGEX_GRP = 2 };
 #include "graph_buffer/graph_buffer.h"
 #include "foundation/log.h"
 #include "foundation/compat.h"
+#include "foundation/compat_fs.h"
 #include "foundation/str_util.h"
 #include "cbm.h"
 #include "service_patterns.h"
@@ -43,7 +44,7 @@ static bool pc_module_is_dir(CBMLanguage lang) {
 
 /* Read entire file into heap-allocated buffer. Caller must free(). */
 static char *read_file(const char *path, int *out_len) {
-    FILE *f = fopen(path, "rb");
+    FILE *f = cbm_fopen(path, "rb");
     if (!f) {
         return NULL;
     }
diff --git a/src/pipeline/pass_definitions.c b/src/pipeline/pass_definitions.c
index f0816068c..767703d34 100644
--- a/src/pipeline/pass_definitions.c
+++ b/src/pipeline/pass_definitions.c
@@ -22,6 +22,7 @@ enum { PD_JSON_FIELD_OVERHEAD = 6 };
 #include "graph_buffer/graph_buffer.h"
 #include "foundation/log.h"
 #include "foundation/compat.h"
+#include "foundation/compat_fs.h"
 #include "cbm.h"
 #include "simhash/minhash.h"
 #include "semantic/ast_profile.h"
@@ -33,7 +34,7 @@ enum { PD_JSON_FIELD_OVERHEAD = 6 };
 /* Read entire file into heap-allocated buffer. Returns NULL on error.
  * Caller must free(). Sets *out_len to byte count. */
 static char *read_file(const char *path, int *out_len) {
-    FILE *f = fopen(path, "rb");
+    FILE *f = cbm_fopen(path, "rb");
     if (!f) {
         return NULL;
     }
diff --git a/src/pipeline/pass_envscan.c b/src/pipeline/pass_envscan.c
index f2a6ae606..766392ba7 100644
--- a/src/pipeline/pass_envscan.c
+++ b/src/pipeline/pass_envscan.c
@@ -316,7 +316,7 @@ static int scan_line(const char *line, file_type_t ft, char *key_out, size_t key
 /* Scan a single file for env URL bindings. Returns number of bindings added. */
 static int scan_env_file(const char *full_path, const char *rel, file_type_t ft,
                          cbm_env_binding_t *out, int max_out) {
-    FILE *f = fopen(full_path, "r");
+    FILE *f = cbm_fopen(full_path, "r");
     if (!f) {
         return 0;
     }
diff --git a/src/pipeline/pass_k8s.c b/src/pipeline/pass_k8s.c
index 0a99443f5..494e13895 100644
--- a/src/pipeline/pass_k8s.c
+++ b/src/pipeline/pass_k8s.c
@@ -19,6 +19,7 @@
 #include "discover/discover.h"
 #include "foundation/log.h"
 #include "foundation/compat.h"
+#include "foundation/compat_fs.h"
 #include "cbm.h"
 
 #include <stdlib.h>
@@ -30,7 +31,7 @@
 /* Read entire file into heap-allocated buffer. Returns NULL on error.
  * Caller must free(). Sets *out_len to byte count. */
 static char *k8s_read_file(const char *path, int *out_len) {
-    FILE *f = fopen(path, "rb");
+    FILE *f = cbm_fopen(path, "rb");
     if (!f) {
         return NULL;
     }
diff --git a/src/pipeline/pass_lsp_cross.c b/src/pipeline/pass_lsp_cross.c
index 31a7500aa..d2ad23079 100644
--- a/src/pipeline/pass_lsp_cross.c
+++ b/src/pipeline/pass_lsp_cross.c
@@ -28,6 +28,7 @@
 #include "foundation/constants.h"
 #include "foundation/hash_table.h"
 #include "foundation/log.h"
+#include "foundation/compat_fs.h"
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -67,7 +68,7 @@ static bool pxc_module_is_dir(CBMLanguage lang) {
  * read_file helper in pass_calls.c / pass_parallel.c (kept local so the
  * pipeline doesn't grow a public read-file API just for this pass). */
 static char *pxc_read_file(const char *path, int *out_len) {
-    FILE *f = fopen(path, "rb");
+    FILE *f = cbm_fopen(path, "rb");
     if (!f)
         return NULL;
     (void)fseek(f, 0, SEEK_END);
diff --git a/src/pipeline/pass_parallel.c b/src/pipeline/pass_parallel.c
index fefcf736a..93656b5ec 100644
--- a/src/pipeline/pass_parallel.c
+++ b/src/pipeline/pass_parallel.c
@@ -56,6 +56,7 @@ enum { PP_CSHARP_M_PREFIX_LEN = 2 };
 #include "helpers.h" /* cbm_kind_in_set_free_cache — per-worker-thread cache teardown */
 #include "pipeline/worker_pool.h"
 #include "foundation/compat.h"
+#include "foundation/compat_fs.h"
 #include "foundation/compat_thread.h"
 #include "graph_buffer/graph_buffer.h"
 #include "service_patterns.h"
@@ -88,7 +89,7 @@ static uint64_t extract_now_ns(void) {
 
 /* Read file into a malloc'd buffer (= mimalloc in production). */
 static char *read_file(const char *path, int *out_len) {
-    FILE *f = fopen(path, "rb");
+    FILE *f = cbm_fopen(path, "rb");
     if (!f) {
         return NULL;
     }
diff --git a/src/pipeline/pass_pkgmap.c b/src/pipeline/pass_pkgmap.c
index 5b2ce8e5a..97dfb2ad0 100644
--- a/src/pipeline/pass_pkgmap.c
+++ b/src/pipeline/pass_pkgmap.c
@@ -33,7 +33,7 @@
 
 /* Read an entire file into a malloc'd buffer. Returns NULL on failure. */
 static char *pkgmap_read_file(const char *path, int *out_len) {
-    FILE *f = fopen(path, "rb");
+    FILE *f = cbm_fopen(path, "rb");
     if (!f) {
         return NULL;
     }
diff --git a/src/pipeline/pass_semantic.c b/src/pipeline/pass_semantic.c
index 3c3c76da7..2b9c03b46 100644
--- a/src/pipeline/pass_semantic.c
+++ b/src/pipeline/pass_semantic.c
@@ -19,6 +19,7 @@
 #include "graph_buffer/graph_buffer.h"
 #include "foundation/log.h"
 #include "foundation/compat.h"
+#include "foundation/compat_fs.h"
 #include "cbm.h"
 
 #include <stdio.h>
@@ -34,7 +35,7 @@ static bool ps_module_is_dir(CBMLanguage lang) {
 }
 
 static char *read_file(const char *path, int *out_len) {
-    FILE *f = fopen(path, "rb");
+    FILE *f = cbm_fopen(path, "rb");
     if (!f) {
         return NULL;
     }
diff --git a/src/pipeline/pass_usages.c b/src/pipeline/pass_usages.c
index 7f9c72c82..ec01a0ab6 100644
--- a/src/pipeline/pass_usages.c
+++ b/src/pipeline/pass_usages.c
@@ -18,6 +18,7 @@
 #include "graph_buffer/graph_buffer.h"
 #include "foundation/log.h"
 #include "foundation/compat.h"
+#include "foundation/compat_fs.h"
 #include "cbm.h"
 
 #include <stdio.h>
@@ -33,7 +34,7 @@ static bool pu_module_is_dir(CBMLanguage lang) {
 
 /* Read file into heap buffer. Caller must free(). */
 static char *read_file(const char *path, int *out_len) {
-    FILE *f = fopen(path, "rb");
+    FILE *f = cbm_fopen(path, "rb");
     if (!f) {
         return NULL;
     }
diff --git a/src/pipeline/path_alias.c b/src/pipeline/path_alias.c
index 0c4cc3cf6..79e26b08b 100644
--- a/src/pipeline/path_alias.c
+++ b/src/pipeline/path_alias.c
@@ -123,7 +123,7 @@ static int cmp_scope_by_specificity(const void *a, const void *b) {
  * (e.g. "apps/manager", or "" for repo root). Returns NULL if the file is
  * missing, malformed, or has neither a usable paths block nor a baseUrl. */
 static cbm_path_alias_map_t *load_tsconfig_file(const char *abs_path, const char *dir_prefix) {
-    FILE *f = fopen(abs_path, "r");
+    FILE *f = cbm_fopen(abs_path, "r");
     if (!f) {
         return NULL;
     }
@@ -346,7 +346,7 @@ static void find_alias_files(const char *abs_dir, const char *rel_dir, alias_con
     for (int i = 0; i < TS_CONFIG_NAMES_COUNT && *count < max_count; i++) {
         char check[CBM_SZ_512];
         snprintf(check, sizeof(check), "%s/%s", abs_dir, TS_CONFIG_NAMES[i]);
-        FILE *f = fopen(check, "r");
+        FILE *f = cbm_fopen(check, "r");
         if (f) {
             fclose(f);
             snprintf(out[*count].abs, sizeof(out[*count].abs), "%s", check);