Initial CST-Agent: portable Linux/Termux/Windows coding agent.

Vendored sashidown, OpenAI-compatible env (OPENAI_*), and bootstrap scripts.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/creds.c

@@ -0,0 +1,140 @@
+#define _DEFAULT_SOURCE
+
+#include "cst_agent.h"
+#include "os_compat.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef _WIN32
+#include <io.h>
+#else
+#include <unistd.h>
+#endif
+
+/* Config dir via os_compat: ~/.config/cst-agent or %APPDATA%\cst-agent */
+
+static int credentials_path(char *out, size_t n) {
+  char dir[OS_PATH_MAX];
+  if (os_config_dir(dir, sizeof(dir)) != 0)
+    return -1;
+  return os_path_join(out, n, dir, "credentials");
+}
+
+int cst_creds_load_api_key(char *out, size_t out_sz) {
+  if (!out || out_sz < 2)
+    return -1;
+  out[0] = 0;
+  char path[OS_PATH_MAX];
+  if (credentials_path(path, sizeof(path)) != 0)
+    return -1;
+  FILE *fp = fopen(path, "r");
+  if (!fp)
+    return -1;
+  char line[1024];
+  while (fgets(line, sizeof(line), fp)) {
+    if (strncmp(line, "api_key=", 8) != 0)
+      continue;
+    char *v = line + 8;
+    size_t len = strlen(v);
+    while (len > 0 && (v[len - 1] == '\n' || v[len - 1] == '\r'))
+      v[--len] = 0;
+    if (len == 0 || len + 1 > out_sz) {
+      fclose(fp);
+      return -1;
+    }
+    memcpy(out, v, len + 1);
+    fclose(fp);
+    return 0;
+  }
+  fclose(fp);
+  return -1;
+}
+
+int cst_creds_save_api_key(const char *key) {
+  if (!key || !key[0])
+    return -1;
+  char dir[OS_PATH_MAX], path[OS_PATH_MAX];
+  if (os_config_dir(dir, sizeof(dir)) != 0)
+    return -1;
+  if (os_mkdir(dir, 0700) != 0)
+    return -1;
+  if (credentials_path(path, sizeof(path)) != 0)
+    return -1;
+  FILE *fp = fopen(path, "w");
+  if (!fp)
+    return -1;
+  fprintf(fp, "api_key=%s\n", key);
+  fprintf(fp, "api_base=https://api.minimax.cn/v1\n");
+  fprintf(fp, "model=MiniMax-M2.7\n");
+  fclose(fp);
+  (void)os_chmod_private(path);
+  return 0;
+}
+
+/* Zenity on Unix; stdin prompt elsewhere / when zenity missing. */
+int cst_creds_prompt_api_key(char *out, size_t out_sz) {
+  if (!out || out_sz < 2)
+    return -1;
+  out[0] = 0;
+
+#ifndef _WIN32
+  FILE *fp = popen(
+      "zenity --password --title='CST-Agent / MiniMax' "
+      "--text='请输入 MiniMax API Key（将保存到配置目录 credentials）' "
+      "2>/dev/null",
+      "r");
+  if (fp) {
+    if (fgets(out, (int)out_sz, fp)) {
+      int st = pclose(fp);
+      size_t len = strlen(out);
+      while (len > 0 && (out[len - 1] == '\n' || out[len - 1] == '\r'))
+        out[--len] = 0;
+      if (st == 0 && len > 0)
+        return 0;
+    } else {
+      pclose(fp);
+    }
+    out[0] = 0;
+  }
+#endif
+
+  /* Fallback: console prompt (headless / Windows / no zenity). */
+  fprintf(stderr, "CST-Agent: enter MiniMax API Key (saved to config dir): ");
+  fflush(stderr);
+  if (!fgets(out, (int)out_sz, stdin)) {
+    out[0] = 0;
+    return -1;
+  }
+  size_t len = strlen(out);
+  while (len > 0 && (out[len - 1] == '\n' || out[len - 1] == '\r'))
+    out[--len] = 0;
+  if (len == 0) {
+    out[0] = 0;
+    return -1;
+  }
+  return 0;
+}
+
+int cst_creds_ensure_api_key(char *out, size_t out_sz) {
+  const char *env = getenv("CST_API_KEY");
+  if (!env || !env[0])
+    env = getenv("MINIMAX_API_KEY");
+  if (!env || !env[0])
+    env = getenv("OPENAI_API_KEY");
+  if (env && env[0]) {
+    snprintf(out, out_sz, "%s", env);
+    return 0;
+  }
+  if (cst_creds_load_api_key(out, out_sz) == 0 && out[0])
+    return 0;
+  if (cst_creds_prompt_api_key(out, out_sz) != 0)
+    return -1;
+  if (cst_creds_save_api_key(out) != 0)
+    fprintf(stderr, "warning: failed to save credentials file\n");
+  else
+    fprintf(stderr, "saved API key to config directory\n");
+  return 0;
+}