diff --git a/README.md b/README.md
index f151eaac..862ff919 100644
--- a/README.md
+++ b/README.md
@@ -681,6 +681,9 @@ PROJECT_TYPE="typescript"
 CLAUDE_CODE_CMD="claude"
 # CLAUDE_CODE_CMD="npx @anthropic-ai/claude-code"  # Alternative: use npx
 
+# Optional Anthropic-compatible API base URL override
+# CLAUDE_ANTHROPIC_BASE_URL="https://api.minimax.io/anthropic"
+
 # Shell init file — source before running claude (useful for zsh/fish users
 # whose PATH or env vars are only set in their shell's init file)
 #RALPH_SHELL_INIT_FILE="~/.zshrc"
diff --git a/ralph_loop.sh b/ralph_loop.sh
index a7c2f1e0..260bdab2 100755
--- a/ralph_loop.sh
+++ b/ralph_loop.sh
@@ -78,6 +78,7 @@ _env_CLAUDE_CODE_CMD="${CLAUDE_CODE_CMD:-}"
 _env_CLAUDE_AUTO_UPDATE="${CLAUDE_AUTO_UPDATE:-}"
 _env_CLAUDE_MODEL="${CLAUDE_MODEL:-}"
 _env_CLAUDE_EFFORT="${CLAUDE_EFFORT:-}"
+_env_CLAUDE_ANTHROPIC_BASE_URL="${CLAUDE_ANTHROPIC_BASE_URL:-}"
 _env_RALPH_SHELL_INIT_FILE="${RALPH_SHELL_INIT_FILE:-}"
 _env_ENABLE_NOTIFICATIONS="${ENABLE_NOTIFICATIONS:-}"
 _env_ENABLE_BACKUP="${ENABLE_BACKUP:-}"
@@ -113,6 +114,7 @@ CLAUDE_AUTO_UPDATE="${CLAUDE_AUTO_UPDATE:-true}"  # Auto-update Claude CLI at st
 CLAUDE_CODE_CMD="${CLAUDE_CODE_CMD:-claude}"     # Claude Code CLI command (default: global install)
 CLAUDE_MODEL="${CLAUDE_MODEL:-}"                 # Model override (e.g. claude-sonnet-4-6); empty = CLI default
 CLAUDE_EFFORT="${CLAUDE_EFFORT:-}"               # Effort level override (e.g. high, low); empty = CLI default
+CLAUDE_ANTHROPIC_BASE_URL="${CLAUDE_ANTHROPIC_BASE_URL:-}" # Anthropic-compatible API base URL override; empty = CLI default
 RALPH_SHELL_INIT_FILE="${RALPH_SHELL_INIT_FILE:-}" # Shell init file to source before running claude (e.g. ~/.zshrc)
 DRY_RUN="${DRY_RUN:-false}"                      # Simulate loop without making actual Claude API calls
 ENABLE_NOTIFICATIONS="${ENABLE_NOTIFICATIONS:-false}"  # Enable desktop notifications; set true or use --notify flag
@@ -328,6 +330,7 @@ load_ralphrc() {
     [[ -n "$_env_CLAUDE_AUTO_UPDATE" ]] && CLAUDE_AUTO_UPDATE="$_env_CLAUDE_AUTO_UPDATE"
     [[ -n "$_env_CLAUDE_MODEL" ]] && CLAUDE_MODEL="$_env_CLAUDE_MODEL"
     [[ -n "$_env_CLAUDE_EFFORT" ]] && CLAUDE_EFFORT="$_env_CLAUDE_EFFORT"
+    [[ -n "$_env_CLAUDE_ANTHROPIC_BASE_URL" ]] && CLAUDE_ANTHROPIC_BASE_URL="$_env_CLAUDE_ANTHROPIC_BASE_URL"
     [[ -n "$_env_RALPH_SHELL_INIT_FILE" ]] && RALPH_SHELL_INIT_FILE="$_env_RALPH_SHELL_INIT_FILE"
     [[ -n "$_env_ENABLE_NOTIFICATIONS" ]] && ENABLE_NOTIFICATIONS="$_env_ENABLE_NOTIFICATIONS"
     [[ -n "$_env_ENABLE_BACKUP" ]] && ENABLE_BACKUP="$_env_ENABLE_BACKUP"
@@ -1559,6 +1562,11 @@ build_claude_command() {
         CLAUDE_CMD_ARGS+=("--effort" "$CLAUDE_EFFORT")
     fi
 
+    # Add Anthropic-compatible API base URL override (for custom providers)
+    if [[ -n "${CLAUDE_ANTHROPIC_BASE_URL:-}" ]]; then
+        CLAUDE_CMD_ARGS+=("--anthropic-base-url" "$CLAUDE_ANTHROPIC_BASE_URL")
+    fi
+
     # Add output format flag
     if [[ "$CLAUDE_OUTPUT_FORMAT" == "json" ]]; then
         CLAUDE_CMD_ARGS+=("--output-format" "json")
diff --git a/templates/ralphrc.template b/templates/ralphrc.template
index 9f1baed1..baa66155 100644
--- a/templates/ralphrc.template
+++ b/templates/ralphrc.template
@@ -103,6 +103,10 @@ CLAUDE_AUTO_UPDATE=true
 # Minimum Claude CLI version required
 CLAUDE_MIN_VERSION="2.0.76"
 
+# Optional Anthropic-compatible API base URL override for custom providers
+# Example: MiniMax Claude-compatible endpoint
+# CLAUDE_ANTHROPIC_BASE_URL="https://api.minimax.io/anthropic"
+
 # Enable verbose logging
 RALPH_VERBOSE=false
 
diff --git a/tests/unit/test_cli_modern.bats b/tests/unit/test_cli_modern.bats
index d3228a3e..05fbeb63 100644
--- a/tests/unit/test_cli_modern.bats
+++ b/tests/unit/test_cli_modern.bats
@@ -192,6 +192,7 @@ setup() {
     _env_CLAUDE_CODE_CMD="${CLAUDE_CODE_CMD:-}"
     _env_CLAUDE_MODEL="${CLAUDE_MODEL:-}"
     _env_CLAUDE_EFFORT="${CLAUDE_EFFORT:-}"
+    _env_CLAUDE_ANTHROPIC_BASE_URL="${CLAUDE_ANTHROPIC_BASE_URL:-}"
     _env_RALPH_SHELL_INIT_FILE="${RALPH_SHELL_INIT_FILE:-}"
 
     load_ralphrc() {
@@ -202,6 +203,7 @@ setup() {
         [[ -n "$_env_CLAUDE_CODE_CMD" ]] && CLAUDE_CODE_CMD="$_env_CLAUDE_CODE_CMD"
         [[ -n "$_env_CLAUDE_MODEL" ]] && CLAUDE_MODEL="$_env_CLAUDE_MODEL"
         [[ -n "$_env_CLAUDE_EFFORT" ]] && CLAUDE_EFFORT="$_env_CLAUDE_EFFORT"
+        [[ -n "$_env_CLAUDE_ANTHROPIC_BASE_URL" ]] && CLAUDE_ANTHROPIC_BASE_URL="$_env_CLAUDE_ANTHROPIC_BASE_URL"
         [[ -n "$_env_RALPH_SHELL_INIT_FILE" ]] && RALPH_SHELL_INIT_FILE="$_env_RALPH_SHELL_INIT_FILE"
         RALPHRC_LOADED=true
         return 0
@@ -548,6 +550,11 @@ build_claude_command() {
         CLAUDE_CMD_ARGS+=("--effort" "$CLAUDE_EFFORT")
     fi
 
+    # Add Anthropic-compatible API base URL override
+    if [[ -n "${CLAUDE_ANTHROPIC_BASE_URL:-}" ]]; then
+        CLAUDE_CMD_ARGS+=("--anthropic-base-url" "$CLAUDE_ANTHROPIC_BASE_URL")
+    fi
+
     # Add output format flag
     if [[ "$CLAUDE_OUTPUT_FORMAT" == "json" ]]; then
         CLAUDE_CMD_ARGS+=("--output-format" "json")
@@ -1937,6 +1944,17 @@ EOF
     assert_equal "$CLAUDE_EFFORT" "high"
 }
 
+@test "CLAUDE_ANTHROPIC_BASE_URL from .ralphrc is loaded correctly" {
+    cat > "$TEST_DIR/.ralphrc" << 'EOF'
+CLAUDE_ANTHROPIC_BASE_URL="https://api.minimax.io/anthropic"
+EOF
+    _env_CLAUDE_ANTHROPIC_BASE_URL=""
+    CLAUDE_ANTHROPIC_BASE_URL=""
+
+    load_ralphrc
+    assert_equal "$CLAUDE_ANTHROPIC_BASE_URL" "https://api.minimax.io/anthropic"
+}
+
 @test "CLAUDE_MODEL env var takes precedence over .ralphrc" {
     cat > "$TEST_DIR/.ralphrc" << 'EOF'
 CLAUDE_MODEL="claude-sonnet-4-6"
@@ -1959,6 +1977,17 @@ EOF
     assert_equal "$CLAUDE_EFFORT" "high"
 }
 
+@test "CLAUDE_ANTHROPIC_BASE_URL env var takes precedence over .ralphrc" {
+    cat > "$TEST_DIR/.ralphrc" << 'EOF'
+CLAUDE_ANTHROPIC_BASE_URL="https://api.example.com/anthropic"
+EOF
+    _env_CLAUDE_ANTHROPIC_BASE_URL="https://api.minimax.io/anthropic"
+    CLAUDE_ANTHROPIC_BASE_URL="https://api.minimax.io/anthropic"
+
+    load_ralphrc
+    assert_equal "$CLAUDE_ANTHROPIC_BASE_URL" "https://api.minimax.io/anthropic"
+}
+
 @test "build_claude_command includes --model flag when CLAUDE_MODEL is set" {
     CLAUDE_MODEL="claude-sonnet-4-6"
     CLAUDE_EFFORT=""
@@ -1981,15 +2010,29 @@ EOF
     [[ "${CLAUDE_CMD_ARGS[*]}" == *"high"* ]]
 }
 
-@test "build_claude_command omits --model and --effort when not configured" {
+@test "build_claude_command includes --anthropic-base-url flag when CLAUDE_ANTHROPIC_BASE_URL is set" {
+    CLAUDE_MODEL=""
+    CLAUDE_EFFORT=""
+    CLAUDE_ANTHROPIC_BASE_URL="https://api.minimax.io/anthropic"
+    echo "test prompt" > "$TEST_DIR/PROMPT.md"
+
+    build_claude_command "$TEST_DIR/PROMPT.md" "" ""
+
+    [[ "${CLAUDE_CMD_ARGS[*]}" == *"--anthropic-base-url"* ]]
+    [[ "${CLAUDE_CMD_ARGS[*]}" == *"https://api.minimax.io/anthropic"* ]]
+}
+
+@test "build_claude_command omits --model, --effort, and --anthropic-base-url when not configured" {
     CLAUDE_MODEL=""
     CLAUDE_EFFORT=""
+    CLAUDE_ANTHROPIC_BASE_URL=""
     echo "test prompt" > "$TEST_DIR/PROMPT.md"
 
     build_claude_command "$TEST_DIR/PROMPT.md" "" ""
 
     [[ "${CLAUDE_CMD_ARGS[*]}" != *"--model"* ]]
     [[ "${CLAUDE_CMD_ARGS[*]}" != *"--effort"* ]]
+    [[ "${CLAUDE_CMD_ARGS[*]}" != *"--anthropic-base-url"* ]]
 }
 
 # ==============================================================================