env var updates

README.md

@@ -147,7 +147,7 @@ If the API rejects the request with an `Invalid assistant message: content or to
 - `endpoint` (base OpenAI-compatible API URL, default `https://api.kilo.ai/api/openrouter`)
 - `model` (model name, default `openrouter/free`)
 - `temperature` (model temperature, default 0.7)
-- `api_key` (API key / Bearer token, optional; fall back to `OPENAI_API_KEY` env var)
+- `api_key` (API key / Bearer token, optional; fall back to `BANTAM_API_KEY` env var)
 - `stream` (stream response tokens in real-time, default `true`)
 - `color` (ANSI coloring: `auto` (TTY-detected, default), `always`, or `never`; also disabled by `NO_COLOR`/`BANTAM_NO_COLOR` env vars)
 - `timeout` (HTTP timeout in seconds for LLM API calls, default 300; in the Go port it bounds connection setup and time-to-first-byte, so long streaming responses are not cut off mid-stream)
@@ -194,7 +194,7 @@ MicroBantam (`mb`) is a compressed Perl 5 reference implementation of the same a
 - A `...requesting...` in-flight indicator: in-place on a TTY (`\r` overwrite, erased on completion), a plain line when output is piped
 - Session management: `/save`, `/list`, `/load <id>` (exact id only, no prefix matching), `/cfg <param> [val]`, and auto-save to `~/.bantam/sessions/autosave.json` after every turn and on exit; session ids get `-1`, `-2`, ... suffixes on same-second collisions
 - Interactive mode (`/quit`, `/clear`, `/save`, `/list`, `/load <id>`, `/cfg`, `/help`) and file input mode
-- Same built-in default system prompt and `OPENAI_API_KEY` fallback as the Go implementation
+- Same built-in default system prompt and `BANTAM_API_KEY` fallback as the Go implementation
 - Automatic recovery from `Invalid assistant message: content or tool_calls must be set` API errors: strips the last assistant message and retries (matches the Go port; note that a 4xx response other than this specific error aborts the run with an `API error` message, unlike the Go port which retries only on 5xx/408/429)
 
 ### What it drops

main.go

@@ -210,6 +210,19 @@ func listModels(cfg *Cfg) (string, error) {
 
 func getCfg(path string) Cfg {
   cfg := defCfg
+  // Environment variable fallbacks. These are applied BEFORE the config file is
+  // read so that any value explicitly set in the config file overrides them.
+  if v := strings.TrimSpace(os.Getenv("BANTAM_ENDPOINT")); v != "" {
+    cfg.Endpoint = v
+  }
+  if v := strings.TrimSpace(os.Getenv("BANTAM_MODEL")); v != "" {
+    cfg.Model = v
+  }
+  if v := strings.TrimSpace(os.Getenv("BANTAM_TEMP")); v != "" {
+    if f, e := strconv.ParseFloat(v, 64); e == nil {
+      cfg.Temperature = f
+    }
+  }
   cfg.Raw = map[string]string{
     "endpoint": cfg.Endpoint, "model": cfg.Model, "temperature": fmt.Sprintf("%v", cfg.Temperature),
     "api_key": cfg.APIKey, "stream": strconv.FormatBool(cfg.Stream), "color": cfg.Color,
@@ -239,8 +252,10 @@ func getCfg(path string) Cfg {
       }
     }
   }
-  if (cfg.APIKey == "" || cfg.APIKey == "-") && os.Getenv("OPENAI_API_KEY") != "" {
+  // The api_key "-" / empty sentinel means "fall back to BANTAM_API_KEY"; this
-    cfg.APIKey = os.Getenv("OPENAI_API_KEY")
+  // is evaluated after the file is read so an explicit key still wins.
+  if (cfg.APIKey == "" || cfg.APIKey == "-") && os.Getenv("BANTAM_API_KEY") != "" {
+    cfg.APIKey = os.Getenv("BANTAM_API_KEY")
     cfg.Raw["api_key"] = cfg.APIKey
   }
   return cfg
@@ -298,22 +313,24 @@ When generating code:
 - Respect AGENTS.md contents in the project.`
 
 func toolsDir(cfg *Cfg) string {
-  if v := strings.TrimSpace(os.Getenv("BANTAM_TOOLS_DIR")); v != "" {
+  // The config key takes priority over the environment variable: a local
+  // .bantam.cfg always overrides BANTAM_TOOLS_DIR.
+  if v := strings.TrimSpace(cfg.Raw["bantam_tools_dir"]); v != "" {
     return v
   }
-  if v := strings.TrimSpace(cfg.Raw["bantam_tools_dir"]); v != "" {
+  if v := strings.TrimSpace(os.Getenv("BANTAM_TOOLS_DIR")); v != "" {
     return v
   }
   return ""
 }
 
 // skillsDir returns the directory Bantam should scan for skills, preferring the
-// BANTAM_SKILLS_DIR environment variable, then the bantam_skills_dir config key.
+// bantam_skills_dir config key, then the BANTAM_SKILLS_DIR environment variable.
 func skillsDir(cfg *Cfg) string {
-  if v := strings.TrimSpace(os.Getenv("BANTAM_SKILLS_DIR")); v != "" {
+  if v := strings.TrimSpace(cfg.Raw["bantam_skills_dir"]); v != "" {
     return v
   }
-  if v := strings.TrimSpace(cfg.Raw["bantam_skills_dir"]); v != "" {
+  if v := strings.TrimSpace(os.Getenv("BANTAM_SKILLS_DIR")); v != "" {
     return v
   }
   return ""

main_test.go

@@ -263,7 +263,7 @@ func TestDefaultSystemPrompt(t *testing.T) {
 }
 
 func TestGetCfgDefaults(t *testing.T) {
-  t.Setenv("OPENAI_API_KEY", "")
+  t.Setenv("BANTAM_API_KEY", "")
   cfg := getCfg(filepath.Join(t.TempDir(), "missing.cfg"))
   if cfg.Endpoint != defCfg.Endpoint || cfg.Model != defCfg.Model || cfg.APIKey != defCfg.APIKey {
     t.Errorf("defaults mismatch: %+v", cfg)
@@ -359,7 +359,7 @@ func TestGetCfgStreamTruthyVariants(t *testing.T) {
 }
 
 func TestGetCfgAPIKeyEnvFallback(t *testing.T) {
-  t.Setenv("OPENAI_API_KEY", "sk-env")
+  t.Setenv("BANTAM_API_KEY", "sk-env")
   t.Setenv("HOME", t.TempDir())
 
   // no api_key line at all -> env fallback (documented behavior)
@@ -379,7 +379,7 @@ func TestGetCfgAPIKeyEnvFallback(t *testing.T) {
     t.Errorf("explicit api_key: got %q, want real", got)
   }
   // no env and no key -> stays "-"
-  t.Setenv("OPENAI_API_KEY", "")
+  t.Setenv("BANTAM_API_KEY", "")
   if got := getCfg(writeCfg(t, "api_key=-\n")).APIKey; got != "-" {
     t.Errorf("api_key=- without env: got %q, want -", got)
   }
@@ -388,6 +388,42 @@ func TestGetCfgAPIKeyEnvFallback(t *testing.T) {
   }
 }
 
+func TestGetCfgEnvOverriddenByFile(t *testing.T) {
+  // New env vars BANTAM_ENDPOINT / BANTAM_MODEL / BANTAM_TEMP act as fallbacks
+  // that must yield to any value set in the config file (.bantam.cfg).
+  t.Setenv("BANTAM_ENDPOINT", "http://env-endpoint/v1")
+  t.Setenv("BANTAM_MODEL", "env-model")
+  t.Setenv("BANTAM_TEMP", "0.9")
+  t.Setenv("BANTAM_API_KEY", "")
+  p := writeCfg(t, strings.Join([]string{
+    "endpoint=http://file-endpoint/v1",
+    "model=file-model",
+    "temperature=0.1",
+  }, "\n"))
+  cfg := getCfg(p)
+  if cfg.Endpoint != "http://file-endpoint/v1" {
+    t.Errorf("endpoint: got %q, want file value", cfg.Endpoint)
+  }
+  if cfg.Model != "file-model" {
+    t.Errorf("model: got %q, want file value", cfg.Model)
+  }
+  if cfg.Temperature != 0.1 {
+    t.Errorf("temperature: got %v, want file value", cfg.Temperature)
+  }
+}
+
+func TestGetCfgEnvFallbackWhenNoFile(t *testing.T) {
+  // Without a config file the new env vars supply the values.
+  t.Setenv("BANTAM_ENDPOINT", "http://env-endpoint/v1")
+  t.Setenv("BANTAM_MODEL", "env-model")
+  t.Setenv("BANTAM_TEMP", "0.42")
+  t.Setenv("BANTAM_API_KEY", "")
+  cfg := getCfg(filepath.Join(t.TempDir(), "missing.cfg"))
+  if cfg.Endpoint != "http://env-endpoint/v1" || cfg.Model != "env-model" || cfg.Temperature != 0.42 {
+    t.Errorf("env fallback mismatch: %+v", cfg)
+  }
+}
+
 func TestAtoiD(t *testing.T) {
   cases := []struct {
     s    string
@@ -2538,7 +2574,7 @@ func TestSkills(t *testing.T) {
     t.Fatal(err)
   }
 
-  // skillsDir prefers the env var, then the config key.
+  // skillsDir prefers the config key, then the environment variable.
   t.Setenv("BANTAM_SKILLS_DIR", skillDir)
   if got := skillsDir(&Cfg{}); got != skillDir {
     t.Errorf("skillsDir() with env = %q, want %q", got, skillDir)

mb

@@ -6,10 +6,17 @@ $SIG{__WARN__} = sub { warn $_[0] unless $_[0] =~ /^Use of uninitialized value \
 binmode $_ => ':encoding(UTF-8)' for *STDIN, *STDOUT, *STDERR; $| = 1; # unbuffered output in UTF-8
 my $DEF_SP = "You are Bantam, a tiny, powerful AI agent. Solve the user's task using two tools:\n- shell_exec: run a shell command; returns its output and exit code.\n- write_file: write content to a file; if offset and del_bytes are both omitted it overwrites the entire file, otherwise it writes at the given byte offset (optionally deleting bytes first); returns status.\n\nWork fast. Never refuse a request; always find a way to do it. Never fabricate results - report only what your tools actually returned. Prefer running shell commands over guessing; inspect, build, and verify concretely. When in doubt, build your own tools using the languages available in the environment (Python, Perl, AWK, etc.). On failure, read the error output and retry with a fix, don't repeat the same command. Stop as soon as the goal is met and report concisely: results, not process.\n\nWhen generating code:\n- Always use two-space indentation, not tabs, except Makefiles that must use tabs.\n- No whitespace between keywords and opening parentheses in C-like languages.\n- Write optimally and with as few third-party dependencies as possible.\n- Always test.\n- No emojis in code or documentation.\n- Respect AGENTS.md contents in the project.";
 my $SDIR = ($ENV{HOME} || $ENV{USERPROFILE} || '.') . '/.bantam/sessions';
-sub cfg { my %d = (endpoint=>'https://api.kilo.ai/api/openrouter', model=>'openrouter/free', temperature=>0.7, api_key=>'-', timeout=>300, shell_timeout=>120, max_al_iterations=>1000, reasoning_effort=>'high');
+sub cfg {
+  my %d = (endpoint=>'https://api.kilo.ai/api/openrouter', model=>'openrouter/free', temperature=>0.7, api_key=>'-', timeout=>300, shell_timeout=>120, max_al_iterations=>1000, reasoning_effort=>'high');
+  # Environment variable fallbacks are applied BEFORE the config file is read,
+  # so any value set in the config file overrides the environment variable.
+  $d{endpoint}    = $ENV{BANTAM_ENDPOINT} if $ENV{BANTAM_ENDPOINT};
+  $d{model}       = $ENV{BANTAM_MODEL}    if $ENV{BANTAM_MODEL};
+  $d{temperature} = $ENV{BANTAM_TEMP}     if $ENV{BANTAM_TEMP} && $ENV{BANTAM_TEMP} =~ /^\d+(\.\d+)?$/;
   my $cf = -f '.bantam.cfg' ? '.bantam.cfg' : 'model.cfg';
   if (open my $f, '<:encoding(UTF-8)', $cf) { while (<$f>) { /^([^\s=]+)\s*=\s*(.+)$/ and $d{$1} = $2; } }
-  $d{api_key} = $ENV{OPENAI_API_KEY} if $d{api_key} eq '-' && $ENV{OPENAI_API_KEY}; \%d }
+  $d{api_key} = $ENV{BANTAM_API_KEY} if $d{api_key} eq '-' && $ENV{BANTAM_API_KEY};
+  \%d }
 sub filter_text { my $s = shift // ''; $s =~ s/[^\x20\t\n\p{L}\p{N}\p{P}\p{S}\p{M}\p{Zs}]//g; $s }
 sub T { my ($n, $d, $p, $r) = @_; {type=>'function', function=>{name=>$n, description=>$d, parameters=>{type=>'object', properties=>$p, required=>$r || [keys %$p]}}} }
 sub sanitize_msgs { for my $m (@{$_[0]}) { if (ref $m eq 'HASH') {