diff --git a/pkg/config/config.go b/pkg/config/config.go
index e5161916a..7d1a28ac3 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"os"
+	"strings"
 	"sync/atomic"
 
 	"github.com/caarlos0/env/v11"
@@ -385,24 +386,24 @@ type DevicesConfig struct {
 }
 
 type ProvidersConfig struct {
-	Anthropic     ProviderConfig       `json:"anthropic"`
-	OpenAI        OpenAIProviderConfig `json:"openai"`
-	OpenRouter    ProviderConfig       `json:"openrouter"`
-	Groq          ProviderConfig       `json:"groq"`
-	Zhipu         ProviderConfig       `json:"zhipu"`
-	VLLM          ProviderConfig       `json:"vllm"`
-	Gemini        ProviderConfig       `json:"gemini"`
-	Nvidia        ProviderConfig       `json:"nvidia"`
-	Ollama        ProviderConfig       `json:"ollama"`
-	Moonshot      ProviderConfig       `json:"moonshot"`
-	ShengSuanYun  ProviderConfig       `json:"shengsuanyun"`
-	DeepSeek      ProviderConfig       `json:"deepseek"`
-	Cerebras      ProviderConfig       `json:"cerebras"`
-	VolcEngine    ProviderConfig       `json:"volcengine"`
-	GitHubCopilot ProviderConfig       `json:"github_copilot"`
-	Antigravity   ProviderConfig       `json:"antigravity"`
-	Qwen          ProviderConfig       `json:"qwen"`
-	Mistral       ProviderConfig       `json:"mistral"`
+	Anthropic     ProviderConfig       `json:"anthropic"        envPrefix:"PICOCLAW_PROVIDERS_ANTHROPIC_"`
+	OpenAI        OpenAIProviderConfig `json:"openai"           envPrefix:"PICOCLAW_PROVIDERS_OPENAI_"`
+	OpenRouter    ProviderConfig       `json:"openrouter"       envPrefix:"PICOCLAW_PROVIDERS_OPENROUTER_"`
+	Groq          ProviderConfig       `json:"groq"             envPrefix:"PICOCLAW_PROVIDERS_GROQ_"`
+	Zhipu         ProviderConfig       `json:"zhipu"            envPrefix:"PICOCLAW_PROVIDERS_ZHIPU_"`
+	VLLM          ProviderConfig       `json:"vllm"             envPrefix:"PICOCLAW_PROVIDERS_VLLM_"`
+	Gemini        ProviderConfig       `json:"gemini"           envPrefix:"PICOCLAW_PROVIDERS_GEMINI_"`
+	Nvidia        ProviderConfig       `json:"nvidia"           envPrefix:"PICOCLAW_PROVIDERS_NVIDIA_"`
+	Ollama        ProviderConfig       `json:"ollama"           envPrefix:"PICOCLAW_PROVIDERS_OLLAMA_"`
+	Moonshot      ProviderConfig       `json:"moonshot"         envPrefix:"PICOCLAW_PROVIDERS_MOONSHOT_"`
+	ShengSuanYun  ProviderConfig       `json:"shengsuanyun"     envPrefix:"PICOCLAW_PROVIDERS_SHENGSUANYUN_"`
+	DeepSeek      ProviderConfig       `json:"deepseek"         envPrefix:"PICOCLAW_PROVIDERS_DEEPSEEK_"`
+	Cerebras      ProviderConfig       `json:"cerebras"         envPrefix:"PICOCLAW_PROVIDERS_CEREBRAS_"`
+	VolcEngine    ProviderConfig       `json:"volcengine"       envPrefix:"PICOCLAW_PROVIDERS_VOLCENGINE_"`
+	GitHubCopilot ProviderConfig       `json:"github_copilot"   envPrefix:"PICOCLAW_PROVIDERS_GITHUB_COPILOT_"`
+	Antigravity   ProviderConfig       `json:"antigravity"      envPrefix:"PICOCLAW_PROVIDERS_ANTIGRAVITY_"`
+	Qwen          ProviderConfig       `json:"qwen"             envPrefix:"PICOCLAW_PROVIDERS_QWEN_"`
+	Mistral       ProviderConfig       `json:"mistral"          envPrefix:"PICOCLAW_PROVIDERS_MISTRAL_"`
 }
 
 // IsEmpty checks if all provider configs are empty (no API keys or API bases set)
@@ -439,17 +440,17 @@ func (p ProvidersConfig) MarshalJSON() ([]byte, error) {
 }
 
 type ProviderConfig struct {
-	APIKey         string `json:"api_key"                   env:"PICOCLAW_PROVIDERS_{{.Name}}_API_KEY"`
-	APIBase        string `json:"api_base"                  env:"PICOCLAW_PROVIDERS_{{.Name}}_API_BASE"`
-	Proxy          string `json:"proxy,omitempty"           env:"PICOCLAW_PROVIDERS_{{.Name}}_PROXY"`
-	RequestTimeout int    `json:"request_timeout,omitempty" env:"PICOCLAW_PROVIDERS_{{.Name}}_REQUEST_TIMEOUT"`
-	AuthMethod     string `json:"auth_method,omitempty"     env:"PICOCLAW_PROVIDERS_{{.Name}}_AUTH_METHOD"`
-	ConnectMode    string `json:"connect_mode,omitempty"    env:"PICOCLAW_PROVIDERS_{{.Name}}_CONNECT_MODE"` // only for Github Copilot, `stdio` or `grpc`
+	APIKey         string `json:"api_key"                   env:"API_KEY"`
+	APIBase        string `json:"api_base"                  env:"API_BASE"`
+	Proxy          string `json:"proxy,omitempty"           env:"PROXY"`
+	RequestTimeout int    `json:"request_timeout,omitempty" env:"REQUEST_TIMEOUT"`
+	AuthMethod     string `json:"auth_method,omitempty"     env:"AUTH_METHOD"`
+	ConnectMode    string `json:"connect_mode,omitempty"    env:"CONNECT_MODE"` // only for Github Copilot, `stdio` or `grpc`
 }
 
 type OpenAIProviderConfig struct {
 	ProviderConfig
-	WebSearch bool `json:"web_search" env:"PICOCLAW_PROVIDERS_OPENAI_WEB_SEARCH"`
+	WebSearch bool `json:"web_search" env:"WEB_SEARCH"`
 }
 
 // ModelConfig represents a model-centric provider configuration.
@@ -611,6 +612,20 @@ func LoadConfig(path string) (*Config, error) {
 		return nil, err
 	}
 
+	// Resolve environment variable overrides for model_list API keys.
+	// Convention: PICOCLAW_MODEL_<UPPER_MODEL_NAME>_API_KEY
+	modelNameReplacer := strings.NewReplacer("-", "_", ".", "_")
+	for i := range cfg.ModelList {
+		if cfg.ModelList[i].APIKey == "" && cfg.ModelList[i].ModelName != "" {
+			envKey := "PICOCLAW_MODEL_" + strings.ToUpper(
+				modelNameReplacer.Replace(cfg.ModelList[i].ModelName),
+			) + "_API_KEY"
+			if v := os.Getenv(envKey); v != "" {
+				cfg.ModelList[i].APIKey = v
+			}
+		}
+	}
+
 	// Migrate legacy channel config fields to new unified structures
 	cfg.migrateChannelConfigs()
 
diff --git a/pkg/config/config_test.go b/pkg/config/config_test.go
index ced0d925b..0fd3226d3 100644
--- a/pkg/config/config_test.go
+++ b/pkg/config/config_test.go
@@ -447,6 +447,65 @@ func TestDefaultConfig_SummarizationThresholds(t *testing.T) {
 	}
 }
 
+func TestLoadConfig_ProviderEnvVars(t *testing.T) {
+	tmpDir := t.TempDir()
+	configPath := filepath.Join(tmpDir, "config.json")
+	configJSON := `{
+  "providers": {
+    "anthropic": {},
+    "openai": {}
+  },
+  "model_list": [{"model_name":"test","model":"openai/gpt-5.2","api_key":"x"}]
+}`
+	if err := os.WriteFile(configPath, []byte(configJSON), 0o600); err != nil {
+		t.Fatalf("WriteFile error: %v", err)
+	}
+
+	t.Setenv("PICOCLAW_PROVIDERS_ANTHROPIC_API_KEY", "ant-env-key")
+	t.Setenv("PICOCLAW_PROVIDERS_OPENAI_API_KEY", "oai-env-key")
+
+	cfg, err := LoadConfig(configPath)
+	if err != nil {
+		t.Fatalf("LoadConfig error: %v", err)
+	}
+
+	if cfg.Providers.Anthropic.APIKey != "ant-env-key" {
+		t.Errorf("Anthropic.APIKey = %q, want %q", cfg.Providers.Anthropic.APIKey, "ant-env-key")
+	}
+	if cfg.Providers.OpenAI.APIKey != "oai-env-key" {
+		t.Errorf("OpenAI.APIKey = %q, want %q", cfg.Providers.OpenAI.APIKey, "oai-env-key")
+	}
+}
+
+func TestLoadConfig_ModelListEnvVars(t *testing.T) {
+	tmpDir := t.TempDir()
+	configPath := filepath.Join(tmpDir, "config.json")
+	configJSON := `{
+  "model_list": [
+    {"model_name": "gpt-5.2", "model": "openai/gpt-5.2", "api_key": ""},
+    {"model_name": "claude-sonnet-4.6", "model": "anthropic/claude-sonnet-4.6", "api_key": ""}
+  ]
+}`
+	if err := os.WriteFile(configPath, []byte(configJSON), 0o600); err != nil {
+		t.Fatalf("WriteFile error: %v", err)
+	}
+
+	t.Setenv("PICOCLAW_MODEL_GPT_5_2_API_KEY", "gpt-env-key")
+	t.Setenv("PICOCLAW_MODEL_CLAUDE_SONNET_4_6_API_KEY", "claude-env-key")
+
+	cfg, err := LoadConfig(configPath)
+	if err != nil {
+		t.Fatalf("LoadConfig error: %v", err)
+	}
+
+	if cfg.ModelList[0].APIKey != "gpt-env-key" {
+		t.Errorf("ModelList[0].APIKey = %q, want %q", cfg.ModelList[0].APIKey, "gpt-env-key")
+	}
+	if cfg.ModelList[1].APIKey != "claude-env-key" {
+		t.Errorf("ModelList[1].APIKey = %q, want %q", cfg.ModelList[1].APIKey, "claude-env-key")
+	}
+}
+
 func TestDefaultConfig_DMScope(t *testing.T) {
 	cfg := DefaultConfig()