diff --git a/providertests/.env.sample b/providertests/.env.sample
index db4c285764209ef84a09529c4f591f931b33d53e..97b2e8e94995c88719b509206c95fed24fe2ba9f 100644
--- a/providertests/.env.sample
+++ b/providertests/.env.sample
@@ -1,7 +1,7 @@
-ANTHROPIC_API_KEY=
-GEMINI_API_KEY=
-GROQ_API_KEY=
-OPENAI_API_KEY=
-OPENROUTER_API_KEY=
-XAI_API_KEY=
-ZAI_API_KEY=
+FANTASY_ANTHROPIC_API_KEY=
+FANTASY_GEMINI_API_KEY=
+FANTASY_GROQ_API_KEY=
+FANTASY_OPENAI_API_KEY=
+FANTASY_OPENROUTER_API_KEY=
+FANTASY_XAI_API_KEY=
+FANTASY_ZAI_API_KEY=
diff --git a/providertests/anthropic_test.go b/providertests/anthropic_test.go
index 8797cc09370582ac41cf1aa9a5341dfa575756b8..2526e33ba44f39acba9f1d229bed2c80eb15961b 100644
--- a/providertests/anthropic_test.go
+++ b/providertests/anthropic_test.go
@@ -80,7 +80,7 @@ func testAnthropicThinking(t *testing.T, result *ai.AgentResult) {
 func anthropicBuilder(model string) builderFunc {
 	return func(r *recorder.Recorder) (ai.LanguageModel, error) {
 		provider := anthropic.New(
-			anthropic.WithAPIKey(os.Getenv("ANTHROPIC_API_KEY")),
+			anthropic.WithAPIKey(os.Getenv("FANTASY_ANTHROPIC_API_KEY")),
 			anthropic.WithHTTPClient(&http.Client{Transport: r}),
 		)
 		return provider.LanguageModel(model)
diff --git a/providertests/google_test.go b/providertests/google_test.go
index 3147802d687e8ccfb0458a9a48f45ed6a4eb425f..98ce06565bf54555de50e717252b45679f73efe4 100644
--- a/providertests/google_test.go
+++ b/providertests/google_test.go
@@ -63,7 +63,7 @@ func testGoogleThinking(t *testing.T, result *ai.AgentResult) {
 func googleBuilder(model string) builderFunc {
 	return func(r *recorder.Recorder) (ai.LanguageModel, error) {
 		provider := google.New(
-			google.WithAPIKey(cmp.Or(os.Getenv("GEMINI_API_KEY"), "(missing)")),
+			google.WithAPIKey(cmp.Or(os.Getenv("FANTASY_GEMINI_API_KEY"), "(missing)")),
 			google.WithHTTPClient(&http.Client{Transport: r}),
 		)
 		return provider.LanguageModel(model)
diff --git a/providertests/openai_test.go b/providertests/openai_test.go
index 80759345ace8d91cccb319b9589c559b73c2f20d..52067860de60478a8b708bf64cf42d1c0417ee61 100644
--- a/providertests/openai_test.go
+++ b/providertests/openai_test.go
@@ -20,7 +20,7 @@ func TestOpenAICommon(t *testing.T) {
 
 func builderOpenaiGpt4o(r *recorder.Recorder) (ai.LanguageModel, error) {
 	provider := openai.New(
-		openai.WithAPIKey(os.Getenv("OPENAI_API_KEY")),
+		openai.WithAPIKey(os.Getenv("FANTASY_OPENAI_API_KEY")),
 		openai.WithHTTPClient(&http.Client{Transport: r}),
 	)
 	return provider.LanguageModel("gpt-4o")
@@ -28,7 +28,7 @@ func builderOpenaiGpt4o(r *recorder.Recorder) (ai.LanguageModel, error) {
 
 func builderOpenaiGpt4oMini(r *recorder.Recorder) (ai.LanguageModel, error) {
 	provider := openai.New(
-		openai.WithAPIKey(os.Getenv("OPENAI_API_KEY")),
+		openai.WithAPIKey(os.Getenv("FANTASY_OPENAI_API_KEY")),
 		openai.WithHTTPClient(&http.Client{Transport: r}),
 	)
 	return provider.LanguageModel("gpt-4o-mini")
@@ -36,7 +36,7 @@ func builderOpenaiGpt4oMini(r *recorder.Recorder) (ai.LanguageModel, error) {
 
 func builderOpenaiGpt5(r *recorder.Recorder) (ai.LanguageModel, error) {
 	provider := openai.New(
-		openai.WithAPIKey(os.Getenv("OPENAI_API_KEY")),
+		openai.WithAPIKey(os.Getenv("FANTASY_OPENAI_API_KEY")),
 		openai.WithHTTPClient(&http.Client{Transport: r}),
 	)
 	return provider.LanguageModel("gpt-5")
diff --git a/providertests/openaicompat_test.go b/providertests/openaicompat_test.go
index 7735a5842d242e12b6b4f8b256336e4ba2d6a665..b0837afa56e49854be346619f4e1f1bcd66c3e25 100644
--- a/providertests/openaicompat_test.go
+++ b/providertests/openaicompat_test.go
@@ -50,7 +50,7 @@ func testOpenAICompatThinking(t *testing.T, result *ai.AgentResult) {
 func builderXAIGrokCodeFast(r *recorder.Recorder) (ai.LanguageModel, error) {
 	provider := openaicompat.New(
 		"https://api.x.ai/v1",
-		openaicompat.WithAPIKey(os.Getenv("XAI_API_KEY")),
+		openaicompat.WithAPIKey(os.Getenv("FANTASY_XAI_API_KEY")),
 		openaicompat.WithHTTPClient(&http.Client{Transport: r}),
 	)
 	return provider.LanguageModel("grok-code-fast-1")
@@ -59,7 +59,7 @@ func builderXAIGrokCodeFast(r *recorder.Recorder) (ai.LanguageModel, error) {
 func builderXAIGrok4Fast(r *recorder.Recorder) (ai.LanguageModel, error) {
 	provider := openaicompat.New(
 		"https://api.x.ai/v1",
-		openaicompat.WithAPIKey(os.Getenv("XAI_API_KEY")),
+		openaicompat.WithAPIKey(os.Getenv("FANTASY_XAI_API_KEY")),
 		openaicompat.WithHTTPClient(&http.Client{Transport: r}),
 	)
 	return provider.LanguageModel("grok-4-fast")
@@ -68,7 +68,7 @@ func builderXAIGrok4Fast(r *recorder.Recorder) (ai.LanguageModel, error) {
 func builderXAIGrok3Mini(r *recorder.Recorder) (ai.LanguageModel, error) {
 	provider := openaicompat.New(
 		"https://api.x.ai/v1",
-		openaicompat.WithAPIKey(os.Getenv("XAI_API_KEY")),
+		openaicompat.WithAPIKey(os.Getenv("FANTASY_XAI_API_KEY")),
 		openaicompat.WithHTTPClient(&http.Client{Transport: r}),
 	)
 	return provider.LanguageModel("grok-3-mini")
@@ -77,7 +77,7 @@ func builderXAIGrok3Mini(r *recorder.Recorder) (ai.LanguageModel, error) {
 func builderZAIGLM45(r *recorder.Recorder) (ai.LanguageModel, error) {
 	provider := openaicompat.New(
 		"https://api.z.ai/api/coding/paas/v4",
-		openaicompat.WithAPIKey(os.Getenv("ZAI_API_KEY")),
+		openaicompat.WithAPIKey(os.Getenv("FANTASY_ZAI_API_KEY")),
 		openaicompat.WithHTTPClient(&http.Client{Transport: r}),
 	)
 	return provider.LanguageModel("glm-4.5")
@@ -86,7 +86,7 @@ func builderZAIGLM45(r *recorder.Recorder) (ai.LanguageModel, error) {
 func builderGroq(r *recorder.Recorder) (ai.LanguageModel, error) {
 	provider := openaicompat.New(
 		"https://api.groq.com/openai/v1",
-		openaicompat.WithAPIKey(os.Getenv("GROQ_API_KEY")),
+		openaicompat.WithAPIKey(os.Getenv("FANTASY_GROQ_API_KEY")),
 		openaicompat.WithHTTPClient(&http.Client{Transport: r}),
 	)
 	return provider.LanguageModel("moonshotai/kimi-k2-instruct-0905")
diff --git a/providertests/openrouter_test.go b/providertests/openrouter_test.go
index 50a58790961eb6377252e2f0ba899b4af8559708..1892d60f0b0bb5338480e0b06cfc61b03b6a3215 100644
--- a/providertests/openrouter_test.go
+++ b/providertests/openrouter_test.go
@@ -162,7 +162,7 @@ func TestOpenRouterWithUniqueToolCallIDs(t *testing.T) {
 		r := newRecorder(t)
 
 		provider := openrouter.New(
-			openrouter.WithAPIKey(os.Getenv("OPENROUTER_API_KEY")),
+			openrouter.WithAPIKey(os.Getenv("FANTASY_OPENROUTER_API_KEY")),
 			openrouter.WithHTTPClient(&http.Client{Transport: r}),
 			openrouter.WithLanguageUniqueToolCallIds(),
 			openrouter.WithLanguageModelGenerateIDFunc(generateIDFunc),
@@ -187,7 +187,7 @@ func TestOpenRouterWithUniqueToolCallIDs(t *testing.T) {
 		r := newRecorder(t)
 
 		provider := openrouter.New(
-			openrouter.WithAPIKey(os.Getenv("OPENROUTER_API_KEY")),
+			openrouter.WithAPIKey(os.Getenv("FANTASY_OPENROUTER_API_KEY")),
 			openrouter.WithHTTPClient(&http.Client{Transport: r}),
 			openrouter.WithLanguageUniqueToolCallIds(),
 			openrouter.WithLanguageModelGenerateIDFunc(generateIDFunc),
@@ -213,7 +213,7 @@ func TestOpenRouterWithUniqueToolCallIDs(t *testing.T) {
 func openrouterBuilder(model string) builderFunc {
 	return func(r *recorder.Recorder) (ai.LanguageModel, error) {
 		provider := openrouter.New(
-			openrouter.WithAPIKey(os.Getenv("OPENROUTER_API_KEY")),
+			openrouter.WithAPIKey(os.Getenv("FANTASY_OPENROUTER_API_KEY")),
 			openrouter.WithHTTPClient(&http.Client{Transport: r}),
 		)
 		return provider.LanguageModel(model)