diff --git a/coderd/x/chatd/chatprovider/chatprovider_test.go b/coderd/x/chatd/chatprovider/chatprovider_test.go
index acb0dc9ea1..bb94d3b0c3 100644
--- a/coderd/x/chatd/chatprovider/chatprovider_test.go
+++ b/coderd/x/chatd/chatprovider/chatprovider_test.go
@@ -2,6 +2,7 @@ package chatprovider_test
 
 import (
 	"encoding/json"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -967,6 +968,87 @@ func TestModelFromConfig_Bedrock(t *testing.T) {
 	})
 }
 
+// TestModelFromConfig_BedrockStripsAnthropicHeaders is a regression test
+// for a bug where the Anthropic SDK reads ANTHROPIC_API_KEY from the
+// process environment and adds X-Api-Key and Anthropic-Version headers to
+// every request. On Bedrock, these headers conflict with SigV4 signing and
+// cause auth failures. The SDK's Bedrock middleware strips them before
+// signing. This test verifies the outgoing request shape with both
+// Anthropic and AWS credentials present.
+func TestModelFromConfig_BedrockStripsAnthropicHeaders(t *testing.T) {
+	ctx := testutil.Context(t, testutil.WaitShort)
+
+	t.Setenv("ANTHROPIC_API_KEY", "anthropic-env-key")
+	t.Setenv("AWS_REGION", "us-east-2")
+	t.Setenv("AWS_ACCESS_KEY_ID", "test-access-key")
+	t.Setenv("AWS_SECRET_ACCESS_KEY", "test-secret-key")
+	t.Setenv("AWS_SESSION_TOKEN", "test-session-token")
+
+	type requestCapture struct {
+		Authorization    string
+		AnthropicVersion string
+		XAPIKey          string
+		Body             string
+		ReadError        error
+	}
+
+	requests := make(chan requestCapture, 1)
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		body, err := io.ReadAll(r.Body)
+
+		requests <- requestCapture{
+			Authorization:    r.Header.Get("Authorization"),
+			AnthropicVersion: r.Header.Get("Anthropic-Version"),
+			XAPIKey:          r.Header.Get("X-Api-Key"),
+			Body:             string(body),
+			ReadError:        err,
+		}
+
+		w.Header().Set("Content-Type", "application/json")
+		_ = json.NewEncoder(w).Encode(bedrockNonStreamingResponse())
+	}))
+	defer server.Close()
+
+	model, err := chatprovider.ModelFromConfig(
+		fantasybedrock.Name,
+		"anthropic.claude-opus-4-6-v1",
+		chatprovider.ProviderAPIKeys{
+			ByProvider: map[string]string{
+				fantasybedrock.Name: "",
+			},
+			BaseURLByProvider: map[string]string{
+				fantasybedrock.Name: server.URL,
+			},
+		},
+		chatprovider.UserAgent(),
+		nil,
+		nil,
+	)
+	require.NoError(t, err)
+	require.NotNil(t, model)
+
+	_, err = model.Generate(ctx, fantasy.Call{
+		Prompt: []fantasy.Message{
+			{
+				Role: fantasy.MessageRoleUser,
+				Content: []fantasy.MessagePart{
+					fantasy.TextPart{Text: "hello"},
+				},
+			},
+		},
+	})
+	require.NoError(t, err)
+
+	got := testutil.TryReceive(ctx, t, requests)
+	require.NoError(t, got.ReadError)
+	require.Empty(t, got.AnthropicVersion)
+	require.Empty(t, got.XAPIKey)
+	require.Contains(t, got.Authorization, "AWS4-HMAC-SHA256")
+	require.NotContains(t, got.Authorization, "anthropic-version")
+	require.NotContains(t, got.Authorization, "x-api-key")
+	require.Contains(t, got.Body, `"anthropic_version":"bedrock-2023-05-31"`)
+}
+
 func bedrockNonStreamingResponse() map[string]any {
 	return map[string]any{
 		"id":    "msg_01Test",
diff --git a/go.mod b/go.mod
index c34586470a..c7c4e3552c 100644
--- a/go.mod
+++ b/go.mod
@@ -89,10 +89,10 @@ replace github.com/spf13/afero => github.com/aslilac/afero v0.0.0-20250403163713
 // See: https://github.com/coder/fantasy/commits/f83367a4a205
 replace charm.land/fantasy => github.com/coder/fantasy v0.0.0-20260426185602-951a49c681df
 
-// coder/coder uses a fork of charmbracelet's fork of the Anthropic Go SDK with some
-// additional performance improvements.
-// See: https://github.com/coder/anthropic-sdk-go/commits/a31d7d0e7067
-replace github.com/charmbracelet/anthropic-sdk-go => github.com/coder/anthropic-sdk-go v0.0.0-20260415160422-a31d7d0e7067
+// coder/coder uses a fork of charmbracelet's fork of the Anthropic Go SDK
+// with performance improvements and Bedrock header cleanup.
+// See: https://github.com/coder/anthropic-sdk-go/commits/3be8e193ec89
+replace github.com/charmbracelet/anthropic-sdk-go => github.com/coder/anthropic-sdk-go v0.0.0-20260424230212-3be8e193ec89
 
 // Replace sdks with our own optimized forks until relevant upstream PRs are merged.
 // https://github.com/anthropics/anthropic-sdk-go/pull/262
diff --git a/go.sum b/go.sum
index 26c747b5fc..35bb75efaf 100644
--- a/go.sum
+++ b/go.sum
@@ -314,8 +314,8 @@ github.com/coder/agentapi-sdk-go v0.0.0-20250505131810-560d1d88d225 h1:tRIViZ5JR
 github.com/coder/agentapi-sdk-go v0.0.0-20250505131810-560d1d88d225/go.mod h1:rNLVpYgEVeu1Zk29K64z6Od8RBP9DwqCu9OfCzh8MR4=
 github.com/coder/aisdk-go v0.0.9 h1:Vzo/k2qwVGLTR10ESDeP2Ecek1SdPfZlEjtTfMveiVo=
 github.com/coder/aisdk-go v0.0.9/go.mod h1:KF6/Vkono0FJJOtWtveh5j7yfNrSctVTpwgweYWSp5M=
-github.com/coder/anthropic-sdk-go v0.0.0-20260415160422-a31d7d0e7067 h1:v1RAkUO21u0QH6UlUueSHMbgFf++BZZW41Rj6LM2eWo=
-github.com/coder/anthropic-sdk-go v0.0.0-20260415160422-a31d7d0e7067/go.mod h1:hqlYqR7uPKOKfnNeicUbZp0Ps0GeYFlKYtwh5HGDCx8=
+github.com/coder/anthropic-sdk-go v0.0.0-20260424230212-3be8e193ec89 h1:IVJutHfU944mb4D66K7XdPwKMAJrNC9FOq6JB4bveuI=
+github.com/coder/anthropic-sdk-go v0.0.0-20260424230212-3be8e193ec89/go.mod h1:hqlYqR7uPKOKfnNeicUbZp0Ps0GeYFlKYtwh5HGDCx8=
 github.com/coder/boundary v0.8.4-0.20260304164748-566aeea939ab h1:HrlxyTmMQpOHfSKzRU1vf5TxrmV6vL5OiWq+Dvn5qh0=
 github.com/coder/boundary v0.8.4-0.20260304164748-566aeea939ab/go.mod h1:BhJhyKW/+zZQzaGZ3vn27if2k0Vx5xLXzq7ZCQx5gPk=
 github.com/coder/bubbletea v1.2.2-0.20241212190825-007a1cdb2c41 h1:SBN/DA63+ZHwuWwPHPYoCZ/KLAjHv5g4h2MS4f2/MTI=