diff --git a/v2/ollama/native.go b/v2/ollama/native.go
index 5fd1c83..acbf7ad 100644
--- a/v2/ollama/native.go
+++ b/v2/ollama/native.go
@@ -12,8 +12,11 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"log/slog"
 	"net/http"
+	"strconv"
 	"strings"
+	"time"
 
 	"gitea.stevedudenhoeffer.com/steve/go-llm/v2/provider"
 )
@@ -25,6 +28,22 @@ const DefaultLocalBaseURL = "http://localhost:11434"
 // DefaultCloudBaseURL is the default base URL for Ollama Cloud.
 const DefaultCloudBaseURL = "https://ollama.com"
 
+// retryMaxAttempts is the maximum number of retry attempts for transient HTTP
+// errors (503, 429, 502). Total attempts = 1 initial + retryMaxAttempts.
+const retryMaxAttempts = 3
+
+// retryBaseDelay is the base delay for exponential backoff between retries.
+// Actual delays: 1s, 2s, 4s (base * 2^attempt).
+const retryBaseDelay = 1 * time.Second
+
+// isTransientHTTPStatus reports whether the HTTP status code indicates a
+// transient server-side condition that may resolve on retry.
+func isTransientHTTPStatus(code int) bool {
+	return code == http.StatusBadGateway || // 502
+		code == http.StatusServiceUnavailable || // 503
+		code == http.StatusTooManyRequests // 429
+}
+
 // Provider implements provider.Provider over Ollama's native /api/chat
 // endpoint. An empty apiKey means local-mode (no Authorization header sent);
 // a non-empty apiKey is sent as a Bearer token (cloud-mode).
@@ -32,6 +51,10 @@ type Provider struct {
 	apiKey  string
 	baseURL string
 	client  *http.Client
+
+	// retryBaseDelayOverride, when non-zero, replaces retryBaseDelay for
+	// testing. Production code leaves this at the zero value.
+	retryBaseDelayOverride time.Duration
 }
 
 // newNative constructs a native Ollama provider. Callers should use the
@@ -420,22 +443,81 @@ func (p *Provider) buildChatRequest(req provider.Request, stream bool) ([]byte,
 }
 
 // doChatRequest POSTs the wire body to /api/chat and returns the raw HTTP
-// response. The caller is responsible for closing the response body.
+// response. Transient HTTP errors (502, 503, 429) are retried with exponential
+// backoff up to retryMaxAttempts times. The caller is responsible for closing
+// the response body.
 func (p *Provider) doChatRequest(ctx context.Context, body []byte) (*http.Response, error) {
 	url := strings.TrimRight(p.baseURL, "/") + "/api/chat"
-	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(body))
-	if err != nil {
-		return nil, fmt.Errorf("ollama: build request: %w", err)
+
+	for attempt := 0; ; attempt++ {
+		httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(body))
+		if err != nil {
+			return nil, fmt.Errorf("ollama: build request: %w", err)
+		}
+		httpReq.Header.Set("Content-Type", "application/json")
+		if p.apiKey != "" {
+			httpReq.Header.Set("Authorization", "Bearer "+p.apiKey)
+		}
+
+		resp, err := p.client.Do(httpReq)
+		if err != nil {
+			return nil, fmt.Errorf("ollama: HTTP request: %w", err)
+		}
+
+		// On success or non-transient error, return immediately.
+		if !isTransientHTTPStatus(resp.StatusCode) || attempt >= retryMaxAttempts {
+			return resp, nil
+		}
+
+		// Transient error — drain and close the body before retrying.
+		respBody, _ := io.ReadAll(resp.Body)
+		resp.Body.Close()
+
+		delay := retryBackoff(attempt, resp.Header, p.retryBaseDelayOverride)
+		slog.Info("ollama: retrying after transient HTTP error",
+			"status", resp.StatusCode,
+			"attempt", attempt+1,
+			"max_attempts", retryMaxAttempts,
+			"delay", delay,
+			"body", truncateBody(respBody, 200),
+		)
+
+		// Wait for backoff or context cancellation.
+		timer := time.NewTimer(delay)
+		select {
+		case <-ctx.Done():
+			timer.Stop()
+			return nil, ctx.Err()
+		case <-timer.C:
+		}
 	}
-	httpReq.Header.Set("Content-Type", "application/json")
-	if p.apiKey != "" {
-		httpReq.Header.Set("Authorization", "Bearer "+p.apiKey)
+}
+
+// retryBackoff computes the delay before the next retry attempt. It uses
+// exponential backoff (base * 2^attempt), but respects the Retry-After header
+// when present (for 429 responses). baseOverride, when non-zero, replaces the
+// package-level retryBaseDelay constant (used by tests to avoid real waits).
+func retryBackoff(attempt int, header http.Header, baseOverride time.Duration) time.Duration {
+	// Check Retry-After header (seconds value or HTTP-date; we only parse seconds).
+	if ra := header.Get("Retry-After"); ra != "" {
+		if secs, err := strconv.Atoi(ra); err == nil && secs > 0 {
+			return time.Duration(secs) * time.Second
+		}
 	}
-	resp, err := p.client.Do(httpReq)
-	if err != nil {
-		return nil, fmt.Errorf("ollama: HTTP request: %w", err)
+	base := retryBaseDelay
+	if baseOverride > 0 {
+		base = baseOverride
 	}
-	return resp, nil
+	return base * (1 << attempt)
+}
+
+// truncateBody returns a string of at most maxLen bytes from b, appending
+// "..." when truncated. Used for readable log output of error response bodies.
+func truncateBody(b []byte, maxLen int) string {
+	if len(b) <= maxLen {
+		return string(b)
+	}
+	return string(b[:maxLen]) + "..."
 }
 
 // convertMessage maps a provider.Message into a native wire message.
diff --git a/v2/ollama/native_test.go b/v2/ollama/native_test.go
index 311c45b..3df1007 100644
--- a/v2/ollama/native_test.go
+++ b/v2/ollama/native_test.go
@@ -571,3 +571,317 @@ func equalStrings(a, b []string) bool {
 	}
 	return true
 }
+
+// --- Retry tests ---
+
+// newTestNative creates a Provider with a minimal retry delay so tests run fast.
+func newTestNative(apiKey, baseURL string) *Provider {
+	p := newNative(apiKey, baseURL)
+	p.retryBaseDelayOverride = 1 * time.Millisecond
+	return p
+}
+
+func TestRetryOnTransientHTTPError(t *testing.T) {
+	t.Run("503 retries then succeeds", func(t *testing.T) {
+		var attempts int
+		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			// Drain the request body so the client can reuse the connection.
+			_, _ = io.ReadAll(r.Body)
+			attempts++
+			if attempts <= 2 {
+				w.WriteHeader(503)
+				_, _ = w.Write([]byte(`{"error":"model is temporarily overloaded"}`))
+				return
+			}
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(200)
+			_, _ = w.Write([]byte(`{"message":{"role":"assistant","content":"ok"},"done":true,"prompt_eval_count":1,"eval_count":1}`))
+		}))
+		t.Cleanup(srv.Close)
+
+		p := newTestNative("key", srv.URL)
+		resp, err := p.Complete(context.Background(), provider.Request{
+			Model:    "test",
+			Messages: []provider.Message{{Role: "user", Content: "hi"}},
+		})
+		if err != nil {
+			t.Fatalf("expected success after retries, got error: %v", err)
+		}
+		if resp.Text != "ok" {
+			t.Errorf("Text: want %q, got %q", "ok", resp.Text)
+		}
+		if attempts != 3 {
+			t.Errorf("attempts: want 3, got %d", attempts)
+		}
+	})
+
+	t.Run("429 retries then succeeds", func(t *testing.T) {
+		var attempts int
+		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			_, _ = io.ReadAll(r.Body)
+			attempts++
+			if attempts == 1 {
+				w.WriteHeader(429)
+				_, _ = w.Write([]byte(`{"error":"rate limited"}`))
+				return
+			}
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(200)
+			_, _ = w.Write([]byte(`{"message":{"role":"assistant","content":"done"},"done":true}`))
+		}))
+		t.Cleanup(srv.Close)
+
+		p := newTestNative("", srv.URL)
+		resp, err := p.Complete(context.Background(), provider.Request{
+			Model:    "test",
+			Messages: []provider.Message{{Role: "user", Content: "hi"}},
+		})
+		if err != nil {
+			t.Fatalf("expected success after retry, got error: %v", err)
+		}
+		if resp.Text != "done" {
+			t.Errorf("Text: want %q, got %q", "done", resp.Text)
+		}
+		if attempts != 2 {
+			t.Errorf("attempts: want 2, got %d", attempts)
+		}
+	})
+
+	t.Run("502 retries then succeeds", func(t *testing.T) {
+		var attempts int
+		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			_, _ = io.ReadAll(r.Body)
+			attempts++
+			if attempts == 1 {
+				w.WriteHeader(502)
+				_, _ = w.Write([]byte(`Bad Gateway`))
+				return
+			}
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(200)
+			_, _ = w.Write([]byte(`{"message":{"role":"assistant","content":"yes"},"done":true}`))
+		}))
+		t.Cleanup(srv.Close)
+
+		p := newTestNative("", srv.URL)
+		resp, err := p.Complete(context.Background(), provider.Request{
+			Model:    "test",
+			Messages: []provider.Message{{Role: "user", Content: "hi"}},
+		})
+		if err != nil {
+			t.Fatalf("expected success after retry, got error: %v", err)
+		}
+		if resp.Text != "yes" {
+			t.Errorf("Text: want %q, got %q", "yes", resp.Text)
+		}
+	})
+
+	t.Run("exhausts retries and returns error", func(t *testing.T) {
+		var attempts int
+		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			_, _ = io.ReadAll(r.Body)
+			attempts++
+			w.WriteHeader(503)
+			_, _ = w.Write([]byte(`{"error":"overloaded"}`))
+		}))
+		t.Cleanup(srv.Close)
+
+		p := newTestNative("", srv.URL)
+		_, err := p.Complete(context.Background(), provider.Request{
+			Model:    "test",
+			Messages: []provider.Message{{Role: "user", Content: "hi"}},
+		})
+		if err == nil {
+			t.Fatal("expected error after exhausting retries")
+		}
+		if !strings.Contains(err.Error(), "503") {
+			t.Errorf("error should mention status 503, got: %v", err)
+		}
+		// 1 initial + 3 retries = 4 total
+		if attempts != 4 {
+			t.Errorf("attempts: want 4, got %d", attempts)
+		}
+	})
+
+	t.Run("400 is not retried", func(t *testing.T) {
+		var attempts int
+		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			_, _ = io.ReadAll(r.Body)
+			attempts++
+			w.WriteHeader(400)
+			_, _ = w.Write([]byte(`{"error":"bad request"}`))
+		}))
+		t.Cleanup(srv.Close)
+
+		p := newTestNative("", srv.URL)
+		_, err := p.Complete(context.Background(), provider.Request{
+			Model:    "test",
+			Messages: []provider.Message{{Role: "user", Content: "hi"}},
+		})
+		if err == nil {
+			t.Fatal("expected error for 400")
+		}
+		if attempts != 1 {
+			t.Errorf("attempts: want 1 (no retries for 400), got %d", attempts)
+		}
+	})
+
+	t.Run("context cancellation during backoff aborts retry", func(t *testing.T) {
+		var attempts int
+		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			_, _ = io.ReadAll(r.Body)
+			attempts++
+			w.WriteHeader(503)
+			_, _ = w.Write([]byte(`{"error":"overloaded"}`))
+		}))
+		t.Cleanup(srv.Close)
+
+		ctx, cancel := context.WithCancel(context.Background())
+		// Cancel shortly after the first attempt so the backoff wait is interrupted.
+		go func() {
+			time.Sleep(50 * time.Millisecond)
+			cancel()
+		}()
+
+		p := newTestNative("", srv.URL)
+		// Use a longer backoff so the context cancel fires during the wait.
+		p.retryBaseDelayOverride = 2 * time.Second
+		_, err := p.Complete(ctx, provider.Request{
+			Model:    "test",
+			Messages: []provider.Message{{Role: "user", Content: "hi"}},
+		})
+		if err == nil {
+			t.Fatal("expected error from cancelled context")
+		}
+		if !strings.Contains(err.Error(), "canceled") && !strings.Contains(err.Error(), "context") {
+			t.Errorf("expected context error, got: %v", err)
+		}
+		// Should have made only 1 attempt before the context cancelled during backoff.
+		if attempts != 1 {
+			t.Errorf("attempts: want 1, got %d", attempts)
+		}
+	})
+
+	t.Run("stream retries on 503 then succeeds", func(t *testing.T) {
+		var attempts int
+		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			_, _ = io.ReadAll(r.Body)
+			attempts++
+			if attempts == 1 {
+				w.WriteHeader(503)
+				_, _ = w.Write([]byte(`{"error":"overloaded"}`))
+				return
+			}
+			w.Header().Set("Content-Type", "application/x-ndjson")
+			w.WriteHeader(200)
+			_, _ = w.Write([]byte(`{"message":{"role":"assistant","content":"streamed"},"done":true,"prompt_eval_count":1,"eval_count":1}` + "\n"))
+		}))
+		t.Cleanup(srv.Close)
+
+		p := newTestNative("", srv.URL)
+		events := collectStream(t, p, provider.Request{
+			Model:    "test",
+			Messages: []provider.Message{{Role: "user", Content: "hi"}},
+		})
+
+		var gotDone bool
+		for _, ev := range events {
+			if ev.Type == provider.StreamEventDone && ev.Response != nil {
+				if ev.Response.Text != "streamed" {
+					t.Errorf("Response.Text: want %q, got %q", "streamed", ev.Response.Text)
+				}
+				gotDone = true
+			}
+		}
+		if !gotDone {
+			t.Fatal("expected StreamEventDone")
+		}
+		if attempts != 2 {
+			t.Errorf("attempts: want 2, got %d", attempts)
+		}
+	})
+}
+
+func TestRetryBackoff(t *testing.T) {
+	t.Run("exponential backoff without Retry-After", func(t *testing.T) {
+		h := http.Header{}
+		d0 := retryBackoff(0, h, 0)
+		d1 := retryBackoff(1, h, 0)
+		d2 := retryBackoff(2, h, 0)
+
+		if d0 != 1*time.Second {
+			t.Errorf("attempt 0: want 1s, got %v", d0)
+		}
+		if d1 != 2*time.Second {
+			t.Errorf("attempt 1: want 2s, got %v", d1)
+		}
+		if d2 != 4*time.Second {
+			t.Errorf("attempt 2: want 4s, got %v", d2)
+		}
+	})
+
+	t.Run("Retry-After header overrides backoff", func(t *testing.T) {
+		h := http.Header{}
+		h.Set("Retry-After", "5")
+		d := retryBackoff(0, h, 0)
+		if d != 5*time.Second {
+			t.Errorf("want 5s from Retry-After, got %v", d)
+		}
+	})
+
+	t.Run("invalid Retry-After falls back to exponential", func(t *testing.T) {
+		h := http.Header{}
+		h.Set("Retry-After", "not-a-number")
+		d := retryBackoff(1, h, 0)
+		if d != 2*time.Second {
+			t.Errorf("want 2s fallback, got %v", d)
+		}
+	})
+
+	t.Run("baseOverride replaces default base delay", func(t *testing.T) {
+		h := http.Header{}
+		d := retryBackoff(0, h, 500*time.Millisecond)
+		if d != 500*time.Millisecond {
+			t.Errorf("attempt 0 with 500ms override: want 500ms, got %v", d)
+		}
+		d1 := retryBackoff(2, h, 500*time.Millisecond)
+		if d1 != 2*time.Second {
+			t.Errorf("attempt 2 with 500ms override: want 2s, got %v", d1)
+		}
+	})
+}
+
+func TestIsTransientHTTPStatus(t *testing.T) {
+	cases := []struct {
+		code int
+		want bool
+	}{
+		{200, false},
+		{400, false},
+		{401, false},
+		{403, false},
+		{404, false},
+		{429, true},
+		{500, false},
+		{502, true},
+		{503, true},
+	}
+	for _, c := range cases {
+		if got := isTransientHTTPStatus(c.code); got != c.want {
+			t.Errorf("isTransientHTTPStatus(%d): want %v, got %v", c.code, c.want, got)
+		}
+	}
+}
+
+func TestTruncateBody(t *testing.T) {
+	short := "hello"
+	if got := truncateBody([]byte(short), 10); got != short {
+		t.Errorf("short: want %q, got %q", short, got)
+	}
+
+	long := "hello world this is a very long string"
+	got := truncateBody([]byte(long), 10)
+	if got != "hello worl..." {
+		t.Errorf("long: want %q, got %q", "hello worl...", got)
+	}
+}