Ollama: only treat a 404 as model-not-found when the body says so

A 404 from a proxy without /api/chat, or any other 404 error, was
reported as the configured model being missing. Generate now checks the
{"error": ...} payload for Ollama's model-not-found message naming the
configured model (double- or single-quoted); any other 404 stays a
ProviderError with its redacted body excerpt.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/ai/llm/ollama/ollama.go

@@ -0,0 +1,325 @@
+// Package ollama is the llm.Provider adapter for Ollama's native API. It
+// calls POST {base}/api/chat and GET {base}/api/tags over plain net/http.
+//
+// Ollama takes no credentials: the adapter sends no Authorization header
+// and never logs. The base URL may be a LAN address, and errors for an
+// unreachable server name it, so New refuses a base URL that could carry a
+// credential.
+package ollama
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/ai/llm"
+)
+
+// Config configures a Provider.
+type Config struct {
+	// BaseURL is the Ollama server root the /api endpoint paths are
+	// appended to, e.g. "http://192.168.1.20:11434" or
+	// "http://ollama:11434". It is required.
+	BaseURL string
+	// Model is the model Generate requests, e.g. "llama3.2". ListModels
+	// and Verify do not need it.
+	Model string
+}
+
+// Provider is an Ollama native API llm.Provider.
+type Provider struct {
+	base   string
+	model  string
+	client *http.Client
+}
+
+var _ llm.Provider = (*Provider)(nil)
+
+// New validates cfg and returns a Provider.
+func New(cfg Config) (*Provider, error) {
+	// Base URL errors never echo the URL: a rejected one may hold a
+	// credential.
+	u, err := url.Parse(cfg.BaseURL)
+	if err != nil {
+		return nil, errors.New("ollama: base URL does not parse")
+	}
+	if (u.Scheme != "http" && u.Scheme != "https") || u.Host == "" {
+		return nil, errors.New("ollama: base URL must be an absolute http or https URL")
+	}
+	// A trailing "?" or "#" parses to an empty query or fragment, yet the
+	// endpoint path appended to it would land in the query or fragment.
+	if u.User != nil || strings.ContainsAny(cfg.BaseURL, "?#") {
+		return nil, errors.New("ollama: base URL must not carry credentials, a query or a fragment")
+	}
+	return &Provider{
+		base:   strings.TrimRight(cfg.BaseURL, "/"),
+		model:  cfg.Model,
+		client: noRedirectClient(),
+	}, nil
+}
+
+// maxResponseBody caps a successful response body; a larger one is an error.
+const maxResponseBody = 16 << 20
+
+// maxErrorBody caps how much of an error response body is read; only an
+// llm.MaxBodyExcerpt of it is kept.
+const maxErrorBody = 64 << 10
+
+type message struct {
+	Role    string `json:"role"`
+	Content string `json:"content"`
+}
+
+type options struct {
+	Temperature *float64 `json:"temperature,omitempty"`
+	NumPredict  int      `json:"num_predict,omitempty"`
+}
+
+type chatRequest struct {
+	Model    string          `json:"model"`
+	Messages []message       `json:"messages"`
+	Stream   bool            `json:"stream"`
+	Format   json.RawMessage `json:"format,omitempty"`
+	Options  *options        `json:"options,omitempty"`
+}
+
+type chatResponse struct {
+	Model   string `json:"model"`
+	Message *struct {
+		Role    string `json:"role"`
+		Content string `json:"content"`
+	} `json:"message"`
+	Done            bool   `json:"done"`
+	DoneReason      string `json:"done_reason"`
+	PromptEvalCount int    `json:"prompt_eval_count"`
+	EvalCount       int    `json:"eval_count"`
+}
+
+// Generate sends req to {base}/api/chat without streaming. A Request with a
+// Schema sends it as "format", so Ollama constrains the reply to it;
+// Response.JSON is then the reply text, which must be a JSON object.
+func (p *Provider) Generate(ctx context.Context, req llm.Request) (llm.Response, error) {
+	if err := req.Validate(); err != nil {
+		return llm.Response{}, fmt.Errorf("ollama: generate: %w", err)
+	}
+	if p.model == "" {
+		return llm.Response{}, errors.New("ollama: generate: no model configured")
+	}
+	body := chatRequest{Model: p.model, Stream: false}
+	if req.System != "" {
+		body.Messages = append(body.Messages, message{Role: "system", Content: req.System})
+	}
+	for _, m := range req.Messages {
+		body.Messages = append(body.Messages, message{Role: string(m.Role), Content: m.Content})
+	}
+	if req.Schema != nil {
+		body.Format = req.Schema.Schema
+	}
+	if req.Temperature != nil || req.MaxTokens > 0 {
+		body.Options = &options{Temperature: req.Temperature, NumPredict: req.MaxTokens}
+	}
+	payload, err := json.Marshal(body)
+	if err != nil {
+		return llm.Response{}, fmt.Errorf("ollama: generate: encode request: %w", err)
+	}
+
+	if req.Timeout > 0 {
+		var cancel context.CancelFunc
+		ctx, cancel = context.WithTimeout(ctx, req.Timeout)
+		defer cancel()
+	}
+	raw, err := p.do(ctx, http.MethodPost, "/api/chat", payload)
+	if err != nil {
+		var pe *llm.ProviderError
+		if errors.As(err, &pe) && pe.Status() == http.StatusNotFound && p.modelNotFound(pe.Body()) {
+			// The body is not quoted: the model name is all the caller
+			// needs. Any other 404 keeps its body excerpt below.
+			return llm.Response{}, fmt.Errorf("ollama: generate: model %q not found: %w", p.model, llm.NewProviderError(pe.Status(), nil, ""))
+		}
+		return llm.Response{}, fmt.Errorf("ollama: generate: %w", err)
+	}
+
+	var cr chatResponse
+	if err := json.Unmarshal(raw, &cr); err != nil {
+		return llm.Response{}, fmt.Errorf("ollama: generate: decode response: %w", err)
+	}
+	if !cr.Done || cr.Message == nil {
+		return llm.Response{}, errors.New("ollama: generate: response is not a finished message")
+	}
+	resp := llm.Response{
+		Text:         cr.Message.Content,
+		Usage:        llm.Usage{InputTokens: cr.PromptEvalCount, OutputTokens: cr.EvalCount},
+		Model:        cr.Model,
+		FinishReason: cr.DoneReason,
+	}
+	if req.Schema == nil {
+		return resp, nil
+	}
+	if text := strings.TrimSpace(resp.Text); isJSONObject(text) {
+		resp.JSON = json.RawMessage(text)
+		return resp, nil
+	}
+	return resp, fmt.Errorf("ollama: generate: reply is not a JSON object: %w", llm.ErrBadOutput)
+}
+
+// modelNotFound reports whether body is Ollama's error for the configured
+// model not being pulled: {"error": "model \"name\" not found, ..."}, or
+// with the name in single quotes as newer servers send it. A 404 from
+// anything else, such as a proxy without /api/chat, is not.
+func (p *Provider) modelNotFound(body string) bool {
+	var e struct {
+		Error string `json:"error"`
+	}
+	if err := json.Unmarshal([]byte(body), &e); err != nil {
+		return false
+	}
+	return strings.HasPrefix(e.Error, fmt.Sprintf("model %q not found", p.model)) ||
+		strings.HasPrefix(e.Error, fmt.Sprintf("model '%s' not found", p.model))
+}
+
+// isJSONObject reports whether s is exactly one JSON object.
+func isJSONObject(s string) bool {
+	return strings.HasPrefix(s, "{") && json.Valid([]byte(s))
+}
+
+type tagsResponse struct {
+	Models []struct {
+		Name string `json:"name"`
+	} `json:"models"`
+}
+
+// ListModels returns every model {base}/api/tags lists.
+func (p *Provider) ListModels(ctx context.Context) ([]llm.Model, error) {
+	models, err := p.tags(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("ollama: list models: %w", err)
+	}
+	return models, nil
+}
+
+// Verify checks that the server answers GET {base}/api/tags with a model
+// list.
+func (p *Provider) Verify(ctx context.Context) error {
+	if _, err := p.tags(ctx); err != nil {
+		return fmt.Errorf("ollama: verify: %w", err)
+	}
+	return nil
+}
+
+func (p *Provider) tags(ctx context.Context) ([]llm.Model, error) {
+	raw, err := p.do(ctx, http.MethodGet, "/api/tags", nil)
+	if err != nil {
+		return nil, err
+	}
+	var tr tagsResponse
+	if err := json.Unmarshal(raw, &tr); err != nil {
+		return nil, fmt.Errorf("decode response: %w", err)
+	}
+	if tr.Models == nil {
+		return nil, errors.New("response has no models list")
+	}
+	models := make([]llm.Model, 0, len(tr.Models))
+	for i, m := range tr.Models {
+		if m.Name == "" {
+			return nil, fmt.Errorf("model %d has no name", i)
+		}
+		models = append(models, llm.Model{ID: m.Name, DisplayName: m.Name})
+	}
+	return models, nil
+}
+
+// do sends one request and returns the body of a 2xx response. Any other
+// status, a 3xx included, is an *llm.ProviderError.
+func (p *Provider) do(ctx context.Context, method, path string, payload []byte) ([]byte, error) {
+	var reqBody io.Reader
+	if payload != nil {
+		reqBody = bytes.NewReader(payload)
+	}
+	httpReq, err := http.NewRequestWithContext(ctx, method, p.base+path, reqBody)
+	if err != nil {
+		return nil, fmt.Errorf("build request: %w", err)
+	}
+	httpReq.Header.Set("Accept", "application/json")
+	if payload != nil {
+		httpReq.Header.Set("Content-Type", "application/json")
+	}
+
+	httpResp, err := p.client.Do(httpReq)
+	if err != nil {
+		return nil, p.transportError(err)
+	}
+	defer httpResp.Body.Close()
+
+	if httpResp.StatusCode < 200 || httpResp.StatusCode > 299 {
+		body, err := io.ReadAll(io.LimitReader(httpResp.Body, maxErrorBody))
+		if err != nil {
+			return nil, p.transportError(err)
+		}
+		return nil, llm.NewProviderError(httpResp.StatusCode, body, "")
+	}
+	body, err := io.ReadAll(io.LimitReader(httpResp.Body, maxResponseBody+1))
+	if err != nil {
+		return nil, p.transportError(err)
+	}
+	if len(body) > maxResponseBody {
+		return nil, fmt.Errorf("response body exceeds %d bytes", maxResponseBody)
+	}
+	return body, nil
+}
+
+// noRedirectClient returns an HTTP client that never follows a redirect:
+// the 3xx response is returned and becomes a provider error, so a request
+// is only ever sent to the configured server.
+func noRedirectClient() *http.Client {
+	return &http.Client{
+		CheckRedirect: func(*http.Request, []*http.Request) error {
+			return http.ErrUseLastResponse
+		},
+	}
+}
+
+func isTimeout(err error) bool {
+	var ne net.Error
+	return errors.Is(err, context.DeadlineExceeded) || (errors.As(err, &ne) && ne.Timeout())
+}
+
+// transportFailure is a failed HTTP exchange. Its text names the base URL
+// and the cause; it unwraps only to the cause's category, llm.ErrTimeout or
+// context.Canceled.
+type transportFailure struct {
+	text string
+	kind error
+}
+
+func (e *transportFailure) Error() string { return e.text }
+
+func (e *transportFailure) Unwrap() error { return e.kind }
+
+// transportError reports a failure to complete the HTTP exchange. A
+// cancelled context is the caller's choice and stays context.Canceled.
+// Every other failure, a refused connection or a timeout alike, means the
+// server could not be reached in time: it matches llm.ErrTimeout and says
+// "Ollama not reachable at {base}".
+func (p *Provider) transportError(err error) error {
+	timedOut := isTimeout(err)
+	// The *url.Error repeats the request URL; the base is named once below.
+	var ue *url.Error
+	if errors.As(err, &ue) {
+		err = ue.Err
+	}
+	if !timedOut && errors.Is(err, context.Canceled) {
+		return &transportFailure{text: "request canceled: " + err.Error(), kind: context.Canceled}
+	}
+	text := fmt.Sprintf("Ollama not reachable at %s: %s", p.base, err)
+	if timedOut {
+		text = fmt.Sprintf("Ollama not reachable at %s: %s: %s", p.base, llm.ErrTimeout, err)
+	}
+	return &transportFailure{text: text, kind: llm.ErrTimeout}
+}

internal/ai/llm/ollama/ollama_test.go

@@ -0,0 +1,615 @@
+package ollama
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/ai/llm"
+)
+
+// recorded is one request the test server received.
+type recorded struct {
+	method string
+	path   string
+	query  url.Values
+	header http.Header
+	body   []byte
+}
+
+// reply is a response the test server replays.
+type reply struct {
+	status  int
+	fixture string // testdata file
+	body    string // used when fixture is empty
+	delay   time.Duration
+}
+
+// ollamaServer replays its replies in order, repeating the last, and
+// records every request.
+type ollamaServer struct {
+	*httptest.Server
+	mu  sync.Mutex
+	got []recorded
+}
+
+func newOllamaServer(t *testing.T, replies ...reply) *ollamaServer {
+	t.Helper()
+	payloads := make([][]byte, len(replies))
+	for i, r := range replies {
+		payloads[i] = []byte(r.body)
+		if r.fixture != "" {
+			raw, err := os.ReadFile(filepath.Join("testdata", r.fixture))
+			if err != nil {
+				t.Fatal(err)
+			}
+			payloads[i] = raw
+		}
+	}
+	s := &ollamaServer{}
+	s.Server = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		body, _ := io.ReadAll(req.Body)
+		s.mu.Lock()
+		n := len(s.got)
+		s.got = append(s.got, recorded{req.Method, req.URL.Path, req.URL.Query(), req.Header.Clone(), body})
+		s.mu.Unlock()
+		i := min(n, len(replies)-1)
+		r := replies[i]
+		if r.delay > 0 {
+			select {
+			case <-time.After(r.delay):
+			case <-req.Context().Done():
+				return
+			}
+		}
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(r.status)
+		w.Write(payloads[i])
+	}))
+	t.Cleanup(s.Close)
+	return s
+}
+
+func (s *ollamaServer) requests() []recorded {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return append([]recorded(nil), s.got...)
+}
+
+func (s *ollamaServer) only(t *testing.T) recorded {
+	t.Helper()
+	got := s.requests()
+	if len(got) != 1 {
+		t.Fatalf("server got %d requests, want 1", len(got))
+	}
+	return got[0]
+}
+
+func newProvider(t *testing.T, base string) *Provider {
+	t.Helper()
+	p, err := New(Config{BaseURL: base, Model: "llama3.2"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return p
+}
+
+var dinnersSchema = json.RawMessage(`{"type":"object","properties":{"dinners":{"type":"array"}},"required":["dinners"]}`)
+
+func schemaRequest() llm.Request {
+	temp := 0.0
+	return llm.Request{
+		System: "You plan dinners for Our kitchen.",
+		Messages: []llm.Message{
+			{Role: llm.RoleUser, Content: "Suggest a Side quest."},
+			{Role: llm.RoleAssistant, Content: "Something quick?"},
+			{Role: llm.RoleUser, Content: "Yes, a Quick dinner."},
+		},
+		Temperature: &temp,
+		MaxTokens:   400,
+		Schema:      &llm.JSONSchema{Name: "side_quests", Schema: dinnersSchema},
+	}
+}
+
+func textRequest() llm.Request {
+	return llm.Request{Messages: []llm.Message{{Role: llm.RoleUser, Content: "What should we cook tonight?"}}}
+}
+
+// sentBody decodes a request body into a generic map.
+func sentBody(t *testing.T, r recorded) map[string]any {
+	t.Helper()
+	var m map[string]any
+	if err := json.Unmarshal(r.body, &m); err != nil {
+		t.Fatalf("request body %q: %v", r.body, err)
+	}
+	return m
+}
+
+// canonical re-encodes JSON so two encodings of one value compare equal.
+func canonical(t *testing.T, raw []byte) string {
+	t.Helper()
+	var v any
+	if err := json.Unmarshal(raw, &v); err != nil {
+		t.Fatalf("JSON %q: %v", raw, err)
+	}
+	out, _ := json.Marshal(v)
+	return string(out)
+}
+
+func assertNoAuth(t *testing.T, r recorded) {
+	t.Helper()
+	if got := r.header.Values("Authorization"); len(got) != 0 {
+		t.Errorf("Authorization = %q, want none", got)
+	}
+}
+
+func TestGenerateText(t *testing.T) {
+	s := newOllamaServer(t, reply{status: 200, fixture: "chat_text.json"})
+	p := newProvider(t, s.URL+"/")
+
+	resp, err := p.Generate(context.Background(), textRequest())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if resp.Text != "Try a crock pot chili: it is a Quick dinner." || resp.JSON != nil {
+		t.Errorf("Text, JSON = %q, %s", resp.Text, resp.JSON)
+	}
+	if resp.Usage != (llm.Usage{InputTokens: 26, OutputTokens: 298}) || resp.Model != "llama3.2" || resp.FinishReason != "stop" {
+		t.Errorf("Usage, Model, FinishReason = %+v, %q, %q", resp.Usage, resp.Model, resp.FinishReason)
+	}
+
+	got := s.only(t)
+	if got.method != http.MethodPost || got.path != "/api/chat" || len(got.query) != 0 {
+		t.Errorf("request = %s %s?%s", got.method, got.path, got.query.Encode())
+	}
+	assertNoAuth(t, got)
+	body := sentBody(t, got)
+	if stream, ok := body["stream"]; !ok || stream != false {
+		t.Errorf("stream = %v (present %v), want false", stream, ok)
+	}
+	if body["model"] != "llama3.2" {
+		t.Errorf("model = %v", body["model"])
+	}
+	for _, field := range []string{"format", "options"} {
+		if v, ok := body[field]; ok {
+			t.Errorf("%s = %v, want it omitted", field, v)
+		}
+	}
+	if got, want := canonical(t, mustMarshal(t, body["messages"])), `[{"content":"What should we cook tonight?","role":"user"}]`; got != want {
+		t.Errorf("messages = %s, want %s", got, want)
+	}
+}
+
+func mustMarshal(t *testing.T, v any) []byte {
+	t.Helper()
+	raw, err := json.Marshal(v)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return raw
+}
+
+func TestGenerateSchemaOutput(t *testing.T) {
+	s := newOllamaServer(t, reply{status: 200, fixture: "chat_schema.json"})
+	p := newProvider(t, s.URL)
+
+	resp, err := p.Generate(context.Background(), schemaRequest())
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := `{"dinners":[{"name":"Sheet-pan gnocchi","why":"Like your Regular tray bake, but quicker."}]}`
+	if got := canonical(t, resp.JSON); got != want {
+		t.Errorf("Response.JSON = %s, want %s", got, want)
+	}
+	if canonical(t, []byte(resp.Text)) != want {
+		t.Errorf("Text = %q, want the reply content", resp.Text)
+	}
+	if resp.Usage != (llm.Usage{InputTokens: 147, OutputTokens: 41}) || resp.FinishReason != "stop" {
+		t.Errorf("Usage, FinishReason = %+v, %q", resp.Usage, resp.FinishReason)
+	}
+
+	got := s.only(t)
+	assertNoAuth(t, got)
+	body := sentBody(t, got)
+	if body["stream"] != false {
+		t.Errorf("stream = %v, want false", body["stream"])
+	}
+	if got, want := canonical(t, mustMarshal(t, body["format"])), canonical(t, dinnersSchema); got != want {
+		t.Errorf("format = %s, want the schema %s", got, want)
+	}
+	opts, _ := body["options"].(map[string]any)
+	if len(opts) != 2 || opts["temperature"] != 0.0 || opts["num_predict"] != 400.0 {
+		t.Errorf("options = %v, want temperature 0 and num_predict 400", body["options"])
+	}
+	wantMessages := `[{"content":"You plan dinners for Our kitchen.","role":"system"},` +
+		`{"content":"Suggest a Side quest.","role":"user"},` +
+		`{"content":"Something quick?","role":"assistant"},` +
+		`{"content":"Yes, a Quick dinner.","role":"user"}]`
+	if got := canonical(t, mustMarshal(t, body["messages"])); got != wantMessages {
+		t.Errorf("messages = %s, want %s", got, wantMessages)
+	}
+}
+
+func TestGenerateTemperatureOnlyWhenSet(t *testing.T) {
+	s := newOllamaServer(t, reply{status: 200, fixture: "chat_text.json"})
+	req := textRequest()
+	temp := 0.7
+	req.Temperature = &temp
+	if _, err := newProvider(t, s.URL).Generate(context.Background(), req); err != nil {
+		t.Fatal(err)
+	}
+	opts, _ := sentBody(t, s.only(t))["options"].(map[string]any)
+	if len(opts) != 1 || opts["temperature"] != 0.7 {
+		t.Errorf("options = %v, want only temperature 0.7", opts)
+	}
+}
+
+func TestGenerateBadOutput(t *testing.T) {
+	cases := map[string]string{
+		"prose":        `{"model":"m","message":{"role":"assistant","content":"Sure! Try chili."},"done":true,"done_reason":"stop"}`,
+		"array":        `{"model":"m","message":{"role":"assistant","content":"[1,2]"},"done":true,"done_reason":"stop"}`,
+		"cut-off JSON": `{"model":"m","message":{"role":"assistant","content":"{\"dinners\": ["},"done":true,"done_reason":"length"}`,
+	}
+	for name, body := range cases {
+		t.Run(name, func(t *testing.T) {
+			s := newOllamaServer(t, reply{status: 200, body: body})
+			resp, err := newProvider(t, s.URL).Generate(context.Background(), schemaRequest())
+			if !errors.Is(err, llm.ErrBadOutput) {
+				t.Fatalf("err = %v, want ErrBadOutput", err)
+			}
+			if resp.JSON != nil || resp.Model != "m" || resp.Text == "" {
+				t.Fatalf("Response = %+v, want no JSON and the reply kept", resp)
+			}
+		})
+	}
+}
+
+func TestGenerateRejectsMalformedResponses(t *testing.T) {
+	for name, body := range map[string]string{
+		"not JSON":     `not json`,
+		"not finished": `{"model":"m","message":{"role":"assistant","content":"hi"},"done":false}`,
+		"no message":   `{"model":"m","done":true}`,
+	} {
+		s := newOllamaServer(t, reply{status: 200, body: body})
+		_, err := newProvider(t, s.URL).Generate(context.Background(), textRequest())
+		if err == nil || errors.Is(err, llm.ErrBadOutput) || errors.Is(err, llm.ErrProvider) {
+			t.Errorf("%s: err = %v, want an untyped malformed-response error", name, err)
+		}
+	}
+}
+
+func TestGenerateRejectsInvalidRequests(t *testing.T) {
+	s := newOllamaServer(t, reply{status: 200, fixture: "chat_text.json"})
+	if _, err := newProvider(t, s.URL).Generate(context.Background(), llm.Request{}); err == nil {
+		t.Error("Generate accepted a request with no messages")
+	}
+	noModel, err := New(Config{BaseURL: s.URL})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := noModel.Generate(context.Background(), textRequest()); err == nil {
+		t.Error("Generate ran with no model configured")
+	}
+	if n := len(s.requests()); n != 0 {
+		t.Errorf("server got %d requests, want 0", n)
+	}
+}
+
+func TestGenerateModelMissing(t *testing.T) {
+	s := newOllamaServer(t, reply{status: 404, fixture: "error_model_not_found.json"})
+	p, err := New(Config{BaseURL: s.URL, Model: "llama9"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	_, err = p.Generate(context.Background(), textRequest())
+	var pe *llm.ProviderError
+	if !errors.Is(err, llm.ErrProvider) || !errors.As(err, &pe) || pe.Status() != http.StatusNotFound {
+		t.Fatalf("err = %v, want a ProviderError for HTTP 404", err)
+	}
+	if errors.Is(err, llm.ErrTimeout) || errors.Is(err, llm.ErrBadOutput) {
+		t.Fatalf("err = %v matches an unrelated sentinel", err)
+	}
+	if want := `ollama: generate: model "llama9" not found: llm: provider error: HTTP 404`; err.Error() != want {
+		t.Fatalf("Error() = %q, want %q", err, want)
+	}
+	if pe.Body() != "" {
+		t.Fatalf("Body() = %q, want the response body left out", pe.Body())
+	}
+}
+
+func TestGenerateNotFoundUnrelatedToModel(t *testing.T) {
+	for name, body := range map[string]string{
+		"proxy page":  "404 page not found",
+		"other error": `{"error":"no route for /api/chat"}`,
+		"other model": `{"error":"model \"llama3\" not found, try pulling it first"}`,
+		"empty":       "",
+	} {
+		t.Run(name, func(t *testing.T) {
+			s := newOllamaServer(t, reply{status: 404, body: body})
+			p, err := New(Config{BaseURL: s.URL, Model: "llama9"})
+			if err != nil {
+				t.Fatal(err)
+			}
+			_, err = p.Generate(context.Background(), textRequest())
+			var pe *llm.ProviderError
+			if !errors.Is(err, llm.ErrProvider) || !errors.As(err, &pe) || pe.Status() != http.StatusNotFound {
+				t.Fatalf("err = %v, want a ProviderError for HTTP 404", err)
+			}
+			if strings.Contains(err.Error(), "not found") && !strings.Contains(body, "not found") {
+				t.Fatalf("Error() = %q claims something was not found", err)
+			}
+			if strings.Contains(err.Error(), "llama9") {
+				t.Fatalf("Error() = %q claims the model was not found", err)
+			}
+			if pe.Body() != strings.TrimSpace(body) {
+				t.Fatalf("Body() = %q, want the response body %q", pe.Body(), body)
+			}
+		})
+	}
+}
+
+func TestGenerateModelMissingSingleQuoted(t *testing.T) {
+	s := newOllamaServer(t, reply{status: 404, body: `{"error":"model 'llama9' not found"}`})
+	p, err := New(Config{BaseURL: s.URL, Model: "llama9"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	_, err = p.Generate(context.Background(), textRequest())
+	if want := `ollama: generate: model "llama9" not found: llm: provider error: HTTP 404`; err == nil || err.Error() != want {
+		t.Fatalf("err = %v, want %q", err, want)
+	}
+}
+
+func TestListModels(t *testing.T) {
+	s := newOllamaServer(t, reply{status: 200, fixture: "tags.json"})
+	models, err := newProvider(t, s.URL).ListModels(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := []llm.Model{{ID: "llama3.2:latest", DisplayName: "llama3.2:latest"}, {ID: "qwen3:8b", DisplayName: "qwen3:8b"}}
+	if len(models) != len(want) || models[0] != want[0] || models[1] != want[1] {
+		t.Fatalf("ListModels() = %+v, want %+v", models, want)
+	}
+	got := s.only(t)
+	if got.method != http.MethodGet || got.path != "/api/tags" || len(got.query) != 0 {
+		t.Errorf("request = %s %s?%s", got.method, got.path, got.query.Encode())
+	}
+	assertNoAuth(t, got)
+
+	empty := newOllamaServer(t, reply{status: 200, body: `{"models":[]}`})
+	if models, err := newProvider(t, empty.URL).ListModels(context.Background()); err != nil || models == nil || len(models) != 0 {
+		t.Fatalf("empty list: %v, %v", models, err)
+	}
+	for name, body := range map[string]string{
+		"no models list": `{}`,
+		"unnamed model":  `{"models":[{"model":"x"}]}`,
+		"not JSON":       `<html>`,
+	} {
+		bad := newOllamaServer(t, reply{status: 200, body: body})
+		if _, err := newProvider(t, bad.URL).ListModels(context.Background()); err == nil {
+			t.Errorf("%s: ListModels accepted it", name)
+		}
+	}
+}
+
+func TestVerify(t *testing.T) {
+	ok := newOllamaServer(t, reply{status: 200, fixture: "tags.json"})
+	if err := newProvider(t, ok.URL).Verify(context.Background()); err != nil {
+		t.Fatalf("Verify() = %v", err)
+	}
+	got := ok.only(t)
+	if got.method != http.MethodGet || got.path != "/api/tags" {
+		t.Errorf("Verify called %s %s", got.method, got.path)
+	}
+	assertNoAuth(t, got)
+
+	bad := newOllamaServer(t, reply{status: 500, body: `{"error":"something went wrong"}`})
+	err := newProvider(t, bad.URL).Verify(context.Background())
+	var pe *llm.ProviderError
+	if !errors.As(err, &pe) || pe.Status() != 500 || !strings.Contains(err.Error(), "something went wrong") {
+		t.Fatalf("Verify() = %v, want a ProviderError for HTTP 500", err)
+	}
+	malformed := newOllamaServer(t, reply{status: 200, body: `{}`})
+	if err := newProvider(t, malformed.URL).Verify(context.Background()); err == nil {
+		t.Error("Verify accepted a body with no models list")
+	}
+}
+
+func TestProviderErrors(t *testing.T) {
+	cases := map[string]reply{
+		"400":  {status: 400, body: `{"error":"invalid format"}`},
+		"500":  {status: 500, body: `{"error":"llama runner process has terminated"}`},
+		"503":  {status: 503, body: `{"error":"server busy, please try again"}`},
+		"huge": {status: 500, body: strings.Repeat("x", 1<<20)},
+	}
+	for name, r := range cases {
+		t.Run(name, func(t *testing.T) {
+			s := newOllamaServer(t, r)
+			p := newProvider(t, s.URL)
+			_, genErr := p.Generate(context.Background(), schemaRequest())
+			_, listErr := p.ListModels(context.Background())
+			for _, err := range []error{genErr, listErr} {
+				var pe *llm.ProviderError
+				if !errors.As(err, &pe) || pe.Status() != r.status {
+					t.Fatalf("err = %v, want a ProviderError for HTTP %d", err, r.status)
+				}
+				if errors.Is(err, llm.ErrTimeout) || strings.Contains(err.Error(), "not found") {
+					t.Fatalf("err = %v, want only a provider error", err)
+				}
+				if len(err.Error()) > llm.MaxBodyExcerpt+200 {
+					t.Fatalf("error text has %d bytes, want a bounded excerpt", len(err.Error()))
+				}
+			}
+		})
+	}
+}
+
+// assertUnreachable checks the error a request to an unreachable base
+// returns: it matches llm.ErrTimeout and names the base.
+func assertUnreachable(t *testing.T, err error, base string) {
+	t.Helper()
+	if !errors.Is(err, llm.ErrTimeout) {
+		t.Fatalf("err = %v, want ErrTimeout", err)
+	}
+	if errors.Is(err, llm.ErrProvider) || errors.Is(err, context.Canceled) {
+		t.Fatalf("err = %v matches an unrelated sentinel", err)
+	}
+	if want := "Ollama not reachable at " + base; !strings.Contains(err.Error(), want) {
+		t.Fatalf("Error() = %q, want it to contain %q", err, want)
+	}
+	var ue *url.Error
+	if errors.As(err, &ue) {
+		t.Fatalf("error chain exposes the url.Error: %v", ue)
+	}
+}
+
+func TestUnreachableHost(t *testing.T) {
+	closed := httptest.NewServer(http.NotFoundHandler())
+	base := closed.URL
+	closed.Close()
+
+	p := newProvider(t, base+"/")
+	_, genErr := p.Generate(context.Background(), schemaRequest())
+	_, listErr := p.ListModels(context.Background())
+	verifyErr := p.Verify(context.Background())
+	for _, err := range []error{genErr, listErr, verifyErr} {
+		assertUnreachable(t, err, base)
+		if !strings.Contains(err.Error(), "connection refused") {
+			t.Errorf("Error() = %q, want the cause", err)
+		}
+	}
+
+	dropped := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		conn, _, err := w.(http.Hijacker).Hijack()
+		if err != nil {
+			t.Error(err)
+			return
+		}
+		conn.Close()
+	}))
+	t.Cleanup(dropped.Close)
+	_, err := newProvider(t, dropped.URL).Generate(context.Background(), textRequest())
+	assertUnreachable(t, err, dropped.URL)
+}
+
+func TestTimeouts(t *testing.T) {
+	s := newOllamaServer(t, reply{status: 200, fixture: "chat_schema.json", delay: 5 * time.Second})
+	p := newProvider(t, s.URL)
+
+	req := schemaRequest()
+	req.Timeout = 50 * time.Millisecond
+	start := time.Now()
+	_, err := p.Generate(context.Background(), req)
+	assertUnreachable(t, err, s.URL)
+	if !strings.Contains(err.Error(), llm.ErrTimeout.Error()) {
+		t.Errorf("Error() = %q, want it to say the request timed out", err)
+	}
+	if elapsed := time.Since(start); elapsed > 2*time.Second {
+		t.Fatalf("Request.Timeout not honoured: took %v", elapsed)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond)
+	defer cancel()
+	_, err = p.ListModels(ctx)
+	assertUnreachable(t, err, s.URL)
+	ctx, cancel = context.WithTimeout(context.Background(), 50*time.Millisecond)
+	defer cancel()
+	assertUnreachable(t, p.Verify(ctx), s.URL)
+
+	ctx, cancel = context.WithCancel(context.Background())
+	cancel()
+	_, err = p.Generate(ctx, schemaRequest())
+	if !errors.Is(err, context.Canceled) || errors.Is(err, llm.ErrTimeout) || strings.Contains(err.Error(), "not reachable") {
+		t.Fatalf("cancelled context: err = %v, want context.Canceled only", err)
+	}
+}
+
+func TestRedirectIsNotFollowed(t *testing.T) {
+	var mu sync.Mutex
+	var secondCalls int
+	second := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		mu.Lock()
+		secondCalls++
+		mu.Unlock()
+		w.WriteHeader(http.StatusOK)
+	}))
+	t.Cleanup(second.Close)
+	first := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		http.Redirect(w, req, second.URL+req.URL.Path, http.StatusFound)
+	}))
+	t.Cleanup(first.Close)
+	p := newProvider(t, first.URL)
+
+	_, genErr := p.Generate(context.Background(), textRequest())
+	verifyErr := p.Verify(context.Background())
+	for _, err := range []error{genErr, verifyErr} {
+		var pe *llm.ProviderError
+		if !errors.Is(err, llm.ErrProvider) || !errors.As(err, &pe) || pe.Status() != http.StatusFound {
+			t.Fatalf("err = %v, want a ProviderError for HTTP 302", err)
+		}
+	}
+	mu.Lock()
+	defer mu.Unlock()
+	if secondCalls != 0 {
+		t.Fatalf("redirect target got %d requests, want 0", secondCalls)
+	}
+}
+
+func TestNewRejectsBadConfig(t *testing.T) {
+	const secret = "hunter2-secret"
+	cases := map[string]string{
+		"empty base":         "",
+		"relative base":      "ollama:11434",
+		"host only":          "192.168.1.20",
+		"ftp base":           "ftp://192.168.1.20:11434",
+		"no host":            "http://",
+		"credentials in URL": "http://user:" + secret + "@192.168.1.20:11434",
+		"user in URL":        "http://" + secret + "@ollama:11434",
+		"secret in query":    "http://ollama:11434/?token=" + secret,
+		"secret in fragment": "http://ollama:11434/#" + secret,
+		"unparseable":        "http://ollama:11434/%zz?token=" + secret,
+		"empty query":        "http://ollama:11434?",
+		"empty fragment":     "http://ollama:11434#",
+		"empty both":         "http://ollama:11434/?#",
+	}
+	for name, base := range cases {
+		_, err := New(Config{BaseURL: base, Model: "llama3.2"})
+		if err == nil {
+			t.Errorf("%s: New() = nil error", name)
+			continue
+		}
+		if strings.Contains(err.Error(), secret) {
+			t.Errorf("%s: error echoes the URL: %v", name, err)
+		}
+	}
+	for _, base := range []string{
+		"http://192.168.1.20:11434",
+		"http://ollama:11434",
+		"http://localhost:11434/",
+		"https://ollama.lan/proxy/",
+	} {
+		if _, err := New(Config{BaseURL: base, Model: "llama3.2"}); err != nil {
+			t.Errorf("New(%q) = %v", base, err)
+		}
+	}
+}
+
+func TestBaseWithPath(t *testing.T) {
+	s := newOllamaServer(t, reply{status: 200, fixture: "tags.json"})
+	if err := newProvider(t, s.URL+"/proxy/").Verify(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	if got := s.only(t).path; got != "/proxy/api/tags" {
+		t.Fatalf("path = %s, want /proxy/api/tags", got)
+	}
+}

internal/ai/llm/ollama/testdata/README.md

@@ -0,0 +1,36 @@
+# Ollama adapter fixtures
+
+These are the native Ollama API response bodies the contract tests in
+`ollama_test.go` replay. They are **not live captures**. Product AI is tested
+with fakes and live vendor calls are opt-in, so no request was sent to an
+Ollama server to make them. Each fixture is a sanitized adaptation of the
+response shapes in Ollama's public API documentation
+(<https://github.com/ollama/ollama/blob/main/docs/api.md>):
+
+- Chat, non-streaming: `POST /api/chat` with `"stream": false`.
+- Structured outputs: `POST /api/chat` with a JSON schema in `"format"`.
+- List local models: `GET /api/tags`.
+- Errors: a JSON `{"error": "..."}` body with a non-2xx status; a model
+  that is not pulled is HTTP 404.
+
+Sanitizing:
+
+- Timestamps, durations, sizes, digests and token counts are illustrative
+  values in the documented format, not values from a real server.
+- Message content is replaced with MealQuest dinner text.
+- Ollama takes no credentials, so none appear.
+
+Below, *not in the public example* marks values that were added for a test
+case and do not come from the documented example.
+
+| Fixture | Case | Shape | Not in the public example |
+| --- | --- | --- | --- |
+| `chat_text.json` | Success | Finished chat message, `done_reason: stop`, `prompt_eval_count` and `eval_count`. | — |
+| `chat_schema.json` | Schema output | Finished chat message whose content is a JSON object string. | The dinner object. |
+| `error_model_not_found.json` | Model missing | `{"error": "model \"…\" not found, try pulling it first"}`, served with HTTP 404. | — |
+| `tags.json` | Model list | `{"models": [...]}` with `name`, `model`, `digest` and `details`. | — |
+
+The unreachable-host case has no fixture: there is no response to record.
+The tests close an `httptest` server and dial its address, so the
+connection is refused, and they hold a reply past a short deadline for the
+timeout.

internal/ai/llm/ollama/testdata/chat_schema.json

@@ -0,0 +1,16 @@
+{
+  "model": "llama3.2",
+  "created_at": "2026-10-04T12:20:11.009132Z",
+  "message": {
+    "role": "assistant",
+    "content": "{\"dinners\": [{\"name\": \"Sheet-pan gnocchi\", \"why\": \"Like your Regular tray bake, but quicker.\"}]}"
+  },
+  "done_reason": "stop",
+  "done": true,
+  "total_duration": 1416823291,
+  "load_duration": 12309083,
+  "prompt_eval_count": 147,
+  "prompt_eval_duration": 271802000,
+  "eval_count": 41,
+  "eval_duration": 1130948000
+}

internal/ai/llm/ollama/testdata/chat_text.json

@@ -0,0 +1,16 @@
+{
+  "model": "llama3.2",
+  "created_at": "2026-10-04T12:13:43.416799Z",
+  "message": {
+    "role": "assistant",
+    "content": "Try a crock pot chili: it is a Quick dinner."
+  },
+  "done": true,
+  "done_reason": "stop",
+  "total_duration": 5191566416,
+  "load_duration": 2154458,
+  "prompt_eval_count": 26,
+  "prompt_eval_duration": 383809000,
+  "eval_count": 298,
+  "eval_duration": 4799921000
+}

internal/ai/llm/ollama/testdata/error_model_not_found.json

@@ -0,0 +1 @@
+{"error":"model \"llama9\" not found, try pulling it first"}

internal/ai/llm/ollama/testdata/tags.json

@@ -0,0 +1,34 @@
+{
+  "models": [
+    {
+      "name": "llama3.2:latest",
+      "model": "llama3.2:latest",
+      "modified_at": "2026-09-30T08:06:48.639712648-07:00",
+      "size": 2019393189,
+      "digest": "a80c4f17acd55265feec403c7aef86be0c25983ab279d83f3bcd3abbcb5b8b72",
+      "details": {
+        "parent_model": "",
+        "format": "gguf",
+        "family": "llama",
+        "families": ["llama"],
+        "parameter_size": "3.2B",
+        "quantization_level": "Q4_K_M"
+      }
+    },
+    {
+      "name": "qwen3:8b",
+      "model": "qwen3:8b",
+      "modified_at": "2026-09-28T19:41:02.112408113-07:00",
+      "size": 5225388164,
+      "digest": "500a1f067a9f782620b40bee6f7b0c89e17ae61f686b92c24933e4ca4b2b8b41",
+      "details": {
+        "parent_model": "",
+        "format": "gguf",
+        "family": "qwen3",
+        "families": ["qwen3"],
+        "parameter_size": "8.2B",
+        "quantization_level": "Q4_K_M"
+      }
+    }
+  ]
+}