Support for local agents

README.md

@@ -16,5 +16,6 @@ agent CLIs with generated MCP config, and lets MCPs authenticate lazily.
 - [gitea-mcp](docs/gitea-mcp.md)
 - [grafana-mcp](docs/grafana-mcp.md)
 - [gssh-mcp](docs/gssh-mcp.md)
+- [searxng-mcp](docs/searxng-mcp.md)
 - [gssh integration](docs/gssh-integration.md)
 - [Conventions](docs/conventions.md)

VERSION

@@ -1 +1 @@
-0.1.4
+0.1.8

cmd/gitea-mcp/main.go

@@ -117,7 +117,7 @@ func main() {
 		OnAuthURL: func(u string) {
 			fmt.Fprintln(os.Stderr, "gitea-mcp: opening browser for Gitea OAuth login:")
 			fmt.Fprintln(os.Stderr, "  ", u)
-			if err := browser.Open(u); err != nil {
+			if err := browser.OpenWith(svc.OAuthBrowser, u); err != nil {
 				fmt.Fprintln(os.Stderr, "gitea-mcp: open browser:", err)
 				fmt.Fprintln(os.Stderr, "(visit the URL above manually)")
 			}

cmd/grafana-mcp/main.go

@@ -114,7 +114,7 @@ func main() {
 		OnAuthURL: func(u string) {
 			fmt.Fprintln(os.Stderr, "grafana-mcp: opening browser for Grafana OAuth login:")
 			fmt.Fprintln(os.Stderr, "  ", u)
-			if err := browser.Open(u); err != nil {
+			if err := browser.OpenWith(svc.OAuthBrowser, u); err != nil {
 				fmt.Fprintln(os.Stderr, "grafana-mcp: open browser:", err)
 				fmt.Fprintln(os.Stderr, "(visit the URL above manually)")
 			}

cmd/gssh-mcp/main.go

@@ -101,7 +101,7 @@ func main() {
 		OnAuthURL: func(u string) {
 			fmt.Fprintln(os.Stderr, "gssh-mcp: opening browser for Gssh OAuth login:")
 			fmt.Fprintln(os.Stderr, "  ", u)
-			if err := browser.Open(u); err != nil {
+			if err := browser.OpenWith(svc.OAuthBrowser, u); err != nil {
 				fmt.Fprintln(os.Stderr, "gssh-mcp: open browser:", err)
 				fmt.Fprintln(os.Stderr, "(visit the URL above manually)")
 			}

cmd/searxng-mcp/client.go

@@ -0,0 +1,124 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+)
+
+var ErrUnauthorized = errors.New("searxng: bearer rejected")
+
+type searxngAPI struct {
+	baseURL string
+	token   func(context.Context) (string, error)
+	client  *http.Client
+}
+
+type searchParams struct {
+	Query      string
+	Categories string
+	Engines    string
+	Language   string
+	TimeRange  string
+	SafeSearch *int
+	Page       int
+	Limit      int
+}
+
+type searxngSearchResponse struct {
+	Query           string          `json:"query"`
+	NumberOfResults int             `json:"number_of_results"`
+	Results         []searxngResult `json:"results"`
+	Suggestions     []string        `json:"suggestions,omitempty"`
+	Answers         []string        `json:"answers,omitempty"`
+	Corrections     []string        `json:"corrections,omitempty"`
+}
+
+type searxngResult struct {
+	Title         string   `json:"title"`
+	URL           string   `json:"url"`
+	Content       string   `json:"content,omitempty"`
+	Engine        string   `json:"engine,omitempty"`
+	Engines       []string `json:"engines,omitempty"`
+	Category      string   `json:"category,omitempty"`
+	Score         float64  `json:"score,omitempty"`
+	PublishedDate string   `json:"publishedDate,omitempty"`
+	ImgSrc        string   `json:"img_src,omitempty"`
+	Thumbnail     string   `json:"thumbnail,omitempty"`
+}
+
+func (s *searxngAPI) search(ctx context.Context, p searchParams) (searxngSearchResponse, error) {
+	q := url.Values{
+		"format": []string{"json"},
+		"q":      []string{p.Query},
+	}
+	setIf(q, "categories", p.Categories)
+	setIf(q, "engines", p.Engines)
+	setIf(q, "language", p.Language)
+	setIf(q, "time_range", p.TimeRange)
+	if p.SafeSearch != nil {
+		q.Set("safesearch", strconv.Itoa(*p.SafeSearch))
+	}
+	if p.Page > 0 {
+		q.Set("pageno", strconv.Itoa(p.Page))
+	}
+
+	full := s.baseURL + "/search?" + q.Encode()
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, full, nil)
+	if err != nil {
+		return searxngSearchResponse{}, err
+	}
+	tok, err := s.token(ctx)
+	if err != nil {
+		return searxngSearchResponse{}, err
+	}
+	req.Header.Set("Authorization", "Bearer "+tok)
+	req.Header.Set("Accept", "application/json")
+
+	resp, err := s.client.Do(req)
+	if err != nil {
+		return searxngSearchResponse{}, err
+	}
+	defer func() { _, _ = io.Copy(io.Discard, resp.Body); _ = resp.Body.Close() }()
+	if err := checkStatus(resp, req); err != nil {
+		return searxngSearchResponse{}, err
+	}
+	if ct := resp.Header.Get("Content-Type"); ct != "" && !strings.Contains(ct, "application/json") {
+		return searxngSearchResponse{}, fmt.Errorf("searxng: %s returned %q, not JSON; ensure SearXNG enables format=json and Caddy is not serving a login page", req.URL.Path, ct)
+	}
+
+	var out searxngSearchResponse
+	if err := json.NewDecoder(resp.Body).Decode(&out); err != nil {
+		return searxngSearchResponse{}, fmt.Errorf("searxng: decode JSON search response: %w", err)
+	}
+	if p.Limit > 0 && len(out.Results) > p.Limit {
+		out.Results = out.Results[:p.Limit]
+	}
+	return out, nil
+}
+
+func checkStatus(resp *http.Response, req *http.Request) error {
+	if resp.StatusCode == http.StatusUnauthorized || resp.StatusCode == http.StatusForbidden {
+		return fmt.Errorf("%w by %s (try `sherlock logout searxng` and retry; Caddy must accept the OAuth bearer)", ErrUnauthorized, req.URL.Host)
+	}
+	if resp.StatusCode == http.StatusFound || resp.StatusCode == http.StatusSeeOther || resp.StatusCode == http.StatusTemporaryRedirect || resp.StatusCode == http.StatusPermanentRedirect {
+		return fmt.Errorf("searxng: %s %s redirected to %q; Caddy is likely requiring browser-session auth instead of accepting the OAuth bearer", req.Method, req.URL.Path, resp.Header.Get("Location"))
+	}
+	if resp.StatusCode >= 400 {
+		body, _ := io.ReadAll(io.LimitReader(resp.Body, 4096))
+		return fmt.Errorf("searxng: %s %s: HTTP %d: %s", req.Method, req.URL.Path, resp.StatusCode, strings.TrimSpace(string(body)))
+	}
+	return nil
+}
+
+func setIf(q url.Values, k, v string) {
+	if v != "" {
+		q.Set(k, v)
+	}
+}

cmd/searxng-mcp/main.go

@@ -0,0 +1,149 @@
+// Command searxng-mcp is sherlock's MCP server for SearXNG. It
+// authenticates as the operator against Authentik (OIDC + PKCE,
+// loopback callback) and sends the resulting bearer token to the
+// Caddy-protected SearXNG JSON search API.
+//
+// Two modes:
+//
+//	searxng-mcp           start the stdio MCP server (agents spawn this)
+//	searxng-mcp --probe   run auth + one search, print result, exit
+//
+// Deployment configuration (the Authentik issuer/client ID and the
+// SearXNG base URL) comes entirely from the sherlock config file; there
+// are no compiled-in defaults. See docs/configuration.md.
+package main
+
+import (
+	"context"
+	"errors"
+	"flag"
+	"fmt"
+	"net/http"
+	"os"
+	"os/signal"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/modelcontextprotocol/go-sdk/mcp"
+
+	"gitea.alexandru.macocian.me/amacocian/sherlock/internal/agent"
+	"gitea.alexandru.macocian.me/amacocian/sherlock/internal/authn"
+	"gitea.alexandru.macocian.me/amacocian/sherlock/internal/browser"
+	"gitea.alexandru.macocian.me/amacocian/sherlock/internal/config"
+	"gitea.alexandru.macocian.me/amacocian/sherlock/internal/keyring"
+	"gitea.alexandru.macocian.me/amacocian/sherlock/internal/xdg"
+)
+
+// serviceName is the wallet key under which SearXNG tokens live, and
+// the [services.<serviceName>] section read from the config file. The
+// sherlock CLI's `logout searxng` clears the same wallet entry.
+const serviceName = "searxng"
+
+// Version is overwritten at build time via -ldflags "-X main.Version=...".
+var Version = "0.0.0-dev"
+
+// scopes asked from Authentik. `openid` is required for an ID token;
+// `profile`/`email` populate user-info claims in `sherlock status`.
+var scopes = []string{"openid", "profile", "email"}
+
+func main() {
+	probe := flag.Bool("probe", false, "run auth + one SearXNG search, print result, exit")
+	probeQuery := flag.String("probe-query", "sherlock", "query to use with --probe")
+	showVersion := flag.Bool("version", false, "print version and exit")
+	flag.Parse()
+	if *showVersion {
+		fmt.Println(Version)
+		return
+	}
+
+	svc, err := config.LoadService(serviceName)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "searxng-mcp:", err)
+		if errors.Is(err, config.ErrNotFound) {
+			fmt.Fprintln(os.Stderr, "Create it (see docs/configuration.md) or run the sherlock install script.")
+		}
+		os.Exit(2)
+	}
+
+	store, err := keyring.Open()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "searxng-mcp:", err)
+		os.Exit(3)
+	}
+
+	agent.EnsurePathContainsSiblings()
+
+	lockPath, err := xdg.RefreshLockPath()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "searxng-mcp:", err)
+		os.Exit(1)
+	}
+
+	ctx, cancel := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+	defer cancel()
+
+	cfg := authn.Config{
+		Issuer:       svc.Issuer,
+		ClientID:     svc.ClientID,
+		ClientSecret: svc.ClientSecret,
+		Scopes:       scopes,
+	}
+	holder := authn.NewTokenHolder()
+	src := authn.NewTokenSource(store, serviceName, cfg, authn.EnsureOptions{
+		LockPath: lockPath,
+		OnAuthURL: func(u string) {
+			fmt.Fprintln(os.Stderr, "searxng-mcp: opening browser for SearXNG OAuth login:")
+			fmt.Fprintln(os.Stderr, "  ", u)
+			if err := browser.OpenWith(svc.OAuthBrowser, u); err != nil {
+				fmt.Fprintln(os.Stderr, "searxng-mcp: open browser:", err)
+				fmt.Fprintln(os.Stderr, "(visit the URL above manually)")
+			}
+		},
+	}, holder.Set).Lifetime(ctx)
+
+	// Lazy auth: the token getter triggers the (possibly browser-opening)
+	// OAuth flow on the first tool call and launches the background
+	// renewer. Auth stays off the MCP startup path so the handshake
+	// completes instantly.
+	token := func(reqCtx context.Context) (string, error) {
+		if err := src.EnsureStarted(reqCtx); err != nil {
+			return "", fmt.Errorf("searxng auth: %w", err)
+		}
+		return holder.AccessToken(), nil
+	}
+
+	api := &searxngAPI{
+		baseURL: strings.TrimRight(svc.BaseURL, "/"),
+		token:   token,
+		client: &http.Client{
+			Timeout: 30 * time.Second,
+			CheckRedirect: func(*http.Request, []*http.Request) error {
+				return http.ErrUseLastResponse
+			},
+		},
+	}
+
+	if *probe {
+		// --probe authenticates eagerly: that's the whole point of a probe.
+		if err := src.EnsureStarted(ctx); err != nil {
+			fmt.Fprintln(os.Stderr, "searxng-mcp: auth:", err)
+			os.Exit(5)
+		}
+		resp, err := api.search(ctx, searchParams{Query: *probeQuery, Limit: 1})
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "searxng-mcp: probe:", err)
+			os.Exit(5)
+		}
+		fmt.Printf("OK: searched %s for %q (%d result(s))\n", svc.BaseURL, *probeQuery, len(resp.Results))
+		return
+	}
+
+	server := mcp.NewServer(&mcp.Implementation{Name: "searxng-mcp", Version: Version}, nil)
+	registerTools(server, api)
+
+	if err := server.Run(ctx, &mcp.StdioTransport{}); err != nil && !errors.Is(err, context.Canceled) {
+		fmt.Fprintln(os.Stderr, "searxng-mcp:", err)
+		os.Exit(1)
+	}
+}

cmd/searxng-mcp/tools.go

@@ -0,0 +1,77 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"strings"
+
+	"github.com/modelcontextprotocol/go-sdk/mcp"
+)
+
+func registerTools(server *mcp.Server, api *searxngAPI) {
+	mcp.AddTool(server, &mcp.Tool{
+		Name:        "search_web",
+		Description: "Search the operator's OAuth-protected SearXNG instance and return JSON search results.",
+	}, searchWebHandler(api))
+}
+
+type searchWebInput struct {
+	Query      string `json:"query" jsonschema:"search query"`
+	Categories string `json:"categories,omitempty" jsonschema:"optional comma-separated SearXNG categories, e.g. general, images, news"`
+	Engines    string `json:"engines,omitempty" jsonschema:"optional comma-separated SearXNG engines"`
+	Language   string `json:"language,omitempty" jsonschema:"optional SearXNG language code"`
+	TimeRange  string `json:"time_range,omitempty" jsonschema:"optional time range: day, month, year"`
+	SafeSearch *int   `json:"safesearch,omitempty" jsonschema:"optional SearXNG safesearch value: 0, 1, or 2"`
+	Page       int    `json:"page,omitempty" jsonschema:"optional result page number, default 1"`
+	Limit      int    `json:"limit,omitempty" jsonschema:"max results to return (1-50, default 10)"`
+}
+
+type searchWebOutput struct {
+	Query           string          `json:"query"`
+	NumberOfResults int             `json:"number_of_results,omitempty"`
+	Results         []searxngResult `json:"results"`
+	Suggestions     []string        `json:"suggestions,omitempty"`
+	Answers         []string        `json:"answers,omitempty"`
+	Corrections     []string        `json:"corrections,omitempty"`
+}
+
+func searchWebHandler(api *searxngAPI) mcp.ToolHandlerFor[searchWebInput, searchWebOutput] {
+	return func(ctx context.Context, _ *mcp.CallToolRequest, in searchWebInput) (*mcp.CallToolResult, searchWebOutput, error) {
+		query := strings.TrimSpace(in.Query)
+		if query == "" {
+			return nil, searchWebOutput{}, errors.New("search_web requires query")
+		}
+		limit := clampInt(in.Limit, 1, 50, 10)
+		page := clampInt(in.Page, 1, 100, 1)
+		if in.SafeSearch != nil && (*in.SafeSearch < 0 || *in.SafeSearch > 2) {
+			return nil, searchWebOutput{}, errors.New("safesearch must be 0, 1, or 2")
+		}
+		resp, err := api.search(ctx, searchParams{
+			Query:      query,
+			Categories: strings.TrimSpace(in.Categories),
+			Engines:    strings.TrimSpace(in.Engines),
+			Language:   strings.TrimSpace(in.Language),
+			TimeRange:  strings.TrimSpace(in.TimeRange),
+			SafeSearch: in.SafeSearch,
+			Page:       page,
+			Limit:      limit,
+		})
+		if err != nil {
+			return nil, searchWebOutput{}, err
+		}
+		return nil, searchWebOutput(resp), nil
+	}
+}
+
+func clampInt(v, min, max, dflt int) int {
+	if v <= 0 {
+		return dflt
+	}
+	if v < min {
+		return min
+	}
+	if v > max {
+		return max
+	}
+	return v
+}

cmd/sherlock/main.go

@@ -18,6 +18,7 @@ import (
 	"time"
 
 	"gitea.alexandru.macocian.me/amacocian/sherlock/internal/agent"
+	"gitea.alexandru.macocian.me/amacocian/sherlock/internal/config"
 	"gitea.alexandru.macocian.me/amacocian/sherlock/internal/keyring"
 	"gitea.alexandru.macocian.me/amacocian/sherlock/internal/mcp"
 )
@@ -58,6 +59,13 @@ func main() {
 	// `go install` even if the operator never touched their shell rc.
 	agent.EnsurePathContainsSiblings()
 
+	// Register operator-defined custom agents from config.toml so they
+	// dispatch just like the built-ins below.
+	if err := registerCustomAgents(); err != nil {
+		fmt.Fprintln(os.Stderr, "sherlock:", err)
+		os.Exit(exitUsage)
+	}
+
 	switch sub {
 	case "status":
 		runStatus(store, rest)
@@ -132,6 +140,11 @@ func runStatus(store keyring.Store, _ []string) {
 			if len(ts.Scopes) > 0 {
 				fmt.Printf("       scopes:        %s\n", strings.Join(ts.Scopes, " "))
 			}
+			if !ts.AccessExpAt.IsZero() {
+				fmt.Printf("       access until   %s (%s)\n",
+					ts.AccessExpAt.Format(time.RFC3339),
+					humanizeUntil(ts.AccessExpAt))
+			}
 			if !ts.IDExpiresAt.IsZero() {
 				fmt.Printf("       id token until %s (%s)\n",
 					ts.IDExpiresAt.Format(time.RFC3339),
@@ -220,6 +233,7 @@ func knownMCPs() (mcp.Servers, error) {
 		"gitea":   {Command: "gitea-mcp"},
 		"grafana": {Command: "grafana-mcp"},
 		"gssh":    {Command: "gssh-mcp"},
+		"searxng": {Command: "searxng-mcp"},
 	}
 	for name, spec := range specs {
 		abs, err := agent.LookPath(spec.Command)
@@ -233,6 +247,28 @@ func knownMCPs() (mcp.Servers, error) {
 	return out, nil
 }
 
+// registerCustomAgents loads the operator config (if any) and registers
+// each `[agents.<name>]` entry as a dispatchable agent. A missing config
+// file is not an error — sherlock simply offers only the built-ins. A
+// malformed agent entry (unknown backend, name collision) is fatal, in
+// keeping with the config package's "refuse to start rather than
+// misbehave" philosophy.
+func registerCustomAgents() error {
+	cfg, err := config.Load()
+	if err != nil {
+		if errors.Is(err, config.ErrNotFound) {
+			return nil
+		}
+		return err
+	}
+	for name, a := range cfg.Agents {
+		if err := agent.RegisterCustom(name, a.Command, a.Backend); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 func humanizeUntil(t time.Time) string {
 	d := time.Until(t).Round(time.Second)
 	if d < 0 {

cmd/sherlock/update.go

@@ -78,9 +78,10 @@ func runUpdate(args []string) {
 	}
 
 	// Non-interactive install against the cache checkout (the installer
-	// syncs it to the latest tag and bakes that version). Config is left
-	// untouched — SeedConfig is off, so an update never opens an editor
-	// or clobbers config.
+	// syncs it to the latest tag and bakes that version). SeedConfig is
+	// off, so update never creates a config or opens an editor, but the
+	// installer may append marked templates for newly shipped config
+	// sections. Existing values are never clobbered.
 	if err := installer.Install(context.Background(), installer.Options{
 		Local:      false,
 		SeedConfig: false,

completions/sherlock.fish

@@ -26,6 +26,7 @@ complete -c sherlock -n '__fish_seen_subcommand_from run' -f -a 'claude'  -d 'An
 complete -c sherlock -n '__fish_seen_subcommand_from logout' -f -a 'gitea'   -d 'Forget the gitea session'
 complete -c sherlock -n '__fish_seen_subcommand_from logout' -f -a 'grafana' -d 'Forget the grafana session'
 complete -c sherlock -n '__fish_seen_subcommand_from logout' -f -a 'gssh'    -d 'Forget the gssh session'
+complete -c sherlock -n '__fish_seen_subcommand_from logout' -f -a 'searxng' -d 'Forget the searxng session'
 
 # ── `sherlock update [--force]` ──────────────────────────────────────
 complete -c sherlock -n '__fish_seen_subcommand_from update' -l force -s f -f -d 'Reinstall the latest release even if not newer'

config.example.toml

@@ -1,5 +1,11 @@
 # sherlock conifugration - lives in $XDG_CONFIG_HOME/sherlock/config.toml
 
+# ── OAuth login ───────────────────────────────────────────────────────
+# Optional browser executable/name for OAuth login URLs. Leave unset to
+# use the OS default browser (xdg-open/open/rundll32).
+# [oauth]
+# browser = "firefox"
+
 # ── Providers ────────────────────────────────────────────────────────
 # A [providers.<name>] block is a reusable OAuth/OIDC client. Services
 # point at one via `provider = "<name>"`. Define a provider once and
@@ -36,3 +42,20 @@ base_url = "https://grafana.example.com"
 [services.gssh]
 provider = "sherlock-cli"
 base_url = "https://terminal.example.com"
+
+[services.searxng]
+provider = "sherlock-cli"
+base_url = "https://search.example.com"
+
+# ── Custom agents ────────────────────────────────────────────────────
+# A [agents.<name>] block exposes an operator-owned wrapper command as
+# `sherlock <name>`, reusing a built-in backend's MCP/-env conventions.
+# `backend` must be "copilot" or "claude" — it tells sherlock how to
+# format the MCP config for the wrapped CLI. `command` is the binary to
+# exec and defaults to <name> when omitted.
+#
+# Example: surface a `copilot-local` wrapper (Copilot CLI pointed at a
+# self-hosted model via BYOK) as `sherlock copilot-local`.
+# [agents.copilot-local]
+# command = "copilot-local"
+# backend = "copilot"

docs/agents.md

@@ -13,8 +13,9 @@ equivalent. Unknown agent names exit with usage errors.
 ## Spawn behavior
 
 On spawn, sherlock resolves installed MCP binaries (`gitea-mcp`, `grafana-mcp`,
-`gssh-mcp`), skips missing ones with a warning, renders a 0600 `.mcp.json` file
-under `$XDG_RUNTIME_DIR/sherlock/`, and `exec`s the target agent.
+`gssh-mcp`, `searxng-mcp`), skips missing ones with a warning, renders a 0600
+`.mcp.json` file under `$XDG_RUNTIME_DIR/sherlock/`, and `exec`s the target
+agent.
 
 The child mostly inherits the parent environment. The Claude profile strips
 `ANTHROPIC_API_KEY` so a personal key does not override sherlock-managed
@@ -22,7 +23,31 @@ behavior.
 
 ## Changing agents
 
-Adding an agent is a code change under `internal/agent/`. Implement the small
-agent interface, register it in `init`, and use `internal/mcp` for config
-rendering. The exact API lives in `internal/agent/agent.go`; shared spawn
-helpers live in `internal/agent/exec.go`.
+Adding a built-in agent is a code change under `internal/agent/`. Implement
+the small agent interface, register it in `init`, and use `internal/mcp`
+for config rendering. The exact API lives in `internal/agent/agent.go`;
+shared spawn helpers live in `internal/agent/exec.go`, and the per-CLI
+MCP/-env conventions ("backends") live in `internal/agent/backend.go`.
+
+## Custom agents (config)
+
+Operators can register their own agents from `config.toml` without
+touching code — handy for wrapper commands such as a `copilot-local`
+script that points the Copilot CLI at a self-hosted model:
+
+```toml
+[agents.copilot-local]
+command = "copilot-local"   # binary to exec; defaults to the name if omitted
+backend = "copilot"         # which CLI's MCP/-env conventions to use
+```
+
+`backend` must be one of the built-in backends (`copilot` or `claude`);
+it tells sherlock how to format the MCP config (`--additional-mcp-config
+@<path>` vs `--mcp-config <path>`) and what env to scrub. The rendered
+MCP file is named after the agent (`<name>.mcp.json`).
+
+`sherlock copilot-local [args...]` then dispatches exactly like a
+built-in. A custom agent whose name collides with a built-in agent, or
+that names an unknown backend, is a hard startup error. (Names matching a
+reserved subcommand — `status`, `logout`, `run`, `update`, `version` —
+are shadowed by that subcommand; reach them via `sherlock run <name>`.)

docs/auth-model.md

@@ -5,7 +5,7 @@ master session: each MCP authenticates for the service it calls.
 
 ## Lifecycle
 
-For a service such as `gitea`, `grafana`, or `gssh`, the MCP asks
+For a service such as `gitea`, `grafana`, `gssh`, or `searxng`, the MCP asks
 `internal/authn` for a token on first use:
 
 1. Fresh wallet entry: return it.
@@ -15,17 +15,18 @@ For a service such as `gitea`, `grafana`, or `gssh`, the MCP asks
    serialized by `$XDG_RUNTIME_DIR/sherlock.login.lock`, persist, return.
 
 Long-running MCPs use `TokenSource` and `TokenHolder` so requests always read
-the latest bearer. Refresh never opens a browser; if refresh can no longer
-recover, the next invocation performs a fresh login.
+the latest bearer. Refresh follows access-token expiry, never opens a browser,
+and falls back to a fresh login on the next invocation if refresh can no longer
+recover.
 
 ## Service identity
 
 The config supplies issuer, client ID/secret, and base URL. Scopes are owned by
 each MCP because they follow the tool surface, not the deployment.
 
-Gitea uses Gitea's OAuth2 server. Grafana and Gssh normally reuse the shared
-Authentik `sherlock-cli` provider. Tokens are stored and refreshed per service
-and are not reused across unrelated services.
+Gitea uses Gitea's OAuth2 server. Grafana, Gssh, and SearXNG normally reuse the
+shared Authentik `sherlock-cli` provider. Tokens are stored and refreshed per
+service and are not reused across unrelated services.
 
 ## User controls
 

docs/configuration.md

@@ -5,6 +5,10 @@ required fields are hard errors.
 
 Default source: [`config.example.toml`](../config.example.toml).
 
+Setup and update compare an existing config against the shipped example. Missing
+provider/service sections are appended as marked templates; existing sections
+and values are not rewritten.
+
 ## Location
 
 Resolved in order:
@@ -15,6 +19,10 @@ Resolved in order:
 
 ## Shape
 
+`[oauth]` is optional. Set `browser = "<executable>"` to open OAuth login URLs
+with a specific browser, for example `browser = "firefox"`. Leave it unset to
+use the OS default browser.
+
 `[providers.<name>]` defines a reusable OAuth/OIDC identity: `issuer`,
 `client_id`, optional `client_secret`.
 

docs/conventions.md

@@ -30,9 +30,10 @@ Repository rules that should stay true as the project changes.
 
 ## Naming
 
-- Binaries are kebab-case: `gitea-mcp`, `gssh-mcp`.
+- Binaries are kebab-case: `gitea-mcp`, `gssh-mcp`, `searxng-mcp`.
 - Agent names match the wrapped CLI: `copilot`, `claude`.
-- Service names are the config key and wallet key: `gitea`, `grafana`, `gssh`.
+- Service names are the config key and wallet key: `gitea`, `grafana`, `gssh`,
+  `searxng`.
 
 ## Commits and CI
 

docs/installation.md

@@ -15,8 +15,9 @@ around the same command.
 
 The installer clones or updates a cached source checkout, checks out the latest
 release tag, seeds `config.toml` from `config.example.toml` without overwriting
-existing values, optionally opens the config in an editor, installs `sherlock`
-plus MCP binaries, and installs shell completions when supported.
+existing values, appends marked templates for missing service/provider sections,
+optionally opens the config in an editor, installs `sherlock` plus MCP binaries,
+and installs shell completions when supported.
 
 One implementation backs both bootstrap setup and `sherlock update`.
 
@@ -32,7 +33,8 @@ selects the editor.
 ## Updating
 
 Use `sherlock update` to install a newer release, or `sherlock update --force`
-to reinstall the latest release. Updates rebuild binaries and completions but do
-not touch existing config.
+to reinstall the latest release. Updates rebuild binaries and completions, and
+may append marked config templates for newly shipped service/provider sections.
+They do not rewrite existing config values.
 
 Re-running setup is safe: it preserves config and reinstalls binaries.

docs/searxng-mcp.md

@@ -0,0 +1,23 @@
+# searxng-mcp
+
+Stdio MCP for a SearXNG instance. It exposes web search through SearXNG's JSON
+`/search` API. Exact tool schemas live in `cmd/searxng-mcp/tools.go`.
+
+## Auth
+
+`searxng-mcp` uses sherlock-managed OAuth with wallet key `searxng`, normally
+through the shared Authentik `sherlock-cli` provider. It sends a fresh bearer to
+the Caddy-protected SearXNG origin on every search request.
+
+Caddy must accept that OAuth bearer for API requests. Browser SSO redirects or
+session cookies alone are not enough for an MCP subprocess. SearXNG must also
+enable JSON output for `/search?format=json`.
+
+Config is `[services.searxng]` with provider or inline OAuth identity plus
+`base_url`. `sherlock logout searxng` clears the session.
+
+## Operation
+
+When `searxng-mcp` is installed, `sherlock <agent>` includes it in the generated
+MCP config. The first tool call authenticates lazily. `searxng-mcp --probe`
+verifies auth against Caddy and one SearXNG JSON search without an agent.

go.mod

@@ -7,7 +7,7 @@ require (
 	github.com/coder/websocket v1.8.14
 	github.com/coreos/go-oidc/v3 v3.18.0
 	github.com/go-jose/go-jose/v4 v4.1.4
-	github.com/grafana/mcp-grafana v0.15.2
+	github.com/grafana/mcp-grafana v0.15.3-0.20260613165141-77d81c6b7389
 	github.com/mark3labs/mcp-go v0.46.0
 	github.com/modelcontextprotocol/go-sdk v1.6.1
 	github.com/zalando/go-keyring v0.2.8
@@ -172,5 +172,3 @@ require (
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
-
-replace github.com/grafana/mcp-grafana => github.com/AlexMacocian/mcp-grafana v0.0.0-20260613143711-1f1200568046

go.sum

@@ -7,8 +7,6 @@ cloud.google.com/go/compute/metadata v0.9.0 h1:pDUj4QMoPejqq20dK0Pg2N4yG9zIkYGdB
 cloud.google.com/go/compute/metadata v0.9.0/go.mod h1:E0bWwX5wTnLPedCKqk3pJmVgCBSM6qQI1yTBdEb3C10=
 connectrpc.com/connect v1.19.1 h1:R5M57z05+90EfEvCY1b7hBxDVOUl45PrtXtAV2fOC14=
 connectrpc.com/connect v1.19.1/go.mod h1:tN20fjdGlewnSFeZxLKb0xwIZ6ozc3OQs2hTXy4du9w=
-github.com/AlexMacocian/mcp-grafana v0.0.0-20260613143711-1f1200568046 h1:W2wS3aOdAjhEc/JH8jBDY95YKiU7oq0U9KqoGtwz9M0=
-github.com/AlexMacocian/mcp-grafana v0.0.0-20260613143711-1f1200568046/go.mod h1:LT3LLGh4ZmjqasENuFicV8iJkyuGuVNZztyPolDlBqI=
 github.com/Azure/azure-sdk-for-go/sdk/azcore v1.21.0 h1:fou+2+WFTib47nS+nz/ozhEBnvU96bKHy6LjRsY4E28=
 github.com/Azure/azure-sdk-for-go/sdk/azcore v1.21.0/go.mod h1:t76Ruy8AHvUAC8GfMWJMa0ElSbuIcO03NLpynfbgsPA=
 github.com/Azure/azure-sdk-for-go/sdk/azidentity v1.13.1 h1:Hk5QBxZQC1jb2Fwj6mpzme37xbCDdNTxU7O9eb5+LB4=
@@ -206,6 +204,8 @@ github.com/grafana/grafana-plugin-sdk-go v0.290.1 h1:wNX4R8sHxEAmtmFhmV05IsLGznz
 github.com/grafana/grafana-plugin-sdk-go v0.290.1/go.mod h1:KDkcxp1XqbKz0WD/q9p98Cf5Wp50LG0NkoPlVlptSWs=
 github.com/grafana/incident-go v0.0.0-20251003115753-d71681611ddd h1:y8uJA/UmFHjwNWAvppxDRq+w9zIQmb0z79YVV2vS96g=
 github.com/grafana/incident-go v0.0.0-20251003115753-d71681611ddd/go.mod h1:3QDfdZOWKRxNhMJFL+0C/+12+jLNHDlt0VKNr/i9Daw=
+github.com/grafana/mcp-grafana v0.15.3-0.20260613165141-77d81c6b7389 h1:teRFmGepvMKVA/VNj/IcQkJuS3q0Rijk5yYSCmiLbxE=
+github.com/grafana/mcp-grafana v0.15.3-0.20260613165141-77d81c6b7389/go.mod h1:LT3LLGh4ZmjqasENuFicV8iJkyuGuVNZztyPolDlBqI=
 github.com/grafana/otel-profiling-go v0.5.1 h1:stVPKAFZSa7eGiqbYuG25VcqYksR6iWvF3YH66t4qL8=
 github.com/grafana/otel-profiling-go v0.5.1/go.mod h1:ftN/t5A/4gQI19/8MoWurBEtC6gFw8Dns1sJZ9W4Tls=
 github.com/grafana/pyroscope-go/godeltaprof v0.1.9 h1:c1Us8i6eSmkW+Ez05d3co8kasnuOY813tbMN8i/a3Og=

internal/agent/agent.go

@@ -1,9 +1,15 @@
 // Package agent dispatches `sherlock <name>` invocations to a small
-// set of supported CLIs (Copilot, Claude Code, …). Each agent is a
-// concrete type in its own file that implements the Agent interface;
-// they register themselves at init time. Adding a new agent is a
-// matter of dropping a new file in this package — there is no TOML
-// schema and no user-facing extensibility surface, by design.
+// set of supported CLIs (Copilot, Claude Code, …). Each built-in agent
+// is a concrete type in its own file that implements the Agent
+// interface; they register themselves at init time. Adding a new
+// built-in is a matter of dropping a new file in this package.
+//
+// Operators can also declare custom agents in config.toml's
+// `[agents.<name>]` table — a wrapper command plus a backend type
+// ("copilot" or "claude") that selects the MCP-config and env
+// conventions. Those are added at runtime via RegisterCustom. The
+// per-CLI quirks shared by built-in and custom agents live in
+// backend.go.
 //
 // The reusable bits live in this package too (exec.go for env/exec
 // helpers; the mcp sibling package for MCP-config rendering). Agent

internal/agent/backend.go

@@ -0,0 +1,78 @@
+package agent
+
+import (
+	"fmt"
+	"sort"
+
+	"gitea.alexandru.macocian.me/amacocian/sherlock/internal/mcp"
+)
+
+// backend captures the per-CLI quirks shared by every agent that speaks
+// to a given coding-assistant CLI: how the rendered MCP-config file is
+// passed on the command line, and which env vars must be scrubbed from
+// the child process.
+//
+// Built-in agents (copilot, claude) and operator-defined custom agents
+// from config.toml both spawn through a backend, so a `copilot-local`
+// wrapper formats its MCP config exactly like the real `copilot`.
+type backend struct {
+	// mcpArgs returns the CLI flags that point the agent at the rendered
+	// MCP-config file at path.
+	mcpArgs func(path string) []string
+	// forbidEnv lists env vars stripped from the child (e.g. a personal
+	// ANTHROPIC_API_KEY that must not override broker-managed behavior).
+	forbidEnv []string
+}
+
+// backends is the set of known backend types. The keys are the values
+// operators put in `[agents.<name>].backend`.
+var backends = map[string]backend{
+	"copilot": {
+		// The `@` prefix tells Copilot to treat the argument as a file
+		// path rather than inline JSON.
+		mcpArgs: func(p string) []string { return []string{"--additional-mcp-config", "@" + p} },
+	},
+	"claude": {
+		mcpArgs:   func(p string) []string { return []string{"--mcp-config", p} },
+		forbidEnv: []string{"ANTHROPIC_API_KEY"},
+	},
+}
+
+// backendNames returns the known backend type names, sorted, for error
+// messages.
+func backendNames() []string {
+	out := make([]string, 0, len(backends))
+	for n := range backends {
+		out = append(out, n)
+	}
+	sort.Strings(out)
+	return out
+}
+
+// spawn is the shared spawn path used by both built-in and custom
+// agents. name selects the rendered MCP-config file name; command is the
+// binary to exec. On success it does not return (the process is
+// replaced); any returned error is a setup failure.
+func (b backend) spawn(name, command string, ctx Context, args []string) error {
+	bin, err := LookPath(command)
+	if err != nil {
+		return err
+	}
+	mcpPath, err := mcp.Render(name, ctx.Servers)
+	if err != nil {
+		return err
+	}
+	argv := append([]string{bin}, b.mcpArgs(mcpPath)...)
+	argv = append(argv, args...)
+	return DefaultExecer.Exec(bin, argv, BuildEnv(b.forbidEnv, nil))
+}
+
+// resolveBackend returns the backend for a type name, with a friendly
+// error listing the valid choices when it is unknown.
+func resolveBackend(name string) (backend, error) {
+	b, ok := backends[name]
+	if !ok {
+		return backend{}, fmt.Errorf("unknown backend %q (want one of: %v)", name, backendNames())
+	}
+	return b, nil
+}

internal/agent/claude.go

@@ -1,9 +1,5 @@
 package agent
 
-import (
-	"gitea.alexandru.macocian.me/amacocian/sherlock/internal/mcp"
-)
-
 func init() { Register(&claude{}) }
 
 // claude integrates Anthropic's Claude Code CLI (npm package
@@ -14,27 +10,14 @@ func init() { Register(&claude{}) }
 // We also forbid ANTHROPIC_API_KEY in the child env so an
 // inadvertently-set personal key can't override the broker-managed
 // session. (Phase 2 will surface a proper Anthropic auth grant.)
+//
+// The per-CLI quirks (flag shape, env scrubbing) live in the shared
+// "claude" backend; this type is just the built-in registration.
 type claude struct{}
 
 func (claude) Name() string        { return "claude" }
 func (claude) Description() string { return "Anthropic Claude Code CLI" }
 
 func (c claude) Spawn(ctx Context, args []string) error {
-	bin, err := LookPath("claude")
-	if err != nil {
-		return err
-	}
-	mcpPath, err := mcp.Render(c.Name(), ctx.Servers)
-	if err != nil {
-		return err
-	}
-	argv := c.buildArgv(bin, mcpPath, args)
-	env := BuildEnv([]string{"ANTHROPIC_API_KEY"}, nil)
-	return DefaultExecer.Exec(bin, argv, env)
-}
-
-func (claude) buildArgv(bin, mcpPath string, userArgs []string) []string {
-	argv := []string{bin, "--mcp-config", mcpPath}
-	argv = append(argv, userArgs...)
-	return argv
+	return backends["claude"].spawn(c.Name(), "claude", ctx, args)
 }

internal/agent/copilot.go

@@ -1,9 +1,5 @@
 package agent
 
-import (
-	"gitea.alexandru.macocian.me/amacocian/sherlock/internal/mcp"
-)
-
 func init() { Register(&copilot{}) }
 
 // copilot integrates the GitHub Copilot CLI (npm package `@github/copilot`
@@ -17,26 +13,14 @@ func init() { Register(&copilot{}) }
 // any `--additional-mcp-config` files on top. The merge is additive,
 // so sherlock-injected MCPs coexist with whatever the operator has
 // configured globally.
+//
+// The per-CLI quirks (flag shape, env scrubbing) live in the shared
+// "copilot" backend; this type is just the built-in registration.
 type copilot struct{}
 
 func (copilot) Name() string        { return "copilot" }
 func (copilot) Description() string { return "GitHub Copilot CLI" }
 
 func (c copilot) Spawn(ctx Context, args []string) error {
-	bin, err := LookPath("copilot")
-	if err != nil {
-		return err
-	}
-	mcpPath, err := mcp.Render(c.Name(), ctx.Servers)
-	if err != nil {
-		return err
-	}
-	argv := c.buildArgv(bin, mcpPath, args)
-	return DefaultExecer.Exec(bin, argv, BuildEnv(nil, nil))
-}
-
-func (copilot) buildArgv(bin, mcpPath string, userArgs []string) []string {
-	argv := []string{bin, "--additional-mcp-config", "@" + mcpPath}
-	argv = append(argv, userArgs...)
-	return argv
+	return backends["copilot"].spawn(c.Name(), "copilot", ctx, args)
 }

internal/agent/custom.go

@@ -0,0 +1,56 @@
+package agent
+
+import "fmt"
+
+// custom is an operator-defined agent declared in config.toml's
+// `[agents.<name>]` table. It wraps an arbitrary command — typically a
+// shell wrapper such as `copilot-local` that points a CLI at a
+// self-hosted model — and reuses a built-in backend's MCP-config and
+// env conventions so MCPs are formatted exactly as the underlying CLI
+// expects.
+type custom struct {
+	name    string
+	desc    string
+	command string
+	backend backend
+}
+
+func (c custom) Name() string        { return c.name }
+func (c custom) Description() string { return c.desc }
+
+func (c custom) Spawn(ctx Context, args []string) error {
+	return c.backend.spawn(c.name, c.command, ctx, args)
+}
+
+// RegisterCustom adds an operator-defined agent to the registry.
+//
+//   - name is the subcommand: `sherlock <name>`.
+//   - command is the binary to exec; it defaults to name when empty.
+//   - backendName selects the MCP/-env conventions ("copilot" or
+//     "claude").
+//
+// Unlike Register, it returns an error (rather than panicking) on a bad
+// backend or a name that collides with an already-registered agent,
+// since the input comes from operator config rather than program code.
+func RegisterCustom(name, command, backendName string) error {
+	if name == "" {
+		return fmt.Errorf("agent: custom agent needs a name")
+	}
+	b, err := resolveBackend(backendName)
+	if err != nil {
+		return fmt.Errorf("agent: custom agent %q: %w", name, err)
+	}
+	if command == "" {
+		command = name
+	}
+	if _, dup := registry[name]; dup {
+		return fmt.Errorf("agent: custom agent %q conflicts with an existing agent", name)
+	}
+	registry[name] = custom{
+		name:    name,
+		desc:    fmt.Sprintf("custom %s agent (%s)", backendName, command),
+		command: command,
+		backend: b,
+	}
+	return nil
+}

internal/agent/custom_test.go

@@ -0,0 +1,107 @@
+package agent
+
+import (
+	"os"
+	"slices"
+	"strings"
+	"testing"
+)
+
+func TestRegisterCustom_CopilotBackendSpawn(t *testing.T) {
+	fakeBin := makeFakeBinary(t, "copilot-local")
+	t.Setenv("PATH", fakeBin+":"+os.Getenv("PATH"))
+	t.Setenv("XDG_RUNTIME_DIR", t.TempDir())
+
+	if err := RegisterCustom("copilot-local", "copilot-local", "copilot"); err != nil {
+		t.Fatalf("RegisterCustom: %v", err)
+	}
+	t.Cleanup(func() { delete(registry, "copilot-local") })
+
+	a, ok := Get("copilot-local")
+	if !ok {
+		t.Fatal("custom agent not registered")
+	}
+
+	orig := DefaultExecer
+	defer func() { DefaultExecer = orig }()
+	rec := &recordExecer{}
+	DefaultExecer = rec
+
+	if err := a.Spawn(Context{}, []string{"-p", "hi"}); err != nil {
+		t.Fatalf("Spawn: %v", err)
+	}
+	if !strings.HasSuffix(rec.argv0, "/copilot-local") {
+		t.Fatalf("argv0 = %s", rec.argv0)
+	}
+	// Copilot backend formatting: --additional-mcp-config @<path>.
+	if !slices.Contains(rec.argv, "--additional-mcp-config") {
+		t.Fatalf("argv missing copilot mcp flag: %v", rec.argv)
+	}
+	foundAt := false
+	for _, a := range rec.argv {
+		if strings.HasPrefix(a, "@") && strings.HasSuffix(a, "/copilot-local.mcp.json") {
+			foundAt = true
+		}
+	}
+	if !foundAt {
+		t.Fatalf("argv missing @-prefixed mcp path named after the custom agent: %v", rec.argv)
+	}
+}
+
+func TestRegisterCustom_ClaudeBackendForbidsKeyAndDefaultsCommand(t *testing.T) {
+	fakeBin := makeFakeBinary(t, "claude-local")
+	t.Setenv("PATH", fakeBin+":"+os.Getenv("PATH"))
+	t.Setenv("ANTHROPIC_API_KEY", "leaked")
+	t.Setenv("XDG_RUNTIME_DIR", t.TempDir())
+
+	// Empty command must default to the agent name.
+	if err := RegisterCustom("claude-local", "", "claude"); err != nil {
+		t.Fatalf("RegisterCustom: %v", err)
+	}
+	t.Cleanup(func() { delete(registry, "claude-local") })
+
+	orig := DefaultExecer
+	defer func() { DefaultExecer = orig }()
+	rec := &recordExecer{}
+	DefaultExecer = rec
+
+	a, _ := Get("claude-local")
+	if err := a.Spawn(Context{}, nil); err != nil {
+		t.Fatalf("Spawn: %v", err)
+	}
+	if !strings.HasSuffix(rec.argv0, "/claude-local") {
+		t.Fatalf("argv0 should default to the agent name: %s", rec.argv0)
+	}
+	if !slices.Contains(rec.argv, "--mcp-config") {
+		t.Fatalf("argv missing claude mcp flag: %v", rec.argv)
+	}
+	if hasEnv(rec.env, "ANTHROPIC_API_KEY") {
+		t.Fatal("ANTHROPIC_API_KEY leaked to claude-backed custom agent")
+	}
+}
+
+func TestRegisterCustom_UnknownBackend(t *testing.T) {
+	err := RegisterCustom("weird", "weird", "gemini")
+	if err == nil {
+		t.Fatal("expected error for unknown backend")
+	}
+	if !strings.Contains(err.Error(), "gemini") {
+		t.Fatalf("error should mention the bad backend: %v", err)
+	}
+	if _, ok := Get("weird"); ok {
+		t.Fatal("agent with bad backend should not be registered")
+	}
+}
+
+func TestRegisterCustom_NameCollision(t *testing.T) {
+	// "copilot" is a built-in; a custom agent must not clobber it.
+	if err := RegisterCustom("copilot", "copilot-local", "copilot"); err == nil {
+		t.Fatal("expected error on collision with built-in agent")
+	}
+}
+
+func TestRegisterCustom_EmptyName(t *testing.T) {
+	if err := RegisterCustom("", "cmd", "copilot"); err == nil {
+		t.Fatal("expected error for empty name")
+	}
+}

internal/authn/login.go

@@ -205,6 +205,7 @@ func exchangeAndVerify(ctx context.Context, cfg Config, provider *oidc.Provider,
 		AccessToken:  tok.AccessToken,
 		RefreshToken: tok.RefreshToken,
 		IDExpiresAt:  idTok.Expiry,
+		AccessExpAt:  accessExpiry(tok.Expiry, idTok.Expiry),
 		RefreshExpAt: refreshExpiry(tok),
 		Issuer:       cfg.Issuer,
 		ClientID:     cfg.ClientID,
@@ -239,12 +240,20 @@ func splitScope(s string) []string {
 			if i > start {
 				out = append(out, s[start:i])
 			}
+
 			start = i + 1
 		}
 	}
 	return out
 }
 
+func accessExpiry(access, fallback time.Time) time.Time {
+	if !access.IsZero() {
+		return access
+	}
+	return fallback
+}
+
 // refreshExpiry pulls Authentik's `refresh_expires_in` (an extension
 // to RFC 6749). If absent we conservatively assume 30 days, matching
 // Authentik's default.

internal/authn/login_test.go

@@ -246,6 +246,9 @@ func TestLogin_HappyPath(t *testing.T) {
 	if res.Tokens.ClientID != "test-client" {
 		t.Fatalf("ClientID not persisted: %q", res.Tokens.ClientID)
 	}
+	if res.Tokens.AccessExpAt.IsZero() {
+		t.Fatal("AccessExpAt was not persisted")
+	}
 	if !strings.HasPrefix(res.Tokens.Issuer, "http://127.0.0.1:") {
 		t.Fatalf("Issuer = %q", res.Tokens.Issuer)
 	}

internal/authn/refresh.go

@@ -17,8 +17,8 @@ import (
 	"gitea.alexandru.macocian.me/amacocian/sherlock/internal/keyring"
 )
 
-// RefreshSkew is how much headroom EnsureFresh leaves before the ID
-// token actually expires. Refreshing 30s ahead of expiry avoids
+// RefreshSkew is how much headroom EnsureFresh leaves before the
+// bearer token actually expires. Refreshing 30s ahead of expiry avoids
 // shipping a token that will be rejected by clock-skewed resource
 // servers.
 const RefreshSkew = 30 * time.Second
@@ -39,7 +39,7 @@ type EnsureFreshOptions struct {
 }
 
 // EnsureFresh returns the stored TokenSet for service, refreshing it
-// against its OAuth issuer if the ID token has < RefreshSkew left.
+// against its OAuth issuer if the bearer token has < RefreshSkew left.
 // Cross-process safe: takes an exclusive flock on opts.LockPath,
 // re-reads the keyring after acquiring the lock, and skips the
 // refresh if a concurrent process already rotated the tokens.
@@ -68,7 +68,7 @@ func EnsureFresh(ctx context.Context, store keyring.Store, service string, opts
 	if ts.Empty() {
 		return ts, keyring.ErrNoTokens
 	}
-	if opts.Clock().Add(RefreshSkew).Before(ts.IDExpiresAt) {
+	if opts.Clock().Add(RefreshSkew).Before(expiryForRefresh(ts)) {
 		return ts, nil
 	}
 
@@ -93,7 +93,7 @@ func EnsureFresh(ctx context.Context, store keyring.Store, service string, opts
 	if err != nil {
 		return ts, err
 	}
-	if opts.Clock().Add(RefreshSkew).Before(ts.IDExpiresAt) {
+	if opts.Clock().Add(RefreshSkew).Before(expiryForRefresh(ts)) {
 		return ts, nil
 	}
 	if ts.RefreshToken == "" {
@@ -151,7 +151,18 @@ func refreshOnce(ctx context.Context, ts keyring.TokenSet, disc Discoverer) (key
 		out.RefreshToken = tok.RefreshToken
 	}
 	out.IDExpiresAt = idTok.Expiry
+	out.AccessExpAt = accessExpiry(tok.Expiry, idTok.Expiry)
 	out.RefreshExpAt = refreshExpiry(tok)
 	out.Scopes = grantedScopes(tok, ts.Scopes)
 	return out, nil
 }
+
+func expiryForRefresh(ts keyring.TokenSet) time.Time {
+	if !ts.AccessExpAt.IsZero() {
+		return ts.AccessExpAt
+	}
+	if ts.AccessToken != "" && ts.RefreshToken != "" {
+		return time.Time{}
+	}
+	return ts.IDExpiresAt
+}

internal/authn/source.go

@@ -197,7 +197,7 @@ func (s *TokenSource) Run(ctx context.Context) error {
 }
 
 // nextWait computes how long to sleep before the next proactive
-// renewal: skew before the cached token expires, clamped to minWait so
+// renewal: skew before the bearer token expires, clamped to minWait so
 // a very short TTL doesn't spin.
 func (s *TokenSource) nextWait() time.Duration {
 	s.mu.Lock()
@@ -206,7 +206,7 @@ func (s *TokenSource) nextWait() time.Duration {
 	if cur.Empty() {
 		return s.minWait
 	}
-	wait := cur.IDExpiresAt.Sub(s.clock()) - s.skew
+	wait := expiryForRefresh(cur).Sub(s.clock()) - s.skew
 	if wait < s.minWait {
 		return s.minWait
 	}

internal/authn/source_test.go

@@ -73,13 +73,16 @@ func TestTokenSource_Start_DeliversInitialToken(t *testing.T) {
 func TestTokenSource_Run_RenewsAndNotifies(t *testing.T) {
 	stub := newStubAuthentik(t)
 	store := fakekeyring.New()
-	// Seed a STALE token (already expired) with a refresh token so the
-	// renewal path fires immediately.
+	// Seed a stale bearer with a still-fresh ID token. This mirrors
+	// providers that issue short-lived access tokens and longer-lived ID
+	// tokens; refresh must follow the bearer lifetime because MCPs send
+	// the access token to services.
 	_ = store.Set("gitea", keyring.TokenSet{
 		IDToken:      "old",
 		AccessToken:  "at-stale",
 		RefreshToken: "rt-1",
-		IDExpiresAt:  time.Now().Add(-time.Minute),
+		AccessExpAt:  time.Now().Add(-time.Minute),
+		IDExpiresAt:  time.Now().Add(time.Hour),
 		Issuer:       stub.srv.URL,
 		ClientID:     "test-client",
 		Scopes:       []string{"openid"},
@@ -114,6 +117,9 @@ func TestTokenSource_Run_RenewsAndNotifies(t *testing.T) {
 	if stored.AccessToken != "at-refreshed" {
 		t.Fatalf("wallet access token = %q, want at-refreshed", stored.AccessToken)
 	}
+	if stored.AccessExpAt.IsZero() {
+		t.Fatal("wallet access token expiry was not persisted")
+	}
 
 	cancel()
 	select {

internal/browser/browser.go

@@ -7,6 +7,7 @@ package browser
 import (
 	"os/exec"
 	"runtime"
+	"strings"
 )
 
 // Open starts the OS's default browser pointed at url, then returns
@@ -15,9 +16,29 @@ import (
 // itself reports — there's no portable way to know whether the user
 // actually loaded the page.
 func Open(url string) error {
+	return OpenWith("", url)
+}
+
+// OpenWith starts browser pointed at url, then returns immediately. If
+// browser is empty, it falls back to the OS default helper used by Open.
+func OpenWith(browser, url string) error {
+	bin, args := commandFor(browser, url, runtime.GOOS)
+	cmd := exec.Command(bin, args...)
+	if err := cmd.Start(); err != nil {
+		return err
+	}
+	go func() { _ = cmd.Wait() }()
+	return nil
+}
+
+func commandFor(browser, url, goos string) (string, []string) {
+	if browser = strings.TrimSpace(browser); browser != "" {
+		return browser, []string{url}
+	}
+
 	var bin string
 	var args []string
-	switch runtime.GOOS {
+	switch goos {
 	case "darwin":
 		bin = "open"
 		args = []string{url}
@@ -28,10 +49,5 @@ func Open(url string) error {
 		bin = "xdg-open"
 		args = []string{url}
 	}
-	cmd := exec.Command(bin, args...)
-	if err := cmd.Start(); err != nil {
-		return err
-	}
-	go func() { _ = cmd.Wait() }()
-	return nil
+	return bin, args
 }

internal/browser/browser_test.go

@@ -0,0 +1,36 @@
+package browser
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestCommandFor_Defaults(t *testing.T) {
+	tests := []struct {
+		name     string
+		goos     string
+		wantBin  string
+		wantArgs []string
+	}{
+		{name: "linux", goos: "linux", wantBin: "xdg-open", wantArgs: []string{"https://example.com"}},
+		{name: "darwin", goos: "darwin", wantBin: "open", wantArgs: []string{"https://example.com"}},
+		{name: "windows", goos: "windows", wantBin: "rundll32", wantArgs: []string{"url.dll,FileProtocolHandler", "https://example.com"}},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gotBin, gotArgs := commandFor("", "https://example.com", tt.goos)
+			if gotBin != tt.wantBin || !reflect.DeepEqual(gotArgs, tt.wantArgs) {
+				t.Fatalf("commandFor = %q %v, want %q %v", gotBin, gotArgs, tt.wantBin, tt.wantArgs)
+			}
+		})
+	}
+}
+
+func TestCommandFor_CustomBrowser(t *testing.T) {
+	gotBin, gotArgs := commandFor(" firefox ", "https://example.com", "linux")
+	wantArgs := []string{"https://example.com"}
+	if gotBin != "firefox" || !reflect.DeepEqual(gotArgs, wantArgs) {
+		t.Fatalf("commandFor = %q %v, want firefox %v", gotBin, gotArgs, wantArgs)
+	}
+}

internal/config/config.go

@@ -9,6 +9,9 @@
 //
 // Shape:
 //
+//	[oauth]
+//	browser = "firefox"                    # optional; default OS browser when empty
+//
 //	[providers.sherlock-cli]            # a reusable OAuth provider
 //	issuer    = "https://id.example/application/o/sherlock-cli/"
 //	client_id = "abc123"
@@ -22,6 +25,10 @@
 //	provider  = "sherlock-cli"
 //	base_url  = "https://grafana.example"
 //
+//	[agents.copilot-local]              # a custom wrapper agent
+//	command = "copilot-local"           # binary to exec (defaults to name)
+//	backend = "copilot"                 # MCP/-env conventions to follow
+//
 // A service either references a [providers.<name>] block via `provider`
 // or carries its own inline issuer/client_id (as gitea does, since it
 // authenticates against its own OAuth server rather than Authentik).
@@ -66,10 +73,33 @@ type Service struct {
 	BaseURL      string `toml:"base_url"`
 }
 
+// OAuth contains global OAuth-flow preferences.
+type OAuth struct {
+	// Browser is an optional executable name or path used to open OAuth
+	// login URLs. Empty means the OS default browser.
+	Browser string `toml:"browser"`
+}
+
+// Agent is an operator-defined custom agent: a wrapper command plus the
+// backend whose MCP-config and env conventions it follows. It lets an
+// operator expose, say, a `copilot-local` wrapper (which points the
+// Copilot CLI at a self-hosted model) as `sherlock copilot-local` while
+// reusing the built-in "copilot" backend's MCP formatting.
+//
+// Command is the binary sherlock execs; it defaults to the agent's name
+// when empty. Backend selects the MCP/-env conventions and must name a
+// backend the agent package knows ("copilot" or "claude").
+type Agent struct {
+	Command string `toml:"command"`
+	Backend string `toml:"backend"`
+}
+
 // Config is the whole parsed file.
 type Config struct {
+	OAuth     OAuth               `toml:"oauth"`
 	Providers map[string]Provider `toml:"providers"`
 	Services  map[string]Service  `toml:"services"`
+	Agents    map[string]Agent    `toml:"agents"`
 
 	// path is where this config was loaded from, for error messages.
 	path string
@@ -83,6 +113,7 @@ type Resolved struct {
 	ClientID     string
 	ClientSecret string
 	BaseURL      string
+	OAuthBrowser string
 }
 
 // DefaultPath returns the config-file path sherlock reads, honouring
@@ -155,6 +186,7 @@ func (c *Config) Service(name string) (Resolved, error) {
 		ClientID:     svc.ClientID,
 		ClientSecret: svc.ClientSecret,
 		BaseURL:      svc.BaseURL,
+		OAuthBrowser: c.OAuth.Browser,
 	}
 
 	if svc.Provider != "" {

internal/config/config_test.go

@@ -63,6 +63,26 @@ base_url  = "https://gitea.example"
 	}
 }
 
+func TestService_OAuthBrowser(t *testing.T) {
+	path := writeConfig(t, `
+[oauth]
+browser = "firefox"
+
+[services.gitea]
+issuer    = "https://gitea.example"
+client_id = "gitea-client"
+base_url  = "https://gitea.example"
+`)
+	c, _ := LoadFrom(path)
+	got, err := c.Service("gitea")
+	if err != nil {
+		t.Fatalf("Service: %v", err)
+	}
+	if got.OAuthBrowser != "firefox" {
+		t.Fatalf("OAuthBrowser = %q", got.OAuthBrowser)
+	}
+}
+
 func TestService_UnknownService(t *testing.T) {
 	path := writeConfig(t, `
 [services.gitea]
@@ -164,3 +184,47 @@ func TestDefaultPath_XDG(t *testing.T) {
 		t.Fatalf("DefaultPath = %q", got)
 	}
 }
+
+func TestAgents_Parsed(t *testing.T) {
+	path := writeConfig(t, `
+[agents.copilot-local]
+command = "copilot-local"
+backend = "copilot"
+
+[agents.claude-local]
+backend = "claude"
+`)
+	c, err := LoadFrom(path)
+	if err != nil {
+		t.Fatalf("LoadFrom: %v", err)
+	}
+	if len(c.Agents) != 2 {
+		t.Fatalf("expected 2 agents, got %d: %+v", len(c.Agents), c.Agents)
+	}
+	cp := c.Agents["copilot-local"]
+	if cp.Command != "copilot-local" || cp.Backend != "copilot" {
+		t.Fatalf("copilot-local = %+v", cp)
+	}
+	// command is optional; absence leaves it empty for the agent layer
+	// to default to the name.
+	cl := c.Agents["claude-local"]
+	if cl.Command != "" || cl.Backend != "claude" {
+		t.Fatalf("claude-local = %+v", cl)
+	}
+}
+
+func TestAgents_AbsentIsEmpty(t *testing.T) {
+	path := writeConfig(t, `
+[services.gitea]
+issuer    = "https://gitea.example"
+client_id = "x"
+base_url  = "https://gitea.example"
+`)
+	c, err := LoadFrom(path)
+	if err != nil {
+		t.Fatalf("LoadFrom: %v", err)
+	}
+	if len(c.Agents) != 0 {
+		t.Fatalf("expected no agents, got %+v", c.Agents)
+	}
+}

internal/installer/helpers.go

@@ -53,6 +53,114 @@ func seedConfig(opts *Options, example, cfgPath string) error {
 	return os.WriteFile(cfgPath, data, 0o600)
 }
 
+// appendMissingConfigSections compares the operator config with the
+// shipped example and appends any missing [providers.*] or [services.*]
+// sections as clearly marked templates. It never rewrites existing
+// sections, so operator edits are preserved.
+func appendMissingConfigSections(opts *Options, example, cfgPath string) ([]string, error) {
+	cfg, err := os.ReadFile(cfgPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			opts.warn("no config found at %s; run setup with --config-only to create one.", cfgPath)
+			return nil, nil
+		}
+		return nil, err
+	}
+	exampleBody, err := os.ReadFile(example)
+	if err != nil {
+		return nil, err
+	}
+
+	existing := sectionSet(string(cfg))
+	blocks := configSectionBlocks(string(exampleBody))
+	var missing []configSectionBlock
+	for _, b := range blocks {
+		if !existing[b.Name] {
+			missing = append(missing, b)
+		}
+	}
+	if len(missing) == 0 {
+		return nil, nil
+	}
+
+	var out strings.Builder
+	out.WriteString(string(cfg))
+	if len(cfg) > 0 && cfg[len(cfg)-1] != '\n' {
+		out.WriteByte('\n')
+	}
+	for _, b := range missing {
+		out.WriteString("\n# Added by sherlock because this section was missing from config.toml.\n")
+		out.WriteString("# Template copied from config.example.toml; fill placeholders before use.\n")
+		out.WriteString(strings.TrimSpace(b.Body))
+		out.WriteByte('\n')
+	}
+	if err := os.WriteFile(cfgPath, []byte(out.String()), 0o600); err != nil {
+		return nil, err
+	}
+
+	names := make([]string, 0, len(missing))
+	for _, b := range missing {
+		names = append(names, b.Name)
+	}
+	return names, nil
+}
+
+type configSectionBlock struct {
+	Name string
+	Body string
+}
+
+func sectionSet(body string) map[string]bool {
+	out := map[string]bool{}
+	for _, line := range strings.Split(body, "\n") {
+		if name, ok := configSectionName(line); ok {
+			out[name] = true
+		}
+	}
+	return out
+}
+
+func configSectionBlocks(body string) []configSectionBlock {
+	lines := strings.Split(body, "\n")
+	var blocks []configSectionBlock
+	for i := 0; i < len(lines); i++ {
+		name, ok := configSectionName(lines[i])
+		if !ok {
+			continue
+		}
+		start := i
+		end := len(lines)
+		for j := i + 1; j < len(lines); j++ {
+			if _, ok := configSectionName(lines[j]); ok {
+				end = j
+				break
+			}
+		}
+		blocks = append(blocks, configSectionBlock{
+			Name: name,
+			Body: strings.Join(lines[start:end], "\n"),
+		})
+		i = end - 1
+	}
+	return blocks
+}
+
+func configSectionName(line string) (string, bool) {
+	s := strings.TrimSpace(line)
+	if !strings.HasPrefix(s, "[") {
+		return "", false
+	}
+	end := strings.IndexByte(s, ']')
+	if end < 0 {
+		return "", false
+	}
+	name := s[1:end]
+	if strings.HasPrefix(name, "providers.") || strings.HasPrefix(name, "services.") {
+		return name, true
+	}
+	return "", false
+}
+
 // pickEditor resolves the editor command: $VISUAL, then $EDITOR, then
 // the first of sensible-editor/nano/vi found on PATH. Returns "" if none.
 func pickEditor() string {

internal/installer/installer.go

@@ -31,7 +31,7 @@ const devVersion = "0.0.0-dev"
 // binaries are the cmd/<name> packages installed. `go install ./cmd/...`
 // covers exactly these (the setup entry lives outside cmd/, so it is
 // never installed).
-var binaries = []string{"sherlock", "gitea-mcp", "grafana-mcp", "gssh-mcp"}
+var binaries = []string{"sherlock", "gitea-mcp", "grafana-mcp", "gssh-mcp", "searxng-mcp"}
 
 // Options controls one Install run.
 type Options struct {
@@ -49,7 +49,8 @@ type Options struct {
 	// SeedConfig copies config.example.toml to the operator's config
 	// path when none exists yet (never clobbers a filled-in file).
 	SeedConfig bool
-	// OpenEditor opens $VISUAL/$EDITOR on the config after seeding.
+	// OpenEditor opens $VISUAL/$EDITOR on the config after seeding and
+	// appending any missing section templates.
 	OpenEditor bool
 	// ConfigOnly stops after the config step (no build/install).
 	ConfigOnly bool
@@ -97,14 +98,26 @@ func Install(ctx context.Context, opts Options) error {
 		return fmt.Errorf("config.example.toml not found in the source (%s): %w", example, err)
 	}
 
+	cfgPath, err := config.DefaultPath()
+	if err != nil {
+		return err
+	}
 	if opts.SeedConfig {
-		cfgPath, err := config.DefaultPath()
-		if err != nil {
-			return err
-		}
 		if err := seedConfig(&opts, example, cfgPath); err != nil {
 			return err
 		}
+	}
+
+	addedSections, err := appendMissingConfigSections(&opts, example, cfgPath)
+	if err != nil {
+		return err
+	}
+	if len(addedSections) > 0 {
+		opts.warn("%s was missing section(s): %s. Appended marked templates from config.example.toml; fill placeholders before use.",
+			cfgPath, strings.Join(addedSections, ", "))
+	}
+
+	if opts.SeedConfig {
 		if opts.OpenEditor {
 			if err := openEditor(&opts, cfgPath); err != nil {
 				return err

internal/installer/installer_test.go

@@ -3,6 +3,7 @@ package installer
 import (
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 )
 
@@ -70,6 +71,68 @@ func TestSeedConfig_DoesNotClobber(t *testing.T) {
 	}
 }
 
+func TestAppendMissingConfigSections(t *testing.T) {
+	dir := t.TempDir()
+	example := filepath.Join(dir, "config.example.toml")
+	cfg := filepath.Join(dir, "config.toml")
+	if err := os.WriteFile(example, []byte(`
+[providers.sherlock-cli]
+issuer = "https://id.example/"
+client_id = "REPLACE"
+
+[services.gitea]
+issuer = "https://gitea.example"
+client_id = "gitea"
+base_url = "https://gitea.example"
+
+[services.searxng]
+provider = "sherlock-cli"
+base_url = "https://search.example"
+`), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(cfg, []byte(`
+[providers.sherlock-cli]
+issuer = "https://id.real/"
+client_id = "real"
+
+[services.gitea]
+issuer = "https://gitea.real"
+client_id = "gitea-real"
+base_url = "https://gitea.real"
+`), 0o600); err != nil {
+		t.Fatal(err)
+	}
+
+	opts := &Options{Out: io_discard{}, Err: io_discard{}}
+	added, err := appendMissingConfigSections(opts, example, cfg)
+	if err != nil {
+		t.Fatalf("appendMissingConfigSections: %v", err)
+	}
+	if len(added) != 1 || added[0] != "services.searxng" {
+		t.Fatalf("added = %v, want [services.searxng]", added)
+	}
+	b, err := os.ReadFile(cfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+	body := string(b)
+	if !strings.Contains(body, "Added by sherlock") {
+		t.Fatalf("missing marker comment in %q", body)
+	}
+	if strings.Count(body, "[services.searxng]") != 1 {
+		t.Fatalf("searxng section count wrong in %q", body)
+	}
+
+	added, err = appendMissingConfigSections(opts, example, cfg)
+	if err != nil {
+		t.Fatalf("second appendMissingConfigSections: %v", err)
+	}
+	if len(added) != 0 {
+		t.Fatalf("second added = %v, want none", added)
+	}
+}
+
 func TestFishCompletionsDir(t *testing.T) {
 	tmp := t.TempDir()
 	t.Setenv("__fish_config_dir", "")

internal/keyring/keyring.go

@@ -139,6 +139,7 @@ type TokenSet struct {
 	IDToken      string    `json:"id_token"`
 	AccessToken  string    `json:"access_token,omitempty"`
 	RefreshToken string    `json:"refresh_token,omitempty"`
+	AccessExpAt  time.Time `json:"access_expires_at,omitempty"`
 	IDExpiresAt  time.Time `json:"id_expires_at"`
 	RefreshExpAt time.Time `json:"refresh_expires_at"`
 	Issuer       string    `json:"issuer"`