diff --git a/knotmirror/knotstream/knotstream.go b/knotmirror/knotstream/knotstream.go
--- a/knotmirror/knotstream/knotstream.go
+++ b/knotmirror/knotstream/knotstream.go
@@ -24,7 +24,7 @@ l = log.SubLogger(l, "knotstream")
 	return &KnotStream{
 		logger:  l,
 		db:      db,
-		slurper: NewKnotSlurper(l, db, cfg.Slurper),
+		slurper: NewKnotSlurper(l, db, cfg),
 	}
 }
 
diff --git a/knotmirror/knotstream/slurper.go b/knotmirror/knotstream/slurper.go
--- a/knotmirror/knotstream/slurper.go
+++ b/knotmirror/knotstream/slurper.go
@@ -25,16 +25,18 @@ type KnotSlurper struct {
 	logger *slog.Logger
 	db     *sql.DB
 	cfg    config.SlurperConfig
+	ssrf   bool
 
 	subsLk sync.Mutex
 	subs   map[string]*subscription
 }
 
-func NewKnotSlurper(l *slog.Logger, db *sql.DB, cfg config.SlurperConfig) *KnotSlurper {
+func NewKnotSlurper(l *slog.Logger, db *sql.DB, cfg *config.Config) *KnotSlurper {
 	return &KnotSlurper{
 		logger: log.SubLogger(l, "slurper"),
 		db:     db,
-		cfg:    cfg,
+		cfg:    cfg.Slurper,
+		ssrf:   cfg.KnotSSRF,
 		subs:   make(map[string]*subscription),
 	}
 }
@@ -132,7 +134,7 @@ HandshakeTimeout: time.Second * 5,
 	}
 
 	// if this isn't a localhost / private connection, then we should enable SSRF protections
-	if !host.NoSSL {
+	if !host.NoSSL || s.ssrf {
 		netDialer := ssrf.PublicOnlyDialer()
 		dialer.NetDialContext = netDialer.DialContext
 	}
diff --git a/knotmirror/xrpc/proxy.go b/knotmirror/xrpc/proxy.go
--- a/knotmirror/xrpc/proxy.go
+++ b/knotmirror/xrpc/proxy.go
@@ -2,6 +2,7 @@ package xrpc
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -45,6 +46,30 @@ baseURL        string
 	repoIdentifier string
 }
 
+// validateKnotURL ensures a knot base URL is safe to proxy to.
+// It rejects URLs with path components, query strings, or fragments
+// that could be used for path injection.
+func validateKnotURL(raw string) (string, error) {
+	u, err := url.Parse(raw)
+	if err != nil {
+		return "", fmt.Errorf("invalid knot URL: %w", err)
+	}
+	if u.Scheme != "http" && u.Scheme != "https" {
+		return "", errors.New("knot URL must use http or https scheme")
+	}
+	if u.Path != "" && u.Path != "/" {
+		return "", fmt.Errorf("knot URL must not contain a path: %q", raw)
+	}
+	if u.RawQuery != "" || u.Fragment != "" {
+		return "", fmt.Errorf("knot URL must not contain query or fragment: %q", raw)
+	}
+	if u.User != nil {
+		return "", fmt.Errorf("knot URL must not contain userinfo: %q", raw)
+	}
+	// Strip trailing slash for consistent formatting
+	return strings.TrimRight(u.String(), "/"), nil
+}
+
 func (x *Xrpc) resolveKnot(ctx context.Context, repoAt syntax.ATURI) (*knotInfo, error) {
 	repo, err := db.GetRepoByAtUri(ctx, x.db, repoAt)
 	if err == nil && repo != nil {
@@ -60,6 +85,10 @@ } else {
 					knotURL = "http://" + knotURL
 				}
 			}
+		}
+		knotURL, err = validateKnotURL(knotURL)
+		if err != nil {
+			return nil, err
 		}
 		return &knotInfo{baseURL: knotURL, repoIdentifier: repo.RepoIdentifier()}, nil
 	}
@@ -111,6 +140,10 @@ x.logger.Error("failed to upsert repo after proxy resolution", "err", upsertErr)
 		}
 	}()
 
+	knotURL, err = validateKnotURL(knotURL)
+	if err != nil {
+		return nil, err
+	}
 	return &knotInfo{
 		baseURL:        knotURL,
 		repoIdentifier: repoDid.String(),
diff --git a/knotmirror/xrpc/xrpc.go b/knotmirror/xrpc/xrpc.go
--- a/knotmirror/xrpc/xrpc.go
+++ b/knotmirror/xrpc/xrpc.go
@@ -9,6 +9,7 @@ "net/http"
 	"time"
 
 	"github.com/bluesky-social/indigo/atproto/atclient"
+	"github.com/bluesky-social/indigo/util/ssrf"
 	"github.com/go-chi/chi/v5"
 	"github.com/redis/go-redis/v9"
 	"tangled.org/core/api/tangled"
@@ -30,17 +31,21 @@ inflight   *inflightTracker
 }
 
 func New(logger *slog.Logger, cfg *config.Config, db *sql.DB, rdb *redis.Client, resolver *idresolver.Resolver, ks *knotstream.KnotStream) *Xrpc {
+	httpClient := &http.Client{
+		Timeout: 30 * time.Second,
+	}
+	if cfg.KnotSSRF {
+		httpClient.Transport = ssrf.PublicOnlyTransport()
+	}
 	return &Xrpc{
-		cfg:      cfg,
-		db:       db,
-		rdb:      rdb,
-		resolver: resolver,
-		ks:       ks,
-		logger:   log.SubLogger(logger, "xrpc"),
-		httpClient: &http.Client{
-			Timeout: 30 * time.Second,
-		},
-		inflight: newInflightTracker(),
+		cfg:        cfg,
+		db:         db,
+		rdb:        rdb,
+		resolver:   resolver,
+		ks:         ks,
+		logger:     log.SubLogger(logger, "xrpc"),
+		httpClient: httpClient,
+		inflight:   newInflightTracker(),
 	}
 }