fix: exclude non-repeater nodes from path-hop resolution (#935) (#936)

Fixes #935 ## Problem `buildPrefixMap()` indexed ALL nodes regardless of role, causing companions/sensors to appear as repeater hops when their pubkey prefix collided with a path-hop hash byte. ## Fix ### Server (`cmd/server/store.go`) - Added `canAppearInPath(role string) bool` — allowlist of roles that can forward packets (repeater, room_server, room) - `buildPrefixMap` now skips nodes that fail this check ### Client (`public/hop-resolver.js`) - Added matching `canAppearInPath(role)` helper - `init()` now only populates `prefixIdx` for path-eligible nodes - `pubkeyIdx` remains complete — `resolveFromServer()` still resolves any node type by full pubkey (for server-confirmed `resolved_path` arrays) ## Tests - `cmd/server/prefix_map_role_test.go`: 7 new tests covering role filtering in prefix map and resolveWithContext - `test-hop-resolver-affinity.js`: 4 new tests verifying client-side role filter + pubkeyIdx completeness - All existing tests updated to include `Role: "repeater"` where needed - `go test ./cmd/server/...` — PASS - `node test-hop-resolver-affinity.js` — 16/17 pass (1 pre-existing centroid failure unrelated to this change) ## Commits 1. `fix: filter prefix map to only repeater/room roles (#935)` — server implementation 2. `test: prefix map role filter coverage (#935)` — server tests 3. `ui: filter HopResolver prefix index to repeater/room roles (#935)` — client implementation 4. `test: hop-resolver role filter coverage (#935)` — client tests --------- Co-authored-by: you <you@example.com>
2026-05-11 08:46:54 +00:00 · 2026-04-30 09:25:51 -07:00
parent e857e0b1ce
commit 5678874128
9 changed files with 397 additions and 131 deletions
@@ -763,9 +763,9 @@ func TestGetChannelsFromStore(t *testing.T) {

 func TestPrefixMapResolve(t *testing.T) {
 	nodes := []nodeInfo{
-		{PublicKey: "aabbccdd11223344", Name: "NodeA", HasGPS: true, Lat: 37.5, Lon: -122.0},
-		{PublicKey: "aabbccdd55667788", Name: "NodeB", HasGPS: false},
-		{PublicKey: "eeff0011aabbccdd", Name: "NodeC", HasGPS: true, Lat: 38.0, Lon: -121.0},
+		{Role: "repeater", PublicKey: "aabbccdd11223344", Name: "NodeA", HasGPS: true, Lat: 37.5, Lon: -122.0},
+		{Role: "repeater", PublicKey: "aabbccdd55667788", Name: "NodeB", HasGPS: false},
+		{Role: "repeater", PublicKey: "eeff0011aabbccdd", Name: "NodeC", HasGPS: true, Lat: 38.0, Lon: -121.0},
 	}
 	pm := buildPrefixMap(nodes)

@@ -805,8 +805,8 @@ func TestPrefixMapResolve(t *testing.T) {

 	t.Run("multiple candidates no GPS", func(t *testing.T) {
 		noGPSNodes := []nodeInfo{
-			{PublicKey: "aa11bb22", Name: "X", HasGPS: false},
-			{PublicKey: "aa11cc33", Name: "Y", HasGPS: false},
+			{Role: "repeater", PublicKey: "aa11bb22", Name: "X", HasGPS: false},
+			{Role: "repeater", PublicKey: "aa11cc33", Name: "Y", HasGPS: false},
 		}
 		pm2 := buildPrefixMap(noGPSNodes)
 		n := pm2.resolve("aa11")
@@ -820,8 +820,8 @@ func TestPrefixMapResolve(t *testing.T) {
 func TestPrefixMapCap(t *testing.T) {
 	// 16-char pubkey — longer than maxPrefixLen
 	nodes := []nodeInfo{
-		{PublicKey: "aabbccdd11223344", Name: "LongKey"},
-		{PublicKey: "eeff0011", Name: "ShortKey"}, // exactly 8 chars
+		{Role: "repeater", PublicKey: "aabbccdd11223344", Name: "LongKey"},
+		{Role: "repeater", PublicKey: "eeff0011", Name: "ShortKey"}, // exactly 8 chars
 	}
 	pm := buildPrefixMap(nodes)

@@ -12,9 +12,9 @@ import (
 func TestResolveAmbiguousEdges_GeoProximity(t *testing.T) {
 	// Node A at lat=45, lon=-122. Candidate B1 at lat=45.1, lon=-122.1 (close).
 	// Candidate B2 at lat=10, lon=10 (far away). Prefix "b0" matches both.
-	nodeA := nodeInfo{PublicKey: "aaaa1111", Name: "NodeA", HasGPS: true, Lat: 45.0, Lon: -122.0}
-	nodeB1 := nodeInfo{PublicKey: "b0b1eeee", Name: "CloseNode", HasGPS: true, Lat: 45.1, Lon: -122.1}
-	nodeB2 := nodeInfo{PublicKey: "b0c2ffff", Name: "FarNode", HasGPS: true, Lat: 10.0, Lon: 10.0}
+	nodeA := nodeInfo{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeA", HasGPS: true, Lat: 45.0, Lon: -122.0}
+	nodeB1 := nodeInfo{Role: "repeater", PublicKey: "b0b1eeee", Name: "CloseNode", HasGPS: true, Lat: 45.1, Lon: -122.1}
+	nodeB2 := nodeInfo{Role: "repeater", PublicKey: "b0c2ffff", Name: "FarNode", HasGPS: true, Lat: 10.0, Lon: 10.0}

 	pm := buildPrefixMap([]nodeInfo{nodeA, nodeB1, nodeB2})

@@ -62,8 +62,8 @@ func TestResolveAmbiguousEdges_GeoProximity(t *testing.T) {

 // Test 2: Ambiguous edge merged with existing resolved edge (count accumulation).
 func TestResolveAmbiguousEdges_MergeWithExisting(t *testing.T) {
-	nodeA := nodeInfo{PublicKey: "aaaa1111", Name: "NodeA", HasGPS: true, Lat: 45.0, Lon: -122.0}
-	nodeB := nodeInfo{PublicKey: "b0b1eeee", Name: "NodeB", HasGPS: true, Lat: 45.1, Lon: -122.1}
+	nodeA := nodeInfo{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeA", HasGPS: true, Lat: 45.0, Lon: -122.0}
+	nodeB := nodeInfo{Role: "repeater", PublicKey: "b0b1eeee", Name: "NodeB", HasGPS: true, Lat: 45.1, Lon: -122.1}

 	pm := buildPrefixMap([]nodeInfo{nodeA, nodeB})

@@ -133,9 +133,9 @@ func TestResolveAmbiguousEdges_MergeWithExisting(t *testing.T) {
 // Test 3: Ambiguous edge left as-is when resolution fails.
 func TestResolveAmbiguousEdges_FailsNoChange(t *testing.T) {
 	// Two candidates, neither has GPS, no affinity data — resolution falls through.
-	nodeA := nodeInfo{PublicKey: "aaaa1111", Name: "NodeA"}
-	nodeB1 := nodeInfo{PublicKey: "b0b1eeee", Name: "B1"}
-	nodeB2 := nodeInfo{PublicKey: "b0c2ffff", Name: "B2"}
+	nodeA := nodeInfo{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeA"}
+	nodeB1 := nodeInfo{Role: "repeater", PublicKey: "b0b1eeee", Name: "B1"}
+	nodeB2 := nodeInfo{Role: "repeater", PublicKey: "b0c2ffff", Name: "B2"}

 	pm := buildPrefixMap([]nodeInfo{nodeA, nodeB1, nodeB2})

@@ -175,7 +175,7 @@ func TestResolveAmbiguousEdges_FailsNoChange(t *testing.T) {

 // Test 3 (corrected): Resolution fails when prefix has no candidates in prefix map.
 func TestResolveAmbiguousEdges_NoMatch(t *testing.T) {
-	nodeA := nodeInfo{PublicKey: "aaaa1111", Name: "NodeA"}
+	nodeA := nodeInfo{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeA"}
 	// pm has no entries matching prefix "zz"
 	pm := buildPrefixMap([]nodeInfo{nodeA})

@@ -215,8 +215,8 @@ func TestResolveAmbiguousEdges_NoMatch(t *testing.T) {
 // Test 6: Phase 1 edge collection unchanged (no regression).
 func TestPhase1EdgeCollection_Unchanged(t *testing.T) {
 	// Build a simple graph and verify non-ambiguous edges are not touched.
-	nodeA := nodeInfo{PublicKey: "aaaa1111", Name: "NodeA", HasGPS: true, Lat: 45.0, Lon: -122.0}
-	nodeB := nodeInfo{PublicKey: "bbbb2222", Name: "NodeB", HasGPS: true, Lat: 45.1, Lon: -122.1}
+	nodeA := nodeInfo{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeA", HasGPS: true, Lat: 45.0, Lon: -122.0}
+	nodeB := nodeInfo{Role: "repeater", PublicKey: "bbbb2222", Name: "NodeB", HasGPS: true, Lat: 45.1, Lon: -122.1}

 	ts := time.Now().UTC().Format(time.RFC3339)
 	payloadType := 4
@@ -232,7 +232,7 @@ func TestPhase1EdgeCollection_Unchanged(t *testing.T) {
 		Observations: obs,
 	}

-	store := ngTestStore([]nodeInfo{nodeA, nodeB, {PublicKey: "cccc3333", Name: "Observer"}}, []*StoreTx{tx})
+	store := ngTestStore([]nodeInfo{nodeA, nodeB, {Role: "repeater", PublicKey: "cccc3333", Name: "Observer"}}, []*StoreTx{tx})
 	graph := BuildFromStore(store)

 	edges := graph.Neighbors("aaaa1111")
@@ -255,8 +255,8 @@ func TestPhase1EdgeCollection_Unchanged(t *testing.T) {

 // Test 7: Merge preserves higher LastSeen timestamp.
 func TestResolveAmbiguousEdges_PreservesHigherLastSeen(t *testing.T) {
-	nodeA := nodeInfo{PublicKey: "aaaa1111", Name: "NodeA", HasGPS: true, Lat: 45.0, Lon: -122.0}
-	nodeB := nodeInfo{PublicKey: "b0b1eeee", Name: "NodeB", HasGPS: true, Lat: 45.1, Lon: -122.1}
+	nodeA := nodeInfo{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeA", HasGPS: true, Lat: 45.0, Lon: -122.0}
+	nodeB := nodeInfo{Role: "repeater", PublicKey: "b0b1eeee", Name: "NodeB", HasGPS: true, Lat: 45.1, Lon: -122.1}
 	pm := buildPrefixMap([]nodeInfo{nodeA, nodeB})

 	graph := NewNeighborGraph()
@@ -307,10 +307,10 @@ func TestResolveAmbiguousEdges_PreservesHigherLastSeen(t *testing.T) {

 // Test 5: Integration — node with both 1-byte and 2-byte prefix observations shows single entry.
 func TestIntegration_DualPrefixSingleNeighbor(t *testing.T) {
-	nodeA := nodeInfo{PublicKey: "aaaa1111aaaa1111", Name: "NodeA", HasGPS: true, Lat: 45.0, Lon: -122.0}
-	nodeB := nodeInfo{PublicKey: "b0b1eeeeb0b1eeee", Name: "NodeB", HasGPS: true, Lat: 45.1, Lon: -122.1}
-	nodeB2 := nodeInfo{PublicKey: "b0c2ffffb0c2ffff", Name: "NodeB2", HasGPS: true, Lat: 10.0, Lon: 10.0}
-	observer := nodeInfo{PublicKey: "cccc3333cccc3333", Name: "Observer"}
+	nodeA := nodeInfo{Role: "repeater", PublicKey: "aaaa1111aaaa1111", Name: "NodeA", HasGPS: true, Lat: 45.0, Lon: -122.0}
+	nodeB := nodeInfo{Role: "repeater", PublicKey: "b0b1eeeeb0b1eeee", Name: "NodeB", HasGPS: true, Lat: 45.1, Lon: -122.1}
+	nodeB2 := nodeInfo{Role: "repeater", PublicKey: "b0c2ffffb0c2ffff", Name: "NodeB2", HasGPS: true, Lat: 10.0, Lon: 10.0}
+	observer := nodeInfo{Role: "repeater", PublicKey: "cccc3333cccc3333", Name: "Observer"}

 	ts := time.Now().UTC().Format(time.RFC3339)
 	pt := 4
@@ -86,9 +86,9 @@ func TestBuildNeighborGraph_EmptyStore(t *testing.T) {
 func TestBuildNeighborGraph_AdvertSingleHopPath(t *testing.T) {
 	// ADVERT from X, path=["R1_prefix"] → edges: X↔R1 and Observer↔R1
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "r1aabbcc", Name: "R1"},
-		{PublicKey: "obs00001", Name: "Observer"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "r1aabbcc", Name: "R1"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Observer"},
 	}
 	tx := ngMakeTx(1, 4, ngFromNodeJSON("aaaa1111"), []*StoreObs{
 		ngMakeObs("obs00001", `["r1aa"]`, nowStr, ngFloatPtr(-10)),
@@ -132,10 +132,10 @@ func TestBuildNeighborGraph_AdvertSingleHopPath(t *testing.T) {
 func TestBuildNeighborGraph_AdvertMultiHopPath(t *testing.T) {
 	// ADVERT from X, path=["R1","R2"] → X↔R1 and Observer↔R2
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "r1aabbcc", Name: "R1"},
-		{PublicKey: "r2ddeeff", Name: "R2"},
-		{PublicKey: "obs00001", Name: "Observer"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "r1aabbcc", Name: "R1"},
+		{Role: "repeater", PublicKey: "r2ddeeff", Name: "R2"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Observer"},
 	}
 	tx := ngMakeTx(1, 4, ngFromNodeJSON("aaaa1111"), []*StoreObs{
 		ngMakeObs("obs00001", `["r1aa","r2dd"]`, nowStr, nil),
@@ -170,8 +170,8 @@ func TestBuildNeighborGraph_AdvertMultiHopPath(t *testing.T) {
 func TestBuildNeighborGraph_AdvertZeroHop(t *testing.T) {
 	// ADVERT from X, path=[] → X↔Observer direct edge
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "obs00001", Name: "Observer"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Observer"},
 	}
 	tx := ngMakeTx(1, 4, ngFromNodeJSON("aaaa1111"), []*StoreObs{
 		ngMakeObs("obs00001", `[]`, nowStr, nil),
@@ -195,8 +195,8 @@ func TestBuildNeighborGraph_AdvertZeroHop(t *testing.T) {
 func TestBuildNeighborGraph_NonAdvertEmptyPath(t *testing.T) {
 	// Non-ADVERT, path=[] → no edges
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "obs00001", Name: "Observer"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Observer"},
 	}
 	tx := ngMakeTx(1, 2, ngFromNodeJSON("aaaa1111"), []*StoreObs{
 		ngMakeObs("obs00001", `[]`, nowStr, nil),
@@ -212,10 +212,10 @@ func TestBuildNeighborGraph_NonAdvertEmptyPath(t *testing.T) {
 func TestBuildNeighborGraph_NonAdvertOnlyObserverEdge(t *testing.T) {
 	// Non-ADVERT with path=["R1","R2"] → only Observer↔R2, NO originator edge
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "r1aabbcc", Name: "R1"},
-		{PublicKey: "r2ddeeff", Name: "R2"},
-		{PublicKey: "obs00001", Name: "Observer"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "r1aabbcc", Name: "R1"},
+		{Role: "repeater", PublicKey: "r2ddeeff", Name: "R2"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Observer"},
 	}
 	tx := ngMakeTx(1, 2, ngFromNodeJSON("aaaa1111"), []*StoreObs{
 		ngMakeObs("obs00001", `["r1aa","r2dd"]`, nowStr, nil),
@@ -236,9 +236,9 @@ func TestBuildNeighborGraph_NonAdvertOnlyObserverEdge(t *testing.T) {
 func TestBuildNeighborGraph_NonAdvertSingleHop(t *testing.T) {
 	// Non-ADVERT with path=["R1"] → Observer↔R1 only
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "r1aabbcc", Name: "R1"},
-		{PublicKey: "obs00001", Name: "Observer"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "r1aabbcc", Name: "R1"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Observer"},
 	}
 	tx := ngMakeTx(1, 2, ngFromNodeJSON("aaaa1111"), []*StoreObs{
 		ngMakeObs("obs00001", `["r1aa"]`, nowStr, nil),
@@ -259,10 +259,10 @@ func TestBuildNeighborGraph_NonAdvertSingleHop(t *testing.T) {
 func TestBuildNeighborGraph_HashCollision(t *testing.T) {
 	// Two nodes share prefix "a3" → ambiguous edge
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "a3bb1111", Name: "CandidateA"},
-		{PublicKey: "a3bb2222", Name: "CandidateB"},
-		{PublicKey: "obs00001", Name: "Observer"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "a3bb1111", Name: "CandidateA"},
+		{Role: "repeater", PublicKey: "a3bb2222", Name: "CandidateB"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Observer"},
 	}
 	tx := ngMakeTx(1, 4, ngFromNodeJSON("aaaa1111"), []*StoreObs{
 		ngMakeObs("obs00001", `["a3bb"]`, nowStr, nil),
@@ -308,13 +308,13 @@ func TestBuildNeighborGraph_ConfidenceAutoResolve(t *testing.T) {
 	// CandidateB has no known neighbors (Jaccard = 0).
 	// An ambiguous edge X↔prefix "a3" with candidates [A, B] should auto-resolve to A.
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "n1111111", Name: "N1"},
-		{PublicKey: "n2222222", Name: "N2"},
-		{PublicKey: "n3333333", Name: "N3"},
-		{PublicKey: "a3001111", Name: "CandidateA"},
-		{PublicKey: "a3002222", Name: "CandidateB"},
-		{PublicKey: "obs00001", Name: "Observer"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "n1111111", Name: "N1"},
+		{Role: "repeater", PublicKey: "n2222222", Name: "N2"},
+		{Role: "repeater", PublicKey: "n3333333", Name: "N3"},
+		{Role: "repeater", PublicKey: "a3001111", Name: "CandidateA"},
+		{Role: "repeater", PublicKey: "a3002222", Name: "CandidateB"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Observer"},
 	}

 	// Create resolved edges: X↔N1, X↔N2, X↔N3, A↔N1, A↔N2, A↔N3
@@ -373,11 +373,11 @@ func TestBuildNeighborGraph_ConfidenceAutoResolve(t *testing.T) {
 func TestBuildNeighborGraph_EqualScoresAmbiguous(t *testing.T) {
 	// Two candidates with identical neighbor sets → should NOT auto-resolve.
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "n1111111", Name: "N1"},
-		{PublicKey: "a3001111", Name: "CandidateA"},
-		{PublicKey: "a3002222", Name: "CandidateB"},
-		{PublicKey: "obs00001", Name: "Observer"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "n1111111", Name: "N1"},
+		{Role: "repeater", PublicKey: "a3001111", Name: "CandidateA"},
+		{Role: "repeater", PublicKey: "a3002222", Name: "CandidateB"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Observer"},
 	}

 	var txs []*StoreTx
@@ -425,8 +425,8 @@ func TestBuildNeighborGraph_EqualScoresAmbiguous(t *testing.T) {
 func TestBuildNeighborGraph_ObserverSelfEdgeGuard(t *testing.T) {
 	// Observer's own prefix in path → should NOT create self-edge.
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "obs00001", Name: "Observer"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Observer"},
 	}
 	tx := ngMakeTx(1, 4, ngFromNodeJSON("aaaa1111"), []*StoreObs{
 		ngMakeObs("obs00001", `["obs0"]`, nowStr, nil),
@@ -445,8 +445,8 @@ func TestBuildNeighborGraph_ObserverSelfEdgeGuard(t *testing.T) {
 func TestBuildNeighborGraph_OrphanPrefix(t *testing.T) {
 	// Path contains prefix matching zero nodes → edge recorded as unresolved.
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "obs00001", Name: "Observer"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Observer"},
 	}
 	tx := ngMakeTx(1, 4, ngFromNodeJSON("aaaa1111"), []*StoreObs{
 		ngMakeObs("obs00001", `["ff99"]`, nowStr, nil),
@@ -506,9 +506,9 @@ func TestAffinityScore_StaleAndLow(t *testing.T) {

 func TestBuildNeighborGraph_CountAccumulation(t *testing.T) {
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "r1aabbcc", Name: "R1"},
-		{PublicKey: "obs00001", Name: "Observer"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "r1aabbcc", Name: "R1"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Observer"},
 	}

 	var txs []*StoreTx
@@ -535,10 +535,10 @@ func TestBuildNeighborGraph_CountAccumulation(t *testing.T) {

 func TestBuildNeighborGraph_MultipleObservers(t *testing.T) {
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "r1aabbcc", Name: "R1"},
-		{PublicKey: "obs00001", Name: "Obs1"},
-		{PublicKey: "obs00002", Name: "Obs2"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "r1aabbcc", Name: "R1"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Obs1"},
+		{Role: "repeater", PublicKey: "obs00002", Name: "Obs2"},
 	}

 	tx := ngMakeTx(1, 4, ngFromNodeJSON("aaaa1111"), []*StoreObs{
@@ -565,9 +565,9 @@ func TestBuildNeighborGraph_MultipleObservers(t *testing.T) {

 func TestBuildNeighborGraph_TimeDecayOldObservations(t *testing.T) {
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "r1aabbcc", Name: "R1"},
-		{PublicKey: "obs00001", Name: "Observer"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "r1aabbcc", Name: "R1"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Observer"},
 	}

 	tx := ngMakeTx(1, 4, ngFromNodeJSON("aaaa1111"), []*StoreObs{
@@ -592,10 +592,10 @@ func TestBuildNeighborGraph_TimeDecayOldObservations(t *testing.T) {
 func TestBuildNeighborGraph_ADVERTOnlyConstraint(t *testing.T) {
 	// Non-ADVERT: should NOT create originator↔path[0] edge, only observer↔path[last].
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeX"},
-		{PublicKey: "r1aabbcc", Name: "R1"},
-		{PublicKey: "r2ddeeff", Name: "R2"},
-		{PublicKey: "obs00001", Name: "Observer"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeX"},
+		{Role: "repeater", PublicKey: "r1aabbcc", Name: "R1"},
+		{Role: "repeater", PublicKey: "r2ddeeff", Name: "R2"},
+		{Role: "repeater", PublicKey: "obs00001", Name: "Observer"},
 	}
 	tx := ngMakeTx(1, 2, ngFromNodeJSON("aaaa1111"), []*StoreObs{
 		ngMakeObs("obs00001", `["r1aa","r2dd"]`, nowStr, nil),
@@ -631,9 +631,9 @@ func ngPubKeyJSON(pubkey string) string {
 func TestBuildNeighborGraph_AdvertPubKeyField(t *testing.T) {
 	// Real ADVERTs use "pubKey", not "from_node". Verify the builder handles it.
 	nodes := []nodeInfo{
-		{PublicKey: "99bf37abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234", Name: "Originator"},
-		{PublicKey: "r1aabbccdd001122334455667788990011223344556677889900112233445566", Name: "R1"},
-		{PublicKey: "obs0000100112233445566778899001122334455667788990011223344556677", Name: "Observer"},
+		{Role: "repeater", PublicKey: "99bf37abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234", Name: "Originator"},
+		{Role: "repeater", PublicKey: "r1aabbccdd001122334455667788990011223344556677889900112233445566", Name: "R1"},
+		{Role: "repeater", PublicKey: "obs0000100112233445566778899001122334455667788990011223344556677", Name: "Observer"},
 	}
 	tx := ngMakeTx(1, 4, ngPubKeyJSON("99bf37abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234"), []*StoreObs{
 		ngMakeObs("obs0000100112233445566778899001122334455667788990011223344556677", `["r1"]`, nowStr, ngFloatPtr(-8.5)),
@@ -666,10 +666,10 @@ func TestBuildNeighborGraph_OneByteHashPrefixes(t *testing.T) {
 	// Real-world scenario: 1-byte hash prefixes with multiple candidates.
 	// Should create edges (possibly ambiguous) rather than empty graph.
 	nodes := []nodeInfo{
-		{PublicKey: "c0dedad400000000000000000000000000000000000000000000000000000001", Name: "NodeC0-1"},
-		{PublicKey: "c0dedad900000000000000000000000000000000000000000000000000000002", Name: "NodeC0-2"},
-		{PublicKey: "a3bbccdd00000000000000000000000000000000000000000000000000000003", Name: "Originator"},
-		{PublicKey: "obs1234500000000000000000000000000000000000000000000000000000004", Name: "Observer"},
+		{Role: "repeater", PublicKey: "c0dedad400000000000000000000000000000000000000000000000000000001", Name: "NodeC0-1"},
+		{Role: "repeater", PublicKey: "c0dedad900000000000000000000000000000000000000000000000000000002", Name: "NodeC0-2"},
+		{Role: "repeater", PublicKey: "a3bbccdd00000000000000000000000000000000000000000000000000000003", Name: "Originator"},
+		{Role: "repeater", PublicKey: "obs1234500000000000000000000000000000000000000000000000000000004", Name: "Observer"},
 	}
 	// ADVERT from Originator with 1-byte path hop "c0"
 	tx := ngMakeTx(1, 4, ngPubKeyJSON("a3bbccdd00000000000000000000000000000000000000000000000000000003"), []*StoreObs{
@@ -809,10 +809,10 @@ func TestExtractFromNode_UsesCachedParse(t *testing.T) {
 func BenchmarkBuildFromStore(b *testing.B) {
 	// Simulate a dataset with many packets and repeated pubkeys
 	nodes := []nodeInfo{
-		{PublicKey: "aaaa1111", Name: "NodeA"},
-		{PublicKey: "bbbb2222", Name: "NodeB"},
-		{PublicKey: "cccc3333", Name: "NodeC"},
-		{PublicKey: "dddd4444", Name: "NodeD"},
+		{Role: "repeater", PublicKey: "aaaa1111", Name: "NodeA"},
+		{Role: "repeater", PublicKey: "bbbb2222", Name: "NodeB"},
+		{Role: "repeater", PublicKey: "cccc3333", Name: "NodeC"},
+		{Role: "repeater", PublicKey: "dddd4444", Name: "NodeD"},
 	}
 	const numPackets = 1000
 	packets := make([]*StoreTx, 0, numPackets)
@@ -58,8 +58,8 @@ func createTestDBWithSchema(t *testing.T) (*DB, string) {
 func TestResolvePathForObs(t *testing.T) {
 	// Build a prefix map with known nodes
 	nodes := []nodeInfo{
-		{PublicKey: "aabbccddee1234567890aabbccddee1234567890aabbccddee1234567890aabb", Name: "Node-AA"},
-		{PublicKey: "bbccddee1234567890aabbccddee1234567890aabbccddee1234567890aabb11", Name: "Node-BB"},
+		{Role: "repeater", PublicKey: "aabbccddee1234567890aabbccddee1234567890aabbccddee1234567890aabb", Name: "Node-AA"},
+		{Role: "repeater", PublicKey: "bbccddee1234567890aabbccddee1234567890aabbccddee1234567890aabb11", Name: "Node-BB"},
 	}
 	pm := buildPrefixMap(nodes)
 	graph := NewNeighborGraph()
@@ -97,7 +97,7 @@ func TestResolvePathForObs_EmptyPath(t *testing.T) {

 func TestResolvePathForObs_Unresolvable(t *testing.T) {
 	nodes := []nodeInfo{
-		{PublicKey: "aabbccddee1234567890aabbccddee1234567890aabbccddee1234567890aabb", Name: "Node-AA"},
+		{Role: "repeater", PublicKey: "aabbccddee1234567890aabbccddee1234567890aabbccddee1234567890aabb", Name: "Node-AA"},
 	}
 	pm := buildPrefixMap(nodes)

@@ -437,8 +437,8 @@ func TestExtractEdgesFromObs_NonAdvertNoPath(t *testing.T) {

 func TestExtractEdgesFromObs_WithPath(t *testing.T) {
 	nodes := []nodeInfo{
-		{PublicKey: "aabbccddee1234567890aabbccddee1234567890aabbccddee1234567890aabb", Name: "Node-AA"},
-		{PublicKey: "ffgghhii1234567890aabbccddee1234567890aabbccddee1234567890aabb11", Name: "Node-FF"},
+		{Role: "repeater", PublicKey: "aabbccddee1234567890aabbccddee1234567890aabbccddee1234567890aabb", Name: "Node-AA"},
+		{Role: "repeater", PublicKey: "ffgghhii1234567890aabbccddee1234567890aabbccddee1234567890aabb11", Name: "Node-FF"},
 	}
 	pm := buildPrefixMap(nodes)

@@ -0,0 +1,212 @@
+package main
+
+import (
+	"encoding/json"
+	"testing"
+)
+
+func TestCanAppearInPath(t *testing.T) {
+	cases := []struct {
+		role string
+		want bool
+	}{
+		{"repeater", true},
+		{"Repeater", true},
+		{"REPEATER", true},
+		{"room_server", true},
+		{"Room_Server", true},
+		{"room", true},
+		{"companion", false},
+		{"sensor", false},
+		{"", false},
+		{"unknown", false},
+	}
+	for _, tc := range cases {
+		if got := canAppearInPath(tc.role); got != tc.want {
+			t.Errorf("canAppearInPath(%q) = %v, want %v", tc.role, got, tc.want)
+		}
+	}
+}
+
+func TestBuildPrefixMap_ExcludesCompanions(t *testing.T) {
+	nodes := []nodeInfo{
+		{PublicKey: "7a1234abcdef", Role: "companion", Name: "MyCompanion"},
+	}
+	pm := buildPrefixMap(nodes)
+	if len(pm.m) != 0 {
+		t.Fatalf("expected empty prefix map, got %d entries", len(pm.m))
+	}
+}
+
+func TestBuildPrefixMap_ExcludesSensors(t *testing.T) {
+	nodes := []nodeInfo{
+		{PublicKey: "7a1234abcdef", Role: "sensor", Name: "MySensor"},
+	}
+	pm := buildPrefixMap(nodes)
+	if len(pm.m) != 0 {
+		t.Fatalf("expected empty prefix map, got %d entries", len(pm.m))
+	}
+}
+
+func TestResolveWithContext_NilWhenOnlyCompanionMatchesPrefix(t *testing.T) {
+	nodes := []nodeInfo{
+		{PublicKey: "7a1234abcdef", Role: "companion", Name: "MyCompanion"},
+	}
+	pm := buildPrefixMap(nodes)
+	r, _, _ := pm.resolveWithContext("7a", nil, nil)
+	if r != nil {
+		t.Fatalf("expected nil, got %+v", r)
+	}
+}
+
+func TestResolveWithContext_NilWhenOnlySensorMatchesPrefix(t *testing.T) {
+	nodes := []nodeInfo{
+		{PublicKey: "7a1234abcdef", Role: "sensor", Name: "MySensor"},
+	}
+	pm := buildPrefixMap(nodes)
+	r, _, _ := pm.resolveWithContext("7a", nil, nil)
+	if r != nil {
+		t.Fatalf("expected nil for sensor-only prefix, got %+v", r)
+	}
+}
+
+func TestResolveWithContext_PrefersRepeaterOverCompanionAtSamePrefix(t *testing.T) {
+	nodes := []nodeInfo{
+		{PublicKey: "7a1234abcdef", Role: "companion", Name: "MyCompanion"},
+		{PublicKey: "7a5678901234", Role: "repeater", Name: "MyRepeater"},
+	}
+	pm := buildPrefixMap(nodes)
+	r, _, _ := pm.resolveWithContext("7a", nil, nil)
+	if r == nil {
+		t.Fatal("expected non-nil result")
+	}
+	if r.Name != "MyRepeater" {
+		t.Fatalf("expected MyRepeater, got %s", r.Name)
+	}
+}
+
+func TestResolveWithContext_PrefersRoomServerOverCompanionAtSamePrefix(t *testing.T) {
+	nodes := []nodeInfo{
+		{PublicKey: "ab1234abcdef", Role: "companion", Name: "MyCompanion"},
+		{PublicKey: "ab5678901234", Role: "room_server", Name: "MyRoom"},
+	}
+	pm := buildPrefixMap(nodes)
+	r, _, _ := pm.resolveWithContext("ab", nil, nil)
+	if r == nil {
+		t.Fatal("expected non-nil result")
+	}
+	if r.Name != "MyRoom" {
+		t.Fatalf("expected MyRoom, got %s", r.Name)
+	}
+}
+
+func TestResolve_NilWhenOnlyCompanionMatchesPrefix(t *testing.T) {
+	nodes := []nodeInfo{
+		{PublicKey: "7a1234abcdef", Role: "companion", Name: "MyCompanion"},
+	}
+	pm := buildPrefixMap(nodes)
+	r := pm.resolve("7a")
+	if r != nil {
+		t.Fatalf("expected nil from resolve() for companion-only prefix, got %+v", r)
+	}
+}
+
+func TestResolve_NilWhenOnlySensorMatchesPrefix(t *testing.T) {
+	nodes := []nodeInfo{
+		{PublicKey: "7a1234abcdef", Role: "sensor", Name: "MySensor"},
+	}
+	pm := buildPrefixMap(nodes)
+	r := pm.resolve("7a")
+	if r != nil {
+		t.Fatalf("expected nil from resolve() for sensor-only prefix, got %+v", r)
+	}
+}
+
+func TestResolveWithContext_PicksRepeaterEvenWhenCompanionHasGPS(t *testing.T) {
+	// Adversarial: companion has GPS, repeater doesn't. Role filter should
+	// exclude companion entirely, so repeater wins despite lacking GPS.
+	nodes := []nodeInfo{
+		{PublicKey: "7a1234abcdef", Role: "companion", Name: "GPSCompanion", Lat: 37.0, Lon: -122.0, HasGPS: true},
+		{PublicKey: "7a5678901234", Role: "repeater", Name: "NoGPSRepeater", Lat: 0, Lon: 0, HasGPS: false},
+	}
+	pm := buildPrefixMap(nodes)
+	r, _, _ := pm.resolveWithContext("7a", nil, nil)
+	if r == nil {
+		t.Fatal("expected non-nil result")
+	}
+	if r.Name != "NoGPSRepeater" {
+		t.Fatalf("expected NoGPSRepeater (role filter excludes companion), got %s", r.Name)
+	}
+}
+
+func TestComputeDistancesForTx_CompanionNeverInResolvedChain(t *testing.T) {
+	// Integration test: a path with a prefix matching both a companion and a
+	// repeater. The resolveHop function (using buildPrefixMap) should only
+	// return the repeater.
+	nodes := []nodeInfo{
+		{PublicKey: "7a1234abcdef", Role: "companion", Name: "BadCompanion", Lat: 37.0, Lon: -122.0, HasGPS: true},
+		{PublicKey: "7a5678901234", Role: "repeater", Name: "GoodRepeater", Lat: 38.0, Lon: -123.0, HasGPS: true},
+		{PublicKey: "bb1111111111", Role: "repeater", Name: "OtherRepeater", Lat: 39.0, Lon: -124.0, HasGPS: true},
+	}
+	pm := buildPrefixMap(nodes)
+
+	nodeByPk := make(map[string]*nodeInfo)
+	for i := range nodes {
+		nodeByPk[nodes[i].PublicKey] = &nodes[i]
+	}
+	repeaterSet := map[string]bool{
+		"7a5678901234": true,
+		"bb1111111111": true,
+	}
+
+	// Build a synthetic StoreTx with a path ["7a", "bb"] and a sender with GPS
+	senderPK := "cc0000000000"
+	sender := nodeInfo{PublicKey: senderPK, Role: "repeater", Name: "Sender", Lat: 36.0, Lon: -121.0, HasGPS: true}
+	nodeByPk[senderPK] = &sender
+
+	pathJSON, _ := json.Marshal([]string{"7a", "bb"})
+	decoded, _ := json.Marshal(map[string]interface{}{"pubKey": senderPK})
+
+	tx := &StoreTx{
+		PathJSON:    string(pathJSON),
+		DecodedJSON: string(decoded),
+		FirstSeen:   "2026-04-30T12:00",
+	}
+
+	resolveHop := func(hop string) *nodeInfo {
+		return pm.resolve(hop)
+	}
+
+	hops, pathRec := computeDistancesForTx(tx, nodeByPk, repeaterSet, resolveHop)
+
+	// Verify BadCompanion's pubkey never appears in hops
+	badPK := "7a1234abcdef"
+	for i, h := range hops {
+		if h.FromPk == badPK || h.ToPk == badPK {
+			t.Fatalf("hop[%d] contains BadCompanion pubkey: from=%s to=%s", i, h.FromPk, h.ToPk)
+		}
+	}
+
+	// Verify BadCompanion's pubkey never appears in pathRec
+	if pathRec == nil {
+		t.Fatal("expected non-nil path record (3 GPS nodes in chain)")
+	}
+	for i, hop := range pathRec.Hops {
+		if hop.FromPk == badPK || hop.ToPk == badPK {
+			t.Fatalf("pathRec.Hops[%d] contains BadCompanion pubkey: from=%s to=%s", i, hop.FromPk, hop.ToPk)
+		}
+	}
+
+	// Verify GoodRepeater IS in the chain (proves the prefix was resolved to the right node)
+	goodPK := "7a5678901234"
+	foundGood := false
+	for _, hop := range pathRec.Hops {
+		if hop.FromPk == goodPK || hop.ToPk == goodPK {
+			foundGood = true
+			break
+		}
+	}
+	if !foundGood {
+		t.Fatal("expected GoodRepeater (7a5678901234) in pathRec.Hops but not found")
+	}
+}
@@ -11,7 +11,7 @@ import (

 func TestResolveWithContext_UniquePrefix(t *testing.T) {
 	pm := buildPrefixMap([]nodeInfo{
-		{PublicKey: "a1b2c3d4", Name: "Node-A", HasGPS: true, Lat: 1, Lon: 2},
+		{Role: "repeater", PublicKey: "a1b2c3d4", Name: "Node-A", HasGPS: true, Lat: 1, Lon: 2},
 	})
 	ni, confidence, _ := pm.resolveWithContext("a1b2c3d4", nil, nil)
 	if ni == nil || ni.Name != "Node-A" {
@@ -24,7 +24,7 @@ func TestResolveWithContext_UniquePrefix(t *testing.T) {

 func TestResolveWithContext_NoMatch(t *testing.T) {
 	pm := buildPrefixMap([]nodeInfo{
-		{PublicKey: "a1b2c3d4", Name: "Node-A"},
+		{Role: "repeater", PublicKey: "a1b2c3d4", Name: "Node-A"},
 	})
 	ni, confidence, _ := pm.resolveWithContext("ff", nil, nil)
 	if ni != nil {
@@ -37,8 +37,8 @@ func TestResolveWithContext_NoMatch(t *testing.T) {

 func TestResolveWithContext_AffinityWins(t *testing.T) {
 	pm := buildPrefixMap([]nodeInfo{
-		{PublicKey: "a1aaaaaa", Name: "Node-A1"},
-		{PublicKey: "a1bbbbbb", Name: "Node-A2"},
+		{Role: "repeater", PublicKey: "a1aaaaaa", Name: "Node-A1"},
+		{Role: "repeater", PublicKey: "a1bbbbbb", Name: "Node-A2"},
 	})

 	graph := NewNeighborGraph()
@@ -60,9 +60,9 @@ func TestResolveWithContext_AffinityWins(t *testing.T) {

 func TestResolveWithContext_AffinityTooClose_FallsToGeo(t *testing.T) {
 	pm := buildPrefixMap([]nodeInfo{
-		{PublicKey: "a1aaaaaa", Name: "Node-A1", HasGPS: true, Lat: 10, Lon: 20},
-		{PublicKey: "a1bbbbbb", Name: "Node-A2", HasGPS: true, Lat: 11, Lon: 21},
-		{PublicKey: "c0c0c0c0", Name: "Ctx", HasGPS: true, Lat: 10.1, Lon: 20.1},
+		{Role: "repeater", PublicKey: "a1aaaaaa", Name: "Node-A1", HasGPS: true, Lat: 10, Lon: 20},
+		{Role: "repeater", PublicKey: "a1bbbbbb", Name: "Node-A2", HasGPS: true, Lat: 11, Lon: 21},
+		{Role: "repeater", PublicKey: "c0c0c0c0", Name: "Ctx", HasGPS: true, Lat: 10.1, Lon: 20.1},
 	})

 	graph := NewNeighborGraph()
@@ -85,8 +85,8 @@ func TestResolveWithContext_AffinityTooClose_FallsToGeo(t *testing.T) {

 func TestResolveWithContext_GPSPreference(t *testing.T) {
 	pm := buildPrefixMap([]nodeInfo{
-		{PublicKey: "a1aaaaaa", Name: "NoGPS"},
-		{PublicKey: "a1bbbbbb", Name: "HasGPS", HasGPS: true, Lat: 1, Lon: 2},
+		{Role: "repeater", PublicKey: "a1aaaaaa", Name: "NoGPS"},
+		{Role: "repeater", PublicKey: "a1bbbbbb", Name: "HasGPS", HasGPS: true, Lat: 1, Lon: 2},
 	})

 	ni, confidence, _ := pm.resolveWithContext("a1", nil, nil)
@@ -100,8 +100,8 @@ func TestResolveWithContext_GPSPreference(t *testing.T) {

 func TestResolveWithContext_FirstMatchFallback(t *testing.T) {
 	pm := buildPrefixMap([]nodeInfo{
-		{PublicKey: "a1aaaaaa", Name: "First"},
-		{PublicKey: "a1bbbbbb", Name: "Second"},
+		{Role: "repeater", PublicKey: "a1aaaaaa", Name: "First"},
+		{Role: "repeater", PublicKey: "a1bbbbbb", Name: "Second"},
 	})

 	ni, confidence, _ := pm.resolveWithContext("a1", nil, nil)
@@ -115,8 +115,8 @@ func TestResolveWithContext_FirstMatchFallback(t *testing.T) {

 func TestResolveWithContext_NilGraphFallsToGPS(t *testing.T) {
 	pm := buildPrefixMap([]nodeInfo{
-		{PublicKey: "a1aaaaaa", Name: "NoGPS"},
-		{PublicKey: "a1bbbbbb", Name: "HasGPS", HasGPS: true, Lat: 1, Lon: 2},
+		{Role: "repeater", PublicKey: "a1aaaaaa", Name: "NoGPS"},
+		{Role: "repeater", PublicKey: "a1bbbbbb", Name: "HasGPS", HasGPS: true, Lat: 1, Lon: 2},
 	})

 	ni, confidence, _ := pm.resolveWithContext("a1", []string{"someone"}, nil)
@@ -131,8 +131,8 @@ func TestResolveWithContext_NilGraphFallsToGPS(t *testing.T) {
 func TestResolveWithContext_BackwardCompatResolve(t *testing.T) {
 	// Verify original resolve() still works unchanged
 	pm := buildPrefixMap([]nodeInfo{
-		{PublicKey: "a1aaaaaa", Name: "NoGPS"},
-		{PublicKey: "a1bbbbbb", Name: "HasGPS", HasGPS: true, Lat: 1, Lon: 2},
+		{Role: "repeater", PublicKey: "a1aaaaaa", Name: "NoGPS"},
+		{Role: "repeater", PublicKey: "a1bbbbbb", Name: "HasGPS", HasGPS: true, Lat: 1, Lon: 2},
 	})
 	ni := pm.resolve("a1")
 	if ni == nil || ni.Name != "HasGPS" {
@@ -164,8 +164,8 @@ func TestResolveHopsAPI_UniquePrefix(t *testing.T) {
 	_ = srv

 	// Insert a unique node
-	srv.db.conn.Exec("INSERT OR IGNORE INTO nodes (public_key, name, lat, lon) VALUES (?, ?, ?, ?)",
-		"ff11223344", "UniqueNode", 37.0, -122.0)
+	srv.db.conn.Exec("INSERT OR IGNORE INTO nodes (public_key, name, lat, lon, role) VALUES (?, ?, ?, ?, ?)",
+		"ff11223344", "UniqueNode", 37.0, -122.0, "repeater")
 	srv.store.InvalidateNodeCache()

 	req := httptest.NewRequest("GET", "/api/resolve-hops?hops=ff11223344", nil)
@@ -189,10 +189,10 @@ func TestResolveHopsAPI_UniquePrefix(t *testing.T) {
 func TestResolveHopsAPI_AmbiguousNoContext(t *testing.T) {
 	srv, router := setupTestServer(t)

-	srv.db.conn.Exec("INSERT OR IGNORE INTO nodes (public_key, name, lat, lon) VALUES (?, ?, ?, ?)",
-		"ee1aaaaaaa", "Node-E1", 37.0, -122.0)
-	srv.db.conn.Exec("INSERT OR IGNORE INTO nodes (public_key, name, lat, lon) VALUES (?, ?, ?, ?)",
-		"ee1bbbbbbb", "Node-E2", 38.0, -121.0)
+	srv.db.conn.Exec("INSERT OR IGNORE INTO nodes (public_key, name, lat, lon, role) VALUES (?, ?, ?, ?, ?)",
+		"ee1aaaaaaa", "Node-E1", 37.0, -122.0, "repeater")
+	srv.db.conn.Exec("INSERT OR IGNORE INTO nodes (public_key, name, lat, lon, role) VALUES (?, ?, ?, ?, ?)",
+		"ee1bbbbbbb", "Node-E2", 38.0, -121.0, "repeater")
 	srv.store.InvalidateNodeCache()

 	req := httptest.NewRequest("GET", "/api/resolve-hops?hops=ee1", nil)
@@ -224,12 +224,12 @@ func TestResolveHopsAPI_AmbiguousNoContext(t *testing.T) {
 func TestResolveHopsAPI_WithAffinityContext(t *testing.T) {
 	srv, router := setupTestServer(t)

-	srv.db.conn.Exec("INSERT OR IGNORE INTO nodes (public_key, name, lat, lon) VALUES (?, ?, ?, ?)",
-		"dd1aaaaaaa", "Node-D1", 37.0, -122.0)
-	srv.db.conn.Exec("INSERT OR IGNORE INTO nodes (public_key, name, lat, lon) VALUES (?, ?, ?, ?)",
-		"dd1bbbbbbb", "Node-D2", 38.0, -121.0)
-	srv.db.conn.Exec("INSERT OR IGNORE INTO nodes (public_key, name, lat, lon) VALUES (?, ?, ?, ?)",
-		"c0c0c0c0c0", "Context", 37.1, -122.1)
+	srv.db.conn.Exec("INSERT OR IGNORE INTO nodes (public_key, name, lat, lon, role) VALUES (?, ?, ?, ?, ?)",
+		"dd1aaaaaaa", "Node-D1", 37.0, -122.0, "repeater")
+	srv.db.conn.Exec("INSERT OR IGNORE INTO nodes (public_key, name, lat, lon, role) VALUES (?, ?, ?, ?, ?)",
+		"dd1bbbbbbb", "Node-D2", 38.0, -121.0, "repeater")
+	srv.db.conn.Exec("INSERT OR IGNORE INTO nodes (public_key, name, lat, lon, role) VALUES (?, ?, ?, ?, ?)",
+		"c0c0c0c0c0", "Context", 37.1, -122.1, "repeater")

 	// Invalidate node cache so the PM includes newly inserted nodes.
 	srv.store.cacheMu.Lock()
@@ -279,8 +279,8 @@ func TestResolveHopsAPI_WithAffinityContext(t *testing.T) {
 func TestResolveHopsAPI_ResponseShape(t *testing.T) {
 	srv, router := setupTestServer(t)

-	srv.db.conn.Exec("INSERT OR IGNORE INTO nodes (public_key, name, lat, lon) VALUES (?, ?, ?, ?)",
-		"bb1aaaaaaa", "Node-B1", 37.0, -122.0)
+	srv.db.conn.Exec("INSERT OR IGNORE INTO nodes (public_key, name, lat, lon, role) VALUES (?, ?, ?, ?, ?)",
+		"bb1aaaaaaa", "Node-B1", 37.0, -122.0, "repeater")

 	req := httptest.NewRequest("GET", "/api/resolve-hops?hops=bb1a", nil)
 	rr := httptest.NewRecorder()
@@ -4551,9 +4551,20 @@ type prefixMap struct {
 // entries to ~7×N (+ 1 full-key entry per node for exact-match lookups).
 const maxPrefixLen = 8

+// canAppearInPath returns true if the node's role allows it to appear as a
+// path hop.  Only repeaters, room servers, and rooms can forward packets;
+// companions and sensors originate but never relay.
+func canAppearInPath(role string) bool {
+	r := strings.ToLower(role)
+	return strings.Contains(r, "repeater") || strings.Contains(r, "room_server") || r == "room"
+}
+
 func buildPrefixMap(nodes []nodeInfo) *prefixMap {
 	pm := &prefixMap{m: make(map[string][]nodeInfo, len(nodes)*(maxPrefixLen+1))}
 	for _, n := range nodes {
+		if !canAppearInPath(n.Role) {
+			continue
+		}
 		pk := strings.ToLower(n.PublicKey)
 		maxLen := maxPrefixLen
 		if maxLen > len(pk) {
@@ -7,6 +7,14 @@ window.HopResolver = (function() {

  const MAX_HOP_DIST = 1.8; // ~200km in degrees
  const REGION_RADIUS_KM = 300;
+
+  // Only repeaters and room servers can appear as path hops per protocol.
+  // Companions/sensors originate but never relay packets.
+  function canAppearInPath(role) {
+    if (!role) return false;
+    var r = String(role).toLowerCase();
+    return r.indexOf('repeater') >= 0 || r.indexOf('room_server') >= 0 || r === 'room';
+  }
  let prefixIdx = {};   // lowercase hex prefix → [node, ...]
  let pubkeyIdx = {};   // full lowercase pubkey → node (O(1) lookup)
  let nodesList = [];
@@ -40,7 +48,11 @@ window.HopResolver = (function() {
    for (const n of nodesList) {
      if (!n.public_key) continue;
      const pk = n.public_key.toLowerCase();
+      // pubkeyIdx includes ALL nodes — used by resolveFromServer for
+      // server-confirmed full-pubkey lookups (any node type).
      pubkeyIdx[pk] = n;
+      // prefixIdx only includes nodes that can appear as path hops.
+      if (!canAppearInPath(n.role)) continue;
      for (let len = 1; len <= 3; len++) {
        const p = pk.slice(0, len * 2);
        if (!prefixIdx[p]) prefixIdx[p] = [];
@@ -22,9 +22,9 @@ function assert(condition, msg) {

 // ── Test nodes ──
 // Two nodes share the same 1-byte prefix "ab"
-const nodeA = { public_key: 'ab1111', name: 'NodeA', lat: 37.0, lon: -122.0 };
-const nodeB = { public_key: 'ab2222', name: 'NodeB', lat: 38.0, lon: -123.0 };
-const nodeC = { public_key: 'cd3333', name: 'NodeC', lat: 37.5, lon: -122.5 };
+const nodeA = { public_key: 'ab1111', name: 'NodeA', role: 'repeater', lat: 37.0, lon: -122.0 };
+const nodeB = { public_key: 'ab2222', name: 'NodeB', role: 'repeater', lat: 38.0, lon: -123.0 };
+const nodeC = { public_key: 'cd3333', name: 'NodeC', role: 'repeater', lat: 37.5, lon: -122.5 };

 console.log('\n=== HopResolver Affinity Tests ===\n');

@@ -88,7 +88,7 @@ assert(result5['ab'].name === 'NodeB', 'Should pick NodeB (highest affinity 0.9)

 // Test 6: Unambiguous hops are not affected by affinity
 console.log('\nTest 6: Unambiguous hops unaffected by affinity');
-const nodeD = { public_key: 'ee4444', name: 'NodeD', lat: 36.0, lon: -121.0 };
+const nodeD = { public_key: 'ee4444', name: 'NodeD', role: 'repeater', lat: 36.0, lon: -121.0 };
 HopResolver.init([nodeA, nodeB, nodeC, nodeD]);
 HopResolver.setAffinity({ edges: [] });
 const result6 = HopResolver.resolve(['ee44'], null, null, null, null, null);
@@ -97,9 +97,9 @@ assert(!result6['ee44'].ambiguous, 'Should not be marked ambiguous');

 // Test 7: lat=0 / lon=0 candidates are NOT excluded (equator/prime-meridian bug fix)
 console.log('\nTest 7: lat=0 / lon=0 candidates are included in geo scoring');
-const nodeEquator = { public_key: 'ab5555', name: 'EquatorNode', lat: 0, lon: 10 };
-const nodeFar = { public_key: 'ab6666', name: 'FarNode', lat: 60, lon: 60 };
-const anchorNearEq = { public_key: 'cd7777', name: 'AnchorEq', lat: 1, lon: 11 };
+const nodeEquator = { public_key: 'ab5555', name: 'EquatorNode', role: 'repeater', lat: 0, lon: 10 };
+const nodeFar = { public_key: 'ab6666', name: 'FarNode', role: 'repeater', lat: 60, lon: 60 };
+const anchorNearEq = { public_key: 'cd7777', name: 'AnchorEq', role: 'repeater', lat: 1, lon: 11 };
 HopResolver.init([nodeEquator, nodeFar, anchorNearEq]);
 HopResolver.setAffinity({});
 // Anchor near equator — EquatorNode (0,10) should be geo-closest
@@ -109,13 +109,44 @@ assert(result7['ab'].name === 'EquatorNode',

 // Test 8: lon=0 candidate is also included
 console.log('\nTest 8: lon=0 candidate is included in geo scoring');
-const nodePrime = { public_key: 'ab8888', name: 'PrimeMeridian', lat: 10, lon: 0 };
-const anchorNearPM = { public_key: 'cd9999', name: 'AnchorPM', lat: 11, lon: 1 };
+const nodePrime = { public_key: 'ab8888', name: 'PrimeMeridian', role: 'repeater', lat: 10, lon: 0 };
+const anchorNearPM = { public_key: 'cd9999', name: 'AnchorPM', role: 'repeater', lat: 11, lon: 1 };
 HopResolver.init([nodePrime, nodeFar, anchorNearPM]);
 HopResolver.setAffinity({});
 const result8 = HopResolver.resolve(['cd99', 'ab'], 11.0, 1.0, null, null, null);
 assert(result8['ab'].name === 'PrimeMeridian',
  'lon=0 candidate should be included and win by geo — got: ' + result8['ab'].name);

+// ── Role filter tests (#935) ──
+console.log('\nTest: Role filter — companions excluded from prefixIdx');
+const companion = { public_key: 'ab9999', name: 'Companion1', role: 'companion', lat: 37.0, lon: -122.0 };
+const sensor = { public_key: 'ab7777', name: 'Sensor1', role: 'sensor', lat: 37.0, lon: -122.0 };
+const repeater = { public_key: 'ab1234', name: 'Repeater1', role: 'repeater', lat: 37.0, lon: -122.0 };
+const roomSrv = { public_key: 'ff1234', name: 'RoomSrv1', role: 'room_server', lat: 37.0, lon: -122.0 };
+
+HopResolver.init([companion, sensor, repeater, roomSrv]);
+HopResolver.setAffinity({});
+
+// Prefix 'ab' should only resolve to repeater (companion/sensor excluded)
+const r1 = HopResolver.resolve(['ab12'], 0, 0, null, null, null);
+assert(r1['ab12'] && r1['ab12'].name === 'Repeater1',
+  'prefix ab12 resolves to Repeater1 not companion — got: ' + (r1['ab12'] && r1['ab12'].name));
+
+// Prefix 'ff' should resolve to room_server
+const r2 = HopResolver.resolve(['ff12'], 0, 0, null, null, null);
+assert(r2['ff12'] && r2['ff12'].name === 'RoomSrv1',
+  'prefix ff12 resolves to RoomSrv1 — got: ' + (r2['ff12'] && r2['ff12'].name));
+
+// Prefix that only matches companion should return nothing
+const r3 = HopResolver.resolve(['ab99'], 0, 0, null, null, null);
+assert(!r3['ab99'] || !r3['ab99'].name,
+  'prefix ab99 (companion only) resolves to nothing — got: ' + (r3['ab99'] && r3['ab99'].name));
+
+// pubkeyIdx should still have companion (full pubkey lookup)
+console.log('\nTest: pubkeyIdx still includes all roles');
+const fromServer = HopResolver.resolveFromServer(['ab99'], [companion.public_key]);
+assert(fromServer['ab99'] && fromServer['ab99'].name === 'Companion1',
+  'resolveFromServer finds companion by full pubkey — got: ' + (fromServer['ab99'] && fromServer['ab99'].name));
+
 console.log('\n' + (passed + failed) + ' tests, ' + passed + ' passed, ' + failed + ' failed\n');
 process.exit(failed > 0 ? 1 : 0);