diff --git a/ingestion/internal/pipeline/build.go b/ingestion/internal/pipeline/build.go
index 5479db5..d0f57b0 100644
--- a/ingestion/internal/pipeline/build.go
+++ b/ingestion/internal/pipeline/build.go
@@ -28,7 +28,7 @@ func BuildPagesIn(wing string, rawPages []RawPage, sourceSlug, date string) ([]w
 	for _, rp := range rawPages {
 		// The type becomes a directory under wiki/; "../raw" wrote outside it
 		// (PR #147 review). Only a plain lower-case name is a page type.
-		if !validPageType.MatchString(rp.Type) {
+		if !validPageType.MatchString(rp.Type) || (wing != "" && !layoutType(rp.Type)) {
 			warnings = append(warnings, fmt.Sprintf("skipped page with invalid type %q", rp.Type))
 			continue
 		}
@@ -42,6 +42,11 @@ func BuildPagesIn(wing string, rawPages []RawPage, sourceSlug, date string) ([]w
 	return out, warnings
 }
 
+// layoutType reports whether a wing-mode page type has a place in the layout.
+// The type comes from the model, so from the clip being ingested: anything else
+// would name a directory (wiki/<type>/) of the model's choosing.
+func layoutType(t string) bool { return t == "source" || t == "concept" || t == "entity" }
+
 var validPageType = regexp.MustCompile(`^[a-z][a-z0-9-]*$`)
 
 func computeSlug(rp RawPage, sourceSlug string) string {
diff --git a/ingestion/internal/pipeline/pipeline.go b/ingestion/internal/pipeline/pipeline.go
index eab1e3e..51d5dd3 100644
--- a/ingestion/internal/pipeline/pipeline.go
+++ b/ingestion/internal/pipeline/pipeline.go
@@ -10,6 +10,7 @@ import (
 	"github.com/mathiasbq/hyperguild/ingestion/internal/brain"
 	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
 	"io/fs"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -52,20 +53,6 @@ func Run(ctx context.Context, cfg Config, brainDir, content, source string, dryR
 	var inventory map[wiki.PageType][]wiki.Entry
 	var err error
 	if cfg.Wing != "" {
-		// A source slug is a page's graph identity: refuse to take over a slug
-		// that lives anywhere but this wing's own sources/ — including when
-		// this wing's own page of that name also exists.
-		slug := wiki.Slug(source)
-		own := "wiki/" + cfg.Wing + "/sources/" + slug + ".md"
-		existing, ferr := wiki.FindSlugs(brainDir, slug)
-		if ferr != nil {
-			return Result{}, fmt.Errorf("check source slug: %w", ferr)
-		}
-		for _, p := range existing {
-			if p != own {
-				return Result{}, fmt.Errorf("source slug %q is already used by %s", slug, p)
-			}
-		}
 		inventory, err = wiki.LoadWingInventory(brainDir, cfg.Wing)
 	} else {
 		inventory, err = wiki.LoadInventory(brainDir)
@@ -80,6 +67,12 @@ func Run(ctx context.Context, cfg Config, brainDir, content, source string, dryR
 	}
 
 	sourceSlug := wiki.Slug(source)
+	if cfg.Wing != "" {
+		var rerr error
+		if sourceSlug, rerr = resolveSourceSlug(brainDir, cfg.Wing, sourceSlug); rerr != nil {
+			return Result{}, rerr
+		}
+	}
 	date := time.Now().UTC().Format("2006-01-02")
 
 	// Drift check BEFORE any extraction: an unchanged source costs a full LLM
@@ -151,6 +144,15 @@ func buildAndWrite(ctx context.Context, wing string, rawPages []RawPage, sourceS
 	warnings = append(warnings, linkWarnings...)
 	withRefs := injectSourceRefs(canonicalized, inventory, brainDir)
 	merged := mergeAll(withRefs)
+	if wing != "" {
+		var clashWarnings []string
+		var cerr error
+		merged, clashWarnings, cerr = dropSlugClashes(brainDir, merged)
+		if cerr != nil {
+			return Result{}, cerr
+		}
+		warnings = append(warnings, clashWarnings...)
+	}
 
 	var written []string
 	for _, page := range merged {
@@ -333,3 +335,68 @@ func loadSchema(brainDir string) string {
 	}
 	return strings.TrimSpace(string(b))
 }
+
+// resolveSourceSlug returns the slug this wing's source page uses. A slug is a
+// page's graph identity and must be unique brain-wide, but two wings dropping a
+// file of the same name (notes.md, readme.md) is ordinary, so when the plain
+// slug is taken by anything but this wing's own source page the wing name is
+// appended (talk-homelab, then talk-homelab-2, ...). The choice is stable: a
+// re-ingest finds the page it made, because that page is "its own".
+func resolveSourceSlug(brainDir, wing, base string) (string, error) {
+	for n := 1; n <= 100; n++ {
+		cand := base
+		switch n {
+		case 1:
+		case 2:
+			cand = base + "-" + wing
+		default:
+			cand = fmt.Sprintf("%s-%s-%d", base, wing, n-1)
+		}
+		existing, err := wiki.FindSlugs(brainDir, cand)
+		if err != nil {
+			return "", fmt.Errorf("check source slug: %w", err)
+		}
+		own := "wiki/" + wing + "/sources/" + cand + ".md"
+		free := true
+		for _, p := range existing {
+			if p != own {
+				free = false
+				break
+			}
+		}
+		if free {
+			return cand, nil
+		}
+	}
+	return "", fmt.Errorf("no free source slug for %q in wing %q", base, wing)
+}
+
+// dropSlugClashes removes, from the pages about to be written in a wing, any
+// page whose slug already belongs to a different page elsewhere in the brain.
+// The page's own path is not a clash (a shared entity merging into itself).
+// A skipped page is a warning, not a failure: the ingest as a whole is fine,
+// and one extracted page must not be able to lock a source out of re-ingest.
+func dropSlugClashes(brainDir string, pages []wiki.Page) ([]wiki.Page, []string, error) {
+	var kept []wiki.Page
+	var warnings []string
+	for _, p := range pages {
+		slug := strings.TrimSuffix(filepath.Base(p.Path), ".md")
+		existing, err := wiki.FindSlugs(brainDir, slug)
+		if err != nil {
+			return nil, nil, fmt.Errorf("check slug %q: %w", slug, err)
+		}
+		clash := ""
+		for _, e := range existing {
+			if e != p.Path {
+				clash = e
+				break
+			}
+		}
+		if clash != "" {
+			warnings = append(warnings, fmt.Sprintf("skipped %s: slug %q is already used by %s", p.Path, slug, clash))
+			continue
+		}
+		kept = append(kept, p)
+	}
+	return kept, warnings, nil
+}
diff --git a/ingestion/internal/pipeline/wing_layout_test.go b/ingestion/internal/pipeline/wing_layout_test.go
index d53b514..5664e4c 100644
--- a/ingestion/internal/pipeline/wing_layout_test.go
+++ b/ingestion/internal/pipeline/wing_layout_test.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -92,27 +93,77 @@ func TestRun_TheSameEntityCitedFromTwoWingsIsOnePageWithBothSources(t *testing.T
 }
 
 // A source slug is the graph's identity too: a second wing must not take over
-// the slug of a source that lives elsewhere.
-func TestRun_ASourceSlugAlreadyUsedInAnotherWingIsRefused(t *testing.T) {
+// the slug of a page that lives elsewhere. Two wings dropping a file of the same
+// name (notes.md, readme.md) is ordinary, so the second source gets a distinct,
+// stable slug instead of failing.
+func TestRun_ASourceWhoseSlugIsTakenElsewhereGetsADistinctStableSlug(t *testing.T) {
 	dir := t.TempDir()
 	_, err := Run(context.Background(), wingCfg("web-clip", sourceEntityConcept()...), dir, "body", "talk", false)
 	require.NoError(t, err)
 	require.NoError(t, os.MkdirAll(filepath.Join(dir, "wiki/homelab/facts"), 0o755))
 
 	_, err = Run(context.Background(), wingCfg("homelab", sourceEntityConcept()...), dir, "different body", "talk", false)
-	require.Error(t, err)
-	assert.Contains(t, err.Error(), "already used")
+	require.NoError(t, err)
+	assert.True(t, exists(dir, "wiki/web-clip/sources/talk.md"), "the first wing's page is untouched")
+	assert.True(t, exists(dir, "wiki/homelab/sources/talk-homelab.md"), "the second gets a wing-qualified slug")
 	assert.False(t, exists(dir, "wiki/homelab/sources/talk.md"))
+
+	_, err = Run(context.Background(), wingCfg("homelab", sourceEntityConcept()...), dir, "different body, edited", "talk", false)
+	require.NoError(t, err)
+	files, _ := filepath.Glob(filepath.Join(dir, "wiki/homelab/sources/*.md"))
+	assert.Len(t, files, 1, "re-ingesting finds the same page, it does not make talk-homelab-2")
 }
 
-func TestRun_ASourceSlugAlreadyInTheRetiredLayoutIsRefused(t *testing.T) {
+func TestRun_ASourceWhoseSlugIsTakenByARetiredPageOrASharedPageGetsADistinctSlug(t *testing.T) {
 	dir := t.TempDir()
 	require.NoError(t, os.MkdirAll(filepath.Join(dir, "wiki/sources"), 0o755))
 	require.NoError(t, os.WriteFile(filepath.Join(dir, "wiki/sources/talk.md"), []byte("---\ntitle: Talk\n---\nold"), 0o644))
+	require.NoError(t, os.MkdirAll(filepath.Join(dir, "wiki/entities"), 0o755))
+	require.NoError(t, os.WriteFile(filepath.Join(dir, "wiki/entities/other.md"), []byte("---\ntitle: Other\n---\nx"), 0o644))
 
 	_, err := Run(context.Background(), wingCfg("web-clip", sourceEntityConcept()...), dir, "body", "talk", false)
-	require.Error(t, err)
-	assert.Contains(t, err.Error(), "already used")
+	require.NoError(t, err)
+	assert.True(t, exists(dir, "wiki/web-clip/sources/talk-web-clip.md"))
+	assert.Equal(t, "---\ntitle: Talk\n---\nold", read(t, dir, "wiki/sources/talk.md"), "the retired page is untouched")
+}
+
+// The other direction: a model-extracted entity or concept whose slug is a
+// source's slug in some wing would lock that source out of re-ingest. The page
+// is skipped with a warning; the ingest itself succeeds.
+func TestRun_AnEntityWhoseSlugIsASourceElsewhereIsSkippedNotWritten(t *testing.T) {
+	dir := t.TempDir()
+	_, err := Run(context.Background(), wingCfg("web-clip", []RawPage{
+		{Title: "Jev", Type: "source", Subtype: "video", Content: "## Summary\n\nA clip titled Jev.\n"},
+	}...), dir, "body", "jev", false)
+	require.NoError(t, err)
+	require.NoError(t, os.MkdirAll(filepath.Join(dir, "wiki/homelab/facts"), 0o755))
+
+	res, err := Run(context.Background(), wingCfg("homelab", sourceEntityConcept()...), dir, "another body", "other-talk", false)
+	require.NoError(t, err)
+	assert.False(t, exists(dir, "wiki/entities/jev.md"), "the entity would take the source's slug")
+	assert.Contains(t, strings.Join(res.Warnings, "\n"), "jev")
+
+	_, err = Run(context.Background(), wingCfg("web-clip", []RawPage{
+		{Title: "Jev", Type: "source", Subtype: "video", Content: "## Summary\n\nEdited.\n"},
+	}...), dir, "body, edited", "jev", false)
+	require.NoError(t, err, "the first wing can still re-ingest its own source")
+}
+
+// The type comes from the model, so from the clip: in a wing it may only be one
+// of the three the layout has a place for.
+func TestRun_WithAWingAModelChosenTypeCannotWriteOutsideTheLayout(t *testing.T) {
+	dir := t.TempDir()
+	require.NoError(t, os.MkdirAll(filepath.Join(dir, "wiki/alpha/facts"), 0o755))
+	pages := append(sourceEntityConcept(),
+		RawPage{Title: "Planted", Type: "sources", Content: "## x\n\nplanted\n"},
+		RawPage{Title: "Loose", Type: "alpha", Content: "## x\n\nloose\n"},
+		RawPage{Title: "Sneaky", Type: "homelab", Content: "## x\n\nsneaky\n"})
+	res, err := Run(context.Background(), wingCfg("web-clip", pages...), dir, "body", "talk", false)
+	require.NoError(t, err)
+	assert.False(t, exists(dir, "wiki/sources/planted.md"))
+	assert.False(t, exists(dir, "wiki/alpha/loose.md"))
+	assert.False(t, exists(dir, "wiki/homelab"))
+	assert.Contains(t, strings.Join(res.Warnings, "\n"), "invalid type")
 }
 
 func TestRun_ReIngestingTheSameSourceIntoItsOwnWingIsNotACollision(t *testing.T) {
@@ -141,16 +192,44 @@ func listAll(t *testing.T, dir string) []string {
 	return out
 }
 
-// The first match must not hide a second one: this wing's own page of the name
-// exists AND a page of the same name lives elsewhere.
-func TestRun_ASlugUsedInTwoPlacesIsRefusedEvenWhenTheOwnPageIsOneOfThem(t *testing.T) {
+// Title resolution can mask a wrong slug choice at the Run level, so the
+// stability of the choice is pinned directly: the page this wing made earlier
+// under the qualified slug is "its own" and is found again.
+func TestResolveSourceSlug(t *testing.T) {
 	dir := t.TempDir()
-	require.NoError(t, os.MkdirAll(filepath.Join(dir, "wiki/web-clip/sources"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "wiki/web-clip/sources/talk.md"), []byte("---\ntitle: Talk\n---\nown"), 0o644))
-	require.NoError(t, os.MkdirAll(filepath.Join(dir, "wiki/entities"), 0o755))
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "wiki/entities/talk.md"), []byte("---\ntitle: Talk\n---\nan entity"), 0o644))
+	for _, rel := range []string{
+		"wiki/web-clip/sources/talk.md",
+		"wiki/homelab/sources/talk-homelab.md",
+		"wiki/entities/kube.md",
+	} {
+		require.NoError(t, os.MkdirAll(filepath.Dir(filepath.Join(dir, rel)), 0o755))
+		require.NoError(t, os.WriteFile(filepath.Join(dir, rel), []byte("---\ntitle: x\n---\n"), 0o644))
+	}
+	tests := []struct {
+		name, wing, base, want string
+	}{
+		{"free slug is used as is", "homelab", "fresh", "fresh"},
+		{"own page under the plain slug", "web-clip", "talk", "talk"},
+		{"taken elsewhere: wing-qualified", "tapir", "talk", "talk-tapir"},
+		{"own earlier qualified page is found again", "homelab", "talk", "talk-homelab"},
+		{"taken by a shared page", "tapir", "kube", "kube-tapir"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := resolveSourceSlug(dir, tt.wing, tt.base)
+			require.NoError(t, err)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
 
-	_, err := Run(context.Background(), wingCfg("web-clip", sourceEntityConcept()...), dir, "body", "talk", false)
-	require.Error(t, err)
-	assert.Contains(t, err.Error(), "already used")
+func TestResolveSourceSlug_AFurtherClashGetsANumber(t *testing.T) {
+	dir := t.TempDir()
+	for _, rel := range []string{"wiki/a/sources/talk.md", "wiki/entities/talk-b.md"} {
+		require.NoError(t, os.MkdirAll(filepath.Dir(filepath.Join(dir, rel)), 0o755))
+		require.NoError(t, os.WriteFile(filepath.Join(dir, rel), []byte("x"), 0o644))
+	}
+	got, err := resolveSourceSlug(dir, "b", "talk")
+	require.NoError(t, err)
+	assert.Equal(t, "talk-b-2", got)
 }