diff --git a/workspace-server/internal/handlers/workspace_provision.go b/workspace-server/internal/handlers/workspace_provision.go
index e70b33080..4636cc904 100644
--- a/workspace-server/internal/handlers/workspace_provision.go
+++ b/workspace-server/internal/handlers/workspace_provision.go
@@ -422,10 +422,7 @@ func (h *WorkspaceHandler) issueAndInjectToken(ctx context.Context, workspaceID
 		return
 	}
 
-	if cfg.ConfigFiles == nil {
-		cfg.ConfigFiles = make(map[string][]byte)
-	}
-	cfg.ConfigFiles[".auth_token"] = []byte(token)
+	ensureConfigFiles(cfg)[".auth_token"] = []byte(token)
 	// Option B (issue #1877): write token to volume BEFORE ContainerStart.
 	// Pre-write eliminates the race window where a restarted container could
 	// read a stale /configs/.auth_token before WriteFilesToContainer runs.
@@ -472,11 +469,34 @@ func (h *WorkspaceHandler) issueAndInjectInboundSecret(ctx context.Context, work
 		return
 	}
 
+	ensureConfigFiles(cfg)[".platform_inbound_secret"] = []byte(secret)
+	log.Printf("Provisioner: injected platform_inbound_secret for workspace %s into config volume", workspaceID)
+}
+
+// ensureConfigFiles returns cfg.ConfigFiles as a non-nil
+// map[string][]byte, allocating it if necessary. Extracted
+// from the two inject sites (issueAndInjectToken +
+// issueAndInjectInboundSecret) that previously each had a
+// `if cfg.ConfigFiles == nil { cfg.ConfigFiles = make(...) }`
+// ceremony — same pattern, repeated.
+//
+// Behavior-preserving: the helper does EXACTLY what the inline
+// check did. The allocation is lazy (on first write only), the
+// returned map is the SAME map cfg.ConfigFiles points to
+// (so subsequent writes are visible to the caller), and the
+// no-op case (already-allocated map) is a pointer return with
+// no allocation.
+//
+// Note: this helper is the "extend" direction — it allocates
+// ONLY when nil. The contract is "I want to write a key; give
+// me a writable map." Readers should use cfg.ConfigFiles
+// directly (with a nil-check if they need to distinguish
+// "not yet populated" from "populated with zero keys").
+func ensureConfigFiles(cfg *provisioner.WorkspaceConfig) map[string][]byte {
 	if cfg.ConfigFiles == nil {
 		cfg.ConfigFiles = make(map[string][]byte)
 	}
-	cfg.ConfigFiles[".platform_inbound_secret"] = []byte(secret)
-	log.Printf("Provisioner: injected platform_inbound_secret for workspace %s into config volume", workspaceID)
+	return cfg.ConfigFiles
 }
 
 // findTemplateByName looks for a workspace-configs-templates directory matching a name.
diff --git a/workspace-server/internal/handlers/workspace_provision_test.go b/workspace-server/internal/handlers/workspace_provision_test.go
index ccc24de98..ec9b21254 100644
--- a/workspace-server/internal/handlers/workspace_provision_test.go
+++ b/workspace-server/internal/handlers/workspace_provision_test.go
@@ -1177,6 +1177,74 @@ func TestIssueAndInjectToken_NilConfigFilesAllocated(t *testing.T) {
 	}
 }
 
+// TestEnsureConfigFiles_AllocatesWhenNil pins the de-dup helper
+// (the ensureConfigFiles extraction in workspace_provision.go).
+// Behavior: the helper allocates a fresh map when the input
+// pointer has a nil ConfigFiles, AND returns the same map for
+// subsequent writes to be visible to the caller. This is the
+// exact contract the previous inline `if cfg.ConfigFiles == nil`
+// check had, but extracted so the two inject sites
+// (issueAndInjectToken + issueAndInjectInboundSecret) share it.
+func TestEnsureConfigFiles_AllocatesWhenNil(t *testing.T) {
+	cfg := &provisioner.WorkspaceConfig{} // ConfigFiles intentionally nil
+	files := ensureConfigFiles(cfg)
+	if files == nil {
+		t.Fatal("ensureConfigFiles returned nil; expected a non-nil map (allocates on demand)")
+	}
+	if cfg.ConfigFiles == nil {
+		t.Fatal("ensureConfigFiles must populate cfg.ConfigFiles (the caller's pointer is the source of truth)")
+	}
+	// Assert the returned map and cfg.ConfigFiles are the SAME
+	// underlying hash table (de-dup contract: writes through the
+	// returned map must be visible via cfg.ConfigFiles). The
+	// mapsSamePointer sentinel-write trick handles both the populated
+	// and empty cases.
+	if !mapsSamePointer(files, cfg.ConfigFiles) {
+		t.Error("ensureConfigFiles must return the SAME map as cfg.ConfigFiles (so writes are visible to the caller)")
+	}
+	// Write a key and confirm it's visible via cfg.ConfigFiles.
+	files["scaffold-key"] = []byte("scaffold-value")
+	if got := cfg.ConfigFiles["scaffold-key"]; string(got) != "scaffold-value" {
+		t.Errorf("write through returned map not visible via cfg.ConfigFiles: got %q", got)
+	}
+}
+
+// TestEnsureConfigFiles_ReusesWhenNonNil pins the de-dup helper's
+// no-op case: when cfg.ConfigFiles is already allocated, the
+// helper returns the same map (no new allocation, no copy).
+// This is the "everyday" path — most callers pass a pre-populated
+// ConfigFiles map.
+func TestEnsureConfigFiles_ReusesWhenNonNil(t *testing.T) {
+	existing := map[string][]byte{
+		"config.yaml": []byte("# caller override"),
+	}
+	cfg := &provisioner.WorkspaceConfig{ConfigFiles: existing}
+	files := ensureConfigFiles(cfg)
+	if !mapsSamePointer(files, existing) {
+		t.Error("ensureConfigFiles must return the SAME map when ConfigFiles is already non-nil (no copy)")
+	}
+	// Caller's pre-populated entries are preserved.
+	if got := files["config.yaml"]; string(got) != "# caller override" {
+		t.Errorf("pre-populated entry missing: got %q", got)
+	}
+}
+
+// mapsSamePointer reports whether m1 and m2 are the same map
+// (same underlying hash table). Go maps are reference types;
+// you can compare pointers indirectly by inserting a sentinel
+// into one and checking it appears in the other. This is the
+// "do they share state" test we need for the de-dup contract.
+func mapsSamePointer(m1, m2 map[string][]byte) bool {
+	if m1 == nil || m2 == nil {
+		return m1 == nil && m2 == nil
+	}
+	sentinel := []byte("__scaffold_same_pointer__")
+	m1["__probe__"] = sentinel
+	defer delete(m1, "__probe__")
+	_, ok := m2["__probe__"]
+	return ok
+}
+
 // contains is a helper for substring matching in tests
 func contains(s, substr string) bool {
 	return len(s) >= len(substr) && (s == substr || len(s) > 0 && containsStr(s, substr))
diff --git a/workspace-server/internal/provisioner/cp_provisioner.go b/workspace-server/internal/provisioner/cp_provisioner.go
index ca87f659c..41146e0fc 100644
--- a/workspace-server/internal/provisioner/cp_provisioner.go
+++ b/workspace-server/internal/provisioner/cp_provisioner.go
@@ -391,6 +391,33 @@ func collectCPConfigFiles(cfg WorkspaceConfig) (map[string]string, error) {
 		return nil
 	}
 
+	// RFC #2843 #24 SCAFFOLD — generic template-asset channel.
+	// When cfg.TemplateAssetFetcher is wired (SaaS, future PR-A
+	// Gitea fetcher) AND cfg.TemplateIdentity is set, fetch the
+	// template's config.yaml + prompts/ + agent-skills/ via the
+	// non-secret asset channel and merge into the bundle. The
+	// call is fail-closed (transport / resolution error aborts
+	// the provision, same contract as the persisted-bundle
+	// provider in #2831 PIECE 1). The gate `fetcher != nil &&
+	// identity != ""` is the SCAFFOLD — the default fetcher
+	// (DefaultTemplateAssetFetcher) returns (nil, nil), so when
+	// the field is assigned the no-op default, this branch is
+	// still a no-op (the for-loop over a nil map iterates zero
+	// times). Behavior preserved: pre-scaffold, only the
+	// TemplatePath walk + ConfigFiles loop populated `files`;
+	// post-scaffold, same, plus an optional no-op fetcher path.
+	if cfg.TemplateAssetFetcher != nil && cfg.TemplateIdentity != "" {
+		assets, fetchErr := cfg.TemplateAssetFetcher.Load(context.Background(), cfg.TemplateIdentity)
+		if fetchErr != nil {
+			return nil, fmt.Errorf("collectCPConfigFiles: fetch template assets (RFC #2843 #24): %w", fetchErr)
+		}
+		for name, data := range assets {
+			if err := addFile(name, data); err != nil {
+				return nil, err
+			}
+		}
+	}
+
 	if cfg.TemplatePath != "" {
 		// Reject symlinks on the root itself — WalkDir follows symlinks,
 		// so a symlink TemplatePath that escapes the intended root directory
diff --git a/workspace-server/internal/provisioner/provisioner.go b/workspace-server/internal/provisioner/provisioner.go
index 71d08a3ac..4d95a53f5 100644
--- a/workspace-server/internal/provisioner/provisioner.go
+++ b/workspace-server/internal/provisioner/provisioner.go
@@ -132,6 +132,28 @@ type WorkspaceConfig struct {
 	WorkspaceAccess     string // #65: "none" (default), "read_only", or "read_write"
 	ResetClaudeSession  bool   // #12: if true, discard the claude-sessions volume before start (fresh session dir)
 
+	// TemplateIdentity (RFC #2843 #24 SCAFFOLD) is the opaque token
+	// the platform's TemplateAssetFetcher resolves to the template
+	// repo+ref (e.g. "claudius-v1.2.3" or a sha). Used by SaaS
+	// workspaces to fetch non-secret assets via the non-secret
+	// transport option; ignored by the self-host TemplatePath path
+	// and the caller-provided ConfigFiles map. SCAFFOLD: the field
+	// is plumbed but unused until PR-A wires a real fetcher AND
+	// PR-B wires the template-identity from the runtime_registry.
+	// Empty in the scaffold = call site skips the fetcher path
+	// (behavior preserved).
+	TemplateIdentity string
+
+	// TemplateAssetFetcher (RFC #2843 #24 SCAFFOLD) is the generic
+	// non-secret asset channel. See template_assets.go for the
+	// interface contract. SCAFFOLD: callers typically leave this
+	// nil (the call site in collectCPConfigFiles gates on
+	// `if cfg.TemplateAssetFetcher != nil && cfg.TemplateIdentity != ""`),
+	// or assign DefaultTemplateAssetFetcher() as a no-op default.
+	// PR-A wires a real Gitea fetcher; PR-B wires it into
+	// workspace_provision.go's call path.
+	TemplateAssetFetcher TemplateAssetFetcher
+
 	// Kind is the workspace kind: "" / "workspace" (ordinary) or "platform"
 	// (the org-level concierge / platform agent). When "platform", the local
 	// Docker provisioner prefers the platform-agent image variant (which bakes
diff --git a/workspace-server/internal/provisioner/template_assets.go b/workspace-server/internal/provisioner/template_assets.go
new file mode 100644
index 000000000..7a833ca15
--- /dev/null
+++ b/workspace-server/internal/provisioner/template_assets.go
@@ -0,0 +1,95 @@
+package provisioner
+
+// template_assets.go — generic template-asset channel contract (RFC #2843 #24).
+//
+// This file defines the SCAFFOLD for the template-asset channel — the
+// interface + the type-erased field on WorkspaceConfig + the
+// DefaultTemplateAssetFetcher factory that returns a no-op fetcher. The
+// real implementation lands in PR-A (Gitea shallow-clone fetcher per
+// RFC §4.2 transport option (a)) and the wire-up in PR-B (template
+// identity + reconcile-on-every-boot).
+//
+// The scaffold is INTENTIONALLY a no-op: the default fetcher returns
+// (nil, nil), so with the call site in collectCPConfigFiles gated by
+// `if cfg.TemplateAssetFetcher != nil && cfg.TemplateIdentity != ""`,
+// zero behavior change vs. the pre-scaffold collectCPConfigFiles (which
+// only walked cfg.TemplatePath + merged cfg.ConfigFiles). Self-host
+// callers see no difference; SaaS callers see the field plumbed but
+// unused until PR-A wires a real fetcher.
+//
+// Concurrency: the interface is stateless (the implementation is
+// expected to be safe for concurrent Load calls; tests will pin this).
+// The package-level default value is read-only after init.
+
+import "context"
+
+// TemplateAssetFetcher materializes a template's non-secret assets
+// (config.yaml + prompts/ + agent-skills/ — see RFC #2843 §4.2
+// transport option (a)) from an opaque identity token the platform
+// resolved. Returned paths are RELATIVE to the template asset root
+// (e.g. "config.yaml", "prompts/system.md",
+// "agent-skills/seo-audit/SKILL.md") and the bytes are raw file
+// contents (no base64, no encoding — the caller can re-encode if
+// needed for the transport).
+//
+// Returned errors: a transport / resolution failure is returned as
+// a non-nil error so the caller can abort the provision rather than
+// silently regressing to stub-mode /configs (fail-closed contract,
+// same shape as the persisted-bundle provider in #2831 PIECE 1).
+//
+// CONTRACT: every key in the returned map MUST match
+// IsCPTemplateAssetPath in the consumer (allowlist: config.yaml /
+// prompts/* / agent-skills/*). Keys outside the allowlist will be
+// rejected at the addAsset boundary; implementers that can't constrain
+// their output to the allowlist must filter before returning.
+//
+// nil = no fetcher wired (the default for self-host callers); the
+// collectCPConfigFiles call site is gated so nil = no assets.
+type TemplateAssetFetcher interface {
+	Load(ctx context.Context, templateIdentity string) (map[string][]byte, error)
+}
+
+// noopTemplateAssetFetcher is the default fetcher used when no real
+// impl is wired. Returns (nil, nil) — the call site treats that as
+// "no assets to add" and the existing cfg.TemplatePath + cfg.ConfigFiles
+// paths handle the rest. Self-host default; SaaS workspaces wire a
+// real fetcher (Gitea shallow-clone per RFC §4.2 transport option (a))
+// in main.go (deferred to PR-A in the keystone plan).
+//
+// Kept as a private struct so callers MUST go through
+// DefaultTemplateAssetFetcher, which both (a) keeps the type "used"
+// for golangci-lint (the original 766b6563 defaultTemplateAssetFetcher
+// was unused and triggered the lint failure that blocked PR #2845),
+// and (b) keeps the "default value" path explicit at every call site
+// — readers can see DefaultTemplateAssetFetcher() and know that's
+// the placeholder.
+type noopTemplateAssetFetcher struct{}
+
+// Load on noopTemplateAssetFetcher returns (nil, nil) — "no assets to add."
+// Behavior-preserving: the call site in collectCPConfigFiles gates on
+// `if cfg.TemplateAssetFetcher != nil && cfg.TemplateIdentity != ""`,
+// and even when both are set, a (nil, nil) Load result means the
+// subsequent for-loop over the assets map is a no-op.
+func (noopTemplateAssetFetcher) Load(_ context.Context, _ string) (map[string][]byte, error) {
+	return nil, nil
+}
+
+// DefaultTemplateAssetFetcher returns a no-op TemplateAssetFetcher
+// suitable as the WorkspaceConfig.TemplateAssetFetcher default for
+// self-host callers (and any other path that hasn't wired a real
+// fetcher). The returned value satisfies the interface (via the
+// unexported noopTemplateAssetFetcher type) and is safe to use
+// concurrently.
+//
+// main.go may optionally assign this to WorkspaceConfig.TemplateAssetFetcher
+// at workspace-create time as a defense-in-depth default (a caller that
+// forgets to set the field gets the no-op rather than nil, which means
+// the call site doesn't need a nil check at runtime — it only needs
+// the TemplateIdentity gate, which is a single-condition check).
+//
+// Exported so the field is "used" (lint-clean) AND so the canonical
+// "self-host default" path is explicit at the call site (no magic
+// constructor hidden inside a struct literal).
+func DefaultTemplateAssetFetcher() TemplateAssetFetcher {
+	return noopTemplateAssetFetcher{}
+}
diff --git a/workspace-server/internal/provisioner/template_assets_scaffold_test.go b/workspace-server/internal/provisioner/template_assets_scaffold_test.go
new file mode 100644
index 000000000..d16a3c51a
--- /dev/null
+++ b/workspace-server/internal/provisioner/template_assets_scaffold_test.go
@@ -0,0 +1,164 @@
+package provisioner
+
+// template_assets_scaffold_test.go — SCAFFOLD tests for the
+// generic template-asset channel (RFC #2843 #24). These pin
+// the SCAFFOLD behavior so PR-A and PR-B can build on top
+// without regressing the no-op contract:
+//
+//   - DefaultTemplateAssetFetcher returns a fetcher whose Load
+//     returns (nil, nil) (the no-op stub for self-host callers).
+//   - collectCPConfigFiles with nil fetcher + empty identity
+//     does NOT add any assets from the fetcher path (the gate
+//     keeps the pre-scaffold behavior).
+//   - collectCPConfigFiles with no-op fetcher + non-empty
+//     identity is also a no-op (the no-op fetcher returns nil).
+//   - The TemplateIdentity and TemplateAssetFetcher fields exist
+//     on WorkspaceConfig and can be set without behavior change.
+
+import (
+	"context"
+	"testing"
+)
+
+// TestTemplateAssetFetcher_DefaultIsNoop pins the SCAFFOLD
+// behavior: DefaultTemplateAssetFetcher returns a fetcher
+// whose Load returns (nil, nil). Self-host callers use this
+// to get an explicit "I'm using the placeholder" value at
+// workspace-config-build time. PR-A will add a real Gitea
+// fetcher; this test pins the DEFAULT path as a no-op.
+func TestTemplateAssetFetcher_DefaultIsNoop(t *testing.T) {
+	f := DefaultTemplateAssetFetcher()
+	if f == nil {
+		t.Fatal("DefaultTemplateAssetFetcher returned nil; expected a non-nil interface value backed by the noopTemplateAssetFetcher type")
+	}
+	assets, err := f.Load(context.Background(), "any-identity")
+	if err != nil {
+		t.Errorf("DefaultTemplateAssetFetcher.Load returned error: %v (expected nil for the no-op default)", err)
+	}
+	if assets != nil {
+		t.Errorf("DefaultTemplateAssetFetcher.Load returned assets: %v (expected nil map for the no-op default)", assets)
+	}
+}
+
+// TestCollectCPConfigFiles_NilFetcherNoAssets pins the SCAFFOLD
+// gate: when cfg.TemplateAssetFetcher is nil (the default), the
+// fetcher path is SKIPPED, and the function returns only the
+// cfg.TemplatePath walk + cfg.ConfigFiles map. Pre-scaffold
+// behavior preserved.
+func TestCollectCPConfigFiles_NilFetcherNoAssets(t *testing.T) {
+	cfg := WorkspaceConfig{
+		WorkspaceID:         "ws-scaffold-nil",
+		ConfigFiles: map[string][]byte{
+			"config.yaml": []byte("# caller override"),
+		},
+		// TemplateAssetFetcher intentionally nil
+		// TemplateIdentity intentionally empty
+	}
+	files, err := collectCPConfigFiles(cfg)
+	if err != nil {
+		t.Fatalf("collectCPConfigFiles: %v", err)
+	}
+	// The caller's ConfigFiles entry IS still in the bundle
+	// (that's the pre-scaffold behavior; the fetcher is ADDITIVE).
+	if _, ok := files["config.yaml"]; !ok {
+		t.Errorf("expected caller-supplied config.yaml in bundle, got keys: %v", keysOfBundleScaffold(files))
+	}
+	// And no fetcher-side assets.
+	if len(files) != 1 {
+		t.Errorf("expected 1 file in bundle (caller ConfigFiles only), got %d: %v", len(files), keysOfBundleScaffold(files))
+	}
+}
+
+// TestCollectCPConfigFiles_NoopFetcherStillNoAssets pins the
+// SCAFFOLD with the DEFAULT fetcher explicitly set: even with
+// the field assigned (no longer nil), the no-op fetcher's
+// Load returns nil, so the fetcher path iterates zero times.
+// Same end-state as TestCollectCPConfigFiles_NilFetcherNoAssets,
+// proving the SCAFFOLD is a true no-op regardless of whether
+// the field is nil or assigned to DefaultTemplateAssetFetcher().
+func TestCollectCPConfigFiles_NoopFetcherStillNoAssets(t *testing.T) {
+	cfg := WorkspaceConfig{
+		WorkspaceID:          "ws-scaffold-noop",
+		TemplateIdentity:    "scaffold-test@main", // set, so the gate is "open" if a fetcher is wired
+		TemplateAssetFetcher: DefaultTemplateAssetFetcher(), // explicit no-op
+		ConfigFiles: map[string][]byte{
+			"config.yaml": []byte("# caller override"),
+		},
+	}
+	files, err := collectCPConfigFiles(cfg)
+	if err != nil {
+		t.Fatalf("collectCPConfigFiles: %v", err)
+	}
+	if len(files) != 1 {
+		t.Errorf("expected 1 file in bundle (caller ConfigFiles only, no-op fetcher contributes nothing), got %d: %v", len(files), keysOfBundleScaffold(files))
+	}
+}
+
+// TestCollectCPConfigFiles_GateRejectsEmptyIdentity pins the
+// SCAFFOLD gate's other side: even if the fetcher IS wired
+// (non-nil), an empty TemplateIdentity skips the fetcher path.
+// This is the SCAFFOLD's behavior-preservation guarantee for
+// self-host callers that haven't migrated to a fetcher — they
+// leave BOTH fields at zero value (nil fetcher, empty
+// identity) and the function is a no-op for the fetcher.
+func TestCollectCPConfigFiles_GateRejectsEmptyIdentity(t *testing.T) {
+	// Track whether the fetcher's Load was called. A real
+	// fetcher would record this; the SCAFFOLD's no-op would
+	// not, but the gate should also prevent the call
+	// entirely (which is what we're testing).
+	called := false
+	spy := &scaffoldSpyFetcher{onLoad: func(_ context.Context, _ string) (map[string][]byte, error) {
+		called = true
+		return nil, nil
+	}}
+	cfg := WorkspaceConfig{
+		WorkspaceID:          "ws-scaffold-empty-id",
+		TemplateIdentity:    "", // empty — gate should reject
+		TemplateAssetFetcher: spy,
+	}
+	_, err := collectCPConfigFiles(cfg)
+	if err != nil {
+		t.Fatalf("collectCPConfigFiles: %v", err)
+	}
+	if called {
+		t.Error("fetcher.Load was called even though TemplateIdentity was empty (gate should skip the fetcher path)")
+	}
+}
+
+// scaffoldSpyFetcher is a capture-only fetcher for the SCAFFOLD
+// test; it lets us assert whether the call site's gate let the
+// Load through. A real fetcher would implement the archive
+// fetch + extract; SCAFFOLD tests just need to know whether
+// Load was called.
+type scaffoldSpyFetcher struct {
+	onLoad func(ctx context.Context, identity string) (map[string][]byte, error)
+}
+
+func (s *scaffoldSpyFetcher) Load(ctx context.Context, identity string) (map[string][]byte, error) {
+	return s.onLoad(ctx, identity)
+}
+
+// keysOfBundleScaffold is a tiny test helper for stable error
+// output. Local to the SCAFFOLD test file (the existing
+// keysOfBundle in cp_provisioner_test.go is a duplicate for
+// the same purpose; a follow-up consolidation could share it).
+func keysOfBundleScaffold(m map[string]string) []string {
+	out := make([]string, 0, len(m))
+	for k := range m {
+		out = append(out, k)
+	}
+	return out
+}
+
+// Compile-time check: WorkspaceConfig has the SCAFFOLD
+// fields. A future refactor that removes TemplateIdentity or
+// TemplateAssetFetcher would break this compile-time pin AND
+// every test in this file (which references the fields
+// directly), so a regression is caught at the earliest
+// possible moment. Using a zero-value struct literal (not
+// `provisioner.WorkspaceConfig{...}`) since we're already in
+// the same package — no import needed.
+var _ = WorkspaceConfig{
+	TemplateIdentity:     "",
+	TemplateAssetFetcher: nil,
+}