diff --git a/kurtosis-devnet/op-program-svc/README.md b/kurtosis-devnet/op-program-svc/README.md
index 4e59ff1a1918a..5ffca686b0454 100644
--- a/kurtosis-devnet/op-program-svc/README.md
+++ b/kurtosis-devnet/op-program-svc/README.md
@@ -1,4 +1,24 @@
-# Trigger new build:
+# op-program-svc
+
+This small service is a temporary measure until we come up with a better way
+of generating/serving prestate files based on chain information.
+
+# API
+
+The API is intentionally extremely simple:
+- `POST /`: generate new prestates from provided inputs
+- `GET /HASH.(bin.gz|json)`: get prestate data
+- `GET /info.json`: get prestates mapping
+
+The idea is for this service to be basically a function
+(chains_specs, deptsets) -> prestates.
+
+In the future, we definitely want to replace the implementation of that
+function (see implementation notes below)
+
+## Trigger new build:
+
+Example using curl
 
 ```
 $ curl -X POST -H "Content-Type: multipart/form-data" \
@@ -9,3 +29,30 @@ $ curl -X POST -H "Content-Type: multipart/form-data" \
     -F "files[]=@depsets.json" \
     http://localhost:8080
 ```
+
+## Retrieve prestates mapping
+
+```
+$ curl -q http://localhost:8080/info.json
+{
+  "prestate": "0x03f4b7435fec731578c72635d8e8180f7b48703073d038fc7f8c494eeed1ce19",
+  "prestate_interop": "0x034731331d519c93fc0562643e0728c43f8e45a0af1160ad4c57c4e5141d2bbb",
+  "prestate_mt64": "0x0325bb0ca8521b468bb8234d8ba54b1b74db60e2b5bc75d0077a0fe2098b6b45"
+}
+```
+
+## Implementation notes
+
+Unfortunately, op-program-client relies on embedded (using `//go:embed`)
+configuration files to store unannounced chain configs.
+
+This means that in the context of devnets, we need to store the configs
+(which are available only mid-deployment) into the **source tree** and
+trigger a late build step.
+
+So effectively, we need to package the relevant part of the sources into
+a container, deploy that one alongside the devnet, and run that build step
+on demand.
+
+This is ugly, unsafe, easy to run a DOS against,... we need to do better.
+But for now this is what we have.
\ No newline at end of file
diff --git a/kurtosis-devnet/op-program-svc/build.go b/kurtosis-devnet/op-program-svc/build.go
index f4e3582ab3459..7da7a4a23d87b 100644
--- a/kurtosis-devnet/op-program-svc/build.go
+++ b/kurtosis-devnet/op-program-svc/build.go
@@ -147,6 +147,7 @@ func (b *Builder) ExecuteBuild() ([]byte, error) {
 	return output.Bytes(), nil
 }
 
+// This is a convenience hack to natively support the file format of op-deployer
 func (b *Builder) normalizeFilename(filename string) string {
 	// Get just the filename without directories
 	filename = filepath.Base(filename)
@@ -156,8 +157,15 @@ func (b *Builder) normalizeFilename(filename string) string {
 		if numStr := strings.TrimSuffix(parts[1], ".json"); numStr != parts[1] {
 			// Check if the number part is actually numeric
 			if _, err := strconv.Atoi(numStr); err == nil {
-				// It matches the pattern and has a valid number, reorder to NUMBER-PREFIX.json
-				return numStr + "-" + parts[0] + ".json"
+				// Handle specific cases
+				switch parts[0] {
+				case "genesis":
+					return fmt.Sprintf("%s-genesis-l2.json", numStr)
+				case "rollup":
+					return fmt.Sprintf("%s-rollup.json", numStr)
+
+				}
+				// For all other cases, leave the filename unchanged
 			}
 		}
 	}
diff --git a/kurtosis-devnet/op-program-svc/build_test.go b/kurtosis-devnet/op-program-svc/build_test.go
index df3b6f879f7c6..70a813f1f3b39 100644
--- a/kurtosis-devnet/op-program-svc/build_test.go
+++ b/kurtosis-devnet/op-program-svc/build_test.go
@@ -167,9 +167,19 @@ func TestNormalizeFilename(t *testing.T) {
 		expected string
 	}{
 		{
-			name:     "standard format",
+			name:     "standard format - unchanged",
 			input:    "prefix-123.json",
-			expected: "123-prefix.json",
+			expected: "prefix-123.json",
+		},
+		{
+			name:     "genesis format",
+			input:    "genesis-123.json",
+			expected: "123-genesis-l2.json",
+		},
+		{
+			name:     "rollup format",
+			input:    "rollup-456.json",
+			expected: "456-rollup.json",
 		},
 		{
 			name:     "no number",
diff --git a/kurtosis-devnet/op-program-svc/defaults.go b/kurtosis-devnet/op-program-svc/defaults.go
index aba44060ae0e1..baf756a0d423d 100644
--- a/kurtosis-devnet/op-program-svc/defaults.go
+++ b/kurtosis-devnet/op-program-svc/defaults.go
@@ -48,6 +48,10 @@ func (fs *DefaultFileSystem) Join(elem ...string) string {
 	return filepath.Join(elem...)
 }
 
+func (fs *DefaultFileSystem) Stat(name string) (fs.FileInfo, error) {
+	return os.Stat(name)
+}
+
 // commandWrapper wraps exec.Cmd to implement CommandRunner
 type commandWrapper struct {
 	*exec.Cmd
diff --git a/kurtosis-devnet/op-program-svc/fs.go b/kurtosis-devnet/op-program-svc/fs.go
index 7408760cf67b8..c79ef00773d69 100644
--- a/kurtosis-devnet/op-program-svc/fs.go
+++ b/kurtosis-devnet/op-program-svc/fs.go
@@ -17,6 +17,11 @@ import (
 	"time"
 )
 
+const (
+	depsetsFilename = "depsets.json"
+	infoFilename    = "info.json"
+)
+
 // proofFileSystem implements http.FileSystem, mapping hash-based virtual paths to actual files
 type proofFileSystem struct {
 	root       string
@@ -69,7 +74,7 @@ func (f *infoFile) Readdir(count int) ([]fs.FileInfo, error) {
 
 func (f *infoFile) Stat() (fs.FileInfo, error) {
 	return virtualFileInfo{
-		name:    "info.json",
+		name:    infoFilename,
 		size:    int64(len(f.content)),
 		mode:    0644,
 		modTime: time.Now(),
@@ -120,8 +125,11 @@ func (d *proofDir) Readdir(count int) ([]fs.FileInfo, error) {
 	d.proofMutex.RLock()
 	defer d.proofMutex.RUnlock()
 
+	// Calculate total number of entries
+	totalEntries := len(d.proofFiles)*2 + 1 // hash.json, hash.bin.gz files + info.json
+
 	// If we've already read all entries
-	if d.pos >= len(d.proofFiles)*2+1 {
+	if d.pos >= totalEntries {
 		if count <= 0 {
 			return nil, nil
 		}
@@ -137,15 +145,15 @@ func (d *proofDir) Readdir(count int) ([]fs.FileInfo, error) {
 
 	start := d.pos
 	end := start + count
-	if count <= 0 || end > len(d.proofFiles)*2+1 {
-		end = len(d.proofFiles)*2 + 1
+	if count <= 0 || end > totalEntries {
+		end = totalEntries
 	}
 
 	for i := start; i < end; i++ {
-		// Special case for info.json (last entry)
+		// Special case for info.json (second to last entry)
 		if i == len(d.proofFiles)*2 {
 			entries = append(entries, virtualFileInfo{
-				name:    "info.json",
+				name:    infoFilename,
 				size:    0, // Size will be determined when actually opening the file
 				mode:    0644,
 				modTime: time.Now(),
@@ -228,7 +236,7 @@ func (fs *proofFileSystem) Open(name string) (http.File, error) {
 	name = strings.TrimPrefix(filepath.Clean(name), "/")
 
 	// Special case for info.json
-	if name == "info.json" {
+	if name == infoFilename {
 		fs.proofMutex.RLock()
 		defer fs.proofMutex.RUnlock()
 		return newInfoFile(fs.proofFiles), nil
@@ -279,12 +287,15 @@ func (fs *proofFileSystem) scanProofFiles() error {
 	proofRegexp := regexp.MustCompile(`^prestate-proof(.*)\.json$`)
 
 	for _, entry := range entries {
+		log.Printf("entry: %s", entry.Name())
 		if entry.IsDir() {
+			log.Printf("entry is a directory: %s", entry.Name())
 			continue
 		}
 
 		matches := proofRegexp.FindStringSubmatch(entry.Name())
 		if matches == nil {
+			log.Printf("Warning: ignoring non-proof file %s", entry.Name())
 			continue
 		}
 
diff --git a/kurtosis-devnet/op-program-svc/fs_test.go b/kurtosis-devnet/op-program-svc/fs_test.go
index 951c292c1a47a..67a1f204dfb3d 100644
--- a/kurtosis-devnet/op-program-svc/fs_test.go
+++ b/kurtosis-devnet/op-program-svc/fs_test.go
@@ -130,15 +130,11 @@ func TestProofFileSystem(t *testing.T) {
 		}
 
 		// Verify info.json is included in the directory listing
-		foundInfoJson := false
 		for _, file := range files {
 			if file.Name() == "info.json" {
-				foundInfoJson = true
-				break
+				return
 			}
 		}
-		if !foundInfoJson {
-			t.Error("info.json not found in directory listing")
-		}
+		t.Error("info.json not found in directory listing")
 	})
 }
diff --git a/kurtosis-devnet/op-program-svc/interfaces.go b/kurtosis-devnet/op-program-svc/interfaces.go
index 701890459c883..0d93ecb8349ed 100644
--- a/kurtosis-devnet/op-program-svc/interfaces.go
+++ b/kurtosis-devnet/op-program-svc/interfaces.go
@@ -20,6 +20,7 @@ type FS interface {
 	ReadDir(name string) ([]fs.DirEntry, error)
 	ReadFile(name string) ([]byte, error)
 	Join(elem ...string) string
+	Stat(name string) (fs.FileInfo, error)
 
 	// Additional FileSystem operations
 	MkdirAll(path string, perm os.FileMode) error
diff --git a/kurtosis-devnet/op-program-svc/mocks.go b/kurtosis-devnet/op-program-svc/mocks.go
index 6d52f31009aa1..8fa108cb0c873 100644
--- a/kurtosis-devnet/op-program-svc/mocks.go
+++ b/kurtosis-devnet/op-program-svc/mocks.go
@@ -67,21 +67,23 @@ func (m *MockFile) Readdir(count int) ([]fs.FileInfo, error) {
 	return nil, fmt.Errorf("not implemented")
 }
 
-// MockFS implements both FS and FileSystem interfaces for testing
+// MockFS implements FS interface for testing
 type MockFS struct {
-	Files       map[string]*MockFile
-	MkdirCalls  []string
-	CreateCalls []string
-	JoinCalls   [][]string
-	ShouldFail  bool
+	Files         map[string]*MockFile
+	ShouldFail    bool
+	StatFailPaths map[string]bool // Paths that should fail for Stat
+	JoinCalls     [][]string
+	MkdirCalls    []string
+	CreateCalls   []string
 }
 
 func NewMockFS() *MockFS {
 	return &MockFS{
-		Files:       make(map[string]*MockFile),
-		MkdirCalls:  make([]string, 0),
-		CreateCalls: make([]string, 0),
-		JoinCalls:   make([][]string, 0),
+		Files:         make(map[string]*MockFile),
+		StatFailPaths: make(map[string]bool),
+		JoinCalls:     make([][]string, 0),
+		MkdirCalls:    make([]string, 0),
+		CreateCalls:   make([]string, 0),
 	}
 }
 
@@ -142,6 +144,16 @@ func (m *MockFS) Join(elem ...string) string {
 	return filepath.Join(elem...)
 }
 
+func (m *MockFS) Stat(name string) (fs.FileInfo, error) {
+	if m.ShouldFail {
+		return nil, fmt.Errorf("mock stat error")
+	}
+	if m.StatFailPaths[name] {
+		return nil, fmt.Errorf("file not found: %s", name)
+	}
+	return m.Files[name], nil
+}
+
 // MockWriteCloser implements io.WriteCloser for testing
 type MockWriteCloser struct {
 	bytes.Buffer
diff --git a/kurtosis-devnet/op-program-svc/server.go b/kurtosis-devnet/op-program-svc/server.go
index 401e92ff9e4dc..ad8e16a15b52e 100644
--- a/kurtosis-devnet/op-program-svc/server.go
+++ b/kurtosis-devnet/op-program-svc/server.go
@@ -77,7 +77,7 @@ func (s *server) handleUpload(w http.ResponseWriter, r *http.Request) {
 	// Check if we need to rebuild
 	if currentHash == s.lastBuildHash {
 		log.Printf("Hash matches last build, skipping")
-		w.WriteHeader(http.StatusOK)
+		w.WriteHeader(http.StatusNotModified)
 		fmt.Fprintf(w, "Files unchanged, skipping build")
 		return
 	}
@@ -111,8 +111,8 @@ func (s *server) handleUpload(w http.ResponseWriter, r *http.Request) {
 	// Update the last successful build hash
 	s.lastBuildHash = currentHash
 
-	// Redirect to the proofs endpoint
-	http.Redirect(w, r, "/proofs", http.StatusSeeOther)
+	log.Printf("Build successful, last build hash: %s", currentHash)
+	w.WriteHeader(http.StatusOK)
 }
 
 func (s *server) processMultipartForm(r *http.Request) ([]*multipart.FileHeader, string, error) {
diff --git a/kurtosis-devnet/op-program-svc/server_test.go b/kurtosis-devnet/op-program-svc/server_test.go
index f66cea90bd0a7..5831e37cfa096 100644
--- a/kurtosis-devnet/op-program-svc/server_test.go
+++ b/kurtosis-devnet/op-program-svc/server_test.go
@@ -108,12 +108,9 @@ func TestHandleUpload_Success(t *testing.T) {
 	w := httptest.NewRecorder()
 	srv.handleUpload(w, req)
 
-	if w.Code != http.StatusSeeOther {
-		t.Errorf("Expected status code %d, got %d", http.StatusSeeOther, w.Code)
-	}
-
-	if location := w.Header().Get("Location"); location != "/proofs" {
-		t.Errorf("Expected redirect to /proofs, got %s", location)
+	// We now expect 200 OK instead of a redirect
+	if w.Code != http.StatusOK {
+		t.Errorf("Expected status code %d, got %d", http.StatusOK, w.Code)
 	}
 }
 
@@ -206,9 +203,9 @@ func TestHandleUpload_ScanError(t *testing.T) {
 	w := httptest.NewRecorder()
 	srv.handleUpload(w, req)
 
-	// Even with scan error, we should still redirect
-	if w.Code != http.StatusSeeOther {
-		t.Errorf("Expected status code %d, got %d", http.StatusSeeOther, w.Code)
+	// Even with scan error, we should still return 200 OK
+	if w.Code != http.StatusOK {
+		t.Errorf("Expected status code %d, got %d", http.StatusOK, w.Code)
 	}
 }
 
@@ -229,8 +226,9 @@ func TestHandleUpload_UnchangedFiles(t *testing.T) {
 	w1 := httptest.NewRecorder()
 	srv.handleUpload(w1, req1)
 
-	if w1.Code != http.StatusSeeOther {
-		t.Errorf("Expected status code %d, got %d", http.StatusSeeOther, w1.Code)
+	// First request should return 200 OK
+	if w1.Code != http.StatusOK {
+		t.Errorf("Expected status code %d, got %d", http.StatusOK, w1.Code)
 	}
 
 	// Second request with same files
@@ -242,8 +240,9 @@ func TestHandleUpload_UnchangedFiles(t *testing.T) {
 	w2 := httptest.NewRecorder()
 	srv.handleUpload(w2, req2)
 
-	if w2.Code != http.StatusOK {
-		t.Errorf("Expected status code %d, got %d", http.StatusOK, w2.Code)
+	// Second request with unchanged files should return 304 Not Modified
+	if w2.Code != http.StatusNotModified {
+		t.Errorf("Expected status code %d, got %d", http.StatusNotModified, w2.Code)
 	}
 
 	if !strings.Contains(w2.Body.String(), "Files unchanged") {