diff --git a/.gitignore b/.gitignore
index 14594515..c6054173 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
 .DS_Store
 # Added by code-review-graph
 .code-review-graph/
+build/
+services/ibl_merge_report_service/ibl-merge-report-service
diff --git a/docs/superpowers/plans/2026-05-29-ibl-merge-report-service.md b/docs/superpowers/plans/2026-05-29-ibl-merge-report-service.md
new file mode 100644
index 00000000..ea071af0
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+++ b/docs/superpowers/plans/2026-05-29-ibl-merge-report-service.md
@@ -0,0 +1,878 @@
+# ibl_merge_report_service Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Build a standalone Go HTTP service (`ibl_merge_report_service`) that fetches multiple PDF URLs, merges them into one PDF, and streams the result — called internally by the one-api-lab PHP gateway.
+
+**Architecture:** The service exposes a single `POST /merge` endpoint. It validates the `X-Internal-Secret` request header, parses the JSON body, fetches each PDF URL sequentially, merges them with pdfcpu, then writes the merged PDF as `application/pdf`. If any source fetch fails, the entire request fails with a mapped HTTP status code. No files are cached on disk.
+
+**Tech Stack:** Go 1.21+, `github.com/pdfcpu/pdfcpu` for in-memory PDF merging, standard library `net/http`.
+
+---
+
+## File Map
+
+| File | Responsibility |
+|------|---------------|
+| `services/ibl_merge_report_service/go.mod` | Module definition |
+| `services/ibl_merge_report_service/main.go` | Entry point — read env config, register route, start HTTP server |
+| `services/ibl_merge_report_service/handler.go` | `mergeRequest` struct, `mergeHandler`, validation, `writeError` |
+| `services/ibl_merge_report_service/handler_test.go` | Unit tests for all handler branches using a mock `mergeFunc` |
+| `services/ibl_merge_report_service/merger.go` | `fetchPDF`, `mergePDFs`, `fetchError` type |
+| `services/ibl_merge_report_service/merger_test.go` | httptest-based tests for `fetchPDF` error paths |
+| `scripts/build-merge-service.sh` | Cross-compile for Linux amd64, output binary to `up/` |
+| `services/ibl_merge_report_service/ibl-merge-report.service` | Systemd unit template for IBL server |
+
+---
+
+### Task 1: Scaffold — module init + empty stubs
+
+**Files:**
+- Create: `services/ibl_merge_report_service/go.mod`
+- Create: `services/ibl_merge_report_service/main.go`
+- Create: `services/ibl_merge_report_service/handler.go`
+- Create: `services/ibl_merge_report_service/merger.go`
+
+- [ ] **Step 1.1: Create go.mod**
+
+```bash
+mkdir -p /Users/fajrihardhitamurti/REPO_GITEA_IBL/BE_IBL/one-api-lab/services/ibl_merge_report_service
+```
+
+`services/ibl_merge_report_service/go.mod`:
+```
+module ibl-merge-report-service
+
+go 1.21
+```
+
+- [ ] **Step 1.2: Create handler.go stub**
+
+`services/ibl_merge_report_service/handler.go`:
+```go
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+)
+
+type mergeRequest struct {
+	Name           string   `json:"name"`
+	URLs           []string `json:"urls"`
+	MergeRequestID int64    `json:"mergeRequestID"`
+	TOrderHeaderID int64    `json:"T_OrderHeaderID"`
+}
+
+type mergeFunc func(urls []string) ([]byte, error)
+
+type mergeHandler struct {
+	secret string
+	merge  mergeFunc
+}
+
+func newMergeHandler(secret string, merge mergeFunc) http.Handler {
+	return &mergeHandler{secret: secret, merge: merge}
+}
+
+func (h *mergeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	// TODO: implement in Task 3
+	writeError(w, http.StatusNotImplemented, "not implemented")
+}
+
+func validateMergeRequest(req *mergeRequest) error {
+	// TODO: implement in Task 2
+	return nil
+}
+
+func writeError(w http.ResponseWriter, code int, msg string) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(code)
+	_ = json.NewEncoder(w).Encode(map[string]string{"error": msg})
+}
+
+// suppress unused-import errors until tasks fill in usage
+var _ = errors.As
+var _ = fmt.Errorf
+```
+
+- [ ] **Step 1.3: Create merger.go stub**
+
+`services/ibl_merge_report_service/merger.go`:
+```go
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+)
+
+var httpClient = &http.Client{Timeout: 25 * time.Second}
+
+type fetchError struct {
+	URL        string
+	HTTPStatus int // 0 = network/timeout
+}
+
+func (e *fetchError) Error() string {
+	if e.HTTPStatus != 0 {
+		return fmt.Sprintf("source %s returned HTTP %d", e.URL, e.HTTPStatus)
+	}
+	return fmt.Sprintf("failed to fetch source %s", e.URL)
+}
+
+func fetchPDF(url string) ([]byte, error) {
+	// TODO: implement in Task 4
+	return nil, fmt.Errorf("not implemented")
+}
+
+func mergePDFs(urls []string) ([]byte, error) {
+	// TODO: implement in Task 5
+	return nil, fmt.Errorf("not implemented")
+}
+```
+
+- [ ] **Step 1.4: Create main.go**
+
+`services/ibl_merge_report_service/main.go`:
+```go
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+)
+
+func main() {
+	secret := os.Getenv("MERGE_INTERNAL_SECRET")
+	if secret == "" {
+		secret = "ibl-merge-secret"
+	}
+	addr := os.Getenv("MERGE_LISTEN_ADDR")
+	if addr == "" {
+		addr = "127.0.0.1:8005"
+	}
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/merge", func(w http.ResponseWriter, r *http.Request) {
+		newMergeHandler(secret, mergePDFs).ServeHTTP(w, r)
+	})
+
+	log.Printf("ibl_merge_report_service listening on %s", addr)
+	if err := http.ListenAndServe(addr, mux); err != nil {
+		fmt.Fprintf(os.Stderr, "fatal: %v\n", err)
+		os.Exit(1)
+	}
+}
+```
+
+- [ ] **Step 1.5: Add pdfcpu dependency and verify build**
+
+```bash
+cd services/ibl_merge_report_service && go get github.com/pdfcpu/pdfcpu@latest && go mod tidy
+```
+
+```bash
+cd services/ibl_merge_report_service && go build ./...
+```
+
+Expected: builds without errors (stubs compile).
+
+---
+
+### Task 2: Validate request TDD
+
+**Files:**
+- Modify: `services/ibl_merge_report_service/handler.go` — implement `validateMergeRequest`
+- Create: `services/ibl_merge_report_service/handler_test.go`
+
+- [ ] **Step 2.1: Write failing tests for validateMergeRequest**
+
+`services/ibl_merge_report_service/handler_test.go`:
+```go
+package main
+
+import (
+	"testing"
+)
+
+func TestValidateMergeRequest_MissingName(t *testing.T) {
+	req := &mergeRequest{URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 1}
+	if err := validateMergeRequest(req); err == nil {
+		t.Fatal("expected error for missing name")
+	}
+}
+
+func TestValidateMergeRequest_EmptyURLs(t *testing.T) {
+	req := &mergeRequest{Name: "a.pdf", URLs: []string{}, MergeRequestID: 1, TOrderHeaderID: 1}
+	if err := validateMergeRequest(req); err == nil {
+		t.Fatal("expected error for empty urls")
+	}
+}
+
+func TestValidateMergeRequest_NilURLs(t *testing.T) {
+	req := &mergeRequest{Name: "a.pdf", URLs: nil, MergeRequestID: 1, TOrderHeaderID: 1}
+	if err := validateMergeRequest(req); err == nil {
+		t.Fatal("expected error for nil urls")
+	}
+}
+
+func TestValidateMergeRequest_MissingMergeRequestID(t *testing.T) {
+	req := &mergeRequest{Name: "a.pdf", URLs: []string{"http://x"}, MergeRequestID: 0, TOrderHeaderID: 1}
+	if err := validateMergeRequest(req); err == nil {
+		t.Fatal("expected error for missing mergeRequestID")
+	}
+}
+
+func TestValidateMergeRequest_MissingTOrderHeaderID(t *testing.T) {
+	req := &mergeRequest{Name: "a.pdf", URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 0}
+	if err := validateMergeRequest(req); err == nil {
+		t.Fatal("expected error for missing T_OrderHeaderID")
+	}
+}
+
+func TestValidateMergeRequest_Valid(t *testing.T) {
+	req := &mergeRequest{Name: "a.pdf", URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 1}
+	if err := validateMergeRequest(req); err != nil {
+		t.Fatalf("expected no error, got: %v", err)
+	}
+}
+```
+
+- [ ] **Step 2.2: Run tests — verify they fail**
+
+```bash
+cd services/ibl_merge_report_service && go test ./... -run TestValidate -v
+```
+
+Expected: `TestValidateMergeRequest_Valid` fails (stub returns nil for everything).
+
+- [ ] **Step 2.3: Implement validateMergeRequest**
+
+Replace the `validateMergeRequest` stub in `handler.go`:
+```go
+func validateMergeRequest(req *mergeRequest) error {
+	if req.Name == "" {
+		return fmt.Errorf("name is required")
+	}
+	if len(req.URLs) == 0 {
+		return fmt.Errorf("urls must not be empty")
+	}
+	if req.MergeRequestID <= 0 {
+		return fmt.Errorf("mergeRequestID is required")
+	}
+	if req.TOrderHeaderID <= 0 {
+		return fmt.Errorf("T_OrderHeaderID is required")
+	}
+	return nil
+}
+```
+
+Remove the now-unused stub lines at the bottom of handler.go:
+```go
+// Remove these two lines:
+var _ = errors.As
+var _ = fmt.Errorf
+```
+
+- [ ] **Step 2.4: Run tests — verify they pass**
+
+```bash
+cd services/ibl_merge_report_service && go test ./... -run TestValidate -v
+```
+
+Expected: all 6 `TestValidateMergeRequest_*` tests PASS.
+
+---
+
+### Task 3: Handler ServeHTTP TDD
+
+**Files:**
+- Modify: `services/ibl_merge_report_service/handler.go` — implement `ServeHTTP`
+- Modify: `services/ibl_merge_report_service/handler_test.go` — add handler tests
+
+- [ ] **Step 3.1: Write failing handler tests**
+
+Append to `handler_test.go`:
+```go
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+)
+
+func TestHandler_WrongMethod(t *testing.T) {
+	h := newMergeHandler("secret", nil)
+	req := httptest.NewRequest(http.MethodGet, "/merge", nil)
+	req.Header.Set("X-Internal-Secret", "secret")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusMethodNotAllowed {
+		t.Fatalf("expected 405, got %d", w.Code)
+	}
+}
+
+func TestHandler_WrongSecret(t *testing.T) {
+	h := newMergeHandler("correct", nil)
+	req := httptest.NewRequest(http.MethodPost, "/merge", bytes.NewBufferString("{}"))
+	req.Header.Set("X-Internal-Secret", "wrong")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusUnauthorized {
+		t.Fatalf("expected 401, got %d", w.Code)
+	}
+}
+
+func TestHandler_InvalidJSON(t *testing.T) {
+	h := newMergeHandler("s", nil)
+	req := httptest.NewRequest(http.MethodPost, "/merge", bytes.NewBufferString("{bad"))
+	req.Header.Set("X-Internal-Secret", "s")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusBadRequest {
+		t.Fatalf("expected 400, got %d", w.Code)
+	}
+}
+
+func TestHandler_ValidationError(t *testing.T) {
+	h := newMergeHandler("s", nil)
+	body, _ := json.Marshal(mergeRequest{Name: "", URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 1})
+	req := httptest.NewRequest(http.MethodPost, "/merge", bytes.NewBuffer(body))
+	req.Header.Set("X-Internal-Secret", "s")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusUnprocessableEntity {
+		t.Fatalf("expected 422, got %d", w.Code)
+	}
+}
+
+func TestHandler_FetchError404(t *testing.T) {
+	mockMerge := func(urls []string) ([]byte, error) {
+		return nil, &fetchError{URL: urls[0], HTTPStatus: http.StatusNotFound}
+	}
+	h := newMergeHandler("s", mockMerge)
+	body, _ := json.Marshal(mergeRequest{Name: "x.pdf", URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 1})
+	req := httptest.NewRequest(http.MethodPost, "/merge", bytes.NewBuffer(body))
+	req.Header.Set("X-Internal-Secret", "s")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusNotFound {
+		t.Fatalf("expected 404, got %d", w.Code)
+	}
+}
+
+func TestHandler_FetchErrorNetwork(t *testing.T) {
+	mockMerge := func(urls []string) ([]byte, error) {
+		return nil, &fetchError{URL: urls[0], HTTPStatus: 0}
+	}
+	h := newMergeHandler("s", mockMerge)
+	body, _ := json.Marshal(mergeRequest{Name: "x.pdf", URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 1})
+	req := httptest.NewRequest(http.MethodPost, "/merge", bytes.NewBuffer(body))
+	req.Header.Set("X-Internal-Secret", "s")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusBadGateway {
+		t.Fatalf("expected 502, got %d", w.Code)
+	}
+}
+
+func TestHandler_MergeError(t *testing.T) {
+	mockMerge := func(urls []string) ([]byte, error) {
+		return nil, fmt.Errorf("pdfcpu: corrupt PDF")
+	}
+	h := newMergeHandler("s", mockMerge)
+	body, _ := json.Marshal(mergeRequest{Name: "x.pdf", URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 1})
+	req := httptest.NewRequest(http.MethodPost, "/merge", bytes.NewBuffer(body))
+	req.Header.Set("X-Internal-Secret", "s")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusInternalServerError {
+		t.Fatalf("expected 500, got %d", w.Code)
+	}
+}
+
+func TestHandler_Success(t *testing.T) {
+	fakeBytes := []byte("%PDF-1.4 fake-merged")
+	mockMerge := func(urls []string) ([]byte, error) { return fakeBytes, nil }
+	h := newMergeHandler("s", mockMerge)
+	body, _ := json.Marshal(mergeRequest{
+		Name: "result.pdf", URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 1,
+	})
+	req := httptest.NewRequest(http.MethodPost, "/merge", bytes.NewBuffer(body))
+	req.Header.Set("X-Internal-Secret", "s")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+	if ct := w.Header().Get("Content-Type"); ct != "application/pdf" {
+		t.Fatalf("expected application/pdf, got %s", ct)
+	}
+	if !bytes.Equal(w.Body.Bytes(), fakeBytes) {
+		t.Fatal("response body does not match expected PDF bytes")
+	}
+}
+```
+
+The top of `handler_test.go` must have a single `import` block with all imports. Replace the import at the top of the file with:
+
+```go
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+```
+
+- [ ] **Step 3.2: Run tests — verify they fail**
+
+```bash
+cd services/ibl_merge_report_service && go test ./... -run TestHandler -v
+```
+
+Expected: all 8 `TestHandler_*` tests FAIL (stub returns 501).
+
+- [ ] **Step 3.3: Implement ServeHTTP**
+
+Replace the stub `ServeHTTP` in `handler.go` with:
+
+```go
+func (h *mergeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
+		return
+	}
+
+	if r.Header.Get("X-Internal-Secret") != h.secret {
+		writeError(w, http.StatusUnauthorized, "unauthorized")
+		return
+	}
+
+	var req mergeRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+
+	if err := validateMergeRequest(&req); err != nil {
+		writeError(w, http.StatusUnprocessableEntity, err.Error())
+		return
+	}
+
+	pdfBytes, err := h.merge(req.URLs)
+	if err != nil {
+		var fe *fetchError
+		if errors.As(err, &fe) {
+			if fe.HTTPStatus == http.StatusNotFound {
+				writeError(w, http.StatusNotFound, "source PDF not found")
+				return
+			}
+			writeError(w, http.StatusBadGateway, "source PDF unavailable")
+			return
+		}
+		writeError(w, http.StatusInternalServerError, "merge failed")
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/pdf")
+	w.Header().Set("Content-Disposition", `inline; filename="`+req.Name+`"`)
+	w.WriteHeader(http.StatusOK)
+	_, _ = w.Write(pdfBytes)
+}
+```
+
+- [ ] **Step 3.4: Run tests — verify all pass**
+
+```bash
+cd services/ibl_merge_report_service && go test ./... -run TestHandler -v
+```
+
+Expected: all 8 `TestHandler_*` tests PASS.
+
+- [ ] **Step 3.5: Commit**
+
+```bash
+cd /Users/fajrihardhitamurti/REPO_GITEA_IBL/BE_IBL/one-api-lab
+git add services/ibl_merge_report_service/
+git commit -m "TASKCODE - scaffold ibl_merge_report_service with handler logic and tests"
+```
+
+(Replace TASKCODE with the actual task code from user before committing.)
+
+---
+
+### Task 4: fetchPDF TDD
+
+**Files:**
+- Modify: `services/ibl_merge_report_service/merger.go` — implement `fetchPDF`
+- Create: `services/ibl_merge_report_service/merger_test.go`
+
+- [ ] **Step 4.1: Write failing fetchPDF tests**
+
+`services/ibl_merge_report_service/merger_test.go`:
+```go
+package main
+
+import (
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestFetchPDF_Returns404Error(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusNotFound)
+	}))
+	defer srv.Close()
+
+	_, err := fetchPDF(srv.URL)
+	if err == nil {
+		t.Fatal("expected error for 404 response")
+	}
+
+	var fe *fetchError
+	if !errors.As(err, &fe) {
+		t.Fatalf("expected *fetchError, got %T: %v", err, err)
+	}
+	if fe.HTTPStatus != http.StatusNotFound {
+		t.Fatalf("expected HTTPStatus 404, got %d", fe.HTTPStatus)
+	}
+}
+
+func TestFetchPDF_Returns500Error(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusInternalServerError)
+	}))
+	defer srv.Close()
+
+	_, err := fetchPDF(srv.URL)
+	if err == nil {
+		t.Fatal("expected error for 500 response")
+	}
+
+	var fe *fetchError
+	if !errors.As(err, &fe) {
+		t.Fatalf("expected *fetchError, got %T", err)
+	}
+	if fe.HTTPStatus != http.StatusInternalServerError {
+		t.Fatalf("expected HTTPStatus 500, got %d", fe.HTTPStatus)
+	}
+}
+
+func TestFetchPDF_ReturnsBytes(t *testing.T) {
+	expected := []byte("%PDF-1.4 test content")
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/pdf")
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write(expected)
+	}))
+	defer srv.Close()
+
+	got, err := fetchPDF(srv.URL)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if string(got) != string(expected) {
+		t.Fatalf("expected %q, got %q", expected, got)
+	}
+}
+
+func TestFetchPDF_NetworkError(t *testing.T) {
+	// Port that's almost certainly not listening
+	_, err := fetchPDF("http://127.0.0.1:19999/notexist")
+	if err == nil {
+		t.Fatal("expected error for unreachable host")
+	}
+	var fe *fetchError
+	if !errors.As(err, &fe) {
+		t.Fatalf("expected *fetchError, got %T: %v", err, err)
+	}
+	if fe.HTTPStatus != 0 {
+		t.Fatalf("expected HTTPStatus 0 for network error, got %d", fe.HTTPStatus)
+	}
+}
+```
+
+- [ ] **Step 4.2: Run tests — verify they fail**
+
+```bash
+cd services/ibl_merge_report_service && go test ./... -run TestFetchPDF -v
+```
+
+Expected: all 4 `TestFetchPDF_*` tests FAIL (stub returns generic error).
+
+- [ ] **Step 4.3: Implement fetchPDF**
+
+Replace the `fetchPDF` stub in `merger.go`:
+
+```go
+func fetchPDF(url string) ([]byte, error) {
+	resp, err := httpClient.Get(url)
+	if err != nil {
+		return nil, &fetchError{URL: url, HTTPStatus: 0}
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, &fetchError{URL: url, HTTPStatus: resp.StatusCode}
+	}
+
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, &fetchError{URL: url, HTTPStatus: 0}
+	}
+	return data, nil
+}
+```
+
+Add `"io"` to the import block in `merger.go`.
+
+- [ ] **Step 4.4: Run tests — verify all pass**
+
+```bash
+cd services/ibl_merge_report_service && go test ./... -run TestFetchPDF -v
+```
+
+Expected: all 4 `TestFetchPDF_*` tests PASS.
+
+---
+
+### Task 5: mergePDFs implementation
+
+**Files:**
+- Modify: `services/ibl_merge_report_service/merger.go` — implement `mergePDFs`
+
+No unit test is written for `mergePDFs` because testing requires valid PDF binaries which are awkward to embed. Error propagation from `fetchPDF` is already covered by `TestFetchPDF_*`. End-to-end correctness is verified manually in Task 8.
+
+- [ ] **Step 5.1: Implement mergePDFs**
+
+Replace the `mergePDFs` stub in `merger.go`:
+
+```go
+func mergePDFs(urls []string) ([]byte, error) {
+	readers := make([]io.ReadSeeker, 0, len(urls))
+	for _, url := range urls {
+		data, err := fetchPDF(url)
+		if err != nil {
+			return nil, err
+		}
+		readers = append(readers, bytes.NewReader(data))
+	}
+
+	var buf bytes.Buffer
+	if err := api.MergeRaw(readers, &buf, nil); err != nil {
+		return nil, fmt.Errorf("PDF merge error: %w", err)
+	}
+	return buf.Bytes(), nil
+}
+```
+
+Add `"bytes"` and `"github.com/pdfcpu/pdfcpu/pkg/api"` to the import block in `merger.go`.
+
+Remove the now-unused `"time"` import only if `httpClient` is still using it — keep `time` because `httpClient` uses `25 * time.Second`.
+
+The full import block for `merger.go` after this step:
+```go
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/pdfcpu/pdfcpu/pkg/api"
+)
+```
+
+- [ ] **Step 5.2: Run all tests**
+
+```bash
+cd services/ibl_merge_report_service && go test ./... -v
+```
+
+Expected: all previously passing tests still pass. No new tests in this task.
+
+- [ ] **Step 5.3: Build to verify no compile errors**
+
+```bash
+cd services/ibl_merge_report_service && go build ./...
+```
+
+Expected: compiles cleanly.
+
+- [ ] **Step 5.4: Commit**
+
+```bash
+cd /Users/fajrihardhitamurti/REPO_GITEA_IBL/BE_IBL/one-api-lab
+git add services/ibl_merge_report_service/
+git commit -m "TASKCODE - implement fetchPDF and mergePDFs"
+```
+
+---
+
+### Task 6: Deployment files
+
+**Files:**
+- Create: `scripts/build-merge-service.sh`
+- Create: `services/ibl_merge_report_service/ibl-merge-report.service`
+
+- [ ] **Step 6.1: Create build script**
+
+`scripts/build-merge-service.sh`:
+```bash
+#!/usr/bin/env bash
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+REPO_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
+SRC_DIR="$REPO_ROOT/services/ibl_merge_report_service"
+OUT_DIR="$REPO_ROOT/up"
+
+mkdir -p "$OUT_DIR"
+
+echo "Building ibl_merge_report_service for linux/amd64..."
+cd "$SRC_DIR"
+GOOS=linux GOARCH=amd64 go build -o "$OUT_DIR/ibl-merge-report-service" .
+echo "Binary written to: $OUT_DIR/ibl-merge-report-service"
+```
+
+Make executable:
+```bash
+chmod +x scripts/build-merge-service.sh
+```
+
+- [ ] **Step 6.2: Create systemd unit template**
+
+`services/ibl_merge_report_service/ibl-merge-report.service`:
+```ini
+[Unit]
+Description=IBL Merge Report Service
+After=network.target
+
+[Service]
+Type=simple
+User=one
+WorkingDirectory=/home/one/project/ibl_merge_report_service
+ExecStart=/home/one/project/ibl_merge_report_service/ibl-merge-report-service
+Environment=MERGE_LISTEN_ADDR=127.0.0.1:8005
+Environment=MERGE_INTERNAL_SECRET=REPLACE_WITH_VALUE_FROM_DB
+Restart=always
+RestartSec=5
+StandardOutput=journal
+StandardError=journal
+
+[Install]
+WantedBy=multi-user.target
+```
+
+`MERGE_INTERNAL_SECRET` must match the value of `S_SystemsMergeReportServiceSecret` in `conf_systems`.
+
+Deployment steps on IBL server:
+1. Build: `bash scripts/build-merge-service.sh`
+2. Copy binary: `scp -i /Users/fajrihardhitamurti/id_rsa up/ibl-merge-report-service one@10.9.20.31:/home/one/project/ibl_merge_report_service/`
+3. Copy unit file: `scp -i /Users/fajrihardhitamurti/id_rsa services/ibl_merge_report_service/ibl-merge-report.service one@10.9.20.31:/tmp/`
+4. On server: `sudo mv /tmp/ibl-merge-report.service /etc/systemd/system/`
+5. On server: edit `/etc/systemd/system/ibl-merge-report.service` to set the real `MERGE_INTERNAL_SECRET`
+6. On server: `sudo systemctl daemon-reload && sudo systemctl enable ibl-merge-report && sudo systemctl start ibl-merge-report`
+7. Verify: `sudo systemctl status ibl-merge-report`
+
+- [ ] **Step 6.3: Run build script to verify it compiles for Linux**
+
+```bash
+cd /Users/fajrihardhitamurti/REPO_GITEA_IBL/BE_IBL/one-api-lab && bash scripts/build-merge-service.sh
+```
+
+Expected: `up/ibl-merge-report-service` is created (Linux ELF binary).
+
+- [ ] **Step 6.4: Commit**
+
+```bash
+cd /Users/fajrihardhitamurti/REPO_GITEA_IBL/BE_IBL/one-api-lab
+git add scripts/build-merge-service.sh services/ibl_merge_report_service/ibl-merge-report.service up/ibl-merge-report-service
+git commit -m "TASKCODE - add build script and systemd unit for merge report service"
+```
+
+---
+
+### Task 7: Run all tests and final verification
+
+- [ ] **Step 7.1: Run full test suite**
+
+```bash
+cd services/ibl_merge_report_service && go test ./... -v
+```
+
+Expected: all tests pass. Final count: 6 `TestValidate*` + 8 `TestHandler*` + 4 `TestFetchPDF*` = 18 tests.
+
+- [ ] **Step 7.2: Run go vet**
+
+```bash
+cd services/ibl_merge_report_service && go vet ./...
+```
+
+Expected: no output (no issues).
+
+- [ ] **Step 7.3: Smoke test locally (macOS)**
+
+```bash
+cd services/ibl_merge_report_service && go run . &
+sleep 1
+curl -s -o /dev/null -w "%{http_code}" -X POST http://127.0.0.1:8005/merge \
+  -H "X-Internal-Secret: ibl-merge-secret" \
+  -H "Content-Type: application/json" \
+  -d '{"name":"test.pdf","urls":["http://127.0.0.1:9999/nope"],"mergeRequestID":1,"T_OrderHeaderID":1}'
+```
+
+Expected: HTTP `502` (source unavailable — correct error code for unreachable source).
+
+Kill background process: `kill %1`
+
+- [ ] **Step 7.4: Verify secret validation**
+
+```bash
+curl -s -o /dev/null -w "%{http_code}" -X POST http://127.0.0.1:8005/merge \
+  -H "X-Internal-Secret: wrong-secret" \
+  -H "Content-Type: application/json" \
+  -d '{}'
+```
+
+Expected: `401`.
+
+---
+
+## Error Code Reference
+
+| Go returns | PHP maps to | Meaning |
+|------------|------------|---------|
+| `401` | `MERGE_SERVICE_UNAUTHORIZED` | Bad secret |
+| `404` | `MERGE_SOURCE_NOT_FOUND` | Source PDF returned 404 |
+| `422` | `MERGE_SERVICE_REJECTED` | Validation error |
+| `500` | `MERGE_SERVICE_FAILED` | pdfcpu merge error |
+| `502` | `MERGE_SERVICE_FAILED` | Source fetch network/non-404 error |
+
+---
+
+## Self-Review: Spec Coverage
+
+- [x] Service listens on `127.0.0.1:8005` (configurable via `MERGE_LISTEN_ADDR`)
+- [x] `POST /merge` endpoint
+- [x] Validates `X-Internal-Secret` header → 401
+- [x] Validates JSON body fields (name, urls, mergeRequestID, T_OrderHeaderID) → 422
+- [x] Fetches each URL sequentially — if any fails, entire request fails
+- [x] Merges with pdfcpu, streams as `application/pdf`
+- [x] No cache / no file artifacts (in-memory only)
+- [x] Error responses use HTTP status codes that map correctly to PHP gateway error codes
+- [x] Build script for Linux amd64
+- [x] Systemd unit for IBL server deployment
diff --git a/scripts/build-merge-service.sh b/scripts/build-merge-service.sh
new file mode 100755
index 00000000..56def58c
--- /dev/null
+++ b/scripts/build-merge-service.sh
@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+REPO_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
+SRC_DIR="$REPO_ROOT/services/ibl_merge_report_service"
+OUT_DIR="$REPO_ROOT/build"
+
+mkdir -p "$OUT_DIR"
+
+echo "Building ibl_merge_report_service for linux/amd64..."
+cd "$SRC_DIR"
+GOOS=linux GOARCH=amd64 go build -o "$OUT_DIR/ibl-merge-report-service" .
+echo "Binary written to: $OUT_DIR/ibl-merge-report-service"
diff --git a/services/ibl_merge_report_service/go.mod b/services/ibl_merge_report_service/go.mod
new file mode 100644
index 00000000..24ea6b39
--- /dev/null
+++ b/services/ibl_merge_report_service/go.mod
@@ -0,0 +1,18 @@
+module ibl-merge-report-service
+
+go 1.24.0
+
+require github.com/pdfcpu/pdfcpu v0.11.1
+
+require (
+	github.com/clipperhouse/uax29/v2 v2.2.0 // indirect
+	github.com/hhrutter/lzw v1.0.0 // indirect
+	github.com/hhrutter/pkcs7 v0.2.0 // indirect
+	github.com/hhrutter/tiff v1.0.2 // indirect
+	github.com/mattn/go-runewidth v0.0.19 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	golang.org/x/crypto v0.43.0 // indirect
+	golang.org/x/image v0.32.0 // indirect
+	golang.org/x/text v0.30.0 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+)
diff --git a/services/ibl_merge_report_service/go.sum b/services/ibl_merge_report_service/go.sum
new file mode 100644
index 00000000..ca71ded3
--- /dev/null
+++ b/services/ibl_merge_report_service/go.sum
@@ -0,0 +1,24 @@
+github.com/clipperhouse/uax29/v2 v2.2.0 h1:ChwIKnQN3kcZteTXMgb1wztSgaU+ZemkgWdohwgs8tY=
+github.com/clipperhouse/uax29/v2 v2.2.0/go.mod h1:EFJ2TJMRUaplDxHKj1qAEhCtQPW2tJSwu5BF98AuoVM=
+github.com/hhrutter/lzw v1.0.0 h1:laL89Llp86W3rRs83LvKbwYRx6INE8gDn0XNb1oXtm0=
+github.com/hhrutter/lzw v1.0.0/go.mod h1:2HC6DJSn/n6iAZfgM3Pg+cP1KxeWc3ezG8bBqW5+WEo=
+github.com/hhrutter/pkcs7 v0.2.0 h1:i4HN2XMbGQpZRnKBLsUwO3dSckzgX142TNqY/KfXg+I=
+github.com/hhrutter/pkcs7 v0.2.0/go.mod h1:aEzKz0+ZAlz7YaEMY47jDHL14hVWD6iXt0AgqgAvWgE=
+github.com/hhrutter/tiff v1.0.2 h1:7H3FQQpKu/i5WaSChoD1nnJbGx4MxU5TlNqqpxw55z8=
+github.com/hhrutter/tiff v1.0.2/go.mod h1:pcOeuK5loFUE7Y/WnzGw20YxUdnqjY1P0Jlcieb/cCw=
+github.com/mattn/go-runewidth v0.0.19 h1:v++JhqYnZuu5jSKrk9RbgF5v4CGUjqRfBm05byFGLdw=
+github.com/mattn/go-runewidth v0.0.19/go.mod h1:XBkDxAl56ILZc9knddidhrOlY5R/pDhgLpndooCuJAs=
+github.com/pdfcpu/pdfcpu v0.11.1 h1:htHBSkGH5jMKWC6e0sihBFbcKZ8vG1M67c8/dJxhjas=
+github.com/pdfcpu/pdfcpu v0.11.1/go.mod h1:pP3aGga7pRvwFWAm9WwFvo+V68DfANi9kxSQYioNYcw=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+golang.org/x/crypto v0.43.0 h1:dduJYIi3A3KOfdGOHX8AVZ/jGiyPa3IbBozJ5kNuE04=
+golang.org/x/crypto v0.43.0/go.mod h1:BFbav4mRNlXJL4wNeejLpWxB7wMbc79PdRGhWKncxR0=
+golang.org/x/image v0.32.0 h1:6lZQWq75h7L5IWNk0r+SCpUJ6tUVd3v4ZHnbRKLkUDQ=
+golang.org/x/image v0.32.0/go.mod h1:/R37rrQmKXtO6tYXAjtDLwQgFLHmhW+V6ayXlxzP2Pc=
+golang.org/x/text v0.30.0 h1:yznKA/E9zq54KzlzBEAWn1NXSQ8DIp/NYMy88xJjl4k=
+golang.org/x/text v0.30.0/go.mod h1:yDdHFIX9t+tORqspjENWgzaCVXgk0yYnYuSZ8UzzBVM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
diff --git a/services/ibl_merge_report_service/handler.go b/services/ibl_merge_report_service/handler.go
new file mode 100644
index 00000000..58fbc3d6
--- /dev/null
+++ b/services/ibl_merge_report_service/handler.go
@@ -0,0 +1,91 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+)
+
+type mergeRequest struct {
+	Name           string   `json:"name"`
+	URLs           []string `json:"urls"`
+	MergeRequestID int64    `json:"mergeRequestID"`
+	TOrderHeaderID int64    `json:"T_OrderHeaderID"`
+}
+
+type mergeFunc func(urls []string) ([]byte, error)
+
+type mergeHandler struct {
+	secret string
+	merge  mergeFunc
+}
+
+func newMergeHandler(secret string, merge mergeFunc) http.Handler {
+	return &mergeHandler{secret: secret, merge: merge}
+}
+
+func (h *mergeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
+		return
+	}
+
+	if r.Header.Get("X-Internal-Secret") != h.secret {
+		writeError(w, http.StatusUnauthorized, "unauthorized")
+		return
+	}
+
+	var req mergeRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+
+	if err := validateMergeRequest(&req); err != nil {
+		writeError(w, http.StatusUnprocessableEntity, err.Error())
+		return
+	}
+
+	pdfBytes, err := h.merge(req.URLs)
+	if err != nil {
+		var fe *fetchError
+		if errors.As(err, &fe) {
+			if fe.HTTPStatus == http.StatusNotFound {
+				writeError(w, http.StatusNotFound, "source PDF not found")
+				return
+			}
+			writeError(w, http.StatusBadGateway, "source PDF unavailable")
+			return
+		}
+		writeError(w, http.StatusInternalServerError, "merge failed")
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/pdf")
+	w.Header().Set("Content-Disposition", `inline; filename="`+req.Name+`"`)
+	w.WriteHeader(http.StatusOK)
+	_, _ = w.Write(pdfBytes)
+}
+
+func validateMergeRequest(req *mergeRequest) error {
+	if req.Name == "" {
+		return fmt.Errorf("name is required")
+	}
+	if len(req.URLs) == 0 {
+		return fmt.Errorf("urls must not be empty")
+	}
+	if req.MergeRequestID <= 0 {
+		return fmt.Errorf("mergeRequestID is required")
+	}
+	if req.TOrderHeaderID <= 0 {
+		return fmt.Errorf("T_OrderHeaderID is required")
+	}
+	return nil
+}
+
+func writeError(w http.ResponseWriter, code int, msg string) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(code)
+	_ = json.NewEncoder(w).Encode(map[string]string{"error": msg})
+}
diff --git a/services/ibl_merge_report_service/handler_test.go b/services/ibl_merge_report_service/handler_test.go
new file mode 100644
index 00000000..fd069c79
--- /dev/null
+++ b/services/ibl_merge_report_service/handler_test.go
@@ -0,0 +1,164 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestValidateMergeRequest_MissingName(t *testing.T) {
+	req := &mergeRequest{URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 1}
+	if err := validateMergeRequest(req); err == nil {
+		t.Fatal("expected error for missing name")
+	}
+}
+
+func TestValidateMergeRequest_EmptyURLs(t *testing.T) {
+	req := &mergeRequest{Name: "a.pdf", URLs: []string{}, MergeRequestID: 1, TOrderHeaderID: 1}
+	if err := validateMergeRequest(req); err == nil {
+		t.Fatal("expected error for empty urls")
+	}
+}
+
+func TestValidateMergeRequest_NilURLs(t *testing.T) {
+	req := &mergeRequest{Name: "a.pdf", URLs: nil, MergeRequestID: 1, TOrderHeaderID: 1}
+	if err := validateMergeRequest(req); err == nil {
+		t.Fatal("expected error for nil urls")
+	}
+}
+
+func TestValidateMergeRequest_MissingMergeRequestID(t *testing.T) {
+	req := &mergeRequest{Name: "a.pdf", URLs: []string{"http://x"}, MergeRequestID: 0, TOrderHeaderID: 1}
+	if err := validateMergeRequest(req); err == nil {
+		t.Fatal("expected error for missing mergeRequestID")
+	}
+}
+
+func TestValidateMergeRequest_MissingTOrderHeaderID(t *testing.T) {
+	req := &mergeRequest{Name: "a.pdf", URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 0}
+	if err := validateMergeRequest(req); err == nil {
+		t.Fatal("expected error for missing T_OrderHeaderID")
+	}
+}
+
+func TestValidateMergeRequest_Valid(t *testing.T) {
+	req := &mergeRequest{Name: "a.pdf", URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 1}
+	if err := validateMergeRequest(req); err != nil {
+		t.Fatalf("expected no error, got: %v", err)
+	}
+}
+
+func TestHandler_WrongMethod(t *testing.T) {
+	h := newMergeHandler("secret", nil)
+	req := httptest.NewRequest(http.MethodGet, "/merge", nil)
+	req.Header.Set("X-Internal-Secret", "secret")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusMethodNotAllowed {
+		t.Fatalf("expected 405, got %d", w.Code)
+	}
+}
+
+func TestHandler_WrongSecret(t *testing.T) {
+	h := newMergeHandler("correct", nil)
+	req := httptest.NewRequest(http.MethodPost, "/merge", bytes.NewBufferString("{}"))
+	req.Header.Set("X-Internal-Secret", "wrong")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusUnauthorized {
+		t.Fatalf("expected 401, got %d", w.Code)
+	}
+}
+
+func TestHandler_InvalidJSON(t *testing.T) {
+	h := newMergeHandler("s", nil)
+	req := httptest.NewRequest(http.MethodPost, "/merge", bytes.NewBufferString("{bad"))
+	req.Header.Set("X-Internal-Secret", "s")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusBadRequest {
+		t.Fatalf("expected 400, got %d", w.Code)
+	}
+}
+
+func TestHandler_ValidationError(t *testing.T) {
+	h := newMergeHandler("s", nil)
+	body, _ := json.Marshal(mergeRequest{Name: "", URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 1})
+	req := httptest.NewRequest(http.MethodPost, "/merge", bytes.NewBuffer(body))
+	req.Header.Set("X-Internal-Secret", "s")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusUnprocessableEntity {
+		t.Fatalf("expected 422, got %d", w.Code)
+	}
+}
+
+func TestHandler_FetchError404(t *testing.T) {
+	mockMerge := func(urls []string) ([]byte, error) {
+		return nil, &fetchError{URL: urls[0], HTTPStatus: http.StatusNotFound}
+	}
+	h := newMergeHandler("s", mockMerge)
+	body, _ := json.Marshal(mergeRequest{Name: "x.pdf", URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 1})
+	req := httptest.NewRequest(http.MethodPost, "/merge", bytes.NewBuffer(body))
+	req.Header.Set("X-Internal-Secret", "s")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusNotFound {
+		t.Fatalf("expected 404, got %d", w.Code)
+	}
+}
+
+func TestHandler_FetchErrorNetwork(t *testing.T) {
+	mockMerge := func(urls []string) ([]byte, error) {
+		return nil, &fetchError{URL: urls[0], HTTPStatus: 0}
+	}
+	h := newMergeHandler("s", mockMerge)
+	body, _ := json.Marshal(mergeRequest{Name: "x.pdf", URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 1})
+	req := httptest.NewRequest(http.MethodPost, "/merge", bytes.NewBuffer(body))
+	req.Header.Set("X-Internal-Secret", "s")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusBadGateway {
+		t.Fatalf("expected 502, got %d", w.Code)
+	}
+}
+
+func TestHandler_MergeError(t *testing.T) {
+	mockMerge := func(urls []string) ([]byte, error) {
+		return nil, fmt.Errorf("pdfcpu: corrupt PDF")
+	}
+	h := newMergeHandler("s", mockMerge)
+	body, _ := json.Marshal(mergeRequest{Name: "x.pdf", URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 1})
+	req := httptest.NewRequest(http.MethodPost, "/merge", bytes.NewBuffer(body))
+	req.Header.Set("X-Internal-Secret", "s")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusInternalServerError {
+		t.Fatalf("expected 500, got %d", w.Code)
+	}
+}
+
+func TestHandler_Success(t *testing.T) {
+	fakeBytes := []byte("%PDF-1.4 fake-merged")
+	mockMerge := func(urls []string) ([]byte, error) { return fakeBytes, nil }
+	h := newMergeHandler("s", mockMerge)
+	body, _ := json.Marshal(mergeRequest{
+		Name: "result.pdf", URLs: []string{"http://x"}, MergeRequestID: 1, TOrderHeaderID: 1,
+	})
+	req := httptest.NewRequest(http.MethodPost, "/merge", bytes.NewBuffer(body))
+	req.Header.Set("X-Internal-Secret", "s")
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+	if ct := w.Header().Get("Content-Type"); ct != "application/pdf" {
+		t.Fatalf("expected application/pdf, got %s", ct)
+	}
+	if !bytes.Equal(w.Body.Bytes(), fakeBytes) {
+		t.Fatal("response body does not match expected PDF bytes")
+	}
+}
diff --git a/services/ibl_merge_report_service/ibl-merge-report.service b/services/ibl_merge_report_service/ibl-merge-report.service
new file mode 100644
index 00000000..37fc863f
--- /dev/null
+++ b/services/ibl_merge_report_service/ibl-merge-report.service
@@ -0,0 +1,18 @@
+[Unit]
+Description=IBL Merge Report Service
+After=network.target
+
+[Service]
+Type=simple
+User=one
+WorkingDirectory=/home/one/project/ibl_merge_report_service
+ExecStart=/home/one/project/ibl_merge_report_service/ibl-merge-report-service
+Environment=MERGE_LISTEN_ADDR=127.0.0.1:8005
+Environment=MERGE_INTERNAL_SECRET=REPLACE_WITH_VALUE_FROM_DB
+Restart=always
+RestartSec=5
+StandardOutput=journal
+StandardError=journal
+
+[Install]
+WantedBy=multi-user.target
diff --git a/services/ibl_merge_report_service/main.go b/services/ibl_merge_report_service/main.go
new file mode 100644
index 00000000..f34d9d44
--- /dev/null
+++ b/services/ibl_merge_report_service/main.go
@@ -0,0 +1,30 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+)
+
+func main() {
+	secret := os.Getenv("MERGE_INTERNAL_SECRET")
+	if secret == "" {
+		secret = "ibl-merge-secret"
+	}
+	addr := os.Getenv("MERGE_LISTEN_ADDR")
+	if addr == "" {
+		addr = "127.0.0.1:8005"
+	}
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/merge", func(w http.ResponseWriter, r *http.Request) {
+		newMergeHandler(secret, mergePDFs).ServeHTTP(w, r)
+	})
+
+	log.Printf("ibl_merge_report_service listening on %s", addr)
+	if err := http.ListenAndServe(addr, mux); err != nil {
+		fmt.Fprintf(os.Stderr, "fatal: %v\n", err)
+		os.Exit(1)
+	}
+}
diff --git a/services/ibl_merge_report_service/merger.go b/services/ibl_merge_report_service/merger.go
new file mode 100644
index 00000000..bba86216
--- /dev/null
+++ b/services/ibl_merge_report_service/merger.go
@@ -0,0 +1,60 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/pdfcpu/pdfcpu/pkg/api"
+)
+
+var httpClient = &http.Client{Timeout: 25 * time.Second}
+
+type fetchError struct {
+	URL        string
+	HTTPStatus int // 0 = network/timeout
+}
+
+func (e *fetchError) Error() string {
+	if e.HTTPStatus != 0 {
+		return fmt.Sprintf("source %s returned HTTP %d", e.URL, e.HTTPStatus)
+	}
+	return fmt.Sprintf("failed to fetch source %s", e.URL)
+}
+
+func fetchPDF(url string) ([]byte, error) {
+	resp, err := httpClient.Get(url)
+	if err != nil {
+		return nil, &fetchError{URL: url, HTTPStatus: 0}
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, &fetchError{URL: url, HTTPStatus: resp.StatusCode}
+	}
+
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, &fetchError{URL: url, HTTPStatus: 0}
+	}
+	return data, nil
+}
+
+func mergePDFs(urls []string) ([]byte, error) {
+	readers := make([]io.ReadSeeker, 0, len(urls))
+	for _, url := range urls {
+		data, err := fetchPDF(url)
+		if err != nil {
+			return nil, err
+		}
+		readers = append(readers, bytes.NewReader(data))
+	}
+
+	var buf bytes.Buffer
+	if err := api.MergeRaw(readers, &buf, false, nil); err != nil {
+		return nil, fmt.Errorf("PDF merge error: %w", err)
+	}
+	return buf.Bytes(), nil
+}
diff --git a/services/ibl_merge_report_service/merger_test.go b/services/ibl_merge_report_service/merger_test.go
new file mode 100644
index 00000000..af6a44ea
--- /dev/null
+++ b/services/ibl_merge_report_service/merger_test.go
@@ -0,0 +1,81 @@
+package main
+
+import (
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestFetchPDF_Returns404Error(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusNotFound)
+	}))
+	defer srv.Close()
+
+	_, err := fetchPDF(srv.URL)
+	if err == nil {
+		t.Fatal("expected error for 404 response")
+	}
+
+	var fe *fetchError
+	if !errors.As(err, &fe) {
+		t.Fatalf("expected *fetchError, got %T: %v", err, err)
+	}
+	if fe.HTTPStatus != http.StatusNotFound {
+		t.Fatalf("expected HTTPStatus 404, got %d", fe.HTTPStatus)
+	}
+}
+
+func TestFetchPDF_Returns500Error(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusInternalServerError)
+	}))
+	defer srv.Close()
+
+	_, err := fetchPDF(srv.URL)
+	if err == nil {
+		t.Fatal("expected error for 500 response")
+	}
+
+	var fe *fetchError
+	if !errors.As(err, &fe) {
+		t.Fatalf("expected *fetchError, got %T", err)
+	}
+	if fe.HTTPStatus != http.StatusInternalServerError {
+		t.Fatalf("expected HTTPStatus 500, got %d", fe.HTTPStatus)
+	}
+}
+
+func TestFetchPDF_ReturnsBytes(t *testing.T) {
+	expected := []byte("%PDF-1.4 test content")
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/pdf")
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write(expected)
+	}))
+	defer srv.Close()
+
+	got, err := fetchPDF(srv.URL)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if string(got) != string(expected) {
+		t.Fatalf("expected %q, got %q", expected, got)
+	}
+}
+
+func TestFetchPDF_NetworkError(t *testing.T) {
+	// Port that's almost certainly not listening
+	_, err := fetchPDF("http://127.0.0.1:19999/notexist")
+	if err == nil {
+		t.Fatal("expected error for unreachable host")
+	}
+	var fe *fetchError
+	if !errors.As(err, &fe) {
+		t.Fatalf("expected *fetchError, got %T: %v", err, err)
+	}
+	if fe.HTTPStatus != 0 {
+		t.Fatalf("expected HTTPStatus 0 for network error, got %d", fe.HTTPStatus)
+	}
+}