chore(release): prepare for v0.7.1

## [0.7.0] - 2026-09-16

### 🐛 Bug Fixes

- [**breaking**] Order privilege events by sequence number and merge snapshots by position (#333)

<!-- generated by git-cliff -->

---

**Note:** Please use **Squash Merge** when merging this PR.

Reviewed-on: https://gitea.unbound.se/shiny/authz_client/pulls/334
Co-authored-by: Unbound Releaser <releaser@unbound.se>

.gitea/workflows/ci.yaml

@@ -10,18 +10,69 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-go@v6
+      - uses: actions/checkout@v7
+      - uses: actions/setup-go@v7
         with:
           go-version: 'stable'
       - name: Run tests
         run: go test -race -coverprofile=coverage.txt ./...
 
+      - name: Check coverage
+        id: coverage
+        run: |
+          go install github.com/vladopajic/go-test-coverage/v2@latest
+          go-test-coverage --config ./.testcoverage.yml --github-action-output
+      - name: Download baseline coverage
+        if: gitea.event_name == 'pull_request'
+        uses: actions/download-artifact@v3
+        with:
+          name: coverage-baseline
+          path: ./baseline
+        continue-on-error: true
+      - name: Compare coverage
+        if: gitea.event_name == 'pull_request'
+        run: |
+          CURRENT="${{ steps.coverage.outputs.total-coverage }}"
+          if [ -f ./baseline/coverage.txt ]; then
+            BASE=$(cat ./baseline/coverage.txt)
+            echo "Base coverage: ${BASE}%"
+            echo "Current coverage: ${CURRENT}%"
+            if [ "$(echo "$CURRENT < $BASE" | bc -l)" -eq 1 ]; then
+              echo "::error::Coverage decreased from ${BASE}% to ${CURRENT}%"
+              exit 1
+            fi
+            echo "Coverage maintained or improved: ${BASE}% -> ${CURRENT}%"
+          else
+            echo "No baseline coverage found, skipping comparison"
+            echo "Current coverage: ${CURRENT}%"
+          fi
+      - name: Save coverage baseline
+        if: gitea.ref == 'refs/heads/main'
+        run: echo "${{ steps.coverage.outputs.total-coverage }}" > coverage.txt
+      - name: Upload coverage baseline
+        if: gitea.ref == 'refs/heads/main'
+        uses: actions/upload-artifact@v3
+        with:
+          name: coverage-baseline
+          path: coverage.txt
+          retention-days: 90
+      - name: Post coverage comment
+        if: gitea.event_name == 'pull_request'
+        env:
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
+          GITEA_URL: ${{ gitea.server_url }}
+        run: |
+          COVERAGE="${{ steps.coverage.outputs.total-coverage }}"
+          curl -X POST "${GITEA_URL}/api/v1/repos/${{ gitea.repository }}/issues/${{ gitea.event.pull_request.number }}/comments" \
+            -H "Authorization: token ${GITEA_TOKEN}" \
+            -H "Content-Type: application/json" \
+            -d "{\"body\": \"## Coverage Report\n\nTotal coverage: **${COVERAGE}%**\"}"
+
   vulnerabilities:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-go@v6
+      - uses: actions/checkout@v7
+      - uses: actions/setup-go@v7
         with:
           go-version: 'stable'
       - name: Check vulnerabilities

.gitea/workflows/pre-commit.yaml

@@ -13,11 +13,11 @@ jobs:
     env:
       SKIP: no-commit-to-branch
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-go@v6
+      - uses: actions/checkout@v7
+      - uses: actions/setup-go@v7
         with:
           go-version: stable
-      - uses: actions/setup-python@v6
+      - uses: actions/setup-python@v7
         with:
           python-version: '3.14'
       - name: Install goimports

.gitlab-ci.yml

@@ -1,38 +0,0 @@
-include:
-- template: 'Workflows/MergeRequest-Pipelines.gitlab-ci.yml'
-- project: unboundsoftware/ci-templates
-  file: Defaults.gitlab-ci.yml
-- project: unboundsoftware/ci-templates
-  file: Release.gitlab-ci.yml
-- project: unboundsoftware/ci-templates
-  file: Pre-Commit-Go.gitlab-ci.yml
-
-image: amd64/golang:1.25.5@sha256:ad03ba93327b8a6143b49373790b5d92c28067bdb814418509466122ee9c9e63
-
-stages:
-- deps
-- test
-
-deps:
-  stage: deps
-  script:
-  - go mod download
-
-test:
-  stage: test
-  dependencies:
-  - deps
-  script:
-  - CGO_ENABLED=1 go test -mod=readonly -race -coverprofile=coverage.txt -covermode=atomic -coverpkg=$(go list ./... | tr '\n' , | sed 's/,$//') ./...
-  - go tool cover -html=coverage.txt -o coverage.html
-  - go tool cover -func=coverage.txt
-  - curl -Os https://uploader.codecov.io/latest/linux/codecov
-  - chmod +x codecov
-  - ./codecov -t ${CODECOV_TOKEN} -R $CI_PROJECT_DIR -C $CI_COMMIT_SHA -r $CI_PROJECT_PATH
-
-vulnerabilities:
-  stage: test
-  image: amd64/golang:1.25.5@sha256:ad03ba93327b8a6143b49373790b5d92c28067bdb814418509466122ee9c9e63
-  script:
-  - go install golang.org/x/vuln/cmd/govulncheck@latest
-  - govulncheck ./...

.pre-commit-config.yaml

@@ -11,7 +11,7 @@ repos:
     - --allow-multiple-documents
   - id: check-added-large-files
 - repo: https://github.com/alessandrojcm/commitlint-pre-commit-hook
-  rev: v9.23.0
+  rev: v9.27.0
   hooks:
   - id: commitlint
     stages: [ commit-msg ]
@@ -30,10 +30,10 @@ repos:
   - id: go-test
   - id: gofumpt
 - repo: https://github.com/golangci/golangci-lint
-  rev: v2.8.0
+  rev: v2.14.0
   hooks:
   - id: golangci-lint-full
 - repo: https://github.com/gitleaks/gitleaks
-  rev: v8.30.0
+  rev: v8.30.1
   hooks:
   - id: gitleaks

.testcoverage.yml

@@ -0,0 +1,13 @@
+# Coverage configuration for go-test-coverage
+# https://github.com/vladopajic/go-test-coverage
+
+profile: coverage.txt
+
+threshold:
+  file: 0
+  package: 0
+  total: 0
+
+exclude:
+  paths:
+    - _test\.go$

.version

@@ -1,3 +1,3 @@
 {
-  "version": "v0.4.1"
+  "version": "v0.7.1"
 }

CHANGELOG.md

@@ -2,6 +2,92 @@
 
 All notable changes to this project will be documented in this file.
 
+## [0.7.1] - 2026-10-05
+
+### 🐛 Bug Fixes
+
+- *(deps)* Update module codeberg.org/messaging/go-messaging-amqp to v0.0.6 (#337)
+
+### 📚 Documentation
+
+- Deploy authz-service first when the /authz contract changes (#335)
+
+### ⚙️ Miscellaneous Tasks
+
+- *(deps)* Update pre-commit hook alessandrojcm/commitlint-pre-commit-hook to v9.27.0 (#339)
+- *(deps)* Update pre-commit hook golangci/golangci-lint to v2.14.0 (#341)
+- *(renovate)* Group OpenTelemetry, otelsetup and logging updates (#343)
+
+## [0.7.0] - 2026-09-16
+
+### 🐛 Bug Fixes
+
+- [**breaking**] Order privilege events by sequence number and merge snapshots by position (#333)
+
+## [0.6.1] - 2026-09-16
+
+### 🐛 Bug Fixes
+
+- Keep existing privileges when User.Added is processed late (#331)
+
+## [0.6.0] - 2026-09-14
+
+### 🚀 Features
+
+- [**breaking**] Consume privilege events with go-messaging-amqp (#327)
+
+### ⚙️ Miscellaneous Tasks
+
+- *(deps)* Update pre-commit hook golangci/golangci-lint to v2.13.2 (#325)
+- Bump the minor version for breaking changes before 1.0.0 (#328)
+
+## [0.5.1] - 2026-08-29
+
+### 🐛 Bug Fixes
+
+- *(ci)* Use go-test-coverage binary directly to fix Gitea Actions (#303)
+- *(deps)* Update module github.com/stretchr/testify to v1.12.0 (#319)
+- *(deps)* Update module github.com/stretchr/testify to v1.12.1 (#321)
+
+### ⚙️ Miscellaneous Tasks
+
+- *(deps)* Update pre-commit hook gitleaks/gitleaks to v8.30.1 (#296)
+- *(deps)* Update pre-commit hook golangci/golangci-lint to v2.11.4 (#298)
+- *(deps)* Update dependency go to v1.26.2 (#300)
+- *(deps)* Update pre-commit hook alessandrojcm/commitlint-pre-commit-hook to v9.25.0 (#304)
+- *(deps)* Update pre-commit hook golangci/golangci-lint to v2.12.0 (#306)
+- *(deps)* Update pre-commit hook golangci/golangci-lint to v2.12.1 (#308)
+- *(deps)* Update pre-commit hook golangci/golangci-lint to v2.12.2 (#309)
+- *(deps)* Update actions/checkout action to v7 (#311)
+- *(deps)* Update pre-commit hook alessandrojcm/commitlint-pre-commit-hook to v9.26.0 (#313)
+- *(deps)* Update actions/setup-go action to v7 (#315)
+- *(deps)* Update actions/setup-python action to v7 (#317)
+- *(deps)* Update pre-commit hook golangci/golangci-lint to v2.13.1 (#322)
+
+## [0.5.0] - 2026-03-12
+
+### 🚀 Features
+
+- *(client)* Add API key authentication for /authz endpoint (#294)
+
+### ⚙️ Miscellaneous Tasks
+
+- *(deps)* Update golang:1.25.5 docker digest to 3a01526 (#271)
+- *(deps)* Update pre-commit hook alessandrojcm/commitlint-pre-commit-hook to v9.24.0 (#273)
+- *(deps)* Update dependency go to v1.25.6 (#274)
+- *(deps)* Update golang docker tag to v1.25.6 (#275)
+- Remove GitLab CI configuration
+- Add code coverage integration
+- *(deps)* Update dependency go to v1.25.7 (#279)
+- *(deps)* Update dependency go to v1.26.0 (#280)
+- *(deps)* Update pre-commit hook golangci/golangci-lint to v2.9.0 (#281)
+- *(deps)* Update pre-commit hook golangci/golangci-lint to v2.10.0 (#282)
+- *(deps)* Update pre-commit hook golangci/golangci-lint to v2.10.1 (#283)
+- *(deps)* Update dependency go to v1.26.1 (#286)
+- *(deps)* Update pre-commit hook golangci/golangci-lint to v2.11.1 (#288)
+- *(deps)* Update pre-commit hook golangci/golangci-lint to v2.11.2 (#290)
+- *(deps)* Update pre-commit hook golangci/golangci-lint to v2.11.3 (#292)
+
 ## [0.4.1] - 2026-01-09
 
 ### ⚙️ Miscellaneous Tasks

CLAUDE.md

@@ -23,10 +23,9 @@ import client "gitea.unbound.se/shiny/authz_client"
 handler := client.New(client.WithBaseURL("http://authz-service"))
 
 // Check user privileges
-privileges := handler.Get(email, companyID)
-if privileges.Invoicing {
-    // User has invoicing privileges
-}
+allowed := handler.IsAllowed(email, companyID, func(p client.CompanyPrivileges) bool {
+    return p.Invoicing
+})
 ```
 
 ### Privileges
@@ -43,4 +42,10 @@ The `CompanyPrivileges` struct contains permission flags:
 
 ### Event Handling
 
-Implements `goamqp` message handlers to receive privilege update events from the authz-service, keeping the local privilege cache up-to-date.
+Registers per-replica (transient) go-messaging-amqp consumers for privilege events from authz-service (`Setup()`). Each routing key gets its own queue, so events arrive in any order. `Process` orders them by the `sequenceNo` authz-service's event store stamps on every event: all four events come from authz-service's `Company` aggregate, so the global sequence number orders them within a company. Each (email, company) keeps the sequence number of the last fact about membership and about each privilege; an event only overrides older facts. `User.Removed` stamps every privilege, so a late grant can't come back. An event without `sequenceNo` fails closed: additions are dropped, and removals apply and block every later event for those facts until the next snapshot. An event with a negative or implausibly large `sequenceNo` is dropped. Tests that seed the handler must set `SequenceNo`.
+
+### Startup
+
+Call `Fetch()` **after** `conn.Start` (consumers bound), never before: events published between the snapshot and the binding would otherwise be lost. authz-service only serves a snapshot whose read view has applied every stored event. It sends that position in the `X-Authz-Sequence` header and answers 503 while the read view lags (backlog, backfill, reset); `Fetch` retries 503 for about a minute. `Fetch` merges the snapshot as facts at that sequence number (newer event facts win, pairs missing from the snapshot are removed) and drops later events at or below it. A snapshot older than one already merged is ignored, so concurrent or repeated fetches are safe. A snapshot without the header merges at 0 and logs a warning (rollout window only). When the `/authz` contract changes, deploy authz-service before the services that use this library.
+
+Don't combine `Setup()` with go-messaging-amqp's `WithReconnect`: a reconnect declares new per-replica queues, so revocations published during the outage are lost unless `Fetch()` runs again. Services exit on connection loss (`CloseListener`) and re-fetch on start.

client.go

@@ -1,16 +1,31 @@
 package client
 
 import (
+	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
+	"log/slog"
+	"math"
 	"net/http"
 	"reflect"
+	"strconv"
 	"sync"
+	"time"
 
-	"github.com/sparetimecoders/goamqp"
+	goamqp "codeberg.org/messaging/go-messaging-amqp"
+	spec "codeberg.org/messaging/messaging"
 )
 
+// SequenceHeader carries the global sequence number of the authz-service read view the
+// /authz snapshot was read at.
+const SequenceHeader = "X-Authz-Sequence"
+
+// pending marks a fact cleared by an event without a sequence number. No event can
+// override it; only a snapshot can.
+const pending = math.MaxInt
+
 // CompanyPrivileges contains the privileges for a combination of email address and company id
 type CompanyPrivileges struct {
 	Admin      bool `json:"admin"`
@@ -23,12 +38,84 @@ type CompanyPrivileges struct {
 	Salary     bool `json:"salary"`
 }
 
+// field returns the flag for privilege, or nil for an unknown privilege.
+func (c *CompanyPrivileges) field(privilege Privilege) *bool {
+	switch privilege {
+	case PrivilegeAdmin:
+		return &c.Admin
+	case PrivilegeCompany:
+		return &c.Company
+	case PrivilegeConsumer:
+		return &c.Consumer
+	case PrivilegeTime:
+		return &c.Time
+	case PrivilegeInvoicing:
+		return &c.Invoicing
+	case PrivilegeAccounting:
+		return &c.Accounting
+	case PrivilegeSupplier:
+		return &c.Supplier
+	case PrivilegeSalary:
+		return &c.Salary
+	}
+	return nil
+}
+
+// companyState is what the handler knows about one email in one company. Every
+// privilege event for a company comes from authz-service's Company aggregate, so
+// its global sequence number orders the events for the pair. The four routing
+// keys arrive on separate queues in any order; a fact is only overwritten by a
+// fact with a higher sequence number.
+type companyState struct {
+	privileges CompanyPrivileges
+	// privilegeSeq is the sequence number of the last fact about each privilege.
+	privilegeSeq map[Privilege]int
+	// member is whether the user belongs to the company, as of memberSeq. A
+	// User.Removed stamps every privilege with its sequence number, so a grant
+	// older than the removal can't come back.
+	member    bool
+	memberSeq int
+}
+
+func newCompanyState() *companyState {
+	return &companyState{privilegeSeq: map[Privilege]int{}}
+}
+
+// clearPending turns facts cleared without a sequence number into unordered facts, so
+// the snapshot being merged replaces them.
+func (s *companyState) clearPending() {
+	if s.memberSeq == pending {
+		s.memberSeq = 0
+	}
+	for p, seq := range s.privilegeSeq {
+		if seq == pending {
+			s.privilegeSeq[p] = 0
+		}
+	}
+}
+
+// maxSeq is the highest sequence number of any fact in the state.
+func (s *companyState) maxSeq() int {
+	m := s.memberSeq
+	for _, seq := range s.privilegeSeq {
+		m = max(m, seq)
+	}
+	return m
+}
+
 // PrivilegeHandler processes PrivilegeAdded-events and fetches the initial set of privileges from an authz-service
 type PrivilegeHandler struct {
 	*sync.RWMutex
-	client     *http.Client
-	baseURL    string
-	privileges map[string]map[string]*CompanyPrivileges
+	client  *http.Client
+	baseURL string
+	apiKey  string
+	state   map[string]map[string]*companyState
+	// floor is the sequence number of the newest snapshot. Its effects are all in
+	// the state, so an event at or below it is stale.
+	floor int
+	// retries is how many times Fetch retries a snapshot authz-service isn't ready to serve.
+	retries    int
+	retryDelay time.Duration
 }
 
 // OptsFunc is used to configure the PrivilegeHandler
@@ -41,13 +128,22 @@ func WithBaseURL(url string) OptsFunc {
 	}
 }
 
+// WithAPIKey sets an API key used as a Bearer token when fetching privileges
+func WithAPIKey(key string) OptsFunc {
+	return func(handler *PrivilegeHandler) {
+		handler.apiKey = key
+	}
+}
+
 // New creates a new PrivilegeHandler. Pass OptsFuncs to configure.
 func New(opts ...OptsFunc) *PrivilegeHandler {
 	handler := &PrivilegeHandler{
 		RWMutex:    &sync.RWMutex{},
-		client:     &http.Client{},
+		client:     &http.Client{Timeout: 30 * time.Second},
 		baseURL:    "http://authz-service",
-		privileges: map[string]map[string]*CompanyPrivileges{},
+		state:      map[string]map[string]*companyState{},
+		retries:    60,
+		retryDelay: time.Second,
 	}
 	for _, opt := range opts {
 		opt(handler)
@@ -55,101 +151,250 @@ func New(opts ...OptsFunc) *PrivilegeHandler {
 	return handler
 }
 
-// Fetch the initial set of privileges from an authz-service
+// Fetch a snapshot of all privileges from an authz-service and merge it into the state.
+//
+// Call it after the AMQP connection has started: authz-service only serves a snapshot
+// that includes every stored event, so together with the bound queues no event is
+// missed. While its read view is behind it answers 503, and Fetch retries. The snapshot
+// is applied as facts at its sequence number: a fact from an event newer than the
+// snapshot is kept, everything else is replaced, and a pair missing from the snapshot is
+// removed. A snapshot older than one already merged is ignored.
 func (h *PrivilegeHandler) Fetch() error {
-	resp, err := h.client.Get(fmt.Sprintf("%s/authz", h.baseURL))
+	for attempt := 0; ; attempt++ {
+		err := h.fetch()
+		if !errors.Is(err, errNotReady) || attempt >= h.retries {
+			return err
+		}
+		time.Sleep(h.retryDelay)
+	}
+}
+
+var errNotReady = errors.New("fetch privileges: authz-service read view not ready")
+
+func (h *PrivilegeHandler) fetch() error {
+	req, err := http.NewRequest(http.MethodGet, fmt.Sprintf("%s/authz", h.baseURL), nil)
 	if err != nil {
 		return err
 	}
 
+	if h.apiKey != "" {
+		req.Header.Set("Authorization", "Bearer "+h.apiKey)
+	}
+
+	resp, err := h.client.Do(req)
+	if err != nil {
+		return err
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode == http.StatusServiceUnavailable {
+		return errNotReady
+	}
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("fetch privileges: unexpected status %s", resp.Status)
+	}
+
 	buff, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return err
 	}
 
-	h.Lock()
-	defer h.Unlock()
-	err = json.Unmarshal(buff, &h.privileges)
-	if err != nil {
+	var snapshot map[string]map[string]CompanyPrivileges
+	if err := json.Unmarshal(buff, &snapshot); err != nil {
 		return err
 	}
+
+	seq := 0
+	if v := resp.Header.Get(SequenceHeader); v != "" {
+		seq, err = strconv.Atoi(v)
+		if err != nil || seq < 0 {
+			return fmt.Errorf("fetch privileges: invalid %s header %q", SequenceHeader, v)
+		}
+	} else {
+		// ponytail: only during the rollout window, before authz-service sends the header.
+		slog.Warn("authz snapshot has no sequence number; events older than it can revert it", "header", SequenceHeader)
+	}
+
+	h.Lock()
+	defer h.Unlock()
+	h.merge(snapshot, seq)
 	return nil
 }
 
+func (h *PrivilegeHandler) merge(snapshot map[string]map[string]CompanyPrivileges, seq int) {
+	if seq < h.floor {
+		// A newer snapshot is already merged; this one could only bring back removed state.
+		slog.Warn("ignoring authz snapshot older than the one already merged", "seq", seq, "floor", h.floor)
+		return
+	}
+	for email, companies := range h.state {
+		for companyID, s := range companies {
+			s.clearPending()
+			if _, exists := snapshot[email][companyID]; exists {
+				continue
+			}
+			if s.maxSeq() <= seq {
+				// Nothing newer than the snapshot; the floor keeps stale events out.
+				delete(companies, companyID)
+				continue
+			}
+			removeUser(s, seq, false)
+		}
+		if len(companies) == 0 {
+			delete(h.state, email)
+		}
+	}
+	for email, companies := range snapshot {
+		for companyID, privileges := range companies {
+			s := h.company(email, companyID)
+			if s.memberSeq <= seq {
+				s.member = true
+				s.memberSeq = seq
+			}
+			for _, p := range AllPrivilege {
+				if s.privilegeSeq[p] <= seq {
+					*s.privileges.field(p) = *privileges.field(p)
+					s.privilegeSeq[p] = seq
+				}
+			}
+		}
+	}
+	h.floor = max(h.floor, seq)
+}
+
 func (h *PrivilegeHandler) Setup() []goamqp.Setup {
 	return []goamqp.Setup{
-		goamqp.TransientEventStreamConsumer("User.Added", h.Process, UserAdded{}),
-		goamqp.TransientEventStreamConsumer("User.Removed", h.Process, UserRemoved{}),
-		goamqp.TransientEventStreamConsumer("Privilege.Added", h.Process, PrivilegeAdded{}),
-		goamqp.TransientEventStreamConsumer("Privilege.Removed", h.Process, PrivilegeRemoved{}),
+		goamqp.TransientEventStreamConsumer("User.Added", process[UserAdded](h)),
+		goamqp.TransientEventStreamConsumer("User.Removed", process[UserRemoved](h)),
+		goamqp.TransientEventStreamConsumer("Privilege.Added", process[PrivilegeAdded](h)),
+		goamqp.TransientEventStreamConsumer("Privilege.Removed", process[PrivilegeRemoved](h)),
 	}
 }
 
-// Process privilege-related events and update the internal state
-func (h *PrivilegeHandler) Process(msg interface{}, _ goamqp.Headers) (interface{}, error) {
+// privilegeEvent is the set of events Process handles.
+type privilegeEvent interface {
+	UserAdded | UserRemoved | PrivilegeAdded | PrivilegeRemoved
+}
+
+// process adapts Process to a typed go-messaging-amqp handler.
+func process[T privilegeEvent](h *PrivilegeHandler) spec.EventHandler[T] {
+	return func(_ context.Context, event spec.ConsumableEvent[T]) error {
+		return h.Process(&event.Payload)
+	}
+}
+
+// Process privilege-related events and update the internal state.
+//
+// Events are applied by sequence number, not by arrival order. An event without a
+// sequence number can't be ordered, so it fails closed: a removal is applied and an
+// addition is dropped.
+func (h *PrivilegeHandler) Process(msg any) error {
+	h.Lock()
+	defer h.Unlock()
+
 	switch ev := msg.(type) {
 	case *UserAdded:
-		if priv, exists := h.privileges[ev.Email]; exists {
-			priv[ev.CompanyID] = &CompanyPrivileges{}
-		} else {
-			h.Lock()
-			defer h.Unlock()
-			h.privileges[ev.Email] = map[string]*CompanyPrivileges{
-				ev.CompanyID: {},
-			}
+		if h.stale(ev.SequenceNo, true, ev) {
+			return nil
 		}
-		return nil, nil
+		s := h.company(ev.Email, ev.CompanyID)
+		if ev.SequenceNo > s.memberSeq {
+			s.member = true
+			s.memberSeq = ev.SequenceNo
+		}
+		return nil
 	case *UserRemoved:
-		if priv, exists := h.privileges[ev.Email]; exists {
-			h.Lock()
-			defer h.Unlock()
-			delete(priv, ev.CompanyID)
+		if h.stale(ev.SequenceNo, false, ev) {
+			return nil
 		}
-		return nil, nil
+		removeUser(h.company(ev.Email, ev.CompanyID), ev.SequenceNo, ev.SequenceNo == 0)
+		return nil
 	case *PrivilegeAdded:
-		h.Lock()
-		defer h.Unlock()
-		h.setPrivileges(ev.Email, ev.CompanyID, ev.Privilege, true)
-		return nil, nil
+		if h.stale(ev.SequenceNo, true, ev) {
+			return nil
+		}
+		h.setPrivilege(ev.Email, ev.CompanyID, ev.Privilege, ev.SequenceNo, true)
+		return nil
 	case *PrivilegeRemoved:
-		h.Lock()
-		defer h.Unlock()
-		h.setPrivileges(ev.Email, ev.CompanyID, ev.Privilege, false)
-		return nil, nil
+		if h.stale(ev.SequenceNo, false, ev) {
+			return nil
+		}
+		h.setPrivilege(ev.Email, ev.CompanyID, ev.Privilege, ev.SequenceNo, false)
+		return nil
 	default:
-		fmt.Printf("Got unexpected message type (%s): '%+v'\n", reflect.TypeOf(msg).String(), msg)
-		return nil, fmt.Errorf("unexpected event type: '%s'", reflect.TypeOf(msg))
+		slog.Error("unexpected privilege message type", "type", reflect.TypeOf(msg).String())
+		return fmt.Errorf("unexpected event type: '%s'", reflect.TypeOf(msg))
 	}
 }
 
-func (h *PrivilegeHandler) setPrivileges(email, companyId string, privilege Privilege, set bool) {
-	if priv, exists := h.privileges[email]; exists {
-		if c, exists := priv[companyId]; exists {
-			switch privilege {
-			case PrivilegeAdmin:
-				c.Admin = set
-			case PrivilegeCompany:
-				c.Company = set
-			case PrivilegeConsumer:
-				c.Consumer = set
-			case PrivilegeTime:
-				c.Time = set
-			case PrivilegeInvoicing:
-				c.Invoicing = set
-			case PrivilegeAccounting:
-				c.Accounting = set
-			case PrivilegeSupplier:
-				c.Supplier = set
-			case PrivilegeSalary:
-				c.Salary = set
-			}
-		} else {
-			priv[companyId] = &CompanyPrivileges{}
-			h.setPrivileges(email, companyId, privilege, set)
+// stale reports whether an event must be skipped: an addition without a sequence
+// number, or any event already covered by the latest snapshot.
+func (h *PrivilegeHandler) stale(seq int, addition bool, ev any) bool {
+	if seq < 0 || seq >= pending {
+		slog.Error("dropping privilege event with invalid sequence number", "type", reflect.TypeOf(ev).String(), "seq", seq)
+		return true
+	}
+	if seq == 0 {
+		if addition {
+			slog.Warn("dropping privilege addition without sequence number", "type", reflect.TypeOf(ev).String())
 		}
-	} else {
-		h.privileges[email] = map[string]*CompanyPrivileges{}
-		h.setPrivileges(email, companyId, privilege, set)
+		return addition
+	}
+	return seq <= h.floor
+}
+
+func (h *PrivilegeHandler) company(email, companyID string) *companyState {
+	companies, exists := h.state[email]
+	if !exists {
+		companies = map[string]*companyState{}
+		h.state[email] = companies
+	}
+	s, exists := companies[companyID]
+	if !exists {
+		s = newCompanyState()
+		companies[companyID] = s
+	}
+	return s
+}
+
+// removeUser removes the user at seq, overriding every fact older than seq. An
+// unordered removal (all) overrides every fact and marks them pending, so no event can
+// bring them back before the next snapshot.
+func removeUser(s *companyState, seq int, all bool) {
+	stamp := seq
+	if all {
+		stamp = pending
+	}
+	if all || s.memberSeq < seq {
+		s.member = false
+		s.memberSeq = max(s.memberSeq, stamp)
+	}
+	for _, p := range AllPrivilege {
+		if all || s.privilegeSeq[p] < seq {
+			*s.privileges.field(p) = false
+			s.privilegeSeq[p] = max(s.privilegeSeq[p], stamp)
+		}
+	}
+}
+
+func (h *PrivilegeHandler) setPrivilege(email, companyID string, privilege Privilege, seq int, set bool) {
+	if !privilege.IsValid() {
+		return
+	}
+	s := h.company(email, companyID)
+	if seq != 0 && seq <= s.privilegeSeq[privilege] {
+		return
+	}
+	*s.privileges.field(privilege) = set
+	if seq == 0 {
+		// Only an unordered removal gets here; keep it until the next snapshot.
+		seq = pending
+	}
+	s.privilegeSeq[privilege] = max(s.privilegeSeq[privilege], seq)
+	// authz-service's aggregate adds the user when a privilege is granted.
+	if set && seq > s.memberSeq {
+		s.member = true
+		s.memberSeq = seq
 	}
 }
 
@@ -157,12 +402,10 @@ func (h *PrivilegeHandler) setPrivileges(email, companyId string, privilege Priv
 func (h *PrivilegeHandler) CompaniesByUser(email string, predicate func(privileges CompanyPrivileges) bool) []string {
 	h.RLock()
 	defer h.RUnlock()
-	var result []string
-	if p, exists := h.privileges[email]; exists {
-		for k, v := range p {
-			if predicate(*v) {
-				result = append(result, k)
-			}
+	result := []string{}
+	for k, s := range h.state[email] {
+		if s.member && predicate(s.privileges) {
+			result = append(result, k)
 		}
 	}
 	return result
@@ -172,11 +415,8 @@ func (h *PrivilegeHandler) CompaniesByUser(email string, predicate func(privileg
 func (h *PrivilegeHandler) IsAllowed(email, companyID string, predicate func(privileges CompanyPrivileges) bool) bool {
 	h.RLock()
 	defer h.RUnlock()
-	if p, exists := h.privileges[email]; exists {
-		if v, exists := p[companyID]; exists {
-			return predicate(*v)
-		}
+	if s, exists := h.state[email][companyID]; exists && s.member {
+		return predicate(s.privileges)
 	}
-
 	return false
 }

client_test.go

@@ -1,35 +1,40 @@
 package client
 
 import (
+	"context"
 	"fmt"
+	"math"
 	"net/http"
 	"net/http/httptest"
 	"sort"
 	"sync"
+	"sync/atomic"
 	"testing"
+	"time"
 
-	"github.com/sparetimecoders/goamqp"
+	goamqp "codeberg.org/messaging/go-messaging-amqp"
+	spec "codeberg.org/messaging/messaging"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestPrivilegeHandler_Process_InvalidType(t *testing.T) {
 	handler := New(WithBaseURL("base"))
 
-	result, err := handler.Process("abc", goamqp.Headers{})
+	err := handler.Process("abc")
 
-	assert.Nil(t, result)
 	assert.EqualError(t, err, "unexpected event type: 'string'")
 }
 
 func TestPrivilegeHandler_Process_PrivilegeRemoved(t *testing.T) {
 	handler := New(WithBaseURL("base"))
 
-	result, err := handler.Process(&PrivilegeAdded{
-		Email:     "jim@example.org",
-		CompanyID: "abc-123",
-		Privilege: PrivilegeAdmin,
-	}, goamqp.Headers{})
-	assert.Nil(t, result)
+	err := handler.Process(&PrivilegeAdded{
+		SequenceNo: 1,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-123",
+		Privilege:  PrivilegeAdmin,
+	})
 	assert.NoError(t, err)
 
 	companies := handler.CompaniesByUser("jim@example.org", func(privileges CompanyPrivileges) bool {
@@ -38,12 +43,12 @@ func TestPrivilegeHandler_Process_PrivilegeRemoved(t *testing.T) {
 
 	assert.Equal(t, []string{"abc-123"}, companies)
 
-	result, err = handler.Process(&PrivilegeRemoved{
-		Email:     "jim@example.org",
-		CompanyID: "abc-123",
-		Privilege: PrivilegeAdmin,
-	}, goamqp.Headers{})
-	assert.Nil(t, result)
+	err = handler.Process(&PrivilegeRemoved{
+		SequenceNo: 2,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-123",
+		Privilege:  PrivilegeAdmin,
+	})
 	assert.NoError(t, err)
 
 	companies = handler.CompaniesByUser("jim@example.org", func(privileges CompanyPrivileges) bool {
@@ -56,18 +61,18 @@ func TestPrivilegeHandler_Process_PrivilegeRemoved(t *testing.T) {
 func TestPrivilegeHandler_Process_UserAdded_And_UserRemoved(t *testing.T) {
 	handler := New(WithBaseURL("base"))
 
-	result, err := handler.Process(&UserAdded{
-		Email:     "jim@example.org",
-		CompanyID: "abc-123",
-	}, goamqp.Headers{})
-	assert.Nil(t, result)
+	err := handler.Process(&UserAdded{
+		SequenceNo: 1,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-123",
+	})
 	assert.NoError(t, err)
 
-	result, err = handler.Process(&UserAdded{
-		Email:     "jim@example.org",
-		CompanyID: "abc-456",
-	}, goamqp.Headers{})
-	assert.Nil(t, result)
+	err = handler.Process(&UserAdded{
+		SequenceNo: 2,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-456",
+	})
 	assert.NoError(t, err)
 
 	companies := handler.CompaniesByUser("jim@example.org", func(privileges CompanyPrivileges) bool {
@@ -76,18 +81,18 @@ func TestPrivilegeHandler_Process_UserAdded_And_UserRemoved(t *testing.T) {
 	sort.Strings(companies)
 	assert.Equal(t, []string{"abc-123", "abc-456"}, companies)
 
-	result, err = handler.Process(&UserRemoved{
-		Email:     "jim@example.org",
-		CompanyID: "abc-123",
-	}, goamqp.Headers{})
-	assert.Nil(t, result)
+	err = handler.Process(&UserRemoved{
+		SequenceNo: 3,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-123",
+	})
 	assert.NoError(t, err)
 
-	result, err = handler.Process(&UserRemoved{
-		Email:     "jim@example.org",
-		CompanyID: "abc-456",
-	}, goamqp.Headers{})
-	assert.Nil(t, result)
+	err = handler.Process(&UserRemoved{
+		SequenceNo: 4,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-456",
+	})
 	assert.NoError(t, err)
 
 	companies = handler.CompaniesByUser("jim@example.org", func(privileges CompanyPrivileges) bool {
@@ -96,6 +101,51 @@ func TestPrivilegeHandler_Process_UserAdded_And_UserRemoved(t *testing.T) {
 	assert.Empty(t, companies)
 }
 
+func TestPrivilegeHandler_Process_UserAdded_Keeps_Existing_Privileges(t *testing.T) {
+	// Each routing key has its own transient queue, so Privilege.Added can be
+	// processed before the User.Added published before it. The privilege must
+	// survive either order: nothing re-reads it until the next Fetch at start.
+	userAdded := &UserAdded{SequenceNo: 1, Email: "jim@example.org", CompanyID: "abc-123"}
+	privilegeAdded := &PrivilegeAdded{SequenceNo: 2, Email: "jim@example.org", CompanyID: "abc-123", Privilege: PrivilegeAdmin}
+	for name, order := range map[string][]any{
+		"user added first":      {userAdded, privilegeAdded},
+		"privilege added first": {privilegeAdded, userAdded},
+	} {
+		t.Run(name, func(t *testing.T) {
+			handler := New(WithBaseURL("base"))
+			for _, event := range order {
+				require.NoError(t, handler.Process(event))
+			}
+
+			assert.True(t, handler.IsAllowed("jim@example.org", "abc-123", func(privileges CompanyPrivileges) bool {
+				return privileges.Admin
+			}))
+		})
+	}
+}
+
+func TestPrivilegeHandler_Process_UserAdded_After_UserRemoved_Starts_Empty(t *testing.T) {
+	handler := New(WithBaseURL("base"))
+
+	assert.NoError(t, handler.Process(&UserAdded{SequenceNo: 1, Email: "jim@example.org", CompanyID: "abc-123"}))
+	assert.NoError(t, handler.Process(&PrivilegeAdded{
+		SequenceNo: 2,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-123",
+		Privilege:  PrivilegeAdmin,
+	}))
+	assert.NoError(t, handler.Process(&UserRemoved{SequenceNo: 3, Email: "jim@example.org", CompanyID: "abc-123"}))
+	assert.NoError(t, handler.Process(&UserAdded{SequenceNo: 4, Email: "jim@example.org", CompanyID: "abc-123"}))
+
+	// Membership is back, without the privileges the removal took away.
+	assert.Equal(t, []string{"abc-123"}, handler.CompaniesByUser("jim@example.org", func(CompanyPrivileges) bool {
+		return true
+	}))
+	assert.False(t, handler.IsAllowed("jim@example.org", "abc-123", func(privileges CompanyPrivileges) bool {
+		return privileges.Admin
+	}))
+}
+
 func TestPrivilegeHandler_GetCompanies_Email_Not_Found(t *testing.T) {
 	handler := New(WithBaseURL("base"))
 
@@ -109,11 +159,11 @@ func TestPrivilegeHandler_GetCompanies_Email_Not_Found(t *testing.T) {
 func TestPrivilegeHandler_GetCompanies_No_Companies_Found(t *testing.T) {
 	handler := New(WithBaseURL("base"))
 
-	result, err := handler.Process(&UserAdded{
-		Email:     "jim@example.org",
-		CompanyID: "abc-123",
-	}, goamqp.Headers{})
-	assert.Nil(t, result)
+	err := handler.Process(&UserAdded{
+		SequenceNo: 1,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-123",
+	})
 	assert.NoError(t, err)
 
 	companies := handler.CompaniesByUser("jim@example.org", func(privileges CompanyPrivileges) bool {
@@ -128,11 +178,11 @@ func TestPrivilegeHandler_GetCompanies_No_Companies_Found(t *testing.T) {
 
 	assert.Equal(t, []string{"abc-123"}, companies)
 
-	result, err = handler.Process(&UserRemoved{
-		Email:     "jim@example.org",
-		CompanyID: "abc-123",
-	}, goamqp.Headers{})
-	assert.Nil(t, result)
+	err = handler.Process(&UserRemoved{
+		SequenceNo: 2,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-123",
+	})
 	assert.NoError(t, err)
 
 	companies = handler.CompaniesByUser("jim@example.org", func(privileges CompanyPrivileges) bool {
@@ -144,12 +194,12 @@ func TestPrivilegeHandler_GetCompanies_No_Companies_Found(t *testing.T) {
 func TestPrivilegeHandler_GetCompanies_Company_With_Company_Access_Found(t *testing.T) {
 	handler := New(WithBaseURL("base"))
 
-	result, err := handler.Process(&PrivilegeAdded{
-		Email:     "jim@example.org",
-		CompanyID: "abc-123",
-		Privilege: PrivilegeCompany,
-	}, goamqp.Headers{})
-	assert.Nil(t, result)
+	err := handler.Process(&PrivilegeAdded{
+		SequenceNo: 1,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-123",
+		Privilege:  PrivilegeCompany,
+	})
 	assert.NoError(t, err)
 
 	companies := handler.CompaniesByUser("jim@example.org", func(privileges CompanyPrivileges) bool {
@@ -162,12 +212,12 @@ func TestPrivilegeHandler_GetCompanies_Company_With_Company_Access_Found(t *test
 func TestPrivilegeHandler_GetCompanies_Company_With_Admin_Access_Found(t *testing.T) {
 	handler := New(WithBaseURL("base"))
 
-	result, err := handler.Process(&PrivilegeAdded{
-		Email:     "jim@example.org",
-		CompanyID: "abc-123",
-		Privilege: PrivilegeConsumer,
-	}, goamqp.Headers{})
-	assert.Nil(t, result)
+	err := handler.Process(&PrivilegeAdded{
+		SequenceNo: 1,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-123",
+		Privilege:  PrivilegeConsumer,
+	})
 	assert.NoError(t, err)
 
 	companies := handler.CompaniesByUser("jim@example.org", func(privileges CompanyPrivileges) bool {
@@ -190,11 +240,12 @@ func TestPrivilegeHandler_IsAllowed_Return_False_If_No_Privileges(t *testing.T)
 func TestPrivilegeHandler_IsAllowed_Return_True_If_Privilege_Exists(t *testing.T) {
 	handler := New(WithBaseURL("base"))
 
-	_, _ = handler.Process(&PrivilegeAdded{
-		Email:     "jim@example.org",
-		CompanyID: "abc-123",
-		Privilege: PrivilegeTime,
-	}, goamqp.Headers{})
+	_ = handler.Process(&PrivilegeAdded{
+		SequenceNo: 1,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-123",
+		Privilege:  PrivilegeTime,
+	})
 
 	result := handler.IsAllowed("jim@example.org", "abc-123", func(privileges CompanyPrivileges) bool {
 		return privileges.Time
@@ -202,11 +253,12 @@ func TestPrivilegeHandler_IsAllowed_Return_True_If_Privilege_Exists(t *testing.T
 
 	assert.True(t, result)
 
-	_, _ = handler.Process(&PrivilegeAdded{
-		Email:     "jim@example.org",
-		CompanyID: "abc-123",
-		Privilege: PrivilegeInvoicing,
-	}, goamqp.Headers{})
+	_ = handler.Process(&PrivilegeAdded{
+		SequenceNo: 2,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-123",
+		Privilege:  PrivilegeInvoicing,
+	})
 
 	result = handler.IsAllowed("jim@example.org", "abc-123", func(privileges CompanyPrivileges) bool {
 		return privileges.Invoicing
@@ -214,11 +266,12 @@ func TestPrivilegeHandler_IsAllowed_Return_True_If_Privilege_Exists(t *testing.T
 
 	assert.True(t, result)
 
-	_, _ = handler.Process(&PrivilegeAdded{
-		Email:     "jim@example.org",
-		CompanyID: "abc-123",
-		Privilege: PrivilegeAccounting,
-	}, goamqp.Headers{})
+	_ = handler.Process(&PrivilegeAdded{
+		SequenceNo: 3,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-123",
+		Privilege:  PrivilegeAccounting,
+	})
 
 	result = handler.IsAllowed("jim@example.org", "abc-123", func(privileges CompanyPrivileges) bool {
 		return privileges.Accounting
@@ -226,11 +279,12 @@ func TestPrivilegeHandler_IsAllowed_Return_True_If_Privilege_Exists(t *testing.T
 
 	assert.True(t, result)
 
-	_, _ = handler.Process(&PrivilegeAdded{
-		Email:     "jim@example.org",
-		CompanyID: "abc-123",
-		Privilege: PrivilegeSupplier,
-	}, goamqp.Headers{})
+	_ = handler.Process(&PrivilegeAdded{
+		SequenceNo: 4,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-123",
+		Privilege:  PrivilegeSupplier,
+	})
 
 	result = handler.IsAllowed("jim@example.org", "abc-123", func(privileges CompanyPrivileges) bool {
 		return privileges.Supplier
@@ -238,11 +292,12 @@ func TestPrivilegeHandler_IsAllowed_Return_True_If_Privilege_Exists(t *testing.T
 
 	assert.True(t, result)
 
-	_, _ = handler.Process(&PrivilegeAdded{
-		Email:     "jim@example.org",
-		CompanyID: "abc-123",
-		Privilege: PrivilegeSalary,
-	}, goamqp.Headers{})
+	_ = handler.Process(&PrivilegeAdded{
+		SequenceNo: 5,
+		Email:      "jim@example.org",
+		CompanyID:  "abc-123",
+		Privilege:  PrivilegeSalary,
+	})
 
 	result = handler.IsAllowed("jim@example.org", "abc-123", func(privileges CompanyPrivileges) bool {
 		return privileges.Salary
@@ -251,6 +306,39 @@ func TestPrivilegeHandler_IsAllowed_Return_True_If_Privilege_Exists(t *testing.T
 	assert.True(t, result)
 }
 
+func TestPrivilegeHandler_Fetch_Sends_Authorization_Header_When_APIKey_Set(t *testing.T) {
+	var receivedAuth string
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		receivedAuth = r.Header.Get("Authorization")
+		_, _ = w.Write([]byte("{}"))
+	}))
+	defer server.Close()
+
+	handler := New(
+		WithBaseURL(server.URL),
+		WithAPIKey("my-secret-key"),
+	)
+
+	err := handler.Fetch()
+	assert.NoError(t, err)
+	assert.Equal(t, "Bearer my-secret-key", receivedAuth)
+}
+
+func TestPrivilegeHandler_Fetch_No_Authorization_Header_Without_APIKey(t *testing.T) {
+	var receivedAuth string
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		receivedAuth = r.Header.Get("Authorization")
+		_, _ = w.Write([]byte("{}"))
+	}))
+	defer server.Close()
+
+	handler := New(WithBaseURL(server.URL))
+
+	err := handler.Fetch()
+	assert.NoError(t, err)
+	assert.Empty(t, receivedAuth)
+}
+
 func TestPrivilegeHandler_Fetch_Error_Response(t *testing.T) {
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(500)
@@ -317,7 +405,7 @@ func TestPrivilegeHandler_Fetch_Valid(t *testing.T) {
 
 	err := handler.Fetch()
 	assert.NoError(t, err)
-	expectedPrivileges := map[string]map[string]*CompanyPrivileges{
+	expectedPrivileges := map[string]map[string]CompanyPrivileges{
 		"jim@example.org": {
 			"00010203-0405-4607-8809-0a0b0c0d0e0f": {
 				Admin:      false,
@@ -331,7 +419,7 @@ func TestPrivilegeHandler_Fetch_Valid(t *testing.T) {
 			},
 		},
 	}
-	assert.Equal(t, expectedPrivileges, handler.privileges)
+	assert.Equal(t, expectedPrivileges, privilegesOf(handler))
 }
 
 func TestPrivilegeHandler_Fetch_Concurrent_Fetches(t *testing.T) {
@@ -381,7 +469,7 @@ func TestPrivilegeHandler_Fetch_Concurrent_Fetches(t *testing.T) {
 	}
 
 	// Verify privileges were set correctly
-	expectedPrivileges := map[string]map[string]*CompanyPrivileges{
+	expectedPrivileges := map[string]map[string]CompanyPrivileges{
 		"jim@example.org": {
 			"00010203-0405-4607-8809-0a0b0c0d0e0f": {
 				Admin:      false,
@@ -395,7 +483,7 @@ func TestPrivilegeHandler_Fetch_Concurrent_Fetches(t *testing.T) {
 			},
 		},
 	}
-	assert.Equal(t, expectedPrivileges, handler.privileges)
+	assert.Equal(t, expectedPrivileges, privilegesOf(handler))
 }
 
 func TestPrivilegeHandler_Concurrent_Fetch_And_Read(t *testing.T) {
@@ -489,11 +577,12 @@ func TestPrivilegeHandler_Concurrent_Process_And_Read(t *testing.T) {
 		companyID := fmt.Sprintf("company-%d", i%10)
 		go func(id string) {
 			defer wg.Done()
-			_, _ = handler.Process(&PrivilegeAdded{
-				Email:     "jim@example.org",
-				CompanyID: id,
-				Privilege: PrivilegeAdmin,
-			}, goamqp.Headers{})
+			_ = handler.Process(&PrivilegeAdded{
+				SequenceNo: 1,
+				Email:      "jim@example.org",
+				CompanyID:  id,
+				Privilege:  PrivilegeAdmin,
+			})
 		}(companyID)
 	}
 
@@ -565,11 +654,12 @@ func TestPrivilegeHandler_Concurrent_Multiple_Operations(t *testing.T) {
 		wg.Add(1)
 		go func(idx int) {
 			defer wg.Done()
-			_, _ = handler.Process(&PrivilegeAdded{
-				Email:     "jane@example.org",
-				CompanyID: fmt.Sprintf("company-%d", idx%5),
-				Privilege: PrivilegeCompany,
-			}, goamqp.Headers{})
+			_ = handler.Process(&PrivilegeAdded{
+				SequenceNo: 1,
+				Email:      "jane@example.org",
+				CompanyID:  fmt.Sprintf("company-%d", idx%5),
+				Privilege:  PrivilegeCompany,
+			})
 		}(i)
 	}
 
@@ -615,3 +705,360 @@ func TestPrivilegeHandler_Concurrent_Multiple_Operations(t *testing.T) {
 	expectedJane := []string{"company-0", "company-1", "company-2", "company-3", "company-4"}
 	assert.Equal(t, expectedJane, janeCompanies)
 }
+
+func TestPrivilegeHandler_Setup(t *testing.T) {
+	handler := New(WithBaseURL("base"))
+
+	topology, err := goamqp.CollectTopology("some-service", handler.Setup()...)
+	assert.NoError(t, err)
+	wiring := map[string]string{}
+	for _, e := range topology.Endpoints {
+		assert.Equal(t, spec.DirectionConsume, e.Direction)
+		assert.True(t, e.Ephemeral, "%s must be a per-replica consumer", e.RoutingKey)
+		wiring[e.RoutingKey] = e.MessageType
+	}
+	// A key wired to the wrong type could turn a revocation into a grant.
+	assert.Equal(t, map[string]string{
+		"User.Added":        "client.UserAdded",
+		"User.Removed":      "client.UserRemoved",
+		"Privilege.Added":   "client.PrivilegeAdded",
+		"Privilege.Removed": "client.PrivilegeRemoved",
+	}, wiring)
+}
+
+func TestPrivilegeHandler_process(t *testing.T) {
+	ctx := context.Background()
+	handler := New(WithBaseURL("base"))
+	admin := func(p CompanyPrivileges) bool { return p.Admin }
+
+	assert.NoError(t, process[UserAdded](handler)(ctx, spec.ConsumableEvent[UserAdded]{
+		Payload: UserAdded{SequenceNo: 1, Email: "jim@example.org", CompanyID: "abc-123"},
+	}))
+	assert.False(t, handler.IsAllowed("jim@example.org", "abc-123", admin))
+
+	assert.NoError(t, process[PrivilegeAdded](handler)(ctx, spec.ConsumableEvent[PrivilegeAdded]{
+		Payload: PrivilegeAdded{SequenceNo: 2, Email: "jim@example.org", CompanyID: "abc-123", Privilege: PrivilegeAdmin},
+	}))
+	assert.True(t, handler.IsAllowed("jim@example.org", "abc-123", admin))
+
+	assert.NoError(t, process[PrivilegeRemoved](handler)(ctx, spec.ConsumableEvent[PrivilegeRemoved]{
+		Payload: PrivilegeRemoved{SequenceNo: 3, Email: "jim@example.org", CompanyID: "abc-123", Privilege: PrivilegeAdmin},
+	}))
+	assert.False(t, handler.IsAllowed("jim@example.org", "abc-123", admin))
+
+	assert.NoError(t, process[UserRemoved](handler)(ctx, spec.ConsumableEvent[UserRemoved]{
+		Payload: UserRemoved{SequenceNo: 4, Email: "jim@example.org", CompanyID: "abc-123"},
+	}))
+	assert.Empty(t, handler.CompaniesByUser("jim@example.org", func(CompanyPrivileges) bool { return true }))
+}
+
+// privilegesOf returns the privileges of every membership in the handler.
+func privilegesOf(h *PrivilegeHandler) map[string]map[string]CompanyPrivileges {
+	h.RLock()
+	defer h.RUnlock()
+	result := map[string]map[string]CompanyPrivileges{}
+	for email, companies := range h.state {
+		for companyID, s := range companies {
+			if !s.member {
+				continue
+			}
+			if result[email] == nil {
+				result[email] = map[string]CompanyPrivileges{}
+			}
+			result[email][companyID] = s.privileges
+		}
+	}
+	return result
+}
+
+func TestPrivilegeHandler_Process_Orders_By_SequenceNo(t *testing.T) {
+	const email, company = "jim@example.org", "abc-123"
+	userAdded := func(seq int) any { return &UserAdded{Email: email, CompanyID: company, SequenceNo: seq} }
+	userRemoved := func(seq int) any { return &UserRemoved{Email: email, CompanyID: company, SequenceNo: seq} }
+	added := func(seq int) any {
+		return &PrivilegeAdded{Email: email, CompanyID: company, Privilege: PrivilegeAdmin, SequenceNo: seq}
+	}
+	removed := func(seq int) any {
+		return &PrivilegeRemoved{Email: email, CompanyID: company, Privilege: PrivilegeAdmin, SequenceNo: seq}
+	}
+	tests := []struct {
+		name      string
+		delivered []any
+		member    bool
+		admin     bool
+	}{
+		{name: "in order", delivered: []any{userAdded(1), added(2)}, member: true, admin: true},
+		{name: "privilege before older user added keeps the grant", delivered: []any{added(2), userAdded(1)}, member: true, admin: true},
+		{name: "late privilege added after user removed", delivered: []any{userAdded(1), userRemoved(3), added(2)}, member: false, admin: false},
+		{name: "late privilege added after privilege removed", delivered: []any{userAdded(1), removed(3), added(2)}, member: true, admin: false},
+		{name: "late user added does not revive privileges removed with the user", delivered: []any{userRemoved(3), added(2), userAdded(1)}, member: false, admin: false},
+		{name: "re-added user starts without the removed privileges", delivered: []any{added(2), userRemoved(3), userAdded(4)}, member: true, admin: false},
+		{name: "privilege granted after re-add", delivered: []any{userAdded(4), userRemoved(3), added(5), added(2)}, member: true, admin: true},
+		{name: "late user removed does not remove a newer grant", delivered: []any{added(4), userRemoved(3)}, member: true, admin: true},
+		{name: "late user removed does not remove a newer membership", delivered: []any{userAdded(4), userRemoved(3)}, member: true, admin: false},
+		{name: "late privilege added before re-add stays revoked", delivered: []any{userAdded(1), userRemoved(3), added(2), userAdded(4)}, member: true, admin: false},
+		{name: "privilege removed after user removed keeps the user out", delivered: []any{userRemoved(2), removed(3)}, member: false, admin: false},
+		{name: "duplicate delivery is idempotent", delivered: []any{added(2), removed(3), added(2)}, member: true, admin: false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			handler := New()
+			for _, event := range tt.delivered {
+				require.NoError(t, handler.Process(event))
+			}
+			all := func(CompanyPrivileges) bool { return true }
+			assert.Equal(t, tt.member, handler.IsAllowed(email, company, all))
+			assert.Equal(t, tt.admin, handler.IsAllowed(email, company, func(p CompanyPrivileges) bool { return p.Admin }))
+			if tt.member {
+				assert.Equal(t, []string{company}, handler.CompaniesByUser(email, all))
+			} else {
+				assert.Equal(t, []string{}, handler.CompaniesByUser(email, all))
+			}
+		})
+	}
+}
+
+func TestPrivilegeHandler_Process_Without_SequenceNo_Fails_Closed(t *testing.T) {
+	const email, company = "jim@example.org", "abc-123"
+	admin := func(p CompanyPrivileges) bool { return p.Admin }
+	handler := New()
+
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: company, Privilege: PrivilegeAdmin}))
+	require.NoError(t, handler.Process(&UserAdded{Email: email, CompanyID: company}))
+	assert.False(t, handler.IsAllowed(email, company, func(CompanyPrivileges) bool { return true }), "an unordered addition is dropped")
+	require.NoError(t, handler.Process(&UserAdded{Email: email, CompanyID: company, SequenceNo: 1}))
+	assert.False(t, handler.IsAllowed(email, company, admin), "the dropped grant doesn't appear with a later membership")
+
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: company, Privilege: PrivilegeAdmin, SequenceNo: 5}))
+	require.NoError(t, handler.Process(&PrivilegeRemoved{Email: email, CompanyID: company, Privilege: PrivilegeAdmin}))
+	assert.False(t, handler.IsAllowed(email, company, admin), "an unordered privilege removal applies")
+
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: company, Privilege: PrivilegeTime, SequenceNo: 6}))
+	require.NoError(t, handler.Process(&UserRemoved{Email: email, CompanyID: company}))
+	assert.False(t, handler.IsAllowed(email, company, func(CompanyPrivileges) bool { return true }), "an unordered user removal applies")
+}
+
+// snapshotServer serves body as the /authz snapshot at seq; a negative seq sends no header.
+func snapshotServer(t *testing.T, seq int, body string) *httptest.Server {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if seq >= 0 {
+			w.Header().Set(SequenceHeader, fmt.Sprint(seq))
+		}
+		_, _ = w.Write([]byte(body))
+	}))
+	t.Cleanup(server.Close)
+	return server
+}
+
+func TestPrivilegeHandler_Fetch_Merges_Snapshot_By_SequenceNo(t *testing.T) {
+	const email = "jim@example.org"
+	admin := func(p CompanyPrivileges) bool { return p.Admin }
+	all := func(CompanyPrivileges) bool { return true }
+	snapshot := `{"jim@example.org": {"in-snapshot": {"admin": true}, "stale-in-snapshot": {"admin": true}}}`
+
+	handler := New(WithBaseURL(snapshotServer(t, 10, snapshot).URL))
+	// Delivered while the snapshot was read.
+	require.NoError(t, handler.Process(&PrivilegeRemoved{Email: email, CompanyID: "in-snapshot", Privilege: PrivilegeAdmin, SequenceNo: 11}))
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: "stale-in-snapshot", Privilege: PrivilegeTime, SequenceNo: 9}))
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: "new", Privilege: PrivilegeAdmin, SequenceNo: 12}))
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: "revoked", Privilege: PrivilegeAdmin, SequenceNo: 8}))
+	require.NoError(t, handler.Process(&UserAdded{Email: email, CompanyID: "revoked-later", SequenceNo: 7}))
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: "revoked-later", Privilege: PrivilegeAdmin, SequenceNo: 13}))
+
+	require.NoError(t, handler.Fetch())
+
+	assert.True(t, handler.IsAllowed(email, "in-snapshot", all))
+	assert.False(t, handler.IsAllowed(email, "in-snapshot", admin), "a removal newer than the snapshot wins")
+	assert.False(t, handler.IsAllowed(email, "stale-in-snapshot", func(p CompanyPrivileges) bool { return p.Time }), "the snapshot replaces an older fact")
+	assert.True(t, handler.IsAllowed(email, "new", admin), "a grant newer than the snapshot is kept")
+	assert.False(t, handler.IsAllowed(email, "revoked", all), "a pair missing from the snapshot is removed")
+	assert.True(t, handler.IsAllowed(email, "revoked-later", admin), "a grant newer than the snapshot survives the removal")
+
+	// Events the snapshot already covers are stale.
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: "revoked", Privilege: PrivilegeAdmin, SequenceNo: 10}))
+	assert.False(t, handler.IsAllowed(email, "revoked", all), "an event at the snapshot sequence is stale")
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: "revoked", Privilege: PrivilegeAdmin, SequenceNo: 14}))
+	assert.True(t, handler.IsAllowed(email, "revoked", admin))
+}
+
+func TestPrivilegeHandler_Fetch_Replaces_Pairs_Missing_From_Snapshot(t *testing.T) {
+	handler := New(WithBaseURL(snapshotServer(t, 10, `{"jim@example.org": {"kept": {"company": true}}}`).URL))
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: "jim@example.org", CompanyID: "gone", Privilege: PrivilegeAdmin, SequenceNo: 3}))
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: "jane@example.org", CompanyID: "gone", Privilege: PrivilegeAdmin, SequenceNo: 4}))
+
+	require.NoError(t, handler.Fetch())
+
+	assert.Equal(t, map[string]map[string]CompanyPrivileges{"jim@example.org": {"kept": {Company: true}}}, privilegesOf(handler))
+	handler.RLock()
+	defer handler.RUnlock()
+	assert.NotContains(t, handler.state, "jane@example.org", "an email without companies is dropped")
+}
+
+func TestPrivilegeHandler_Fetch_Without_SequenceHeader_Keeps_Sequenced_Facts(t *testing.T) {
+	handler := New(WithBaseURL(snapshotServer(t, -1, `{"jim@example.org": {"abc-123": {"admin": true}}}`).URL))
+	require.NoError(t, handler.Process(&PrivilegeRemoved{Email: "jim@example.org", CompanyID: "abc-123", Privilege: PrivilegeAdmin, SequenceNo: 3}))
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: "jim@example.org", CompanyID: "other", Privilege: PrivilegeAdmin, SequenceNo: 4}))
+
+	require.NoError(t, handler.Fetch())
+
+	assert.Equal(t, map[string]map[string]CompanyPrivileges{
+		"jim@example.org": {"abc-123": {}, "other": {Admin: true}},
+	}, privilegesOf(handler))
+}
+
+func TestPrivilegeHandler_Fetch_Rejects_Bad_Responses(t *testing.T) {
+	tests := []struct {
+		name   string
+		status int
+		header string
+		err    string
+	}{
+		{name: "status", status: http.StatusUnauthorized, err: "fetch privileges: unexpected status 401 Unauthorized"},
+		{name: "invalid header", status: http.StatusOK, header: "abc", err: `fetch privileges: invalid X-Authz-Sequence header "abc"`},
+		{name: "negative header", status: http.StatusOK, header: "-1", err: `fetch privileges: invalid X-Authz-Sequence header "-1"`},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				if tt.header != "" {
+					w.Header().Set(SequenceHeader, tt.header)
+				}
+				w.WriteHeader(tt.status)
+				_, _ = w.Write([]byte(`{"jim@example.org": {"abc-123": {"admin": true}}}`))
+			}))
+			defer server.Close()
+			handler := New(WithBaseURL(server.URL))
+			require.NoError(t, handler.Process(&PrivilegeAdded{Email: "jane@example.org", CompanyID: "abc-123", Privilege: PrivilegeTime, SequenceNo: 1}))
+
+			assert.EqualError(t, handler.Fetch(), tt.err)
+			assert.Equal(t, map[string]map[string]CompanyPrivileges{"jane@example.org": {"abc-123": {Time: true}}}, privilegesOf(handler), "state is untouched")
+		})
+	}
+}
+
+func TestPrivilegeHandler_Revocation_During_Fetch_Wins(t *testing.T) {
+	// The consumers are bound before Fetch, so a revocation published after authz-service
+	// read the snapshot is processed while the response is still on its way.
+	handler := New()
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// assert, not require: this runs on the server's goroutine.
+		assert.NoError(t, handler.Process(&UserRemoved{Email: "jim@example.org", CompanyID: "abc-123", SequenceNo: 21}))
+		w.Header().Set(SequenceHeader, "20")
+		_, _ = w.Write([]byte(`{"jim@example.org": {"abc-123": {"admin": true}}}`))
+	}))
+	defer server.Close()
+	handler.baseURL = server.URL
+
+	require.NoError(t, handler.Fetch())
+
+	assert.False(t, handler.IsAllowed("jim@example.org", "abc-123", func(CompanyPrivileges) bool { return true }))
+}
+
+func TestPrivilegeHandler_Fetch_Ignores_Snapshot_Older_Than_Merged_One(t *testing.T) {
+	const email = "jim@example.org"
+	all := func(CompanyPrivileges) bool { return true }
+	handler := New(WithBaseURL(snapshotServer(t, 12, `{}`).URL))
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: "abc-123", Privilege: PrivilegeAdmin, SequenceNo: 5}))
+	require.NoError(t, handler.Process(&UserRemoved{Email: email, CompanyID: "abc-123", SequenceNo: 11}))
+	require.NoError(t, handler.Fetch())
+
+	// A concurrent Fetch read at seq 10, before the removal, merges last.
+	handler.baseURL = snapshotServer(t, 10, `{"jim@example.org": {"abc-123": {"admin": true}}}`).URL
+	require.NoError(t, handler.Fetch())
+	assert.False(t, handler.IsAllowed(email, "abc-123", all))
+
+	// So does a snapshot without a sequence number.
+	handler.baseURL = snapshotServer(t, -1, `{"jim@example.org": {"abc-123": {"admin": true}}}`).URL
+	require.NoError(t, handler.Fetch())
+	assert.False(t, handler.IsAllowed(email, "abc-123", all))
+}
+
+func TestPrivilegeHandler_Unordered_Removal_Holds_Until_Next_Snapshot(t *testing.T) {
+	const email, company = "jim@example.org", "abc-123"
+	all := func(CompanyPrivileges) bool { return true }
+	admin := func(p CompanyPrivileges) bool { return p.Admin }
+	handler := New(WithBaseURL(snapshotServer(t, 30, `{"jim@example.org": {"abc-123": {"admin": true}, "def-456": {"time": true}}}`).URL))
+	require.NoError(t, handler.Process(&UserAdded{Email: email, CompanyID: company, SequenceNo: 10}))
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: company, Privilege: PrivilegeAdmin, SequenceNo: 11}))
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: "def-456", Privilege: PrivilegeTime, SequenceNo: 12}))
+
+	require.NoError(t, handler.Process(&UserRemoved{Email: email, CompanyID: company}))
+	require.NoError(t, handler.Process(&PrivilegeRemoved{Email: email, CompanyID: "def-456", Privilege: PrivilegeTime}))
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: company, Privilege: PrivilegeSalary, SequenceNo: 15}))
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: company, Privilege: PrivilegeAdmin, SequenceNo: 16}))
+	require.NoError(t, handler.Process(&UserAdded{Email: email, CompanyID: company, SequenceNo: 17}))
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: email, CompanyID: "def-456", Privilege: PrivilegeTime, SequenceNo: 18}))
+	assert.False(t, handler.IsAllowed(email, company, all), "no event overrides an unordered user removal")
+	assert.False(t, handler.IsAllowed(email, "def-456", func(p CompanyPrivileges) bool { return p.Time }), "no event overrides an unordered privilege removal")
+
+	require.NoError(t, handler.Fetch())
+	assert.True(t, handler.IsAllowed(email, company, admin), "the next snapshot replaces the unordered removal")
+	assert.True(t, handler.IsAllowed(email, "def-456", func(p CompanyPrivileges) bool { return p.Time }))
+}
+
+func TestPrivilegeHandler_Fetch_Deletes_Unordered_Removal_Missing_From_Snapshot(t *testing.T) {
+	handler := New(WithBaseURL(snapshotServer(t, 30, `{}`).URL))
+	require.NoError(t, handler.Process(&UserRemoved{Email: "jim@example.org", CompanyID: "abc-123"}))
+
+	require.NoError(t, handler.Fetch())
+
+	handler.RLock()
+	defer handler.RUnlock()
+	assert.Empty(t, handler.state)
+}
+
+func TestPrivilegeHandler_Process_Unknown_Privilege_Creates_No_State(t *testing.T) {
+	handler := New()
+	require.NoError(t, handler.Process(&PrivilegeRemoved{Email: "jim@example.org", CompanyID: "abc-123", Privilege: "UNKNOWN", SequenceNo: 1}))
+	require.NoError(t, handler.Process(&PrivilegeAdded{Email: "jim@example.org", CompanyID: "abc-123", Privilege: "UNKNOWN", SequenceNo: 2}))
+
+	handler.RLock()
+	defer handler.RUnlock()
+	assert.Empty(t, handler.state)
+}
+
+func TestPrivilegeHandler_Fetch_Retries_While_ReadView_Not_Ready(t *testing.T) {
+	var calls atomic.Int32
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if calls.Add(1) < 3 {
+			w.WriteHeader(http.StatusServiceUnavailable)
+			return
+		}
+		w.Header().Set(SequenceHeader, "7")
+		_, _ = w.Write([]byte(`{"jim@example.org": {"abc-123": {"admin": true}}}`))
+	}))
+	defer server.Close()
+	handler := New(WithBaseURL(server.URL))
+	handler.retryDelay = time.Millisecond
+
+	require.NoError(t, handler.Fetch())
+
+	assert.Equal(t, int32(3), calls.Load())
+	assert.True(t, handler.IsAllowed("jim@example.org", "abc-123", func(p CompanyPrivileges) bool { return p.Admin }))
+}
+
+func TestPrivilegeHandler_Fetch_Gives_Up_When_ReadView_Stays_Behind(t *testing.T) {
+	var calls atomic.Int32
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		calls.Add(1)
+		w.WriteHeader(http.StatusServiceUnavailable)
+	}))
+	defer server.Close()
+	handler := New(WithBaseURL(server.URL))
+	handler.retryDelay = time.Millisecond
+	handler.retries = 2
+
+	assert.EqualError(t, handler.Fetch(), "fetch privileges: authz-service read view not ready")
+	assert.Equal(t, int32(3), calls.Load())
+}
+
+func TestPrivilegeHandler_Process_Drops_Invalid_SequenceNo(t *testing.T) {
+	for _, seq := range []int{-1, math.MaxInt} {
+		handler := New()
+		require.NoError(t, handler.Process(&PrivilegeAdded{Email: "jim@example.org", CompanyID: "abc-123", Privilege: PrivilegeAdmin, SequenceNo: seq}))
+		require.NoError(t, handler.Process(&UserRemoved{Email: "jim@example.org", CompanyID: "abc-123", SequenceNo: seq}))
+		handler.RLock()
+		assert.Empty(t, handler.state, "seq %d", seq)
+		handler.RUnlock()
+	}
+}

cliff.toml

@@ -78,3 +78,7 @@ filter_commits = false
 topo_order = false
 # sort the commits inside sections by oldest/newest order
 sort_commits = "oldest"
+
+[bump]
+# Before 1.0.0, a breaking change bumps the minor version instead of the major.
+breaking_always_bump_major = false

events.go

@@ -1,15 +1,18 @@
 package client
 
-// UserAdded is the event sent when a new user is added to a company
+// UserAdded is the event sent when a new user is added to a company.
+// SequenceNo is authz-service's global event sequence number; it orders the events.
 type UserAdded struct {
-	Email     string `json:"email"`
-	CompanyID string `json:"companyId"`
+	Email      string `json:"email"`
+	CompanyID  string `json:"companyId"`
+	SequenceNo int    `json:"sequenceNo"`
 }
 
 // UserRemoved is the event sent when a user is removed from a company
 type UserRemoved struct {
-	Email     string `json:"email"`
-	CompanyID string `json:"companyId"`
+	Email      string `json:"email"`
+	CompanyID  string `json:"companyId"`
+	SequenceNo int    `json:"sequenceNo"`
 }
 
 // Privilege is an enumeration of all available privileges
@@ -51,14 +54,16 @@ func (e Privilege) String() string {
 
 // PrivilegeAdded is the event sent when a new privilege is added
 type PrivilegeAdded struct {
-	Email     string    `json:"email"`
-	CompanyID string    `json:"companyId"`
-	Privilege Privilege `json:"privilege"`
+	Email      string    `json:"email"`
+	CompanyID  string    `json:"companyId"`
+	Privilege  Privilege `json:"privilege"`
+	SequenceNo int       `json:"sequenceNo"`
 }
 
 // PrivilegeRemoved is the event sent when a privilege is removed
 type PrivilegeRemoved struct {
-	Email     string    `json:"email"`
-	CompanyID string    `json:"companyId"`
-	Privilege Privilege `json:"privilege"`
+	Email      string    `json:"email"`
+	CompanyID  string    `json:"companyId"`
+	Privilege  Privilege `json:"privilege"`
+	SequenceNo int       `json:"sequenceNo"`
 }

go.mod

@@ -1,19 +1,31 @@
 module gitea.unbound.se/shiny/authz_client
 
-go 1.22.12
-
-toolchain go1.25.5
+go 1.26.2
 
 require (
-	github.com/sparetimecoders/goamqp v0.3.3
-	github.com/stretchr/testify v1.11.1
+	codeberg.org/messaging/go-messaging-amqp v0.0.6
+	codeberg.org/messaging/messaging v0.0.5
+	github.com/stretchr/testify v1.12.1
 )
 
 require (
-	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/go-logr/logr v1.4.3 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/google/uuid v1.6.0 // indirect
-	github.com/pkg/errors v0.9.1 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/rabbitmq/amqp091-go v1.10.0 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/prometheus/client_golang v1.23.2 // indirect
+	github.com/prometheus/client_model v0.6.2 // indirect
+	github.com/prometheus/common v0.66.1 // indirect
+	github.com/prometheus/procfs v0.16.1 // indirect
+	github.com/rabbitmq/amqp091-go v1.15.0 // indirect
+	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
+	go.opentelemetry.io/otel v1.44.0 // indirect
+	go.opentelemetry.io/otel/metric v1.44.0 // indirect
+	go.opentelemetry.io/otel/trace v1.44.0 // indirect
+	go.yaml.in/yaml/v2 v2.4.2 // indirect
+	go.yaml.in/yaml/v3 v3.0.5 // indirect
+	golang.org/x/sys v0.45.0 // indirect
+	google.golang.org/protobuf v1.36.8 // indirect
 )

go.sum

@@ -1,20 +1,72 @@
-github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+codeberg.org/messaging/go-messaging-amqp v0.0.6 h1:TAPcIspjjg44MNXwbcscW+ol1kIX49lnX2N3dsh0e0s=
+codeberg.org/messaging/go-messaging-amqp v0.0.6/go.mod h1:R4Hg1w964P7OP7vQ9AsXdd4KjgN/YlQ/9+XzXKpEVp4=
+codeberg.org/messaging/messaging v0.0.5 h1:/ueH90F4RNPUeeJIwdG9oVhDW7+XjCzwOYq8xc0kfQk=
+codeberg.org/messaging/messaging v0.0.5/go.mod h1:xyWLUcfaVzcN6GWk9uaQsxPVUC2Vm2S89mYZGdiWTWg=
+codeberg.org/messaging/messaging/tck v0.0.3 h1:a4Nr7ytFqEJloTOyVeAtMNgO9Fig1ZUirjW4FVlK0lc=
+codeberg.org/messaging/messaging/tck v0.0.3/go.mod h1:RiOsKXGAhNQK2STBVYGjhN0CFtmcrsEne1qUe15n8Q4=
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
+github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
+github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
+github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
+github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
-github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
-github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/rabbitmq/amqp091-go v1.10.0 h1:STpn5XsHlHGcecLmMFCtg7mqq0RnD+zFr4uzukfVhBw=
-github.com/rabbitmq/amqp091-go v1.10.0/go.mod h1:Hy4jKW5kQART1u+JkDTF9YYOQUHXqMuhrgxOEeS7G4o=
-github.com/sparetimecoders/goamqp v0.3.3 h1:z/nfTPmrjeU/rIVuNOgsVLCimp3WFoNFvS3ZzXRJ6HE=
-github.com/sparetimecoders/goamqp v0.3.3/go.mod h1:W9NRCpWLE+Vruv2dcRSbszNil2O826d2Nv6kAkETW5o=
-github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
-github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+github.com/klauspost/compress v1.18.5 h1:/h1gH5Ce+VWNLSWqPzOVn6XBO+vJbCNGvjoaGBFW2IE=
+github.com/klauspost/compress v1.18.5/go.mod h1:cwPg85FWrGar70rWktvGQj8/hthj3wpl0PGDogxkrSQ=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
+github.com/nats-io/nats.go v1.52.0 h1:n3avV4VBsCgsdwh71TppsTwtv+QdPs7ntSKM8qJLGsc=
+github.com/nats-io/nats.go v1.52.0/go.mod h1:26HypzazeOkyO3/mqd1zZd53STJN0EjCYF9Uy2ZOBno=
+github.com/nats-io/nkeys v0.4.15 h1:JACV5jRVO9V856KOapQ7x+EY8Jo3qw1vJt/9Jpwzkk4=
+github.com/nats-io/nkeys v0.4.15/go.mod h1:CpMchTXC9fxA5zrMo4KpySxNjiDVvr8ANOSZdiNfUrs=
+github.com/nats-io/nuid v1.0.1 h1:5iA8DT8V7q8WK2EScv2padNa/rTESc1KdnPw4TC2paw=
+github.com/nats-io/nuid v1.0.1/go.mod h1:19wcPz3Ph3q0Jbyiqsd0kePYG7A95tJPxeL+1OSON2c=
+github.com/prometheus/client_golang v1.23.2 h1:Je96obch5RDVy3FDMndoUsjAhG5Edi49h0RJWRi/o0o=
+github.com/prometheus/client_golang v1.23.2/go.mod h1:Tb1a6LWHB3/SPIzCoaDXI4I8UHKeFTEQ1YCr+0Gyqmg=
+github.com/prometheus/client_model v0.6.2 h1:oBsgwpGs7iVziMvrGhE53c/GrLUsZdHnqNwqPLxwZyk=
+github.com/prometheus/client_model v0.6.2/go.mod h1:y3m2F6Gdpfy6Ut/GBsUqTWZqCUvMVzSfMLjcu6wAwpE=
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+github.com/rabbitmq/amqp091-go v1.15.0 h1:LEQL4/yp48/Wigt6A6XOu18RQRo8ZHtB5I/KZJn+gkw=
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 go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
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+google.golang.org/protobuf v1.36.8/go.mod h1:fuxRtAxBytpl4zzqUh6/eyUujkJdNiuEkXntxiD/uRU=
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renovate.json

@@ -2,5 +2,15 @@
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
   "extends": [
     "config:recommended"
+  ],
+  "packageRules": [
+    {
+      "groupName": "OpenTelemetry",
+      "matchPackageNames": [
+        "go.opentelemetry.io/**",
+        "gitea.unbound.se/shiny/otelsetup",
+        "gitea.unbound.se/shiny/logging"
+      ]
+    }
   ]
 }