diff --git a/gateway/qualification_contract_test.go b/gateway/qualification_contract_test.go
index 785d519..2760bcb 100644
--- a/gateway/qualification_contract_test.go
+++ b/gateway/qualification_contract_test.go
@@ -39,6 +39,21 @@ func TestQualificationCatalogMatchesSection7(t *testing.T) {
 	}
 }
 
+func TestQualificationProtocolVersionIsExplicitAndImmutable(t *testing.T) {
+	const version = "v1.0.0-phase3c-gateway-rc.6"
+	t.Setenv("VERSEVDI_QUALIFICATION_PROTOCOL_VERSION", version)
+	got, err := qualificationProtocolVersion()
+	if err != nil || got != version {
+		t.Fatalf("qualificationProtocolVersion() = %q, want %q", got, version)
+	}
+	for _, invalid := range []string{"", "unknown", "v1", " v1.0.0", "v1.0.0+mutable"} {
+		t.Setenv("VERSEVDI_QUALIFICATION_PROTOCOL_VERSION", invalid)
+		if _, err := qualificationProtocolVersion(); err == nil {
+			t.Fatalf("qualificationProtocolVersion() accepted %q", invalid)
+		}
+	}
+}
+
 func TestQualificationOutputAndStatisticsFailClosed(t *testing.T) {
 	if err := validateQualificationOutputDir("relative/evidence"); err == nil {
 		t.Fatal("relative evidence directory was accepted")
diff --git a/gateway/qualification_harness_test.go b/gateway/qualification_harness_test.go
index de48852..3abfa8c 100644
--- a/gateway/qualification_harness_test.go
+++ b/gateway/qualification_harness_test.go
@@ -14,8 +14,8 @@ import (
 	"math"
 	"os"
 	"path/filepath"
+	"regexp"
 	"runtime"
-	"runtime/debug"
 	"sort"
 	"strings"
 	"testing"
@@ -585,17 +585,13 @@ func qualificationMaximumFiveSecondBytes(deliveries []syntheticPacerDelivery) in
 	return maximum
 }
 
-func qualificationProtocolVersion() string {
-	info, ok := debug.ReadBuildInfo()
-	if !ok {
-		return "unknown"
+func qualificationProtocolVersion() (string, error) {
+	version := os.Getenv("VERSEVDI_QUALIFICATION_PROTOCOL_VERSION")
+	valid, err := regexp.MatchString(`^v[0-9]+\.[0-9]+\.[0-9]+-[0-9A-Za-z]+(?:[.-][0-9A-Za-z]+)*$`, version)
+	if err != nil || !valid {
+		return "", errors.New("VERSEVDI_QUALIFICATION_PROTOCOL_VERSION must be an immutable prerelease tag")
 	}
-	for _, dependency := range info.Deps {
-		if dependency.Path == "git.sechmachine.io.vn/sechmachine/VerseVDI-Protocol" {
-			return dependency.Version
-		}
-	}
-	return "unknown"
+	return version, nil
 }
 
 func qualificationCandidateCommit() (string, error) {
@@ -633,6 +629,10 @@ func TestSection7Qualification(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	protocolVersion, err := qualificationProtocolVersion()
+	if err != nil {
+		t.Fatal(err)
+	}
 	if err := os.Mkdir(output, 0o750); err != nil {
 		t.Fatalf("create new qualification evidence directory: %v", err)
 	}
@@ -641,8 +641,11 @@ func TestSection7Qualification(t *testing.T) {
 	qualificationTraverseProfiles(t, media)
 	manifest := qualificationManifest{
 		Status: "running", ToolVersion: qualificationToolVersion,
-		Command:         fmt.Sprintf("VERSEVDI_QUALIFICATION_DIR=%s VERSEVDI_QUALIFICATION_COMMIT=%s GOWORK=off go test ./gateway -run '^TestSection7Qualification$' -count=1 -timeout 45m -v", output, commit),
-		CandidateCommit: commit, ProtocolVersion: qualificationProtocolVersion(),
+		Command: fmt.Sprintf(
+			"VERSEVDI_QUALIFICATION_DIR=%s VERSEVDI_QUALIFICATION_COMMIT=%s VERSEVDI_QUALIFICATION_PROTOCOL_VERSION=%s GOWORK=off go test ./gateway -run '^TestSection7Qualification$' -count=1 -timeout 45m -v",
+			output, commit, protocolVersion,
+		),
+		CandidateCommit: commit, ProtocolVersion: protocolVersion,
 		StartedAt: started.Format(time.RFC3339Nano), GoVersion: runtime.Version(),
 		OS: runtime.GOOS, Architecture: runtime.GOARCH,
 		Topology:        "bounded fixture provider -> gateway framing and mTLS/QUIC transport -> fixture client",
diff --git a/openspec/changes/phase3c-gateway-qualification/.openspec.yaml b/openspec/changes/archive/2026-07-29-phase3c-gateway-qualification/.openspec.yaml
similarity index 100%
rename from openspec/changes/phase3c-gateway-qualification/.openspec.yaml
rename to openspec/changes/archive/2026-07-29-phase3c-gateway-qualification/.openspec.yaml
diff --git a/openspec/changes/phase3c-gateway-qualification/design.md b/openspec/changes/archive/2026-07-29-phase3c-gateway-qualification/design.md
similarity index 100%
rename from openspec/changes/phase3c-gateway-qualification/design.md
rename to openspec/changes/archive/2026-07-29-phase3c-gateway-qualification/design.md
diff --git a/openspec/changes/phase3c-gateway-qualification/proposal.md b/openspec/changes/archive/2026-07-29-phase3c-gateway-qualification/proposal.md
similarity index 100%
rename from openspec/changes/phase3c-gateway-qualification/proposal.md
rename to openspec/changes/archive/2026-07-29-phase3c-gateway-qualification/proposal.md
diff --git a/openspec/changes/phase3c-gateway-qualification/specs/gateway-qualification/spec.md b/openspec/changes/archive/2026-07-29-phase3c-gateway-qualification/specs/gateway-qualification/spec.md
similarity index 100%
rename from openspec/changes/phase3c-gateway-qualification/specs/gateway-qualification/spec.md
rename to openspec/changes/archive/2026-07-29-phase3c-gateway-qualification/specs/gateway-qualification/spec.md
diff --git a/openspec/changes/phase3c-gateway-qualification/tasks.md b/openspec/changes/archive/2026-07-29-phase3c-gateway-qualification/tasks.md
similarity index 89%
rename from openspec/changes/phase3c-gateway-qualification/tasks.md
rename to openspec/changes/archive/2026-07-29-phase3c-gateway-qualification/tasks.md
index a80822d..91be1da 100644
--- a/openspec/changes/phase3c-gateway-qualification/tasks.md
+++ b/openspec/changes/archive/2026-07-29-phase3c-gateway-qualification/tasks.md
@@ -18,7 +18,7 @@
 
 - [x] 3.1 Run focused red/green checks, strict OpenSpec validation, `make
   verify`, race/fuzz/resource checks, and freeze the harness commit.
-- [ ] 3.2 Run the opt-in ten-minute and six-profile command exactly once
+- [x] 3.2 Run the opt-in ten-minute and six-profile command exactly once
   against the frozen candidate and archive raw artifacts and hashes.
-- [ ] 3.3 Sync the canonical specification, archive the completed change, and
+- [x] 3.3 Sync the canonical specification, archive the completed change, and
   revalidate strictly without claiming live Apollo/macOS/firewall evidence.
diff --git a/openspec/specs/gateway-qualification/spec.md b/openspec/specs/gateway-qualification/spec.md
new file mode 100644
index 0000000..4d059fc
--- /dev/null
+++ b/openspec/specs/gateway-qualification/spec.md
@@ -0,0 +1,67 @@
+# gateway-qualification Specification
+
+## Purpose
+Define the deterministic processing, impairment, pacing, and evidence boundaries
+for qualifying a frozen Phase 3C gateway candidate.
+## Requirements
+### Requirement: Fixed media processing qualification
+The qualification harness SHALL run 1080p60 H.264 at 20 Mbps, 1440p120 HEVC
+at 50 Mbps, and 4K60 HEVC at 80 Mbps for ten wall-clock minutes each after a
+recorded warm-up. It SHALL preserve encoded payload bytes, record every
+monotonic processing sample, report count, min, median, p90, p95, p99, max,
+mean, standard deviation, timing overhead, and observed bitrate, and fail when
+any p95 exceeds 5 ms.
+
+#### Scenario: Healthy fixed profile
+- **WHEN** a frozen candidate runs one fixed profile for the normative duration
+- **THEN** the harness emits compressed raw samples and a summary tied to the
+  exact source commit, Protocol version, environment, and payload hash.
+
+#### Scenario: Processing gate failure
+- **WHEN** payload integrity fails or measured p95 exceeds 5 ms
+- **THEN** the qualification command exits unsuccessfully without recording a
+  passing candidate.
+
+### Requirement: Bounded impairment qualification
+The harness SHALL run exactly the baseline, latency, jitter, loss, reorder,
+and constrained Section 7.2 profiles once. Baseline SHALL cover all three
+media profiles and the other profiles SHALL cover 1080p60. Each artifact SHALL
+record tool version, exact command/configuration, direction, queue discipline,
+topology, fixed seed, and observed RTT, jitter, loss, reorder, throughput,
+drops, and capacity-step statistics.
+
+#### Scenario: Complete six-profile run
+- **WHEN** the frozen candidate runs impairment qualification
+- **THEN** one result exists for each named profile, with no Cartesian
+  expansion and with observed rather than configured statistics.
+
+#### Scenario: Unsupported or unbounded configuration
+- **WHEN** a profile name, packet count, queue bound, loss, reorder, or
+  bandwidth step falls outside the fixed catalog
+- **THEN** the harness rejects it before allocating or running the simulation.
+
+### Requirement: Fairness and cap qualification
+The harness SHALL exercise the production fair pacer with eight equal-tier
+synthetic sessions for the required 60-second virtual interval, report every
+share error and Jain's fairness index, and fail above 10% share error. It SHALL
+apply 25% and 50% capacity steps, fail convergence beyond ten virtual seconds,
+and fail aggregate egress above 105% of the cap over any rolling five-second
+window.
+
+#### Scenario: Equal-tier and capacity-step evidence
+- **WHEN** the frozen candidate runs scheduler qualification
+- **THEN** the artifact contains per-flow bytes, share errors, Jain's index,
+  step convergence, and rolling cap observations derived from the production
+  pacer.
+
+### Requirement: Honest qualification boundary
+Qualification artifacts SHALL contain no provider endpoint, credential,
+clipboard text, input payload, secret, raw media content, or claim of live
+Apollo/macOS/firewall interoperability. The harness SHALL add no codec
+operation, production dependency, cgo, sidecar, or direct provider route.
+
+#### Scenario: Deterministic evidence publication
+- **WHEN** qualification completes
+- **THEN** the manifest labels fake-provider, virtual impairment, and local
+  processing evidence separately and leaves live interoperability
+  deferred-owner-e2e.