feat(protocol): advertise runtime full access capability

CHANGELOG.md

@@ -23,6 +23,7 @@ Versioning convention (see [README.md](./README.md) for full policy):
 - `PushNotifyResultPayload` for accepted/retryable/permanent Web Push result acknowledgements
 - `CostPayload` shared wire type with additive cached-token, pricing-availability, and Codex credit estimate fields
 - `RateLimitsUpdatedPayload` additive Codex plan and actual credit snapshot fields
+- `AgentCapability.supports_runtime_full_access` additive capability flag for Codex runtime Full access opt-in
 
 ## [v0.1.0] — 2026-04-29
 

capabilities.go

@@ -52,6 +52,13 @@ package protocol
 //     decide whether to include "bypass" in the approval-mode cycle. See
 //     specs/195-bypass-mode-optin/contracts/agent-capability-bypass.md for
 //     the canonical contract.
+//
+// Feature 229 (codex-runtime-full-access) adds one field:
+//   - SupportsRuntimeFullAccess — whether the live session supports the
+//     Codex-only runtime transition to approval_policy=never plus
+//     sandbox=danger-full-access. This is true only when the daemon was
+//     configured with `agents.codex.allow_runtime_full_access_mode: true`.
+//     Claude remains false.
 type AgentCapability struct {
 	// Deprecated: As of feature 186 (codex-remaining-gaps), consumers
 	// should read AnswerQuestionFreeText instead. This field is retained
@@ -71,4 +78,5 @@ type AgentCapability struct {
 	SessionScopedApproval     bool `json:"session_scoped_approval"`
 	AnswerQuestionFreeText    bool `json:"answer_question_free_text"`
 	SupportsBypassPermissions bool `json:"supports_bypass_permissions"`
+	SupportsRuntimeFullAccess bool `json:"supports_runtime_full_access"`
 }

capabilities_test.go

@@ -9,12 +9,13 @@ import (
 	protocol "github.com/hishamkaram/agentd-protocol"
 )
 
-// TestAgentCapabilityFields asserts the struct has exactly the eight required
+// TestAgentCapabilityFields asserts the struct has exactly the required
 // bool fields per specs/185-codex-parity-gaps/contracts/agent-capability.md
 // (original 4 fields) and specs/186-codex-remaining-gaps/contracts/
 // session-scoped-approval-capability.md + answer-question-free-text-capability.md
 // (2 new fields added by feature 186), plus feature 188's two MCP parity
-// flags.
+// flags, feature 195's bypass flag, and feature 229's Codex runtime full-access
+// flag.
 func TestAgentCapabilityFields(t *testing.T) {
 	t.Parallel()
 
@@ -33,6 +34,7 @@ func TestAgentCapabilityFields(t *testing.T) {
 		"SessionScopedApproval":     "session_scoped_approval",
 		"AnswerQuestionFreeText":    "answer_question_free_text",
 		"SupportsBypassPermissions": "supports_bypass_permissions",
+		"SupportsRuntimeFullAccess": "supports_runtime_full_access",
 	}
 
 	if got := typ.NumField(); got != len(want) {
@@ -163,7 +165,7 @@ func TestAgentCapabilityJSONKeys(t *testing.T) {
 	}
 
 	// Assert no CamelCase / PascalCase leakage.
-	forbidden := []string{"AnswerQuestion", "SendToolResult", "RewindFiles", "MCPHotApply", "MCPReconnect", "MCPLiveStatusLimited", "SessionScopedApproval", "AnswerQuestionFreeText", "SupportsBypassPermissions"}
+	forbidden := []string{"AnswerQuestion", "SendToolResult", "RewindFiles", "MCPHotApply", "MCPReconnect", "MCPLiveStatusLimited", "SessionScopedApproval", "AnswerQuestionFreeText", "SupportsBypassPermissions", "SupportsRuntimeFullAccess"}
 	for _, k := range forbidden {
 		if strings.Contains(payload, k) {
 			t.Errorf("unexpected Go field name %q in JSON payload: %s", k, payload)
@@ -264,6 +266,27 @@ func TestAgentCapabilityMCPLiveStatusLimitedField(t *testing.T) {
 	}
 }
 
+func TestAgentCapabilitySupportsRuntimeFullAccessField(t *testing.T) {
+	t.Parallel()
+
+	typ := reflect.TypeOf(protocol.AgentCapability{})
+	field, ok := typ.FieldByName("SupportsRuntimeFullAccess")
+	if !ok {
+		t.Fatalf("AgentCapability missing field SupportsRuntimeFullAccess")
+	}
+	if field.Type.Kind() != reflect.Bool {
+		t.Fatalf("SupportsRuntimeFullAccess: want bool, got %s", field.Type.Kind())
+	}
+	if got := field.Tag.Get("json"); got != "supports_runtime_full_access" {
+		t.Fatalf("SupportsRuntimeFullAccess: json tag want %q, got %q", "supports_runtime_full_access", got)
+	}
+
+	var zero protocol.AgentCapability
+	if zero.SupportsRuntimeFullAccess != false {
+		t.Fatalf("zero-value SupportsRuntimeFullAccess: want false, got %v", zero.SupportsRuntimeFullAccess)
+	}
+}
+
 // TestAgentCapability186RoundTrip verifies the new fields marshal and
 // unmarshal with the other 4 correctly across the per-agent shapes called out
 // in data-model.md (Claude: AnswerQuestionFreeText=true, SSA=false; Codex: