diff --git a/src/ScadaLink.Commons/Messages/Integration/CachedCallTelemetry.cs b/src/ScadaLink.Commons/Messages/Integration/CachedCallTelemetry.cs
new file mode 100644
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+++ b/src/ScadaLink.Commons/Messages/Integration/CachedCallTelemetry.cs
@@ -0,0 +1,34 @@
+using ScadaLink.Commons.Entities.Audit;
+using ScadaLink.Commons.Types;
+
+namespace ScadaLink.Commons.Messages.Integration;
+
+/// <summary>
+/// Combined audit + operational telemetry packet for cached outbound calls
+/// (Audit Log #23 / M3). The site emits one packet per lifecycle event
+/// — <c>Submit</c> (Audit kind <c>CachedSubmit</c>), per-attempt
+/// <c>ApiCallCached</c>/<c>DbWriteCached</c>, terminal <c>CachedResolve</c> —
+/// and central writes the <see cref="AuditEvent"/> row plus the
+/// <see cref="SiteCallOperational"/> upsert in one MS SQL transaction. Two
+/// payload shapes ride on a single wire message so the same on-the-wire batch
+/// can carry mixed lifecycle events without the central dual-write needing a
+/// second RPC for the operational state.
+/// </summary>
+/// <remarks>
+/// <para>
+/// Both inner records carry the same <c>TrackedOperationId</c> — the
+/// idempotency key end-to-end. The <see cref="AuditEvent.CorrelationId"/>
+/// pattern (used by Audit Log #23 to thread cached-call rows together) is
+/// honoured by the site emitter; the packet itself is shape-only and makes no
+/// independent correlation guarantees.
+/// </para>
+/// <para>
+/// Additive-only per Commons REQ-COM-5a (M2 reviewer note) — this is a new
+/// message, not a rename of any existing M2 envelope.
+/// </para>
+/// </remarks>
+/// <param name="Audit">The Audit Log #23 row to insert at central.</param>
+/// <param name="Operational">The <c>SiteCalls</c> upsert mirroring this lifecycle event.</param>
+public sealed record CachedCallTelemetry(
+    AuditEvent Audit,
+    SiteCallOperational Operational);
diff --git a/src/ScadaLink.Commons/Types/SiteCallOperational.cs b/src/ScadaLink.Commons/Types/SiteCallOperational.cs
new file mode 100644
index 0000000..25d9414
--- /dev/null
+++ b/src/ScadaLink.Commons/Types/SiteCallOperational.cs
@@ -0,0 +1,46 @@
+namespace ScadaLink.Commons.Types;
+
+/// <summary>
+/// Operational state of one cached call as seen by the site, carried on the
+/// combined <c>CachedCallTelemetry</c> packet (Audit Log #23 / M3) and persisted
+/// at central as the <c>SiteCalls</c> row mirroring the call's status.
+/// </summary>
+/// <remarks>
+/// <para>
+/// One row per <see cref="TrackedOperationId"/> at central; ingest is
+/// insert-if-not-exists then upsert-on-newer-status (monotonic — never rolls
+/// back). The site remains the source of truth — this record is the
+/// "eventually-consistent mirror" the central UI's Site Calls page reads.
+/// </para>
+/// </remarks>
+/// <param name="TrackedOperationId">Idempotency key shared with the audit row.</param>
+/// <param name="Channel">
+/// Trust-boundary channel — <c>"ApiOutbound"</c> or <c>"DbOutbound"</c>. String form
+/// (not the <see cref="ScadaLink.Commons.Types.Enums.AuditChannel"/> enum) so the
+/// record serialises identically across SQL / gRPC / JSON boundaries.
+/// </param>
+/// <param name="Target">Human-readable target (e.g. <c>"ERP.GetOrder"</c>).</param>
+/// <param name="SourceSite">Site id that submitted the cached call.</param>
+/// <param name="Status">
+/// Lifecycle status — string form of <see cref="ScadaLink.Commons.Types.Enums.AuditStatus"/>:
+/// <c>Submitted</c>, <c>Retrying</c>, <c>Attempted</c>, <c>Delivered</c>,
+/// <c>Failed</c>, <c>Parked</c>, <c>Discarded</c>.
+/// </param>
+/// <param name="RetryCount">Number of dispatch attempts so far; 0 prior to first attempt.</param>
+/// <param name="LastError">Most recent error message; null when no failures have occurred.</param>
+/// <param name="HttpStatus">Most recent HTTP status code (API calls only); null otherwise.</param>
+/// <param name="CreatedAtUtc">UTC timestamp the cached call was first submitted.</param>
+/// <param name="UpdatedAtUtc">UTC timestamp of the latest status mutation.</param>
+/// <param name="TerminalAtUtc">UTC timestamp the row reached a terminal status; null while still active.</param>
+public sealed record SiteCallOperational(
+    TrackedOperationId TrackedOperationId,
+    string Channel,
+    string Target,
+    string SourceSite,
+    string Status,
+    int RetryCount,
+    string? LastError,
+    int? HttpStatus,
+    DateTime CreatedAtUtc,
+    DateTime UpdatedAtUtc,
+    DateTime? TerminalAtUtc);
diff --git a/tests/ScadaLink.Commons.Tests/Messages/Integration/CachedCallTelemetryTests.cs b/tests/ScadaLink.Commons.Tests/Messages/Integration/CachedCallTelemetryTests.cs
new file mode 100644
index 0000000..03980d8
--- /dev/null
+++ b/tests/ScadaLink.Commons.Tests/Messages/Integration/CachedCallTelemetryTests.cs
@@ -0,0 +1,203 @@
+using ScadaLink.Commons.Entities.Audit;
+using ScadaLink.Commons.Messages.Integration;
+using ScadaLink.Commons.Types;
+using ScadaLink.Commons.Types.Enums;
+
+namespace ScadaLink.Commons.Tests.Messages.Integration;
+
+/// <summary>
+/// Audit Log #23 (M3 Bundle A — Task A4) — tests for the combined
+/// audit + operational telemetry packet emitted per cached-call lifecycle event
+/// (<c>Submit</c> → per-attempt <c>ApiCallCached</c> / <c>DbWriteCached</c> →
+/// terminal <c>Resolve</c>). The site emits one packet per event; central writes
+/// <c>AuditLog</c> + <c>SiteCalls</c> in one MS SQL transaction.
+/// </summary>
+public class CachedCallTelemetryTests
+{
+    private static readonly DateTime FixedNowUtc = new(2026, 5, 20, 10, 0, 0, DateTimeKind.Utc);
+
+    private const string SiteId = "site-77";
+    private const string InstanceName = "Plant.Pump42";
+    private const string SourceScript = "ScriptActor:OnTick";
+
+    private static AuditEvent BuildAuditEvent(
+        TrackedOperationId trackedId,
+        AuditKind kind,
+        AuditStatus status,
+        Guid? correlationId = null,
+        string? errorMessage = null,
+        int? httpStatus = null)
+    {
+        return new AuditEvent
+        {
+            EventId = Guid.NewGuid(),
+            OccurredAtUtc = FixedNowUtc,
+            Channel = AuditChannel.ApiOutbound,
+            Kind = kind,
+            CorrelationId = correlationId ?? trackedId.Value,
+            SourceSiteId = SiteId,
+            SourceInstanceId = InstanceName,
+            SourceScript = SourceScript,
+            Target = "ERP.GetOrder",
+            Status = status,
+            HttpStatus = httpStatus,
+            ErrorMessage = errorMessage,
+            PayloadTruncated = false,
+            ForwardState = AuditForwardState.Pending,
+        };
+    }
+
+    private static SiteCallOperational BuildOperational(
+        TrackedOperationId trackedId,
+        AuditStatus status,
+        int retryCount,
+        string? lastError = null,
+        int? httpStatus = null,
+        DateTime? terminalAtUtc = null)
+    {
+        return new SiteCallOperational(
+            TrackedOperationId: trackedId,
+            Channel: nameof(AuditChannel.ApiOutbound),
+            Target: "ERP.GetOrder",
+            SourceSite: SiteId,
+            Status: status.ToString(),
+            RetryCount: retryCount,
+            LastError: lastError,
+            HttpStatus: httpStatus,
+            CreatedAtUtc: FixedNowUtc,
+            UpdatedAtUtc: terminalAtUtc ?? FixedNowUtc,
+            TerminalAtUtc: terminalAtUtc);
+    }
+
+    [Fact]
+    public void SubmitPacket_AuditCarriesCachedSubmit_AndOperationalRetryCountZero()
+    {
+        var trackedId = TrackedOperationId.New();
+        var audit = BuildAuditEvent(trackedId, AuditKind.CachedSubmit, AuditStatus.Submitted);
+        var operational = BuildOperational(trackedId, AuditStatus.Submitted, retryCount: 0);
+
+        var packet = new CachedCallTelemetry(audit, operational);
+
+        Assert.Equal(AuditKind.CachedSubmit, packet.Audit.Kind);
+        Assert.Equal(AuditStatus.Submitted, packet.Audit.Status);
+        Assert.Equal(nameof(AuditStatus.Submitted), packet.Operational.Status);
+        Assert.Equal(0, packet.Operational.RetryCount);
+        Assert.Null(packet.Operational.TerminalAtUtc);
+        Assert.Equal(trackedId, packet.Operational.TrackedOperationId);
+    }
+
+    [Fact]
+    public void AttemptedPacket_AuditCarriesApiCallCached_RetryCountAlignsBetweenAuditAndOperational()
+    {
+        var trackedId = TrackedOperationId.New();
+        var audit = BuildAuditEvent(
+            trackedId,
+            AuditKind.ApiCallCached,
+            AuditStatus.Attempted,
+            errorMessage: "HTTP 503 from ERP",
+            httpStatus: 503);
+        var operational = BuildOperational(
+            trackedId,
+            AuditStatus.Attempted,
+            retryCount: 2,
+            lastError: "HTTP 503 from ERP",
+            httpStatus: 503);
+
+        var packet = new CachedCallTelemetry(audit, operational);
+
+        Assert.Equal(AuditKind.ApiCallCached, packet.Audit.Kind);
+        Assert.Equal(AuditStatus.Attempted, packet.Audit.Status);
+        Assert.Equal(nameof(AuditStatus.Attempted), packet.Operational.Status);
+        // Retry-count alignment: the operational row carries the canonical N;
+        // the audit row's error/http surface the same attempt's outcome.
+        Assert.Equal(packet.Audit.ErrorMessage, packet.Operational.LastError);
+        Assert.Equal(packet.Audit.HttpStatus, packet.Operational.HttpStatus);
+        Assert.Equal(2, packet.Operational.RetryCount);
+        Assert.Null(packet.Operational.TerminalAtUtc);
+    }
+
+    [Fact]
+    public void AttemptedPacket_DbWriteCached_CarriesDbWriteCachedKind()
+    {
+        var trackedId = TrackedOperationId.New();
+        var audit = BuildAuditEvent(
+            trackedId,
+            AuditKind.DbWriteCached,
+            AuditStatus.Attempted,
+            errorMessage: "Timeout",
+            httpStatus: null);
+        var operational = BuildOperational(
+            trackedId,
+            AuditStatus.Attempted,
+            retryCount: 1,
+            lastError: "Timeout");
+
+        var packet = new CachedCallTelemetry(audit, operational);
+
+        Assert.Equal(AuditKind.DbWriteCached, packet.Audit.Kind);
+        Assert.Equal(AuditStatus.Attempted, packet.Audit.Status);
+        Assert.Equal(1, packet.Operational.RetryCount);
+    }
+
+    [Theory]
+    [InlineData(AuditStatus.Delivered)]
+    [InlineData(AuditStatus.Failed)]
+    [InlineData(AuditStatus.Parked)]
+    [InlineData(AuditStatus.Discarded)]
+    public void ResolvePacket_AuditCarriesCachedResolve_OperationalTerminalAtUtcSet(AuditStatus terminalStatus)
+    {
+        var trackedId = TrackedOperationId.New();
+        var terminalAt = FixedNowUtc.AddMinutes(5);
+        var audit = BuildAuditEvent(trackedId, AuditKind.CachedResolve, terminalStatus);
+        var operational = BuildOperational(
+            trackedId,
+            terminalStatus,
+            retryCount: 3,
+            terminalAtUtc: terminalAt);
+
+        var packet = new CachedCallTelemetry(audit, operational);
+
+        Assert.Equal(AuditKind.CachedResolve, packet.Audit.Kind);
+        Assert.Equal(terminalStatus, packet.Audit.Status);
+        Assert.Equal(terminalStatus.ToString(), packet.Operational.Status);
+        Assert.NotNull(packet.Operational.TerminalAtUtc);
+        Assert.Equal(terminalAt, packet.Operational.TerminalAtUtc);
+    }
+
+    [Fact]
+    public void CachedCallTelemetry_RoundTripEquality()
+    {
+        var trackedId = TrackedOperationId.New();
+        var audit = BuildAuditEvent(trackedId, AuditKind.CachedSubmit, AuditStatus.Submitted);
+        var operational = BuildOperational(trackedId, AuditStatus.Submitted, retryCount: 0);
+
+        var a = new CachedCallTelemetry(audit, operational);
+        var b = new CachedCallTelemetry(audit, operational);
+
+        Assert.Equal(a, b);
+        Assert.Equal(a.GetHashCode(), b.GetHashCode());
+
+        var differentOperational = operational with { RetryCount = 1 };
+        var c = a with { Operational = differentOperational };
+
+        Assert.NotEqual(a, c);
+        Assert.Equal(0, a.Operational.RetryCount);
+        Assert.Equal(1, c.Operational.RetryCount);
+    }
+
+    [Fact]
+    public void SiteCallOperational_RoundTripEquality_AndWithExpression()
+    {
+        var trackedId = TrackedOperationId.New();
+        var a = BuildOperational(trackedId, AuditStatus.Submitted, retryCount: 0);
+        var b = BuildOperational(trackedId, AuditStatus.Submitted, retryCount: 0);
+
+        Assert.Equal(a, b);
+        Assert.Equal(a.GetHashCode(), b.GetHashCode());
+
+        var withDifferentRetry = a with { RetryCount = 5 };
+        Assert.NotEqual(a, withDifferentRetry);
+        Assert.Equal(0, a.RetryCount);
+        Assert.Equal(5, withDifferentRetry.RetryCount);
+    }
+}