diff --git a/tests/msgbuf.cpp b/tests/msgbuf.cpp
new file mode 100644
index 0000000..bf2f95e
--- /dev/null
+++ b/tests/msgbuf.cpp
@@ -0,0 +1,317 @@
+#include <endian.h>
+
+#include <cfloat>
+
+#include <gtest/gtest.h>
+
+/* We're exercising the implementation so disable the asserts for now */
+#ifndef NDEBUG
+#define NDEBUG 1
+#endif
+
+/*
+ * Fix up C11's _Static_assert() vs C++'s static_assert().
+ *
+ * Can we please have nice things for once.
+ */
+#ifdef __cplusplus
+// NOLINTNEXTLINE(bugprone-reserved-identifier,cert-dcl37-c,cert-dcl51-cpp)
+#define _Static_assert(...) static_assert(__VA_ARGS__)
+#endif
+
+#include "msgbuf.h"
+
+TEST(msgbuf, init_bad_ctx)
+{
+    EXPECT_NE(pldm_msgbuf_init(NULL, 0, NULL, 0), PLDM_SUCCESS);
+}
+
+TEST(msgbuf, init_bad_minsize)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    uint8_t buf[1] = {};
+
+    EXPECT_NE(pldm_msgbuf_init(ctx, sizeof(buf) + 1U, buf, sizeof(buf)),
+              PLDM_SUCCESS);
+}
+
+TEST(msgbuf, init_bad_buf)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+
+    EXPECT_NE(pldm_msgbuf_init(ctx, 0, NULL, 0), PLDM_SUCCESS);
+}
+
+TEST(msgbuf, init_bad_len)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    uint8_t buf[1] = {};
+
+    EXPECT_NE(pldm_msgbuf_init(ctx, sizeof(buf), buf, SIZE_MAX), PLDM_SUCCESS);
+}
+
+TEST(msgbuf, init_overflow)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    // This is an intrinsic part of the test.
+    // NOLINTNEXTLINE(performance-no-int-to-ptr)
+    uint8_t* buf = (uint8_t*)SIZE_MAX;
+
+    EXPECT_NE(pldm_msgbuf_init(ctx, 0, buf, 2), PLDM_SUCCESS);
+}
+
+TEST(msgbuf, init_success)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    uint8_t buf[1] = {};
+
+    EXPECT_EQ(pldm_msgbuf_init(ctx, sizeof(buf), buf, sizeof(buf)),
+              PLDM_SUCCESS);
+}
+
+TEST(msgbuf, destroy_none)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    uint8_t buf[1] = {};
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, sizeof(buf), buf, sizeof(buf)),
+              PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_SUCCESS);
+}
+
+TEST(msgbuf, destroy_exact)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    uint8_t buf[1] = {0xa5};
+    uint8_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, sizeof(buf), buf, sizeof(buf)),
+              PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_extract_uint8(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(val, 0xa5);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_SUCCESS);
+}
+
+TEST(msgbuf, destroy_over)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    uint8_t buf[1] = {0xa5};
+    uint8_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, sizeof(buf), buf, sizeof(buf)),
+              PLDM_SUCCESS);
+    ASSERT_EQ(pldm_msgbuf_extract_uint8(ctx, &val), PLDM_SUCCESS);
+    ASSERT_EQ(val, 0xa5);
+    EXPECT_NE(pldm_msgbuf_extract_uint8(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_ERROR_INVALID_LENGTH);
+}
+
+TEST(msgbuf, destroy_under)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    uint8_t buf[2] = {0x5a, 0xa5};
+    uint8_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, sizeof(buf), buf, sizeof(buf)),
+              PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_extract_uint8(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(val, 0x5a);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_SUCCESS);
+}
+
+TEST(msgbuf, extract_one_uint8)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    uint8_t buf[1] = {0xa5};
+    uint8_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, sizeof(buf), buf, sizeof(buf)),
+              PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_extract_uint8(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(val, 0xa5);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_SUCCESS);
+}
+
+TEST(msgbuf, extract_over_uint8)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    uint8_t buf[1] = {};
+    uint8_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, 0, buf, 0), PLDM_SUCCESS);
+    EXPECT_NE(pldm_msgbuf_extract_uint8(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_ERROR_INVALID_LENGTH);
+}
+
+TEST(msgbuf, extract_one_int8)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    int8_t buf[1] = {-1};
+    int8_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, sizeof(buf), buf, sizeof(buf)),
+              PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_extract_int8(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(val, -1);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_SUCCESS);
+}
+
+TEST(msgbuf, extract_over_int8)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    int8_t buf[1] = {};
+    int8_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, 0, buf, 0), PLDM_SUCCESS);
+    EXPECT_NE(pldm_msgbuf_extract_int8(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_ERROR_INVALID_LENGTH);
+}
+
+TEST(msgbuf, extract_one_uint16)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    uint16_t buf[1] = {htole16(0x5aa5)};
+    uint16_t val = {};
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, sizeof(buf), buf, sizeof(buf)),
+              PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_extract_uint16(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(val, 0x5aa5);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_SUCCESS);
+}
+
+TEST(msgbuf, extract_over_uint16)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    uint16_t buf[1] = {};
+    uint16_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, 0, buf, 0), PLDM_SUCCESS);
+    EXPECT_NE(pldm_msgbuf_extract_uint16(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_ERROR_INVALID_LENGTH);
+}
+
+TEST(msgbuf, extract_one_int16)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    int16_t buf[1] = {(int16_t)(htole16((uint16_t)INT16_MIN))};
+    int16_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, sizeof(buf), buf, sizeof(buf)),
+              PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_extract_int16(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(val, INT16_MIN);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_SUCCESS);
+}
+
+TEST(msgbuf, extract_over_int16)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    int16_t buf[1] = {};
+    int16_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, 0, buf, 0), PLDM_SUCCESS);
+    EXPECT_NE(pldm_msgbuf_extract_int16(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_ERROR_INVALID_LENGTH);
+}
+
+TEST(msgbuf, extract_one_uint32)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    uint32_t buf[1] = {htole32(0x5a00ffa5)};
+    uint32_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, sizeof(buf), buf, sizeof(buf)),
+              PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_extract_uint32(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(val, 0x5a00ffa5);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_SUCCESS);
+}
+
+TEST(msgbuf, extract_over_uint32)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    uint32_t buf[1] = {};
+    uint32_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, 0, buf, 0), PLDM_SUCCESS);
+    EXPECT_NE(pldm_msgbuf_extract_uint32(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_ERROR_INVALID_LENGTH);
+}
+
+TEST(msgbuf, extract_one_int32)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    int32_t buf[1] = {(int32_t)(htole32((uint32_t)(INT32_MIN)))};
+    int32_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, sizeof(buf), buf, sizeof(buf)),
+              PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_extract_int32(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(val, INT32_MIN);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_SUCCESS);
+}
+
+TEST(msgbuf, extract_over_int32)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    int32_t buf[1] = {};
+    int32_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, 0, buf, 0), PLDM_SUCCESS);
+    EXPECT_NE(pldm_msgbuf_extract_int32(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_ERROR_INVALID_LENGTH);
+}
+
+TEST(msgbuf, extract_one_real32)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    uint32_t buf[1] = {};
+    uint32_t xform;
+    real32_t val;
+
+    val = FLT_MAX;
+    memcpy(&xform, &val, sizeof(val));
+    buf[0] = htole32(xform);
+    val = 0;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, sizeof(buf), buf, sizeof(buf)),
+              PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_extract_real32(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(val, FLT_MAX);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_SUCCESS);
+}
+
+TEST(msgbuf, extract_over_real32)
+{
+    struct pldm_msgbuf _ctx;
+    struct pldm_msgbuf* ctx = &_ctx;
+    real32_t buf[1] = {};
+    real32_t val;
+
+    ASSERT_EQ(pldm_msgbuf_init(ctx, 0, buf, 0), PLDM_SUCCESS);
+    EXPECT_NE(pldm_msgbuf_extract_real32(ctx, &val), PLDM_SUCCESS);
+    EXPECT_EQ(pldm_msgbuf_destroy(ctx), PLDM_ERROR_INVALID_LENGTH);
+}