diff --git a/axl_rle_test.c b/axl_rle_test.c
new file mode 100644
index 0000000..70f7a0c
--- /dev/null
+++ b/axl_rle_test.c
@@ -0,0 +1,233 @@
+#include "axl_memory.h"
+#include "axl_rle.h"
+#include "axl_koan.h"
+
+#define ASSERT_ARRAY_EQ(expected, actual, size) \
+    do { \
+        const u8* _e = (expected); \
+        const u8* _a = (actual); \
+        u32 _s = (size); \
+        for (u32 _i = 0; _i < _s; _i++) { \
+            if (_e[_i] != _a[_i]) { \
+                char _r[256]; \
+                snprintf(_r, sizeof(_r), "Mismatch at index %u: exp 0x%02X, got 0x%02X", \
+                         _i, _e[_i], _a[_i]); \
+                KOAN_FAIL(_r); \
+            } \
+        } \
+    } while (0)
+
+KOAN(encode_empty)
+{
+    u8 src[] = "";
+    u8 dst[32];
+    ASSERT_UINT_EQ(0, axl_rle_encode(src, 0, dst, sizeof(dst)));
+}
+
+KOAN(encode_single)
+{
+    u8 src[] = {0xAA};
+    u8 dst[32];
+    u32 size = axl_rle_encode(src, 1, dst, sizeof(dst));
+    ASSERT_UINT_EQ(2, size);
+    ASSERT_UINT_EQ(0x01, dst[0]);
+    ASSERT_UINT_EQ(0xAA, dst[1]);
+}
+
+KOAN(encode_five_repeats)
+{
+    u8 src[] = {0xAA, 0xAA, 0xAA, 0xAA, 0xAA};
+    u8 dst[32];
+    u32 size = axl_rle_encode(src, 5, dst, sizeof(dst));
+    ASSERT_UINT_EQ(2, size);
+    ASSERT_UINT_EQ(0x05, dst[0]);
+    ASSERT_UINT_EQ(0xAA, dst[1]);
+}
+
+KOAN(encode_three_runs)
+{
+    u8 src[] = {0xAA, 0xAA, 0xAA, 0xBB, 0xBB, 0xCC};
+    u8 expected[] = {0x03, 0xAA, 0x02, 0xBB, 0x01, 0xCC};
+    u8 dst[32];
+    u32 size = axl_rle_encode(src, 6, dst, sizeof(dst));
+    ASSERT_UINT_EQ(6, size);
+    ASSERT_ARRAY_EQ(expected, dst, 6);
+}
+
+KOAN(encode_interleaved)
+{
+    u8 src[] = {0xAA, 0xAA, 0xBB, 0xBB, 0xAA, 0xAA};
+    u8 expected[] = {0x02, 0xAA, 0x02, 0xBB, 0x02, 0xAA};
+    u8 dst[32];
+    u32 size = axl_rle_encode(src, 6, dst, sizeof(dst));
+    ASSERT_UINT_EQ(6, size);
+    ASSERT_ARRAY_EQ(expected, dst, 6);
+}
+
+KOAN(encode_all_different)
+{
+    u8 src[10];
+    u8 dst[32];
+    for (u32 i = 0; i < 10; i++) src[i] = (u8)i;
+    u32 size = axl_rle_encode(src, 10, dst, sizeof(dst));
+    ASSERT_UINT_EQ(20, size);
+    for (u32 i = 0; i < 10; i++) {
+        ASSERT_UINT_EQ(0x01, dst[i*2]);
+        ASSERT_UINT_EQ((u8)i, dst[i*2+1]);
+    }
+}
+
+KOAN(encode_null_ptr)
+{
+    u8 src[] = {0xAA}, dst[32];
+    ASSERT_UINT_EQ(0, axl_rle_encode(NULL, 1, dst, sizeof(dst)));
+    ASSERT_UINT_EQ(0, axl_rle_encode(src, 1, NULL, 32));
+}
+
+KOAN(encode_zero_size)
+{
+    u8 src[] = {0xAA};
+    u8 dst[32];
+    ASSERT_UINT_EQ(0, axl_rle_encode(src, 0, dst, sizeof(dst)));
+    ASSERT_UINT_EQ(0, axl_rle_encode(src, 1, dst, 0));
+}
+
+KOAN(encode_buffer_too_small)
+{
+    u8 src[] = {0xAA, 0xAA, 0xAA, 0xBB};
+    u8 dst[3];
+    ASSERT_UINT_EQ(0, axl_rle_encode(src, 4, dst, sizeof(dst)));
+}
+
+KOAN(encode_max_127)
+{
+    u8 src[127];
+    u8 dst[32];
+    for (u32 i = 0; i < 127; i++) src[i] = 0x77;
+    u32 size = axl_rle_encode(src, 127, dst, sizeof(dst));
+    ASSERT_UINT_EQ(2, size);
+    ASSERT_UINT_EQ(0x7F, dst[0]);
+    ASSERT_UINT_EQ(0x77, dst[1]);
+}
+
+KOAN(encode_decode_300)
+{
+    u8 src[300];
+    u8 encoded[32];
+    u8 decoded[400];
+    for (u32 i = 0; i < 300; i++) src[i] = 0x55;
+    u32 encoded_size = axl_rle_encode(src, 300, encoded, sizeof(encoded));
+    ASSERT_TRUE(encoded_size > 0 && encoded_size <= 6);
+    u32 decoded_size = axl_rle_decode(encoded, encoded_size, decoded, sizeof(decoded));
+    ASSERT_UINT_EQ(300, decoded_size);
+    ASSERT_ARRAY_EQ(src, decoded, 300);
+}
+
+KOAN(decode_empty)
+{
+    u8 src[] = "";
+    u8 dst[32];
+    ASSERT_UINT_EQ(0, axl_rle_decode(src, 0, dst, sizeof(dst)));
+}
+
+KOAN(decode_single)
+{
+    u8 src[] = {0x01, 0xAA};
+    u8 dst[32];
+    u32 size = axl_rle_decode(src, 2, dst, sizeof(dst));
+    ASSERT_UINT_EQ(1, size);
+    ASSERT_UINT_EQ(0xAA, dst[0]);
+}
+
+KOAN(decode_five)
+{
+    u8 src[] = {0x05, 0xAA};
+    u8 dst[32];
+    u32 size = axl_rle_decode(src, 2, dst, sizeof(dst));
+    ASSERT_UINT_EQ(5, size);
+    for (u32 i = 0; i < 5; i++) ASSERT_UINT_EQ(0xAA, dst[i]);
+}
+
+KOAN(decode_three_runs)
+{
+    u8 src[] = {0x03, 0xAA, 0x02, 0xBB, 0x01, 0xCC};
+    u8 expected[] = {0xAA, 0xAA, 0xAA, 0xBB, 0xBB, 0xCC};
+    u8 dst[32];
+    u32 size = axl_rle_decode(src, 6, dst, sizeof(dst));
+    ASSERT_UINT_EQ(6, size);
+    ASSERT_ARRAY_EQ(expected, dst, 6);
+}
+
+KOAN(decode_null_ptr)
+{
+    u8 src[] = {0x01, 0xAA}, dst[32];
+    ASSERT_UINT_EQ(0, axl_rle_decode(NULL, 2, dst, sizeof(dst)));
+    ASSERT_UINT_EQ(0, axl_rle_decode(src, 2, NULL, 32));
+}
+
+KOAN(decode_zero_size)
+{
+    u8 src[] = {0x01, 0xAA};
+    u8 dst[32];
+    ASSERT_UINT_EQ(0, axl_rle_decode(src, 0, dst, sizeof(dst)));
+    ASSERT_UINT_EQ(0, axl_rle_decode(src, 2, dst, 0));
+}
+
+KOAN(decode_buffer_too_small)
+{
+    u8 src[] = {0x05, 0xAA};
+    u8 dst[3];
+    ASSERT_UINT_EQ(0, axl_rle_decode(src, 2, dst, sizeof(dst)));
+}
+
+KOAN(decode_incomplete_vlq)
+{
+    u8 src[] = {0x85};
+    u8 dst[32];
+    ASSERT_UINT_EQ(0, axl_rle_decode(src, 1, dst, sizeof(dst)));
+}
+
+KOAN(decode_missing_value)
+{
+    u8 src[] = {0x05};
+    u8 dst[32];
+    ASSERT_UINT_EQ(0, axl_rle_decode(src, 1, dst, sizeof(dst)));
+}
+
+KOAN(decode_zero_count)
+{
+    u8 src[] = {0x00, 0xAA};
+    u8 dst[32];
+    ASSERT_UINT_EQ(0, axl_rle_decode(src, 2, dst, sizeof(dst)));
+}
+
+KOAN(roundtrip_simple)
+{
+    u8 original[] = {0xAA, 0xAA, 0xAA, 0xBB, 0xBB, 0xCC, 0xCC, 0xCC, 0xCC};
+    u8 encoded[32];
+    u8 decoded[32];
+    u32 encoded_size = axl_rle_encode(original, 9, encoded, sizeof(encoded));
+    ASSERT_TRUE(encoded_size > 0);
+    u32 decoded_size = axl_rle_decode(encoded, encoded_size, decoded, sizeof(decoded));
+    ASSERT_UINT_EQ(9, decoded_size);
+    ASSERT_ARRAY_EQ(original, decoded, 9);
+}
+
+KOAN(roundtrip_all_different)
+{
+    u8 original[10];
+    u8 encoded[32];
+    u8 decoded[32];
+    for (u32 i = 0; i < 10; i++) original[i] = (u8)i;
+    u32 encoded_size = axl_rle_encode(original, 10, encoded, sizeof(encoded));
+    ASSERT_UINT_EQ(20, encoded_size);
+    u32 decoded_size = axl_rle_decode(encoded, encoded_size, decoded, sizeof(decoded));
+    ASSERT_UINT_EQ(10, decoded_size);
+    ASSERT_ARRAY_EQ(original, decoded, 10);
+}
+
+int main(void)
+{
+    axl_init();
+    return koan_run_all();
+}