diff --git a/rock.json b/rock.json
new file mode 100644
index 0000000..6822a14
--- /dev/null
+++ b/rock.json
@@ -0,0 +1,10 @@
+{
+    "configVersion": 1,
+    "rock": {
+        "name": "io",
+        "description": "Input / Output",
+        "dependencies": {
+            "test": "1.0.0"
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..d9f9cc3
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,97 @@
+#include <comet/cometlib.h>
+#include <stdlib.h>
+
+static CometType cometTypeString = cometTypeVoid;
+
+void ensureStringType() {
+    if (cometTypeString.typeKind == COMET_VOID)
+        cometTypeString = createArrayType(cometTypeSmall, 1, (bool[]){false}, (uint64_t[]){});
+}
+
+int64_t impl_print(int64_t* args, CometVM* vm) {
+    ensureStringType();
+
+    CometOperand formatStringArray = deserializeValue(args[0], cometTypeString);
+    char* formatString = (char*)cometArrayToCArray(formatStringArray, cometTypeSmall);
+
+    size_t argIdx = 1;
+
+    for (size_t i = 0; formatString[i] != 0; i++) {
+
+        // look for '%'
+        if (formatString[i] == '%') {
+            switch (formatString[i+1]) {
+                case 'n': {
+                    printf("%ld", deserializeValue(args[argIdx], cometTypeBig).imm.bigVal);
+                    break;
+                }
+                case 'f': {
+                    printf("%f", deserializeValue(args[argIdx], cometTypeDouble).imm.doubleVal);
+                    break;
+                }
+                case 'b': {
+                    bool boolVal = deserializeValue(args[argIdx], cometTypeBool).imm.boolVal;
+                    printf( boolVal ? "true" : "false");
+                    break;
+                }
+                case 's': {
+                    CometOperand strArr = deserializeValue(args[argIdx], cometTypeString);
+                    char* str = (char*)cometArrayToCArray(strArr, cometTypeSmall);
+                    printf("%s", str);
+                    break;
+                }
+                default: 
+                    printf("%%%c", formatString[i+1]);
+                    break;
+            }
+            i++;
+            argIdx++;
+        } else {
+            putchar(formatString[i]);
+        }
+
+    }
+
+    return 0;
+}
+
+int64_t impl_println(int64_t* args, CometVM* vm) {
+    int64_t returnVal = impl_print(args, vm);
+    putchar('\n');
+    return returnVal;
+}
+
+int64_t impl_getline(int64_t* args, CometVM* vm) {
+    ensureStringType();
+
+    char* userInput = NULL;
+    size_t numChars = 0;
+
+    int64_t result = getline(&userInput, &numChars, stdin);
+    if (result == -1) {
+        if (userInput) free(userInput);
+        return 0;
+    }
+
+    if (result > 0 && userInput[result - 1] == '\n') {
+        userInput[result - 1] = '\0';
+        result--;
+    }
+
+    CometOperand strValue = CArrayToCometArray(userInput, result, cometTypeSmall);
+    free(userInput);
+
+    int64_t serializedStr = serializeValue(strValue);
+
+    return serializedStr;
+}
+
+
+on_import {
+    if (cometTypeString.typeKind == COMET_VOID)
+        cometTypeString = createArrayType(cometTypeSmall, 1, (bool[]){false}, (uint64_t[]){});
+
+    cometDefineFunc(env, "print", cometTypeSmall, 1, true, cometTypeString);
+    cometDefineFunc(env, "println", cometTypeSmall, 1, true, cometTypeString);
+    cometDefineFunc(env, "getline", cometTypeString, 0, false);
+}
\ No newline at end of file