diff --git a/CMakeLists.txt b/CMakeLists.txt
index fa6af33..d6c0069 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -61,6 +61,7 @@ set(AMDUAT_UTIL_SRCS
 
 set(AMDUAT_ASL_SRCS
   src/kernel/asl/core.c
+  src/near_core/asl/io.c
   src/near_core/asl/parse.c
   src/near_core/asl/store.c
   src/near_core/asl/ref_text.c
diff --git a/include/amduat/asl/io.h b/include/amduat/asl/io.h
new file mode 100644
index 0000000..2d627ae
--- /dev/null
+++ b/include/amduat/asl/io.h
@@ -0,0 +1,26 @@
+#ifndef AMDUAT_ASL_IO_H
+#define AMDUAT_ASL_IO_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Caller owns any heap allocations returned in out_bytes. */
+bool amduat_asl_read_stream(FILE *stream, uint8_t **out_bytes, size_t *out_len);
+bool amduat_asl_read_path(const char *path, uint8_t **out_bytes, size_t *out_len);
+
+bool amduat_asl_write_stream(FILE *stream, const uint8_t *bytes, size_t len);
+bool amduat_asl_write_path(const char *path, const uint8_t *bytes, size_t len);
+
+bool amduat_asl_write_text_line(const char *path, const char *text);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /* AMDUAT_ASL_IO_H */
diff --git a/src/near_core/asl/io.c b/src/near_core/asl/io.c
new file mode 100644
index 0000000..9b4c1be
--- /dev/null
+++ b/src/near_core/asl/io.c
@@ -0,0 +1,149 @@
+#include "amduat/asl/io.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+enum { AMDUAT_ASL_IO_BUF_CHUNK = 4096 };
+
+bool amduat_asl_read_stream(FILE *stream, uint8_t **out_bytes, size_t *out_len) {
+  uint8_t *buffer;
+  size_t cap;
+  size_t len;
+
+  if (out_bytes == NULL || out_len == NULL) {
+    return false;
+  }
+  *out_bytes = NULL;
+  *out_len = 0;
+
+  buffer = NULL;
+  cap = 0;
+  len = 0;
+
+  while (true) {
+    if (len == cap) {
+      size_t new_cap = cap == 0 ? AMDUAT_ASL_IO_BUF_CHUNK : cap * 2u;
+      uint8_t *next;
+      if (new_cap < cap) {
+        free(buffer);
+        return false;
+      }
+      next = (uint8_t *)realloc(buffer, new_cap);
+      if (next == NULL) {
+        free(buffer);
+        return false;
+      }
+      buffer = next;
+      cap = new_cap;
+    }
+
+    size_t nread = fread(buffer + len, 1u, cap - len, stream);
+    len += nread;
+    if (nread == 0u) {
+      if (ferror(stream)) {
+        free(buffer);
+        return false;
+      }
+      break;
+    }
+  }
+
+  if (len == 0u) {
+    free(buffer);
+    buffer = NULL;
+  }
+  *out_bytes = buffer;
+  *out_len = len;
+  return true;
+}
+
+bool amduat_asl_read_path(const char *path,
+                          uint8_t **out_bytes,
+                          size_t *out_len) {
+  FILE *stream;
+  bool ok;
+
+  if (path == NULL || out_bytes == NULL || out_len == NULL) {
+    return false;
+  }
+
+  if (strcmp(path, "-") == 0) {
+    return amduat_asl_read_stream(stdin, out_bytes, out_len);
+  }
+
+  stream = fopen(path, "rb");
+  if (stream == NULL) {
+    return false;
+  }
+  ok = amduat_asl_read_stream(stream, out_bytes, out_len);
+  if (fclose(stream) != 0) {
+    ok = false;
+  }
+  return ok;
+}
+
+bool amduat_asl_write_stream(FILE *stream, const uint8_t *bytes, size_t len) {
+  size_t offset;
+
+  if (len != 0u && bytes == NULL) {
+    return false;
+  }
+
+  offset = 0u;
+  while (offset < len) {
+    size_t written = fwrite(bytes + offset, 1u, len - offset, stream);
+    if (written == 0u) {
+      return false;
+    }
+    offset += written;
+  }
+  return fflush(stream) == 0;
+}
+
+bool amduat_asl_write_path(const char *path,
+                           const uint8_t *bytes,
+                           size_t len) {
+  FILE *stream;
+  bool ok;
+
+  if (path == NULL) {
+    return false;
+  }
+  if (strcmp(path, "-") == 0) {
+    return amduat_asl_write_stream(stdout, bytes, len);
+  }
+
+  stream = fopen(path, "wb");
+  if (stream == NULL) {
+    return false;
+  }
+  ok = amduat_asl_write_stream(stream, bytes, len);
+  if (fclose(stream) != 0) {
+    ok = false;
+  }
+  return ok;
+}
+
+bool amduat_asl_write_text_line(const char *path, const char *text) {
+  FILE *stream;
+  bool ok;
+
+  if (path == NULL || text == NULL) {
+    return false;
+  }
+  if (strcmp(path, "-") == 0) {
+    stream = stdout;
+  } else {
+    stream = fopen(path, "wb");
+    if (stream == NULL) {
+      return false;
+    }
+  }
+
+  ok = fputs(text, stream) >= 0 && fputc('\n', stream) != EOF &&
+       fflush(stream) == 0;
+  if (stream != stdout && fclose(stream) != 0) {
+    ok = false;
+  }
+  return ok;
+}
diff --git a/src/tools/amduat_asl_cli.c b/src/tools/amduat_asl_cli.c
index 64575f2..487c0e7 100644
--- a/src/tools/amduat_asl_cli.c
+++ b/src/tools/amduat_asl_cli.c
@@ -1,5 +1,6 @@
 #include "amduat/asl/asl_store_fs.h"
 #include "amduat/asl/asl_store_fs_meta.h"
+#include "amduat/asl/io.h"
 #include "amduat/asl/parse.h"
 #include "amduat/asl/ref_text.h"
 #include "amduat/asl/store.h"
@@ -21,10 +22,7 @@ enum {
   AMDUAT_ASL_CLI_EXIT_CONFIG = 8
 };
 
-enum {
-  AMDUAT_ASL_CLI_STORE_ID_MAX = AMDUAT_ASL_STORE_FS_STORE_ID_MAX,
-  AMDUAT_ASL_CLI_BUF_CHUNK = 4096
-};
+enum { AMDUAT_ASL_CLI_STORE_ID_MAX = AMDUAT_ASL_STORE_FS_STORE_ID_MAX };
 
 static const char *const AMDUAT_ASL_CLI_DEFAULT_ROOT = ".amduat-asl";
 
@@ -183,154 +181,6 @@ static bool amduat_asl_cli_parse_io_format(
   return false;
 }
 
-static bool amduat_asl_cli_read_stream(FILE *stream,
-                                       uint8_t **out,
-                                       size_t *out_len) {
-  uint8_t *buffer;
-  size_t cap;
-  size_t len;
-
-  if (out == NULL || out_len == NULL) {
-    return false;
-  }
-  *out = NULL;
-  *out_len = 0;
-
-  buffer = NULL;
-  cap = 0;
-  len = 0;
-
-  while (true) {
-    if (len == cap) {
-      size_t new_cap = cap == 0 ? AMDUAT_ASL_CLI_BUF_CHUNK : cap * 2u;
-      uint8_t *next;
-      if (new_cap < cap) {
-        free(buffer);
-        return false;
-      }
-      next = (uint8_t *)realloc(buffer, new_cap);
-      if (next == NULL) {
-        free(buffer);
-        return false;
-      }
-      buffer = next;
-      cap = new_cap;
-    }
-
-    size_t nread = fread(buffer + len, 1u, cap - len, stream);
-    len += nread;
-    if (nread == 0u) {
-      if (ferror(stream)) {
-        free(buffer);
-        return false;
-      }
-      break;
-    }
-  }
-
-  if (len == 0u) {
-    free(buffer);
-    buffer = NULL;
-  }
-  *out = buffer;
-  *out_len = len;
-  return true;
-}
-
-static bool amduat_asl_cli_read_path(const char *path,
-                                     uint8_t **out,
-                                     size_t *out_len) {
-  FILE *stream;
-  bool ok;
-
-  if (path == NULL || out == NULL || out_len == NULL) {
-    return false;
-  }
-
-  if (strcmp(path, "-") == 0) {
-    return amduat_asl_cli_read_stream(stdin, out, out_len);
-  }
-
-  stream = fopen(path, "rb");
-  if (stream == NULL) {
-    return false;
-  }
-  ok = amduat_asl_cli_read_stream(stream, out, out_len);
-  if (fclose(stream) != 0) {
-    ok = false;
-  }
-  return ok;
-}
-
-static bool amduat_asl_cli_write_stream(FILE *stream,
-                                        const uint8_t *bytes,
-                                        size_t len) {
-  size_t offset;
-
-  if (len != 0u && bytes == NULL) {
-    return false;
-  }
-
-  offset = 0u;
-  while (offset < len) {
-    size_t written = fwrite(bytes + offset, 1u, len - offset, stream);
-    if (written == 0u) {
-      return false;
-    }
-    offset += written;
-  }
-  return fflush(stream) == 0;
-}
-
-static bool amduat_asl_cli_write_path(const char *path,
-                                      const uint8_t *bytes,
-                                      size_t len) {
-  FILE *stream;
-  bool ok;
-
-  if (path == NULL) {
-    return false;
-  }
-  if (strcmp(path, "-") == 0) {
-    return amduat_asl_cli_write_stream(stdout, bytes, len);
-  }
-
-  stream = fopen(path, "wb");
-  if (stream == NULL) {
-    return false;
-  }
-  ok = amduat_asl_cli_write_stream(stream, bytes, len);
-  if (fclose(stream) != 0) {
-    ok = false;
-  }
-  return ok;
-}
-
-static bool amduat_asl_cli_write_text_line(const char *path,
-                                           const char *text) {
-  FILE *stream;
-  bool ok;
-
-  if (path == NULL || text == NULL) {
-    return false;
-  }
-  if (strcmp(path, "-") == 0) {
-    stream = stdout;
-  } else {
-    stream = fopen(path, "wb");
-    if (stream == NULL) {
-      return false;
-    }
-  }
-
-  ok = fputs(text, stream) >= 0 && fputc('\n', stream) != EOF &&
-       fflush(stream) == 0;
-  if (stream != stdout && fclose(stream) != 0) {
-    ok = false;
-  }
-  return ok;
-}
-
 static void amduat_asl_cli_free_reference(amduat_reference_t *ref) {
   if (ref == NULL) {
     return;
@@ -578,7 +428,7 @@ static int amduat_asl_cli_cmd_put(int argc, char **argv) {
 
   input_bytes = NULL;
   input_len = 0u;
-  if (!amduat_asl_cli_read_path(opts.input_path, &input_bytes, &input_len)) {
+  if (!amduat_asl_read_path(opts.input_path, &input_bytes, &input_len)) {
     fprintf(stderr, "error: failed to read input: %s\n", opts.input_path);
     return AMDUAT_ASL_CLI_EXIT_IO;
   }
@@ -616,7 +466,7 @@ static int amduat_asl_cli_cmd_put(int argc, char **argv) {
           fprintf(stderr, "error: failed to encode reference\n");
           exit_code = AMDUAT_ASL_CLI_EXIT_CODEC;
         } else {
-          if (!amduat_asl_cli_write_text_line(opts.output_path, hex_ref)) {
+          if (!amduat_asl_write_text_line(opts.output_path, hex_ref)) {
             fprintf(stderr, "error: failed to write output: %s\n",
                     opts.output_path);
             exit_code = AMDUAT_ASL_CLI_EXIT_IO;
@@ -628,7 +478,7 @@ static int amduat_asl_cli_cmd_put(int argc, char **argv) {
           fprintf(stderr, "error: failed to encode reference\n");
           exit_code = AMDUAT_ASL_CLI_EXIT_CODEC;
         } else {
-          if (!amduat_asl_cli_write_path(opts.output_path,
+          if (!amduat_asl_write_path(opts.output_path,
                                          encoded_ref.data,
                                          encoded_ref.len)) {
             fprintf(stderr, "error: failed to write output: %s\n",
@@ -770,7 +620,7 @@ static int amduat_asl_cli_cmd_get(int argc, char **argv) {
   } else {
     ref_bytes = NULL;
     ref_len = 0u;
-    if (!amduat_asl_cli_read_path(opts.ref, &ref_bytes, &ref_len)) {
+    if (!amduat_asl_read_path(opts.ref, &ref_bytes, &ref_len)) {
       fprintf(stderr, "error: failed to read reference: %s\n", opts.ref);
       return AMDUAT_ASL_CLI_EXIT_IO;
     }
@@ -801,7 +651,7 @@ static int amduat_asl_cli_cmd_get(int argc, char **argv) {
 
       if (exit_code == AMDUAT_ASL_CLI_EXIT_OK) {
         if (opts.output_format == AMDUAT_ASL_CLI_IO_RAW) {
-          if (!amduat_asl_cli_write_path(opts.output_path,
+          if (!amduat_asl_write_path(opts.output_path,
                                          artifact.bytes.data,
                                          artifact.bytes.len)) {
             fprintf(stderr, "error: failed to write output: %s\n",
@@ -814,7 +664,7 @@ static int amduat_asl_cli_cmd_get(int argc, char **argv) {
             fprintf(stderr, "error: failed to encode artifact\n");
             exit_code = AMDUAT_ASL_CLI_EXIT_CODEC;
           } else {
-            if (!amduat_asl_cli_write_path(opts.output_path,
+            if (!amduat_asl_write_path(opts.output_path,
                                            encoded_artifact.data,
                                            encoded_artifact.len)) {
               fprintf(stderr, "error: failed to write output: %s\n",