diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..99142bc
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+/build/
+*.sock
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..d640e9e
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,19 @@
+cmake_minimum_required(VERSION 3.20)
+project(amduat_api LANGUAGES C)
+
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_C_STANDARD_REQUIRED ON)
+set(CMAKE_C_EXTENSIONS OFF)
+
+add_subdirectory(vendor/amduat)
+
+add_executable(amduatd src/amduatd.c)
+
+target_include_directories(amduatd
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/vendor/amduat/src/internal
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/vendor/amduat/include
+)
+
+target_link_libraries(amduatd
+  PRIVATE amduat_asl_store_fs amduat_asl amduat_enc amduat_hash_asl1 amduat_util
+)
diff --git a/src/amduatd.c b/src/amduatd.c
new file mode 100644
index 0000000..f501300
--- /dev/null
+++ b/src/amduatd.c
@@ -0,0 +1,690 @@
+#define _POSIX_C_SOURCE 200809L
+
+#include "amduat/asl/artifact_io.h"
+#include "amduat/asl/asl_store_fs.h"
+#include "amduat/asl/asl_store_fs_meta.h"
+#include "amduat/asl/ref_text.h"
+#include "amduat/asl/store.h"
+#include "amduat/enc/asl1_core_codec.h"
+
+#include <errno.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <strings.h>
+#include <string.h>
+
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+static const char *const AMDUATD_DEFAULT_ROOT = ".amduat-asl";
+static const char *const AMDUATD_DEFAULT_SOCK = "amduatd.sock";
+
+static volatile sig_atomic_t amduatd_should_exit = 0;
+
+static void amduatd_on_signal(int signo) {
+  (void)signo;
+  amduatd_should_exit = 1;
+}
+
+static bool amduatd_write_all(int fd, const uint8_t *buf, size_t len) {
+  size_t off = 0;
+  while (off < len) {
+    ssize_t n = write(fd, buf + off, len - off);
+    if (n < 0) {
+      if (errno == EINTR) {
+        continue;
+      }
+      return false;
+    }
+    if (n == 0) {
+      return false;
+    }
+    off += (size_t)n;
+  }
+  return true;
+}
+
+static bool amduatd_read_exact(int fd, uint8_t *buf, size_t len) {
+  size_t off = 0;
+  while (off < len) {
+    ssize_t n = read(fd, buf + off, len - off);
+    if (n < 0) {
+      if (errno == EINTR) {
+        continue;
+      }
+      return false;
+    }
+    if (n == 0) {
+      return false;
+    }
+    off += (size_t)n;
+  }
+  return true;
+}
+
+static bool amduatd_read_line(int fd, char *buf, size_t cap, size_t *out_len) {
+  size_t len = 0;
+  while (len + 1 < cap) {
+    char c = 0;
+    ssize_t n = read(fd, &c, 1);
+    if (n < 0) {
+      if (errno == EINTR) {
+        continue;
+      }
+      return false;
+    }
+    if (n == 0) {
+      return false;
+    }
+    if (c == '\n') {
+      break;
+    }
+    buf[len++] = c;
+  }
+  if (len == 0) {
+    return false;
+  }
+  if (len > 0 && buf[len - 1] == '\r') {
+    len--;
+  }
+  buf[len] = '\0';
+  if (out_len != NULL) {
+    *out_len = len;
+  }
+  return true;
+}
+
+typedef struct {
+  char method[8];
+  char path[1024];
+  char content_type[128];
+  char accept[128];
+  char x_type_tag[64];
+  size_t content_length;
+} amduatd_http_req_t;
+
+static void amduatd_http_req_init(amduatd_http_req_t *req) {
+  memset(req, 0, sizeof(*req));
+}
+
+static bool amduatd_http_parse_request(int fd, amduatd_http_req_t *out_req) {
+  char line[2048];
+  size_t line_len = 0;
+  char *sp1 = NULL;
+  char *sp2 = NULL;
+
+  if (out_req == NULL) {
+    return false;
+  }
+  amduatd_http_req_init(out_req);
+
+  if (!amduatd_read_line(fd, line, sizeof(line), &line_len)) {
+    return false;
+  }
+
+  sp1 = strchr(line, ' ');
+  if (sp1 == NULL) {
+    return false;
+  }
+  *sp1++ = '\0';
+  sp2 = strchr(sp1, ' ');
+  if (sp2 == NULL) {
+    return false;
+  }
+  *sp2++ = '\0';
+
+  if (strlen(line) >= sizeof(out_req->method)) {
+    return false;
+  }
+  strncpy(out_req->method, line, sizeof(out_req->method) - 1);
+
+  if (strlen(sp1) >= sizeof(out_req->path)) {
+    return false;
+  }
+  strncpy(out_req->path, sp1, sizeof(out_req->path) - 1);
+
+  for (;;) {
+    if (!amduatd_read_line(fd, line, sizeof(line), &line_len)) {
+      return false;
+    }
+    if (line_len == 0) {
+      break;
+    }
+
+    if (strncasecmp(line, "Content-Length:", 15) == 0) {
+      const char *v = line + 15;
+      while (*v == ' ' || *v == '\t') {
+        v++;
+      }
+      out_req->content_length = (size_t)strtoull(v, NULL, 10);
+    } else if (strncasecmp(line, "Content-Type:", 13) == 0) {
+      const char *v = line + 13;
+      while (*v == ' ' || *v == '\t') {
+        v++;
+      }
+      strncpy(out_req->content_type, v, sizeof(out_req->content_type) - 1);
+    } else if (strncasecmp(line, "Accept:", 7) == 0) {
+      const char *v = line + 7;
+      while (*v == ' ' || *v == '\t') {
+        v++;
+      }
+      strncpy(out_req->accept, v, sizeof(out_req->accept) - 1);
+    } else if (strncasecmp(line, "X-Amduat-Type-Tag:", 18) == 0) {
+      const char *v = line + 18;
+      while (*v == ' ' || *v == '\t') {
+        v++;
+      }
+      strncpy(out_req->x_type_tag, v, sizeof(out_req->x_type_tag) - 1);
+    }
+  }
+
+  return true;
+}
+
+static bool amduatd_http_send_status(int fd,
+                                     int code,
+                                     const char *reason,
+                                     const char *content_type,
+                                     const uint8_t *body,
+                                     size_t body_len,
+                                     bool head_only) {
+  char hdr[512];
+  int n = snprintf(hdr,
+                   sizeof(hdr),
+                   "HTTP/1.1 %d %s\r\n"
+                   "Content-Length: %zu\r\n"
+                   "Content-Type: %s\r\n"
+                   "Connection: close\r\n"
+                   "\r\n",
+                   code,
+                   reason != NULL ? reason : "",
+                   body_len,
+                   content_type != NULL ? content_type : "text/plain");
+  if (n <= 0 || (size_t)n >= sizeof(hdr)) {
+    return false;
+  }
+  if (!amduatd_write_all(fd, (const uint8_t *)hdr, (size_t)n)) {
+    return false;
+  }
+  if (!head_only && body != NULL && body_len != 0) {
+    return amduatd_write_all(fd, body, body_len);
+  }
+  return true;
+}
+
+static bool amduatd_http_send_text(int fd,
+                                   int code,
+                                   const char *reason,
+                                   const char *text,
+                                   bool head_only) {
+  const uint8_t *body = (const uint8_t *)(text != NULL ? text : "");
+  size_t len = text != NULL ? strlen(text) : 0;
+  return amduatd_http_send_status(
+      fd, code, reason, "text/plain; charset=utf-8", body, len, head_only);
+}
+
+static bool amduatd_http_send_json(int fd,
+                                   int code,
+                                   const char *reason,
+                                   const char *json,
+                                   bool head_only) {
+  const uint8_t *body = (const uint8_t *)(json != NULL ? json : "{}");
+  size_t len = json != NULL ? strlen(json) : 2;
+  return amduatd_http_send_status(
+      fd, code, reason, "application/json", body, len, head_only);
+}
+
+static const char *amduatd_query_param(const char *path,
+                                       const char *key,
+                                       char *out_value,
+                                       size_t out_cap) {
+  const char *q = strchr(path, '?');
+  size_t key_len = 0;
+  if (out_value != NULL && out_cap != 0) {
+    out_value[0] = '\0';
+  }
+  if (q == NULL || key == NULL || out_value == NULL || out_cap == 0) {
+    return NULL;
+  }
+  q++;
+  key_len = strlen(key);
+
+  while (*q != '\0') {
+    const char *k = q;
+    const char *eq = strchr(k, '=');
+    const char *amp = strchr(k, '&');
+    size_t klen = 0;
+    const char *v = NULL;
+    size_t vlen = 0;
+
+    if (amp == NULL) {
+      amp = q + strlen(q);
+    }
+    if (eq == NULL || eq > amp) {
+      q = (*amp == '&') ? (amp + 1) : amp;
+      continue;
+    }
+    klen = (size_t)(eq - k);
+    if (klen == key_len && strncmp(k, key, key_len) == 0) {
+      v = eq + 1;
+      vlen = (size_t)(amp - v);
+      if (vlen >= out_cap) {
+        vlen = out_cap - 1;
+      }
+      memcpy(out_value, v, vlen);
+      out_value[vlen] = '\0';
+      return out_value;
+    }
+    q = (*amp == '&') ? (amp + 1) : amp;
+  }
+
+  return NULL;
+}
+
+static void amduatd_path_without_query(const char *path,
+                                       char *out,
+                                       size_t cap) {
+  const char *q = NULL;
+  size_t n = 0;
+  if (out == NULL || cap == 0) {
+    return;
+  }
+  out[0] = '\0';
+  if (path == NULL) {
+    return;
+  }
+  q = strchr(path, '?');
+  n = q != NULL ? (size_t)(q - path) : strlen(path);
+  if (n >= cap) {
+    n = cap - 1;
+  }
+  memcpy(out, path, n);
+  out[n] = '\0';
+}
+
+static bool amduatd_parse_type_tag_hex(const char *text,
+                                       bool *out_has_type_tag,
+                                       amduat_type_tag_t *out_type_tag) {
+  char *end = NULL;
+  unsigned long v = 0;
+  if (out_has_type_tag != NULL) {
+    *out_has_type_tag = false;
+  }
+  if (text == NULL || text[0] == '\0' || out_type_tag == NULL ||
+      out_has_type_tag == NULL) {
+    return true;
+  }
+  errno = 0;
+  v = strtoul(text, &end, 0);
+  if (errno != 0 || end == text || *end != '\0' || v > 0xffffffffUL) {
+    return false;
+  }
+  *out_has_type_tag = true;
+  out_type_tag->tag_id = (uint32_t)v;
+  return true;
+}
+
+static bool amduatd_handle_meta(int fd,
+                                const amduat_asl_store_fs_config_t *cfg,
+                                bool head_only) {
+  char json[512];
+  int n = snprintf(json,
+                   sizeof(json),
+                   "{"
+                   "\"store_id\":\"%s\","
+                   "\"encoding_profile_id\":\"0x%04x\","
+                   "\"hash_id\":\"0x%04x\""
+                   "}\n",
+                   cfg != NULL ? cfg->store_id : "",
+                   cfg != NULL ? (unsigned int)cfg->config.encoding_profile_id
+                               : 0u,
+                   cfg != NULL ? (unsigned int)cfg->config.hash_id : 0u);
+  if (n <= 0 || (size_t)n >= sizeof(json)) {
+    return amduatd_http_send_text(fd, 500, "Internal Server Error", "error\n",
+                                 head_only);
+  }
+  return amduatd_http_send_json(fd, 200, "OK", json, head_only);
+}
+
+static bool amduatd_handle_get_artifact(int fd,
+                                        amduat_asl_store_t *store,
+                                        const char *path,
+                                        bool head_only) {
+  char no_query[1024];
+  char format[32];
+  const char *ref_text = NULL;
+  amduat_reference_t ref;
+  amduat_artifact_t artifact;
+  amduat_asl_store_error_t err;
+  bool want_artifact = false;
+
+  memset(&ref, 0, sizeof(ref));
+  memset(&artifact, 0, sizeof(artifact));
+  amduatd_path_without_query(path, no_query, sizeof(no_query));
+
+  if (strncmp(no_query, "/v1/artifacts/", 14) != 0) {
+    return amduatd_http_send_text(fd, 404, "Not Found", "not found\n",
+                                 head_only);
+  }
+  ref_text = no_query + 14;
+  if (ref_text[0] == '\0') {
+    return amduatd_http_send_text(fd, 400, "Bad Request", "missing ref\n",
+                                 head_only);
+  }
+
+  if (!amduat_asl_ref_decode_hex(ref_text, &ref)) {
+    return amduatd_http_send_text(fd, 400, "Bad Request", "invalid ref\n",
+                                 head_only);
+  }
+
+  memset(format, 0, sizeof(format));
+  if (amduatd_query_param(path, "format", format, sizeof(format)) != NULL) {
+    if (strcmp(format, "artifact") == 0) {
+      want_artifact = true;
+    } else if (strcmp(format, "raw") == 0 || format[0] == '\0') {
+      want_artifact = false;
+    } else {
+      free((void *)ref.digest.data);
+      return amduatd_http_send_text(fd, 400, "Bad Request",
+                                   "invalid format\n", head_only);
+    }
+  }
+
+  err = amduat_asl_store_get(store, ref, &artifact);
+  free((void *)ref.digest.data);
+  if (err == AMDUAT_ASL_STORE_ERR_NOT_FOUND) {
+    return amduatd_http_send_text(fd, 404, "Not Found", "not found\n",
+                                 head_only);
+  }
+  if (err != AMDUAT_ASL_STORE_OK) {
+    amduat_asl_artifact_free(&artifact);
+    return amduatd_http_send_text(fd, 500, "Internal Server Error",
+                                 "store error\n", head_only);
+  }
+
+  if (!want_artifact) {
+    bool ok = amduatd_http_send_status(
+        fd,
+        200,
+        "OK",
+        "application/octet-stream",
+        artifact.bytes.data,
+        artifact.bytes.len,
+        head_only);
+    amduat_asl_artifact_free(&artifact);
+    return ok;
+  }
+
+  {
+    amduat_octets_t out = amduat_octets(NULL, 0);
+    bool ok = amduat_enc_asl1_core_encode_artifact_v1(artifact, &out);
+    amduat_asl_artifact_free(&artifact);
+    if (!ok) {
+      return amduatd_http_send_text(fd, 500, "Internal Server Error",
+                                   "encode error\n", head_only);
+    }
+    ok = amduatd_http_send_status(fd,
+                                 200,
+                                 "OK",
+                                 "application/vnd.amduat.asl.artifact+v1",
+                                 out.data,
+                                 out.len,
+                                 head_only);
+    free((void *)out.data);
+    return ok;
+  }
+}
+
+static bool amduatd_handle_head_artifact(int fd,
+                                         amduat_asl_store_t *store,
+                                         const char *path) {
+  return amduatd_handle_get_artifact(fd, store, path, true);
+}
+
+static bool amduatd_handle_post_artifacts(int fd,
+                                          amduat_asl_store_t *store,
+                                          const amduatd_http_req_t *req) {
+  uint8_t *body = NULL;
+  bool has_type_tag = false;
+  amduat_type_tag_t type_tag;
+  amduat_asl_io_format_t input_format = AMDUAT_ASL_IO_RAW;
+  amduat_artifact_t artifact;
+  amduat_reference_t ref;
+  amduat_asl_store_error_t err;
+  char *ref_hex = NULL;
+  char json[2048];
+
+  memset(&artifact, 0, sizeof(artifact));
+  memset(&ref, 0, sizeof(ref));
+  memset(&type_tag, 0, sizeof(type_tag));
+
+  if (req == NULL) {
+    return amduatd_http_send_text(fd, 400, "Bad Request", "bad request\n",
+                                 false);
+  }
+
+  if (req->content_length > (64u * 1024u * 1024u)) {
+    return amduatd_http_send_text(fd, 413, "Payload Too Large",
+                                 "payload too large\n", false);
+  }
+
+  if (req->content_length != 0) {
+    body = (uint8_t *)malloc(req->content_length);
+    if (body == NULL) {
+      return amduatd_http_send_text(fd, 500, "Internal Server Error",
+                                   "oom\n", false);
+    }
+    if (!amduatd_read_exact(fd, body, req->content_length)) {
+      free(body);
+      return false;
+    }
+  } else {
+    body = NULL;
+  }
+
+  if (req->content_type[0] != '\0' &&
+      strstr(req->content_type, "application/vnd.amduat.asl.artifact+v1") !=
+          NULL) {
+    input_format = AMDUAT_ASL_IO_ARTIFACT;
+  }
+
+  if (input_format == AMDUAT_ASL_IO_RAW) {
+    if (!amduatd_parse_type_tag_hex(req->x_type_tag,
+                                   &has_type_tag,
+                                   &type_tag)) {
+      free(body);
+      return amduatd_http_send_text(fd, 400, "Bad Request",
+                                   "invalid X-Amduat-Type-Tag\n", false);
+    }
+  }
+
+  if (!amduat_asl_artifact_from_bytes(amduat_octets(body, req->content_length),
+                                      input_format,
+                                      has_type_tag,
+                                      type_tag,
+                                      &artifact)) {
+    free(body);
+    return amduatd_http_send_text(fd, 400, "Bad Request",
+                                 "invalid artifact\n", false);
+  }
+
+  err = amduat_asl_store_put(store, artifact, &ref);
+  amduat_asl_artifact_free(&artifact);
+  if (err != AMDUAT_ASL_STORE_OK) {
+    free((void *)ref.digest.data);
+    return amduatd_http_send_text(fd, 500, "Internal Server Error",
+                                 "store error\n", false);
+  }
+
+  if (!amduat_asl_ref_encode_hex(ref, &ref_hex)) {
+    free((void *)ref.digest.data);
+    return amduatd_http_send_text(fd, 500, "Internal Server Error",
+                                 "encode ref error\n", false);
+  }
+  free((void *)ref.digest.data);
+
+  {
+    int n = snprintf(json, sizeof(json), "{\"ref\":\"%s\"}\n", ref_hex);
+    free(ref_hex);
+    if (n <= 0 || (size_t)n >= sizeof(json)) {
+      return amduatd_http_send_text(fd, 500, "Internal Server Error",
+                                   "error\n", false);
+    }
+    return amduatd_http_send_json(fd, 200, "OK", json, false);
+  }
+}
+
+static bool amduatd_handle_conn(int fd,
+                                amduat_asl_store_t *store,
+                                const amduat_asl_store_fs_config_t *cfg) {
+  amduatd_http_req_t req;
+  char no_query[1024];
+
+  if (!amduatd_http_parse_request(fd, &req)) {
+    return false;
+  }
+
+  amduatd_path_without_query(req.path, no_query, sizeof(no_query));
+
+  if (strcmp(req.method, "GET") == 0 && strcmp(no_query, "/v1/meta") == 0) {
+    return amduatd_handle_meta(fd, cfg, false);
+  }
+  if (strcmp(req.method, "HEAD") == 0 && strcmp(no_query, "/v1/meta") == 0) {
+    return amduatd_handle_meta(fd, cfg, true);
+  }
+
+  if (strcmp(req.method, "POST") == 0 && strcmp(no_query, "/v1/artifacts") == 0) {
+    return amduatd_handle_post_artifacts(fd, store, &req);
+  }
+  if (strcmp(req.method, "GET") == 0 &&
+      strncmp(no_query, "/v1/artifacts/", 14) == 0) {
+    return amduatd_handle_get_artifact(fd, store, req.path, false);
+  }
+  if (strcmp(req.method, "HEAD") == 0 &&
+      strncmp(no_query, "/v1/artifacts/", 14) == 0) {
+    return amduatd_handle_head_artifact(fd, store, req.path);
+  }
+
+  return amduatd_http_send_text(fd, 404, "Not Found", "not found\n", false);
+}
+
+static void amduatd_print_usage(FILE *stream) {
+  fprintf(stream,
+          "usage:\n"
+          "  amduatd [--root PATH] [--sock PATH]\n"
+          "\n"
+          "defaults:\n"
+          "  --root %s\n"
+          "  --sock %s\n",
+          AMDUATD_DEFAULT_ROOT,
+          AMDUATD_DEFAULT_SOCK);
+}
+
+int main(int argc, char **argv) {
+  const char *root = AMDUATD_DEFAULT_ROOT;
+  const char *sock_path = AMDUATD_DEFAULT_SOCK;
+  amduat_asl_store_fs_config_t cfg;
+  amduat_asl_store_fs_t fs;
+  amduat_asl_store_t store;
+  int i;
+  int sfd = -1;
+
+  for (i = 1; i < argc; ++i) {
+    if (strcmp(argv[i], "--root") == 0) {
+      if (i + 1 >= argc) {
+        fprintf(stderr, "error: --root requires a path\n");
+        return 2;
+      }
+      root = argv[++i];
+    } else if (strcmp(argv[i], "--sock") == 0) {
+      if (i + 1 >= argc) {
+        fprintf(stderr, "error: --sock requires a path\n");
+        return 2;
+      }
+      sock_path = argv[++i];
+    } else if (strcmp(argv[i], "--help") == 0 || strcmp(argv[i], "-h") == 0) {
+      amduatd_print_usage(stdout);
+      return 0;
+    } else {
+      fprintf(stderr, "error: unknown option: %s\n", argv[i]);
+      return 2;
+    }
+  }
+
+  memset(&cfg, 0, sizeof(cfg));
+  if (!amduat_asl_store_fs_load_config(root, &cfg)) {
+    fprintf(stderr, "error: failed to load store config: %s\n", root);
+    return 8;
+  }
+
+  memset(&fs, 0, sizeof(fs));
+  if (!amduat_asl_store_fs_init(&fs, cfg.config, root)) {
+    fprintf(stderr, "error: failed to initialize store: %s\n", root);
+    return 8;
+  }
+  amduat_asl_store_init(&store, cfg.config, amduat_asl_store_fs_ops(), &fs);
+
+  signal(SIGINT, amduatd_on_signal);
+  signal(SIGTERM, amduatd_on_signal);
+
+  sfd = socket(AF_UNIX, SOCK_STREAM, 0);
+  if (sfd < 0) {
+    perror("socket");
+    return 8;
+  }
+
+  {
+    struct sockaddr_un addr;
+    memset(&addr, 0, sizeof(addr));
+    addr.sun_family = AF_UNIX;
+    if (strlen(sock_path) >= sizeof(addr.sun_path)) {
+      fprintf(stderr, "error: socket path too long\n");
+      close(sfd);
+      return 2;
+    }
+    strncpy(addr.sun_path, sock_path, sizeof(addr.sun_path) - 1);
+
+    (void)unlink(sock_path);
+
+    if (bind(sfd, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
+      perror("bind");
+      close(sfd);
+      return 8;
+    }
+    (void)chmod(sock_path, 0660);
+
+    if (listen(sfd, 16) < 0) {
+      perror("listen");
+      (void)unlink(sock_path);
+      close(sfd);
+      return 8;
+    }
+  }
+
+  fprintf(stderr, "amduatd: root=%s sock=%s\n", root, sock_path);
+
+  while (!amduatd_should_exit) {
+    int cfd = accept(sfd, NULL, NULL);
+    if (cfd < 0) {
+      if (errno == EINTR) {
+        continue;
+      }
+      perror("accept");
+      break;
+    }
+
+    (void)amduatd_handle_conn(cfd, &store, &cfg);
+    (void)close(cfd);
+  }
+
+  (void)unlink(sock_path);
+  (void)close(sfd);
+  return 0;
+}