From 8d7c7d93a5a530ba4a0e52a4b813dfdc88421238 Mon Sep 17 00:00:00 2001
From: Carl Niklas Rydberg <carlniklasrydberg@gmail.com>
Date: Sat, 24 Jan 2026 06:50:53 +0100
Subject: [PATCH] http out

---
 CMakeLists.txt         |   4 +-
 src/amduatd.c          | 689 +---------------------------------
 src/amduatd_caps.c     |  72 +---
 src/amduatd_concepts.c |  88 +----
 src/amduatd_http.c     | 819 +++++++++++++++++++++++++++++++++++++++++
 src/amduatd_http.h     | 116 ++++++
 src/amduatd_ui.c       |  38 +-
 src/amduatd_ui.h       |  20 +-
 8 files changed, 951 insertions(+), 895 deletions(-)
 create mode 100644 src/amduatd_http.c
 create mode 100644 src/amduatd_http.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8316992..90ef5d9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,8 +24,8 @@ target_link_libraries(amduat_federation
   PRIVATE amduat_asl amduat_enc amduat_util amduat_fed
 )
 
-set(amduatd_sources src/amduatd.c src/amduatd_caps.c src/amduatd_space.c
-                    src/amduatd_concepts.c)
+set(amduatd_sources src/amduatd.c src/amduatd_http.c src/amduatd_caps.c
+                    src/amduatd_space.c src/amduatd_concepts.c)
 if(AMDUATD_ENABLE_UI)
   list(APPEND amduatd_sources src/amduatd_ui.c)
 endif()
diff --git a/src/amduatd.c b/src/amduatd.c
index 0df8103..2e9a1cb 100644
--- a/src/amduatd.c
+++ b/src/amduatd.c
@@ -34,6 +34,7 @@
 #include "amduat/util/log.h"
 #include "amduat/hash/asl1.h"
 #include "amduatd_concepts.h"
+#include "amduatd_http.h"
 #include "amduatd_ui.h"
 #include "amduatd_caps.h"
 #include "amduatd_space.h"
@@ -64,17 +65,6 @@ typedef struct amduatd_strbuf {
   size_t cap;
 } amduatd_strbuf_t;
 
-bool amduatd_http_send_json(int fd,
-                            int code,
-                            const char *reason,
-                            const char *json,
-                            bool head_only);
-
-bool amduatd_send_json_error(int fd,
-                             int code,
-                             const char *reason,
-                             const char *msg);
-
 amduatd_ref_status_t amduatd_decode_ref_or_name_latest(
     amduat_asl_store_t *store,
     const amduat_asl_store_fs_config_t *cfg,
@@ -282,97 +272,6 @@ static void amduatd_on_signal(int signo) {
   amduatd_should_exit = 1;
 }
 
-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;
-}
-
-bool amduatd_read_exact(int fd, uint8_t *buf, size_t len);
-
-bool amduatd_read_urandom(uint8_t *out, size_t len) {
-  int fd;
-  if (out == NULL || len == 0) {
-    return false;
-  }
-  fd = open("/dev/urandom", O_RDONLY);
-  if (fd < 0) {
-    return false;
-  }
-  if (!amduatd_read_exact(fd, out, len)) {
-    close(fd);
-    return false;
-  }
-  close(fd);
-  return true;
-}
-
-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;
-}
-
-static void amduatd_http_req_init(amduatd_http_req_t *req) {
-  memset(req, 0, sizeof(*req));
-}
-
 typedef struct {
   uid_t *uids;
   size_t len;
@@ -493,258 +392,6 @@ static bool amduatd_get_peer_actor(int client_fd,
   return true;
 }
 
-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);
-    } else if (strncasecmp(line, "X-Amduat-Capability:", 20) == 0) {
-      const char *v = line + 20;
-      while (*v == ' ' || *v == '\t') {
-        v++;
-      }
-      strncpy(out_req->x_capability, v, sizeof(out_req->x_capability) - 1);
-    }
-  }
-
-  return true;
-}
-
-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;
-}
-
-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);
-}
-
-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 bool amduatd_http_req_wants_html(const amduatd_http_req_t *req) {
-  if (req == NULL) {
-    return false;
-  }
-  if (req->accept[0] == '\0') {
-    return false;
-  }
-  return strstr(req->accept, "text/html") != NULL;
-}
-
-static bool amduatd_http_send_not_found(int fd, const amduatd_http_req_t *req) {
-  if (amduatd_http_req_wants_html(req)) {
-    const char *path = (req != NULL && req->path[0] != '\0') ? req->path : "/";
-    const char *method =
-        (req != NULL && req->method[0] != '\0') ? req->method : "GET";
-    char html[4096];
-    int n = snprintf(
-        html,
-        sizeof(html),
-        "<!doctype html>\n"
-        "<html lang=\"en\">\n"
-        "<head>\n"
-        "  <meta charset=\"utf-8\" />\n"
-        "  <meta name=\"viewport\" content=\"width=device-width, initial-scale=1\" />\n"
-        "  <title>amduatd — Not Found</title>\n"
-        "  <style>\n"
-        "    :root{color-scheme:light dark;}\n"
-        "    body{font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,Cantarell,Noto Sans,Arial,sans-serif;"
-        "         margin:0;line-height:1.4;}\n"
-        "    .wrap{max-width:860px;margin:0 auto;padding:40px 20px;}\n"
-        "    .card{border:1px solid rgba(127,127,127,.35);border-radius:14px;padding:22px;"
-        "          background:rgba(127,127,127,.06);}\n"
-        "    h1{margin:0 0 6px;font-size:22px;}\n"
-        "    p{margin:8px 0;opacity:.9;}\n"
-        "    code{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,Liberation Mono,monospace;"
-        "         font-size:13px;}\n"
-        "    ul{margin:10px 0 0;padding-left:18px;}\n"
-        "    a{color:inherit;}\n"
-        "    .muted{opacity:.75;}\n"
-        "  </style>\n"
-        "</head>\n"
-        "<body>\n"
-        "  <div class=\"wrap\">\n"
-        "    <div class=\"card\">\n"
-        "      <h1>404 — Not Found</h1>\n"
-        "      <p>amduatd didn’t recognize <code>%s %s</code>.</p>\n"
-        "      <p class=\"muted\">Try one of these:</p>\n"
-        "      <ul>\n"
-        "        <li><a href=\"/v1/meta\">/v1/meta</a></li>\n"
-        "        <li><a href=\"/v1/contract\">/v1/contract</a></li>\n"
-        "      </ul>\n"
-        "      <p class=\"muted\">Artifact bytes: <code>/v1/artifacts/&lt;ref&gt;</code></p>\n"
-        "    </div>\n"
-        "  </div>\n"
-        "</body>\n"
-        "</html>\n",
-        method,
-        path);
-    if (n <= 0 || (size_t)n >= sizeof(html)) {
-      return amduatd_http_send_text(fd, 404, "Not Found", "not found\n", false);
-    }
-    return amduatd_http_send_status(fd,
-                                   404,
-                                   "Not Found",
-                                   "text/html; charset=utf-8",
-                                   (const uint8_t *)html,
-                                   (size_t)n,
-                                   false);
-  }
-  return amduatd_http_send_text(fd, 404, "Not Found", "not found\n", false);
-}
-
-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_strbuf_free(amduatd_strbuf_t *b) {
   if (b == NULL) {
     return;
@@ -816,73 +463,6 @@ static bool amduatd_strbuf_append_char(amduatd_strbuf_t *b, char c) {
   return amduatd_strbuf_append(b, &c, 1u);
 }
 
-const char *amduatd_json_skip_ws(const char *p, const char *end) {
-  while (p < end) {
-    char c = *p;
-    if (c != ' ' && c != '\t' && c != '\n' && c != '\r') {
-      break;
-    }
-    p++;
-  }
-  return p;
-}
-
-bool amduatd_json_expect(const char **p,
-                         const char *end,
-                         char expected) {
-  const char *cur;
-  if (p == NULL || *p == NULL) {
-    return false;
-  }
-  cur = amduatd_json_skip_ws(*p, end);
-  if (cur >= end || *cur != expected) {
-    return false;
-  }
-  *p = cur + 1;
-  return true;
-}
-
-bool amduatd_json_parse_string_noesc(const char **p,
-                                     const char *end,
-                                     const char **out_start,
-                                     size_t *out_len) {
-  const char *cur;
-  const char *s;
-  if (out_start != NULL) {
-    *out_start = NULL;
-  }
-  if (out_len != NULL) {
-    *out_len = 0;
-  }
-  if (p == NULL || *p == NULL) {
-    return false;
-  }
-  cur = amduatd_json_skip_ws(*p, end);
-  if (cur >= end || *cur != '"') {
-    return false;
-  }
-  cur++;
-  s = cur;
-  while (cur < end) {
-    unsigned char c = (unsigned char)*cur;
-    if (c == '"') {
-      if (out_start != NULL) {
-        *out_start = s;
-      }
-      if (out_len != NULL) {
-        *out_len = (size_t)(cur - s);
-      }
-      *p = cur + 1;
-      return true;
-    }
-    if (c == '\\' || c < 0x20u) {
-      return false;
-    }
-    cur++;
-  }
-  return false;
-}
-
 static bool amduatd_json_parse_u32(const char **p,
                                   const char *end,
                                   uint32_t *out) {
@@ -930,53 +510,6 @@ static bool amduatd_json_parse_u32(const char **p,
   return true;
 }
 
-bool amduatd_json_parse_u64(const char **p,
-                            const char *end,
-                            uint64_t *out) {
-  const char *cur;
-  const char *start;
-  unsigned long long v;
-  char *tmp = NULL;
-  char *endp = NULL;
-  size_t n;
-
-  if (out != NULL) {
-    *out = 0;
-  }
-  if (p == NULL || *p == NULL || out == NULL) {
-    return false;
-  }
-
-  cur = amduatd_json_skip_ws(*p, end);
-  start = cur;
-  if (cur >= end) {
-    return false;
-  }
-  if (*cur < '0' || *cur > '9') {
-    return false;
-  }
-  cur++;
-  while (cur < end && *cur >= '0' && *cur <= '9') {
-    cur++;
-  }
-  n = (size_t)(cur - start);
-  tmp = (char *)malloc(n + 1u);
-  if (tmp == NULL) {
-    return false;
-  }
-  memcpy(tmp, start, n);
-  tmp[n] = '\0';
-  errno = 0;
-  v = strtoull(tmp, &endp, 10);
-  free(tmp);
-  if (errno != 0 || endp == NULL || *endp != '\0') {
-    return false;
-  }
-  *out = (uint64_t)v;
-  *p = cur;
-  return true;
-}
-
 static bool amduatd_json_parse_u32_loose(const char **p,
                                         const char *end,
                                         uint32_t *out) {
@@ -1070,183 +603,6 @@ static void amduatd_json_peek_token(const char *p,
   out[n] = '\0';
 }
 
-static bool amduatd_json_skip_string(const char **p, const char *end) {
-  const char *cur;
-  if (p == NULL || *p == NULL) {
-    return false;
-  }
-  cur = amduatd_json_skip_ws(*p, end);
-  if (cur >= end || *cur != '"') {
-    return false;
-  }
-  cur++;
-  while (cur < end) {
-    unsigned char c = (unsigned char)*cur++;
-    if (c == '"') {
-      *p = cur;
-      return true;
-    }
-    if (c == '\\') {
-      if (cur >= end) {
-        return false;
-      }
-      cur++;
-    } else if (c < 0x20u) {
-      return false;
-    }
-  }
-  return false;
-}
-
-bool amduatd_json_skip_value(const char **p,
-                             const char *end,
-                             int depth);
-
-static bool amduatd_json_skip_array(const char **p,
-                                    const char *end,
-                                    int depth) {
-  const char *cur;
-  if (!amduatd_json_expect(p, end, '[')) {
-    return false;
-  }
-  cur = amduatd_json_skip_ws(*p, end);
-  if (cur < end && *cur == ']') {
-    *p = cur + 1;
-    return true;
-  }
-  for (;;) {
-    if (!amduatd_json_skip_value(p, end, depth + 1)) {
-      return false;
-    }
-    cur = amduatd_json_skip_ws(*p, end);
-    if (cur >= end) {
-      return false;
-    }
-    if (*cur == ',') {
-      *p = cur + 1;
-      continue;
-    }
-    if (*cur == ']') {
-      *p = cur + 1;
-      return true;
-    }
-    return false;
-  }
-}
-
-static bool amduatd_json_skip_object(const char **p,
-                                    const char *end,
-                                    int depth) {
-  const char *cur;
-  if (!amduatd_json_expect(p, end, '{')) {
-    return false;
-  }
-  cur = amduatd_json_skip_ws(*p, end);
-  if (cur < end && *cur == '}') {
-    *p = cur + 1;
-    return true;
-  }
-  for (;;) {
-    if (!amduatd_json_skip_string(p, end)) {
-      return false;
-    }
-    if (!amduatd_json_expect(p, end, ':')) {
-      return false;
-    }
-    if (!amduatd_json_skip_value(p, end, depth + 1)) {
-      return false;
-    }
-    cur = amduatd_json_skip_ws(*p, end);
-    if (cur >= end) {
-      return false;
-    }
-    if (*cur == ',') {
-      *p = cur + 1;
-      continue;
-    }
-    if (*cur == '}') {
-      *p = cur + 1;
-      return true;
-    }
-    return false;
-  }
-}
-
-bool amduatd_json_skip_value(const char **p,
-                             const char *end,
-                             int depth) {
-  const char *cur;
-  if (p == NULL || *p == NULL) {
-    return false;
-  }
-  if (depth > 32) {
-    return false;
-  }
-  cur = amduatd_json_skip_ws(*p, end);
-  if (cur >= end) {
-    return false;
-  }
-  if (*cur == '"') {
-    return amduatd_json_skip_string(p, end);
-  }
-  if (*cur == '{') {
-    return amduatd_json_skip_object(p, end, depth);
-  }
-  if (*cur == '[') {
-    return amduatd_json_skip_array(p, end, depth);
-  }
-  if (*cur == 't' && (end - cur) >= 4 && memcmp(cur, "true", 4) == 0) {
-    *p = cur + 4;
-    return true;
-  }
-  if (*cur == 'f' && (end - cur) >= 5 && memcmp(cur, "false", 5) == 0) {
-    *p = cur + 5;
-    return true;
-  }
-  if (*cur == 'n' && (end - cur) >= 4 && memcmp(cur, "null", 4) == 0) {
-    *p = cur + 4;
-    return true;
-  }
-  if (*cur == '-' || (*cur >= '0' && *cur <= '9')) {
-    cur++;
-    while (cur < end) {
-      char c = *cur;
-      if ((c >= '0' && c <= '9') || c == '.' || c == 'e' || c == 'E' ||
-          c == '+' || c == '-') {
-        cur++;
-        continue;
-      }
-      break;
-    }
-    *p = cur;
-    return true;
-  }
-  return false;
-}
-
-bool amduatd_copy_json_str(const char *s,
-                           size_t len,
-                           char **out) {
-  char *buf;
-  if (out == NULL) {
-    return false;
-  }
-  *out = NULL;
-  if (len > (SIZE_MAX - 1u)) {
-    return false;
-  }
-  buf = (char *)malloc(len + 1u);
-  if (buf == NULL) {
-    return false;
-  }
-  if (len != 0) {
-    memcpy(buf, s, len);
-  }
-  buf[len] = '\0';
-  *out = buf;
-  return true;
-}
-
 static bool amduatd_decode_ref_hex_str(const char *s,
                                       size_t len,
                                       amduat_reference_t *out_ref) {
@@ -1264,47 +620,6 @@ static bool amduatd_decode_ref_hex_str(const char *s,
   return ok;
 }
 
-bool amduatd_send_json_error(int fd,
-                             int code,
-                             const char *reason,
-                             const char *msg) {
-  amduatd_strbuf_t b;
-  memset(&b, 0, sizeof(b));
-  if (!amduatd_strbuf_append_cstr(&b, "{\"error\":\"") ||
-      !amduatd_strbuf_append_cstr(&b, msg != NULL ? msg : "error") ||
-      !amduatd_strbuf_append_cstr(&b, "\"}\n")) {
-    amduatd_strbuf_free(&b);
-    return amduatd_http_send_text(fd, 500, "Internal Server Error", "error\n",
-                                 false);
-  }
-  {
-    bool ok = amduatd_http_send_json(fd, code, reason, b.data, false);
-    amduatd_strbuf_free(&b);
-    return ok;
-  }
-}
-
-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) {
@@ -4695,7 +4010,7 @@ static bool amduatd_handle_conn(int fd,
   ok = amduatd_http_send_not_found(fd, &req);
 
 conn_cleanup:
-  free((void *)req.actor.data);
+  amduatd_http_req_free(&req);
   return ok;
 }
 
diff --git a/src/amduatd_caps.c b/src/amduatd_caps.c
index bf5da80..4f8b818 100644
--- a/src/amduatd_caps.c
+++ b/src/amduatd_caps.c
@@ -1,4 +1,5 @@
 #include "amduatd_caps.h"
+#include "amduatd_http.h"
 
 #include "amduat/asl/asl_pointer_fs.h"
 #include "amduat/asl/ref_text.h"
@@ -23,45 +24,6 @@
 #include <time.h>
 #include <unistd.h>
 
-bool amduatd_write_all(int fd, const uint8_t *buf, size_t len);
-bool amduatd_read_exact(int fd, uint8_t *buf, size_t len);
-bool amduatd_read_urandom(uint8_t *out, size_t len);
-
-bool amduatd_http_send_json(int fd,
-                            int code,
-                            const char *reason,
-                            const char *json,
-                            bool head_only);
-
-bool amduatd_send_json_error(int fd,
-                             int code,
-                             const char *reason,
-                             const char *msg);
-
-const char *amduatd_query_param(const char *path,
-                                const char *key,
-                                char *out_value,
-                                size_t out_cap);
-
-const char *amduatd_json_skip_ws(const char *p, const char *end);
-
-bool amduatd_json_expect(const char **p,
-                         const char *end,
-                         char expected);
-
-bool amduatd_json_parse_string_noesc(const char **p,
-                                     const char *end,
-                                     const char **out,
-                                     size_t *out_len);
-
-bool amduatd_json_parse_u64(const char **p, const char *end, uint64_t *out);
-
-bool amduatd_json_skip_value(const char **p,
-                             const char *end,
-                             int depth);
-
-bool amduatd_copy_json_str(const char *s, size_t len, char **out);
-
 amduatd_ref_status_t amduatd_decode_ref_or_name_latest(
     amduat_asl_store_t *store,
     const amduat_asl_store_fs_config_t *cfg,
@@ -1152,28 +1114,6 @@ static bool amduatd_cap_verify_token(const amduatd_caps_t *cap,
   return true;
 }
 
-static bool amduatd_caps_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 false;
-  }
-  out[0] = '\0';
-  if (path == NULL) {
-    return false;
-  }
-  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';
-  return true;
-}
-
 static bool amduatd_handle_post_capabilities(
     int fd,
     amduat_asl_store_t *store,
@@ -1862,7 +1802,7 @@ bool amduatd_caps_can_handle(const amduatd_http_req_t *req) {
   if (req == NULL) {
     return false;
   }
-  if (!amduatd_caps_path_without_query(req->path, no_query, sizeof(no_query))) {
+  if (!amduatd_path_without_query(req->path, no_query, sizeof(no_query))) {
     return false;
   }
   if (strcmp(req->method, "POST") == 0 &&
@@ -1887,11 +1827,11 @@ bool amduatd_caps_handle(amduatd_ctx_t *ctx,
   if (!amduatd_caps_can_handle(req)) {
     return false;
   }
-  if (!amduatd_caps_path_without_query(req->path, no_query, sizeof(no_query))) {
+  if (!amduatd_path_without_query(req->path, no_query, sizeof(no_query))) {
     resp->ok = amduatd_send_json_error(resp->fd,
-                                      400,
-                                      "Bad Request",
-                                      "invalid path");
+                                       400,
+                                       "Bad Request",
+                                       "invalid path");
     return true;
   }
 
diff --git a/src/amduatd_concepts.c b/src/amduatd_concepts.c
index 50823ca..227a0c7 100644
--- a/src/amduatd_concepts.c
+++ b/src/amduatd_concepts.c
@@ -4,6 +4,7 @@
 #define _POSIX_C_SOURCE 200809L
 
 #include "amduatd_concepts.h"
+#include "amduatd_http.h"
 
 #include "amduatd_caps.h"
 
@@ -34,37 +35,6 @@
 #include <string.h>
 #include <unistd.h>
 
-bool amduatd_read_exact(int fd, uint8_t *buf, size_t len);
-bool amduatd_read_urandom(uint8_t *out, size_t len);
-
-bool amduatd_http_send_json(int fd,
-                            int code,
-                            const char *reason,
-                            const char *json,
-                            bool head_only);
-
-bool amduatd_send_json_error(int fd,
-                             int code,
-                             const char *reason,
-                             const char *msg);
-
-const char *amduatd_json_skip_ws(const char *p, const char *end);
-
-bool amduatd_json_expect(const char **p,
-                         const char *end,
-                         char expected);
-
-bool amduatd_json_parse_string_noesc(const char **p,
-                                     const char *end,
-                                     const char **out,
-                                     size_t *out_len);
-
-bool amduatd_json_skip_value(const char **p,
-                             const char *end,
-                             int depth);
-
-bool amduatd_copy_json_str(const char *s, size_t len, char **out);
-
 typedef struct amduatd_strbuf {
   char *data;
   size_t len;
@@ -2995,37 +2965,6 @@ concepts_cleanup:
   return ok;
 }
 
-static bool amduatd_path_extract_name(const char *path,
-                                     const char *prefix,
-                                     char *out,
-                                     size_t cap) {
-  size_t plen;
-  const char *p;
-  size_t len;
-
-  if (out != NULL && cap != 0) {
-    out[0] = '\0';
-  }
-  if (path == NULL || prefix == NULL || out == NULL || cap == 0) {
-    return false;
-  }
-  plen = strlen(prefix);
-  if (strncmp(path, prefix, plen) != 0) {
-    return false;
-  }
-  p = path + plen;
-  if (*p == '\0') {
-    return false;
-  }
-  len = strlen(p);
-  if (len >= cap) {
-    len = cap - 1;
-  }
-  memcpy(out, p, len);
-  out[len] = '\0';
-  return true;
-}
-
 static bool amduatd_handle_post_concept_publish(int fd,
                                                 amduat_asl_store_t *store,
                                                 amduatd_concepts_t *concepts,
@@ -3219,34 +3158,13 @@ static bool amduatd_handle_get_resolve(int fd,
   return amduatd_http_send_json(fd, 200, "OK", json, false);
 }
 
-static void amduatd_concepts_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';
-}
-
 bool amduatd_concepts_can_handle(const amduatd_http_req_t *req) {
   char no_query[1024];
 
   if (req == NULL) {
     return false;
   }
-  amduatd_concepts_path_without_query(req->path, no_query, sizeof(no_query));
+  amduatd_path_without_query(req->path, no_query, sizeof(no_query));
 
   if (strcmp(req->method, "POST") == 0 &&
       strcmp(no_query, "/v1/concepts") == 0) {
@@ -3286,7 +3204,7 @@ bool amduatd_concepts_handle(amduatd_ctx_t *ctx,
     return false;
   }
 
-  amduatd_concepts_path_without_query(req->path, no_query, sizeof(no_query));
+  amduatd_path_without_query(req->path, no_query, sizeof(no_query));
 
   if (strcmp(req->method, "POST") == 0 && strcmp(no_query, "/v1/concepts") == 0) {
     resp->ok = amduatd_handle_post_concepts(resp->fd,
diff --git a/src/amduatd_http.c b/src/amduatd_http.c
new file mode 100644
index 0000000..1fd40bb
--- /dev/null
+++ b/src/amduatd_http.c
@@ -0,0 +1,819 @@
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#define _POSIX_C_SOURCE 200809L
+
+#include "amduatd_http.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <strings.h>
+#include <string.h>
+#include <unistd.h>
+
+typedef struct amduatd_http_strbuf {
+  char *data;
+  size_t len;
+  size_t cap;
+} amduatd_http_strbuf_t;
+
+static void amduatd_http_strbuf_free(amduatd_http_strbuf_t *b) {
+  if (b == NULL) {
+    return;
+  }
+  free(b->data);
+  b->data = NULL;
+  b->len = 0;
+  b->cap = 0;
+}
+
+static bool amduatd_http_strbuf_reserve(amduatd_http_strbuf_t *b, size_t extra) {
+  size_t need;
+  size_t next_cap;
+  char *next;
+
+  if (b == NULL) {
+    return false;
+  }
+  if (extra > (SIZE_MAX - b->len)) {
+    return false;
+  }
+  need = b->len + extra;
+  if (need <= b->cap) {
+    return true;
+  }
+  next_cap = b->cap != 0 ? b->cap : 256u;
+  while (next_cap < need) {
+    if (next_cap > (SIZE_MAX / 2u)) {
+      next_cap = need;
+      break;
+    }
+    next_cap *= 2u;
+  }
+  next = (char *)realloc(b->data, next_cap);
+  if (next == NULL) {
+    return false;
+  }
+  b->data = next;
+  b->cap = next_cap;
+  return true;
+}
+
+static bool amduatd_http_strbuf_append(amduatd_http_strbuf_t *b,
+                                       const char *s,
+                                       size_t n) {
+  if (b == NULL) {
+    return false;
+  }
+  if (n == 0) {
+    return true;
+  }
+  if (s == NULL) {
+    return false;
+  }
+  if (!amduatd_http_strbuf_reserve(b, n + 1u)) {
+    return false;
+  }
+  memcpy(b->data + b->len, s, n);
+  b->len += n;
+  b->data[b->len] = '\0';
+  return true;
+}
+
+static bool amduatd_http_strbuf_append_cstr(amduatd_http_strbuf_t *b,
+                                            const char *s) {
+  return amduatd_http_strbuf_append(
+      b, s != NULL ? s : "", s != NULL ? strlen(s) : 0u);
+}
+
+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;
+}
+
+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;
+}
+
+bool amduatd_read_urandom(uint8_t *out, size_t len) {
+  int fd;
+  if (out == NULL || len == 0) {
+    return false;
+  }
+  fd = open("/dev/urandom", O_RDONLY);
+  if (fd < 0) {
+    return false;
+  }
+  if (!amduatd_read_exact(fd, out, len)) {
+    close(fd);
+    return false;
+  }
+  close(fd);
+  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;
+}
+
+static void amduatd_http_req_init(amduatd_http_req_t *req) {
+  memset(req, 0, sizeof(*req));
+}
+
+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);
+    } else if (strncasecmp(line, "X-Amduat-Capability:", 20) == 0) {
+      const char *v = line + 20;
+      while (*v == ' ' || *v == '\t') {
+        v++;
+      }
+      strncpy(out_req->x_capability, v, sizeof(out_req->x_capability) - 1);
+    }
+  }
+
+  return true;
+}
+
+void amduatd_http_req_free(amduatd_http_req_t *req) {
+  if (req == NULL) {
+    return;
+  }
+  free((void *)req->actor.data);
+  req->actor = amduat_octets(NULL, 0u);
+  req->has_actor = false;
+  req->has_uid = false;
+  req->uid = 0;
+}
+
+bool amduatd_http_send_response(int fd, const amduatd_http_resp_t *resp) {
+  if (resp == NULL) {
+    return false;
+  }
+  return amduatd_http_send_status(fd,
+                                  resp->status,
+                                  resp->reason,
+                                  resp->content_type,
+                                  resp->body,
+                                  resp->body_len,
+                                  resp->head_only);
+}
+
+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;
+}
+
+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);
+}
+
+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 bool amduatd_http_req_wants_html(const amduatd_http_req_t *req) {
+  if (req == NULL) {
+    return false;
+  }
+  if (req->accept[0] == '\0') {
+    return false;
+  }
+  return strstr(req->accept, "text/html") != NULL;
+}
+
+bool amduatd_http_send_not_found(int fd, const amduatd_http_req_t *req) {
+  if (amduatd_http_req_wants_html(req)) {
+    const char *path = (req != NULL && req->path[0] != '\0') ? req->path : "/";
+    const char *method =
+        (req != NULL && req->method[0] != '\0') ? req->method : "GET";
+    char html[4096];
+    int n = snprintf(
+        html,
+        sizeof(html),
+        "<!doctype html>\n"
+        "<html lang=\"en\">\n"
+        "<head>\n"
+        "  <meta charset=\"utf-8\" />\n"
+        "  <meta name=\"viewport\" content=\"width=device-width, initial-scale=1\" />\n"
+        "  <title>amduatd — Not Found</title>\n"
+        "  <style>\n"
+        "    :root{color-scheme:light dark;}\n"
+        "    body{font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,Cantarell,Noto Sans,Arial,sans-serif;"
+        "         margin:0;line-height:1.4;}\n"
+        "    .wrap{max-width:860px;margin:0 auto;padding:40px 20px;}\n"
+        "    .card{border:1px solid rgba(127,127,127,.35);border-radius:14px;padding:22px;"
+        "          background:rgba(127,127,127,.06);}\n"
+        "    h1{margin:0 0 6px;font-size:22px;}\n"
+        "    p{margin:8px 0;opacity:.9;}\n"
+        "    code{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,Liberation Mono,monospace;"
+        "         font-size:13px;}\n"
+        "    ul{margin:10px 0 0;padding-left:18px;}\n"
+        "    a{color:inherit;}\n"
+        "    .muted{opacity:.75;}\n"
+        "  </style>\n"
+        "</head>\n"
+        "<body>\n"
+        "  <div class=\"wrap\">\n"
+        "    <div class=\"card\">\n"
+        "      <h1>404 — Not Found</h1>\n"
+        "      <p>amduatd didn’t recognize <code>%s %s</code>.</p>\n"
+        "      <p class=\"muted\">Try one of these:</p>\n"
+        "      <ul>\n"
+        "        <li><a href=\"/v1/meta\">/v1/meta</a></li>\n"
+        "        <li><a href=\"/v1/contract\">/v1/contract</a></li>\n"
+        "      </ul>\n"
+        "      <p class=\"muted\">Artifact bytes: <code>/v1/artifacts/&lt;ref&gt;</code></p>\n"
+        "    </div>\n"
+        "  </div>\n"
+        "</body>\n"
+        "</html>\n",
+        method,
+        path);
+    if (n <= 0 || (size_t)n >= sizeof(html)) {
+      return amduatd_http_send_text(fd, 404, "Not Found", "not found\n", false);
+    }
+    return amduatd_http_send_status(fd,
+                                   404,
+                                   "Not Found",
+                                   "text/html; charset=utf-8",
+                                   (const uint8_t *)html,
+                                   (size_t)n,
+                                   false);
+  }
+  return amduatd_http_send_text(fd, 404, "Not Found", "not found\n", false);
+}
+
+bool amduatd_send_json_error(int fd,
+                             int code,
+                             const char *reason,
+                             const char *msg) {
+  amduatd_http_strbuf_t b;
+  memset(&b, 0, sizeof(b));
+  if (!amduatd_http_strbuf_append_cstr(&b, "{\"error\":\"") ||
+      !amduatd_http_strbuf_append_cstr(&b, msg != NULL ? msg : "error") ||
+      !amduatd_http_strbuf_append_cstr(&b, "\"}\n")) {
+    amduatd_http_strbuf_free(&b);
+    return amduatd_http_send_text(fd, 500, "Internal Server Error", "error\n",
+                                 false);
+  }
+  {
+    bool ok = amduatd_http_send_json(fd, code, reason, b.data, false);
+    amduatd_http_strbuf_free(&b);
+    return ok;
+  }
+}
+
+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;
+}
+
+bool 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 false;
+  }
+  out[0] = '\0';
+  if (path == NULL) {
+    return false;
+  }
+  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';
+  return true;
+}
+
+bool amduatd_path_extract_name(const char *path,
+                               const char *prefix,
+                               char *out,
+                               size_t cap) {
+  size_t plen;
+  const char *p;
+  size_t len;
+
+  if (out != NULL && cap != 0) {
+    out[0] = '\0';
+  }
+  if (path == NULL || prefix == NULL || out == NULL || cap == 0) {
+    return false;
+  }
+  plen = strlen(prefix);
+  if (strncmp(path, prefix, plen) != 0) {
+    return false;
+  }
+  p = path + plen;
+  if (*p == '\0') {
+    return false;
+  }
+  len = strlen(p);
+  if (len >= cap) {
+    len = cap - 1;
+  }
+  memcpy(out, p, len);
+  out[len] = '\0';
+  return true;
+}
+
+const char *amduatd_json_skip_ws(const char *p, const char *end) {
+  while (p < end) {
+    char c = *p;
+    if (c != ' ' && c != '\t' && c != '\n' && c != '\r') {
+      break;
+    }
+    p++;
+  }
+  return p;
+}
+
+bool amduatd_json_expect(const char **p,
+                         const char *end,
+                         char expected) {
+  const char *cur;
+  if (p == NULL || *p == NULL) {
+    return false;
+  }
+  cur = amduatd_json_skip_ws(*p, end);
+  if (cur >= end || *cur != expected) {
+    return false;
+  }
+  *p = cur + 1;
+  return true;
+}
+
+bool amduatd_json_parse_string_noesc(const char **p,
+                                     const char *end,
+                                     const char **out_start,
+                                     size_t *out_len) {
+  const char *cur;
+  const char *s;
+  if (out_start != NULL) {
+    *out_start = NULL;
+  }
+  if (out_len != NULL) {
+    *out_len = 0;
+  }
+  if (p == NULL || *p == NULL) {
+    return false;
+  }
+  cur = amduatd_json_skip_ws(*p, end);
+  if (cur >= end || *cur != '"') {
+    return false;
+  }
+  cur++;
+  s = cur;
+  while (cur < end) {
+    unsigned char c = (unsigned char)*cur;
+    if (c == '"') {
+      if (out_start != NULL) {
+        *out_start = s;
+      }
+      if (out_len != NULL) {
+        *out_len = (size_t)(cur - s);
+      }
+      *p = cur + 1;
+      return true;
+    }
+    if (c == '\\' || c < 0x20u) {
+      return false;
+    }
+    cur++;
+  }
+  return false;
+}
+
+bool amduatd_json_parse_u64(const char **p,
+                            const char *end,
+                            uint64_t *out) {
+  const char *cur;
+  const char *start;
+  unsigned long long v;
+  char *tmp = NULL;
+  char *endp = NULL;
+  size_t n;
+
+  if (out != NULL) {
+    *out = 0;
+  }
+  if (p == NULL || *p == NULL || out == NULL) {
+    return false;
+  }
+
+  cur = amduatd_json_skip_ws(*p, end);
+  start = cur;
+  if (cur >= end) {
+    return false;
+  }
+  if (*cur < '0' || *cur > '9') {
+    return false;
+  }
+  cur++;
+  while (cur < end && *cur >= '0' && *cur <= '9') {
+    cur++;
+  }
+  n = (size_t)(cur - start);
+  tmp = (char *)malloc(n + 1u);
+  if (tmp == NULL) {
+    return false;
+  }
+  memcpy(tmp, start, n);
+  tmp[n] = '\0';
+  errno = 0;
+  v = strtoull(tmp, &endp, 10);
+  free(tmp);
+  if (errno != 0 || endp == NULL || *endp != '\0') {
+    return false;
+  }
+  *out = (uint64_t)v;
+  *p = cur;
+  return true;
+}
+
+static bool amduatd_json_skip_string(const char **p, const char *end) {
+  const char *cur;
+  if (p == NULL || *p == NULL) {
+    return false;
+  }
+  cur = amduatd_json_skip_ws(*p, end);
+  if (cur >= end || *cur != '"') {
+    return false;
+  }
+  cur++;
+  while (cur < end) {
+    unsigned char c = (unsigned char)*cur++;
+    if (c == '"') {
+      *p = cur;
+      return true;
+    }
+    if (c == '\\') {
+      if (cur >= end) {
+        return false;
+      }
+      cur++;
+    } else if (c < 0x20u) {
+      return false;
+    }
+  }
+  return false;
+}
+
+bool amduatd_json_skip_value(const char **p,
+                             const char *end,
+                             int depth);
+
+static bool amduatd_json_skip_array(const char **p,
+                                    const char *end,
+                                    int depth) {
+  const char *cur;
+  if (!amduatd_json_expect(p, end, '[')) {
+    return false;
+  }
+  cur = amduatd_json_skip_ws(*p, end);
+  if (cur < end && *cur == ']') {
+    *p = cur + 1;
+    return true;
+  }
+  for (;;) {
+    if (!amduatd_json_skip_value(p, end, depth + 1)) {
+      return false;
+    }
+    cur = amduatd_json_skip_ws(*p, end);
+    if (cur >= end) {
+      return false;
+    }
+    if (*cur == ',') {
+      *p = cur + 1;
+      continue;
+    }
+    if (*cur == ']') {
+      *p = cur + 1;
+      return true;
+    }
+    return false;
+  }
+}
+
+static bool amduatd_json_skip_object(const char **p,
+                                     const char *end,
+                                     int depth) {
+  const char *cur;
+  if (!amduatd_json_expect(p, end, '{')) {
+    return false;
+  }
+  cur = amduatd_json_skip_ws(*p, end);
+  if (cur < end && *cur == '}') {
+    *p = cur + 1;
+    return true;
+  }
+  for (;;) {
+    if (!amduatd_json_skip_string(p, end)) {
+      return false;
+    }
+    if (!amduatd_json_expect(p, end, ':')) {
+      return false;
+    }
+    if (!amduatd_json_skip_value(p, end, depth + 1)) {
+      return false;
+    }
+    cur = amduatd_json_skip_ws(*p, end);
+    if (cur >= end) {
+      return false;
+    }
+    if (*cur == ',') {
+      *p = cur + 1;
+      continue;
+    }
+    if (*cur == '}') {
+      *p = cur + 1;
+      return true;
+    }
+    return false;
+  }
+}
+
+bool amduatd_json_skip_value(const char **p,
+                             const char *end,
+                             int depth) {
+  const char *cur;
+  if (p == NULL || *p == NULL) {
+    return false;
+  }
+  if (depth > 32) {
+    return false;
+  }
+  cur = amduatd_json_skip_ws(*p, end);
+  if (cur >= end) {
+    return false;
+  }
+  if (*cur == '"') {
+    return amduatd_json_skip_string(p, end);
+  }
+  if (*cur == '{') {
+    return amduatd_json_skip_object(p, end, depth);
+  }
+  if (*cur == '[') {
+    return amduatd_json_skip_array(p, end, depth);
+  }
+  if (*cur == 't' && (end - cur) >= 4 && memcmp(cur, "true", 4) == 0) {
+    *p = cur + 4;
+    return true;
+  }
+  if (*cur == 'f' && (end - cur) >= 5 && memcmp(cur, "false", 5) == 0) {
+    *p = cur + 5;
+    return true;
+  }
+  if (*cur == 'n' && (end - cur) >= 4 && memcmp(cur, "null", 4) == 0) {
+    *p = cur + 4;
+    return true;
+  }
+  if (*cur == '-' || (*cur >= '0' && *cur <= '9')) {
+    cur++;
+    while (cur < end) {
+      char c = *cur;
+      if ((c >= '0' && c <= '9') || c == '.' || c == 'e' || c == 'E' ||
+          c == '+' || c == '-') {
+        cur++;
+        continue;
+      }
+      break;
+    }
+    *p = cur;
+    return true;
+  }
+  return false;
+}
+
+bool amduatd_copy_json_str(const char *s,
+                           size_t len,
+                           char **out) {
+  char *buf;
+  if (out == NULL) {
+    return false;
+  }
+  *out = NULL;
+  if (len > (SIZE_MAX - 1u)) {
+    return false;
+  }
+  buf = (char *)malloc(len + 1u);
+  if (buf == NULL) {
+    return false;
+  }
+  if (len != 0) {
+    memcpy(buf, s, len);
+  }
+  buf[len] = '\0';
+  *out = buf;
+  return true;
+}
diff --git a/src/amduatd_http.h b/src/amduatd_http.h
new file mode 100644
index 0000000..f6c2a60
--- /dev/null
+++ b/src/amduatd_http.h
@@ -0,0 +1,116 @@
+#ifndef AMDUATD_HTTP_H
+#define AMDUATD_HTTP_H
+
+#include "amduat/asl/core.h"
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+  char method[8];
+  char path[1024];
+  char content_type[128];
+  char accept[128];
+  char x_type_tag[64];
+  char x_capability[2048];
+  size_t content_length;
+  bool has_actor;
+  amduat_octets_t actor;
+  bool has_uid;
+  uid_t uid;
+} amduatd_http_req_t;
+
+typedef struct {
+  int fd;
+  int status;
+  const char *reason;
+  const char *content_type;
+  const uint8_t *body;
+  size_t body_len;
+  bool head_only;
+  bool ok;
+} amduatd_http_resp_t;
+
+bool amduatd_write_all(int fd, const uint8_t *buf, size_t len);
+
+bool amduatd_read_exact(int fd, uint8_t *buf, size_t len);
+
+bool amduatd_read_urandom(uint8_t *out, size_t len);
+
+bool amduatd_http_parse_request(int fd, amduatd_http_req_t *out_req);
+
+void amduatd_http_req_free(amduatd_http_req_t *req);
+
+bool amduatd_http_send_response(int fd, const amduatd_http_resp_t *resp);
+
+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);
+
+bool amduatd_http_send_text(int fd,
+                            int code,
+                            const char *reason,
+                            const char *text,
+                            bool head_only);
+
+bool amduatd_http_send_json(int fd,
+                            int code,
+                            const char *reason,
+                            const char *json,
+                            bool head_only);
+
+bool amduatd_http_send_not_found(int fd, const amduatd_http_req_t *req);
+
+bool amduatd_send_json_error(int fd,
+                             int code,
+                             const char *reason,
+                             const char *msg);
+
+const char *amduatd_query_param(const char *path,
+                                const char *key,
+                                char *out_value,
+                                size_t out_cap);
+
+bool amduatd_path_without_query(const char *path,
+                                char *out,
+                                size_t cap);
+
+bool amduatd_path_extract_name(const char *path,
+                               const char *prefix,
+                               char *out,
+                               size_t cap);
+
+const char *amduatd_json_skip_ws(const char *p, const char *end);
+
+bool amduatd_json_expect(const char **p,
+                         const char *end,
+                         char expected);
+
+bool amduatd_json_parse_string_noesc(const char **p,
+                                     const char *end,
+                                     const char **out_start,
+                                     size_t *out_len);
+
+bool amduatd_json_parse_u64(const char **p, const char *end, uint64_t *out);
+
+bool amduatd_json_skip_value(const char **p,
+                             const char *end,
+                             int depth);
+
+bool amduatd_copy_json_str(const char *s, size_t len, char **out);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /* AMDUATD_HTTP_H */
diff --git a/src/amduatd_ui.c b/src/amduatd_ui.c
index c4a17a5..b83d994 100644
--- a/src/amduatd_ui.c
+++ b/src/amduatd_ui.c
@@ -1,4 +1,5 @@
 #include "amduatd_ui.h"
+#include "amduatd_http.h"
 
 #include "amduat/asl/artifact_io.h"
 #include "amduat/asl/asl_store_fs.h"
@@ -10,20 +11,6 @@
 #include <stdint.h>
 #include <string.h>
 
-bool amduatd_http_send_text(int fd,
-                            int code,
-                            const char *reason,
-                            const char *text,
-                            bool head_only);
-
-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);
-
 static const char k_amduatd_ui_html[] =
     "<!doctype html>\n"
     "<html lang=\"en\">\n"
@@ -337,27 +324,6 @@ static const char k_amduatd_ui_html[] =
     "</body>\n"
     "</html>\n";
 
-static void amduatd_ui_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';
-}
-
 bool amduatd_ui_can_handle(const amduatd_http_req_t *req) {
   char no_query[1024];
 
@@ -367,7 +333,7 @@ bool amduatd_ui_can_handle(const amduatd_http_req_t *req) {
   if (strcmp(req->method, "GET") != 0) {
     return false;
   }
-  amduatd_ui_path_without_query(req->path, no_query, sizeof(no_query));
+  amduatd_path_without_query(req->path, no_query, sizeof(no_query));
   return strcmp(no_query, "/v1/ui") == 0;
 }
 
diff --git a/src/amduatd_ui.h b/src/amduatd_ui.h
index 2dd9120..7acd8ae 100644
--- a/src/amduatd_ui.h
+++ b/src/amduatd_ui.h
@@ -3,6 +3,7 @@
 
 #include "amduat/asl/asl_store_fs_meta.h"
 #include "amduat/asl/store.h"
+#include "amduatd_http.h"
 
 #include <stdbool.h>
 #include <stddef.h>
@@ -16,25 +17,6 @@ typedef struct amduatd_caps_t amduatd_caps_t;
 typedef struct amduatd_cfg_t amduatd_cfg_t;
 typedef struct amduatd_concepts_t amduatd_concepts_t;
 
-typedef struct {
-  char method[8];
-  char path[1024];
-  char content_type[128];
-  char accept[128];
-  char x_type_tag[64];
-  char x_capability[2048];
-  size_t content_length;
-  bool has_actor;
-  amduat_octets_t actor;
-  bool has_uid;
-  uid_t uid;
-} amduatd_http_req_t;
-
-typedef struct {
-  int fd;
-  bool ok;
-} amduatd_http_resp_t;
-
 typedef struct {
   amduat_asl_store_t *store;
   amduat_reference_t ui_ref;