diff --git a/include/amduat/hash/asl1.h b/include/amduat/hash/asl1.h
index a1b441b..10845f0 100644
--- a/include/amduat/hash/asl1.h
+++ b/include/amduat/hash/asl1.h
@@ -10,15 +10,42 @@
 extern "C" {
 #endif
 
+typedef struct {
+  bool (*digest)(void *ctx,
+                 amduat_octets_t input,
+                 uint8_t *out,
+                 size_t out_len);
+  void *ctx;
+} amduat_hash_asl1_impl_t;
+
 typedef struct {
   amduat_hash_id_t hash_id;
   const char *name;
   size_t digest_len;
-  void *impl;
+  amduat_hash_asl1_impl_t impl;
 } amduat_hash_asl1_desc_t;
 
+enum { AMDUAT_HASH_ASL1_ID_SHA256 = 0x0001 };
+
 amduat_octets_t amduat_hash_asl1_key(amduat_hash_id_t hash_id, uint8_t out[2]);
 
+const amduat_hash_asl1_desc_t *amduat_hash_asl1_desc_lookup(
+    amduat_hash_id_t hash_id);
+
+const amduat_hash_asl1_desc_t *amduat_hash_asl1_descs(size_t *out_len);
+
+bool amduat_hash_asl1_register_impl(amduat_hash_id_t hash_id,
+                                    amduat_hash_asl1_impl_t impl);
+
+bool amduat_hash_asl1_digest(amduat_hash_id_t hash_id,
+                             amduat_octets_t input,
+                             uint8_t *out,
+                             size_t out_len);
+
+/* Optional: registers a non-conformant SHA-256 stub for wiring/tests.
+ * Define AMDUAT_HASH_ASL1_ENABLE_SHA256_STUB to enable. */
+bool amduat_hash_asl1_register_sha256_stub(void);
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
diff --git a/registry/README.md b/registry/README.md
new file mode 100644
index 0000000..dcdde73
--- /dev/null
+++ b/registry/README.md
@@ -0,0 +1,89 @@
+# Registry Model (draft)
+
+This directory documents how Amduat registries are represented in the repo
+before the full stack and code generation are available. The goal is to keep
+registry entries stable and machine-readable so they can drive docs, code, and
+graph mappings later without rewriting identifiers.
+
+## Core idea
+
+- **Registry keys are concepts.** The key itself (for example a `HashId`) has a
+  stable handle like `amduat.hash.asl1.id.0001@1`.
+- **Registry values are data.** Each entry has a descriptor row that is data
+  (name, digest length, status, notes). Values are not treated as concepts.
+
+This matches MS/1: concept handles are stable identifiers; the descriptor bytes
+are data nodes that can be hashed and referenced.
+
+## JSONL manifests
+
+Each registry has a `registry/<name>.jsonl` manifest. Each line is one entry.
+The manifest is the source of truth for codegen and documentation tables.
+
+Common fields (registry-specific schemas may add fields):
+
+- `registry`: registry name (e.g. `HASH/ASL1`).
+- `hash_id` (or other key field): registry key as hex string.
+- `handle`: concept handle for the key.
+- `name`, `digest_len`, `status`, `spec_ref`, `notes`: descriptor fields.
+- `descriptor_sha256`: digest of the canonical descriptor (see below).
+
+## Handle naming scheme
+
+Handles are opaque identifiers in the `amduat` namespace and do **not** depend
+on DNS:
+
+```
+amduat.<domain>.<registry>.<kind>.<id>@<version>
+```
+
+Example (HASH/ASL1):
+
+```
+amduat.hash.asl1.id.0001@1
+```
+
+`id` is the canonical key (often lowercase hex, zero-padded). `version` is
+incremented only when the meaning of that key changes (rare).
+
+## Descriptor digest rule
+
+`descriptor_sha256` is computed over a canonical JSON object with fields in a
+fixed order. Each registry schema defines the exact ordering; for HASH/ASL1
+see `registry/hash-asl1.schema.md`.
+
+This digest can be used as a stable Data-node hash to anchor graphs, evidence,
+or generated artifacts without requiring a full ASL encoder yet.
+
+## Canonical key encoding
+
+Each registry defines the byte encoding of its key. This is the encoding used
+when building an ASL registry artifact:
+
+- HASH/ASL1: `hash_id` is encoded as big-endian `u16` (see
+  `amduat_hash_asl1_key`).
+
+## Mapping into ASL
+
+When the stack is available:
+
+1. Encode each descriptor row as an ASL Artifact (data bytes).
+2. Store it to obtain a `Reference`.
+3. Build a registry value where each entry maps:
+
+```
+key_bytes -> value_ref
+```
+
+This uses the generic registry container in `amduat/asl/registry`.
+
+## Current manifests
+
+- `registry/hash-asl1.jsonl` — ASL1 HashId assignments.
+
+## Design constraints
+
+- Handles MUST be stable and immutable once published.
+- Reserved IDs are explicit rows with `status = reserved`.
+- The manifest should be sufficient to regenerate code tables and docs without
+  additional context.
diff --git a/registry/hash-asl1.jsonl b/registry/hash-asl1.jsonl
new file mode 100644
index 0000000..2b688ea
--- /dev/null
+++ b/registry/hash-asl1.jsonl
@@ -0,0 +1,4 @@
+{"registry":"HASH/ASL1","hash_id":"0x0000","handle":"amduat.hash.asl1.id.0000@1","name":null,"digest_len":null,"status":"reserved","spec_ref":"HASH/ASL1 v0.2.4","notes":"Reserved; never a valid algorithm.","descriptor_sha256":"aef821024f5ec2000b3920eaf6ea3a687690df87417a86b372359b064c7d1ac3"}
+{"registry":"HASH/ASL1","hash_id":"0x0001","handle":"amduat.hash.asl1.id.0001@1","name":"HASH-ASL1-256","digest_len":32,"status":"mandatory","spec_ref":"HASH/ASL1 v0.2.4","notes":"Bit-for-bit SHA-256.","descriptor_sha256":"5082d8280750dc3cff48b48a7a2eda725a16f2902592f13eaf9b677908d7517e"}
+{"registry":"HASH/ASL1","hash_id":"0x0002","handle":"amduat.hash.asl1.id.0002@1","name":"HASH-ASL1-512","digest_len":64,"status":"reserved","spec_ref":"HASH/ASL1 v0.2.4","notes":"Intended classical 512-bit algorithm.","descriptor_sha256":"2063bfe4878add4d2b6c575b95466d433f9c082df5284000ffde972f6a734f6d"}
+{"registry":"HASH/ASL1","hash_id":"0x8001","handle":"amduat.hash.asl1.id.8001@1","name":"HASH-ASL1-PQ1","digest_len":null,"status":"reserved","spec_ref":"HASH/ASL1 v0.2.4","notes":"First PQ algorithm placeholder.","descriptor_sha256":"fca3b7afa0c3257cf0bbef7b8b338c76f0b7c3690e60c9a90ae4a1c0b99f25f0"}
diff --git a/registry/hash-asl1.schema.md b/registry/hash-asl1.schema.md
new file mode 100644
index 0000000..e89af3e
--- /dev/null
+++ b/registry/hash-asl1.schema.md
@@ -0,0 +1,52 @@
+# HASH/ASL1 Registry Manifest (draft)
+
+This file documents the JSONL rows in `registry/hash-asl1.jsonl`. Each line is
+one entry descriptor for a single `HashId` assignment. The key is the `HashId`
+itself (a concept); the descriptor is data.
+
+## Field definitions
+
+- `registry`: string. Constant `"HASH/ASL1"`.
+- `hash_id`: string. Hex `u16` formatted as `0x0000`.
+- `handle`: string. Stable concept handle for this HashId assignment, e.g.
+  `amduat.hash.asl1.id.0001@1`.
+- `name`: string or null. Algorithm name if assigned (e.g. `HASH-ASL1-256`).
+- `digest_len`: integer or null. Digest length in bytes; null if unknown.
+- `status`: string. One of: `mandatory`, `reserved`, `deprecated`, `experimental`.
+- `spec_ref`: string. Document/version that defines the assignment.
+- `notes`: string. Short human-readable note.
+- `descriptor_sha256`: string. Lowercase hex SHA-256 digest of the canonical
+  descriptor (see below).
+
+## Canonical registry key
+
+`hash_id` is the registry key. Its key bytes are the big-endian `u16` encoding
+defined in `ENC/ASL1-CORE` (see `amduat_hash_asl1_key`).
+
+## Handle naming scheme
+
+Handles are opaque identifiers in the `amduat` namespace:
+
+```
+amduat.hash.asl1.id.<hex4>@1
+```
+
+`hex4` is the 4-digit lowercase hex of the `HashId` (zero-padded).
+
+## Descriptor digest rule
+
+`descriptor_sha256` is computed as SHA-256 over the UTF-8 bytes of the
+canonical JSON object with these fields **in order**:
+
+```
+registry, hash_id, handle, name, digest_len, status, spec_ref, notes
+```
+
+The canonical JSON uses no extra whitespace and does **not** include the
+`descriptor_sha256` field itself.
+
+## Intended use
+
+- Source of truth for codegen (C tables, enums) and documentation tables.
+- `descriptor_sha256` can be treated as the stable digest for mapping entries
+  into graph references or evidence tables.
diff --git a/src/near_core/hash/asl1.c b/src/near_core/hash/asl1.c
index 011216d..c1c0047 100644
--- a/src/near_core/hash/asl1.c
+++ b/src/near_core/hash/asl1.c
@@ -1,7 +1,107 @@
 #include "amduat/hash/asl1.h"
 
+static amduat_hash_asl1_desc_t g_hash_asl1_descs[] = {
+    {0x0000, NULL, 0, {NULL, NULL}},
+    {AMDUAT_HASH_ASL1_ID_SHA256, "HASH-ASL1-256", 32, {NULL, NULL}},
+    {0x0002, "HASH-ASL1-512", 64, {NULL, NULL}},
+    {0x8001, "HASH-ASL1-PQ1", 0, {NULL, NULL}}};
+
+#ifdef AMDUAT_HASH_ASL1_ENABLE_SHA256_STUB
+static bool amduat_hash_asl1_sha256_stub(void *ctx,
+                                         amduat_octets_t input,
+                                         uint8_t *out,
+                                         size_t out_len) {
+  size_t i;
+
+  (void)ctx;
+  (void)input;
+
+  if (out == NULL || out_len < 32) {
+    return false;
+  }
+
+  for (i = 0; i < 32; ++i) {
+    out[i] = 0;
+  }
+
+  return true;
+}
+#endif
+
 amduat_octets_t amduat_hash_asl1_key(amduat_hash_id_t hash_id, uint8_t out[2]) {
   out[0] = (uint8_t)(hash_id >> 8);
   out[1] = (uint8_t)(hash_id & 0xff);
   return amduat_octets(out, 2);
 }
+
+const amduat_hash_asl1_desc_t *amduat_hash_asl1_desc_lookup(
+    amduat_hash_id_t hash_id) {
+  size_t i;
+
+  for (i = 0; i < sizeof(g_hash_asl1_descs) / sizeof(g_hash_asl1_descs[0]);
+       ++i) {
+    if (g_hash_asl1_descs[i].hash_id == hash_id) {
+      return &g_hash_asl1_descs[i];
+    }
+  }
+
+  return NULL;
+}
+
+const amduat_hash_asl1_desc_t *amduat_hash_asl1_descs(size_t *out_len) {
+  if (out_len != NULL) {
+    *out_len = sizeof(g_hash_asl1_descs) / sizeof(g_hash_asl1_descs[0]);
+  }
+  return g_hash_asl1_descs;
+}
+
+bool amduat_hash_asl1_register_impl(amduat_hash_id_t hash_id,
+                                    amduat_hash_asl1_impl_t impl) {
+  size_t i;
+
+  for (i = 0; i < sizeof(g_hash_asl1_descs) / sizeof(g_hash_asl1_descs[0]);
+       ++i) {
+    if (g_hash_asl1_descs[i].hash_id == hash_id) {
+      g_hash_asl1_descs[i].impl = impl;
+      return true;
+    }
+  }
+
+  return false;
+}
+
+bool amduat_hash_asl1_digest(amduat_hash_id_t hash_id,
+                             amduat_octets_t input,
+                             uint8_t *out,
+                             size_t out_len) {
+  const amduat_hash_asl1_desc_t *desc;
+
+  if (out == NULL) {
+    return false;
+  }
+
+  desc = amduat_hash_asl1_desc_lookup(hash_id);
+  if (desc == NULL || desc->digest_len == 0) {
+    return false;
+  }
+  if (out_len < desc->digest_len) {
+    return false;
+  }
+  if (desc->impl.digest == NULL) {
+    return false;
+  }
+
+  return desc->impl.digest(desc->impl.ctx, input, out, desc->digest_len);
+}
+
+bool amduat_hash_asl1_register_sha256_stub(void) {
+#ifdef AMDUAT_HASH_ASL1_ENABLE_SHA256_STUB
+  amduat_hash_asl1_impl_t impl;
+
+  impl.digest = amduat_hash_asl1_sha256_stub;
+  impl.ctx = NULL;
+  return amduat_hash_asl1_register_impl(AMDUAT_HASH_ASL1_ID_SHA256, impl);
+#else
+  return false;
+#endif
+}