Fix #150: [milestone Milestone 4 ] Add schemas/aep/memory-evidence.schema.json — tamper-evident memory read/wri...

schemas/aep/memory-evidence.schema.json

@@ -0,0 +1,43 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://wasmagent.dev/schemas/aep/memory-evidence.schema.json",
+  "title": "MemoryEvidence",
+  "description": "Tamper-evident memory read/write record. Each op records the content digest of the memory cell plus the digest observed immediately before the op (prior_digest), so successive records form a hash chain: altering any past write changes its digest and breaks the chain at the next read/write, making tamper detectable. Records are linked into AEP actions via aep-record's memory_read_refs / memory_write_refs.",
+  "type": "object",
+  "required": [
+    "mem_ref",
+    "op",
+    "digest",
+    "prior_digest",
+    "timestamp_ms"
+  ],
+  "properties": {
+    "mem_ref": {
+      "type": "string",
+      "description": "Stable reference (key/path) to the memory cell that was read or written"
+    },
+    "op": {
+      "type": "string",
+      "enum": [
+        "read",
+        "write"
+      ],
+      "description": "Memory operation performed against the referenced cell"
+    },
+    "digest": {
+      "type": "string",
+      "description": "Content digest of the memory cell — post-write content for a write, or the value returned by a read"
+    },
+    "prior_digest": {
+      "type": [
+        "string",
+        "null"
+      ],
+      "description": "Digest of the memory cell's content immediately before this op. Null when the cell did not previously exist (first write / creation). Carries the hash-chain link that makes the record tamper-evident."
+    },
+    "timestamp_ms": {
+      "type": "number",
+      "description": "UTC epoch milliseconds when the memory op was recorded"
+    }
+  }
+}

schemas/index.json

@@ -41,6 +41,22 @@
       ],
       "summary": "Shared envelope base for all AEP evidence records \u2014 schema_version, trace_id, created_at_ms, and optional signature."
     },
+    {
+      "id": "memory-evidence",
+      "title": "MemoryEvidence",
+      "path": "schemas/aep/memory-evidence.schema.json",
+      "canonical_id": "https://wasmagent.dev/schemas/aep/memory-evidence.schema.json",
+      "version": "aep/v0.1",
+      "stability": "evolving",
+      "owners": [
+        "wasmagent-protocol"
+      ],
+      "consumers": [
+        "wasmagent-js",
+        "trace-pipeline"
+      ],
+      "summary": "Tamper-evident memory read/write record \u2014 digest + prior_digest hash chain over a memory cell (keys: mem_ref, op, digest, prior_digest, timestamp_ms)."
+    },
     {
       "id": "constraint-ir",
       "title": "ConstraintIR",

tests/fixtures/invalid/memory-evidence/example.json

@@ -0,0 +1,6 @@
+{
+  "mem_ref": "mem://agent-1/context/window-7",
+  "op": "delete",
+  "digest": "sha256:abc",
+  "timestamp_ms": 1737600000500
+}

tests/fixtures/valid/memory-evidence/example.json

@@ -0,0 +1,7 @@
+{
+  "mem_ref": "mem://agent-1/context/window-7",
+  "op": "write",
+  "digest": "sha256:9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08",
+  "prior_digest": "sha256:2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae",
+  "timestamp_ms": 1737600000500
+}