Initial commit: AS4/411 directory and discovery service for Sankofa Marketplace

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/protocols/_rail-template.md

@@ -0,0 +1,49 @@
+# Rail Definition Template
+
+**Required before implementing a new rail or protocol adapter.** Copy this template, fill every section, and ensure the rail doc is complete before merge. See [catalog.md](catalog.md).
+
+---
+
+## 1. Owner and Authority
+
+- **Governing body / owner:**
+- **Normative specifications (links):**
+- **Message families / standards:**
+
+## 2. Identifier Scheme(s)
+
+- **Identifier types** (e.g. partyId, BIC, BIN):
+- **Validation rules** (format, length, allowed characters):
+- **Uniqueness and scope** (global vs tenant-scoped):
+
+## 3. Addressing and Endpoint Rules
+
+- **Endpoint types** (URL, queue, point code, etc.):
+- **Address format** (regex or pattern):
+- **Transport profiles** (if any):
+
+## 4. Security Model
+
+- **Authentication** (how participants are authenticated):
+- **Integrity** (signing, hashing):
+- **Confidentiality** (encryption, TLS):
+
+## 5. Discovery Model
+
+- **Public directory?** (yes / no / partial)
+- **Contractual only?** (e.g. BIN tables, member config)
+- **Authoritative source** (SML/SMP, vendor API, internal only):
+
+## 6. Compliance Constraints
+
+- **Regulatory** (e.g. PCI-DSS, data residency):
+- **Data handling** (what must not be stored, encryption requirements):
+
+## 7. Sample Payloads and Test Vectors
+
+- **Sample request/response or message** (anonymized):
+- **Test vectors** (identifier in → expected directive or behavior):
+
+---
+
+*Block merge of new rails until this template is completed for the rail.*