2026-04-22 17:17:52 +00:00
12 changed files with 1096 additions and 1 deletions
--- a/orchestrator/src/api/plans.ts
+++ b/orchestrator/src/api/plans.ts
@@ -5,6 +5,11 @@ import { validatePlan, checkStepDependencies } from "../services/planValidation"
 import { storePlan, getPlanById, updatePlanSignature, listPlans } from "../db/plans";
 import { asyncHandler, AppError, ErrorType } from "../services/errorHandler";
 import { getTransactionState, getTransitionHistory } from "../services/stateMachine";
+import {
+  getEventsForPlan,
+  subscribe as subscribeToEvents,
+  verifyChain,
+} from "../services/eventBus";
 import type { Plan, PlanStep } from "../types/plan";

 /**
@@ -220,3 +225,82 @@ export const getPlanState = asyncHandler(async (req: Request, res: Response) =>
  });
 });

+/**
+ * GET /api/plans/:planId/events
+ * Return the full signed + hash-chained event trail for a plan
+ * (arch §4.5 State Registry + §7 Event Model + §14 Audit).
+ *
+ * Query `?verify=1` re-verifies the chain server-side and adds
+ * { chain_valid: true|false, broken_at?: n } to the response.
+ */
+export const getPlanEvents = asyncHandler(async (req: Request, res: Response) => {
+  const { planId } = req.params;
+  const plan = await getPlanById(planId);
+  if (!plan) {
+    throw new AppError(ErrorType.NOT_FOUND_ERROR, 404, "Plan not found");
+  }
+
+  const events = await getEventsForPlan(planId);
+
+  const body: {
+    plan_id: string;
+    count: number;
+    events: typeof events;
+    chain_valid?: boolean;
+    broken_at?: number;
+    broken_reason?: string;
+  } = { plan_id: planId, count: events.length, events };
+
+  if (req.query.verify === "1") {
+    const v = await verifyChain(planId);
+    body.chain_valid = v.ok;
+    if (!v.ok) {
+      body.broken_at = v.brokenAt;
+      body.broken_reason = v.reason;
+    }
+  }
+
+  res.json(body);
+});
+
+/**
+ * GET /api/plans/:planId/events/stream
+ * Server-sent-events stream of live events for a single plan.
+ */
+export const streamPlanEvents = asyncHandler(async (req: Request, res: Response) => {
+  const { planId } = req.params;
+  const plan = await getPlanById(planId);
+  if (!plan) {
+    throw new AppError(ErrorType.NOT_FOUND_ERROR, 404, "Plan not found");
+  }
+
+  res.setHeader("Content-Type", "text/event-stream");
+  res.setHeader("Cache-Control", "no-cache, no-transform");
+  res.setHeader("Connection", "keep-alive");
+  res.setHeader("X-Accel-Buffering", "no");
+  res.flushHeaders?.();
+
+  // Replay the history on connect so clients can reconstruct state
+  // without a separate REST call.
+  const history = await getEventsForPlan(planId);
+  for (const e of history) {
+    res.write(`id: ${e.id}\nevent: ${e.type}\ndata: ${JSON.stringify(e)}\n\n`);
+  }
+
+  const unsubscribe = subscribeToEvents(planId, (record) => {
+    res.write(
+      `id: ${record.id}\nevent: ${record.type}\ndata: ${JSON.stringify(record)}\n\n`,
+    );
+  });
+
+  const keepAlive = setInterval(() => {
+    res.write(": keep-alive\n\n");
+  }, 15_000);
+
+  req.on("close", () => {
+    clearInterval(keepAlive);
+    unsubscribe();
+    res.end();
+  });
+});
+
--- a/orchestrator/src/db/migrations/003_events.ts
+++ b/orchestrator/src/db/migrations/003_events.ts
@@ -0,0 +1,43 @@
+import { query } from "../postgres";
+
+/**
+ * Migration 003 — append-only events journal (arch §4.5, §5.5, §7).
+ *
+ * The `events` table is the system-of-record for normalised workflow
+ * events (arch §7.2: `transaction.created`, `instrument.ready`,
+ * `payment.settled`, `transaction.committed`, …). It is:
+ *
+ *   - append-only (no UPDATE / DELETE)
+ *   - signed (HMAC of (plan_id, type, payload_hash, prev_hash))
+ *   - hash-chained via prev_hash for tamper-evident forensic replay
+ *   - indexed by plan_id so the SSE endpoint can stream efficiently
+ */
+export async function up() {
+  await query(
+    `CREATE TABLE IF NOT EXISTS events (
+       id           UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+       plan_id      UUID NOT NULL REFERENCES plans(plan_id) ON DELETE CASCADE,
+       type         VARCHAR(128) NOT NULL,
+       actor        VARCHAR(255),
+       payload      JSONB NOT NULL DEFAULT '{}'::jsonb,
+       payload_hash CHAR(64) NOT NULL,
+       prev_hash    CHAR(64),
+       signature    CHAR(64) NOT NULL,
+       created_at   TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP
+     )`,
+  );
+
+  await query(
+    `CREATE INDEX IF NOT EXISTS idx_events_plan_id_created
+       ON events(plan_id, created_at)`,
+  );
+
+  await query(
+    `CREATE INDEX IF NOT EXISTS idx_events_type
+       ON events(type)`,
+  );
+}
+
+export async function down() {
+  await query("DROP TABLE IF EXISTS events CASCADE");
+}
--- a/orchestrator/src/db/migrations/index.ts
+++ b/orchestrator/src/db/migrations/index.ts
@@ -1,5 +1,6 @@
 import { up as up001 } from "./001_initial_schema";
 import { up as up002 } from "./002_transaction_state";
+import { up as up003 } from "./003_events";

 /**
 * Run all migrations
@@ -8,6 +9,7 @@ export async function runMigration() {
  try {
    await up001();
    await up002();
+    await up003();
    console.log("All migrations completed");
  } catch (error) {
    console.error("Migration failed:", error);
--- a/orchestrator/src/index.ts
+++ b/orchestrator/src/index.ts
@@ -14,7 +14,7 @@ import { requestTimeout } from "./middleware/timeout";
 import { logger } from "./logging/logger";
 import { getMetrics, httpRequestDuration, httpRequestTotal, register } from "./metrics/prometheus";
 import { healthCheck, readinessCheck, livenessCheck } from "./health/health";
-import { listPlansEndpoint, createPlan, getPlan, getPlanState, addSignature, validatePlanEndpoint } from "./api/plans";
+import { listPlansEndpoint, createPlan, getPlan, getPlanState, getPlanEvents, streamPlanEvents, addSignature, validatePlanEndpoint } from "./api/plans";
 import { streamPlanStatus } from "./api/sse";
 import { executionCoordinator } from "./services/execution";
 import { runMigration } from "./db/migrations";
@@ -89,6 +89,8 @@ app.get("/api/plans", listPlansEndpoint);
 app.post("/api/plans", auditLog("CREATE_PLAN", "plan"), createPlan);
 app.get("/api/plans/:planId", getPlan);
 app.get("/api/plans/:planId/state", getPlanState);
+app.get("/api/plans/:planId/events", getPlanEvents);
+app.get("/api/plans/:planId/events/stream", streamPlanEvents);
 app.post("/api/plans/:planId/signature", addSignature);
 app.post("/api/plans/:planId/validate", validatePlanEndpoint);

--- a/orchestrator/src/services/eventBus.ts
+++ b/orchestrator/src/services/eventBus.ts
@@ -0,0 +1,197 @@
+/**
+ * Typed, signed, append-only Event Bus (arch §5.5 Event Bus + §7).
+ *
+ * Architecture contract
+ * ---------------------
+ * 1. Every event is a normalised category from arch §7.2 — `EventType`.
+ * 2. Every event is persisted to the `events` append-only table.
+ * 3. Every event carries
+ *       payload_hash = sha256(JSON.stringify(payload))
+ *       prev_hash    = signature of the previous event for the same plan
+ *       signature    = hmac_sha256(secret, plan_id|type|payload_hash|prev_hash)
+ *    which gives a tamper-evident per-plan hash chain (arch §14 audit).
+ * 4. Callers can subscribe to live events via `subscribe(planId, cb)` —
+ *    backed by a process-local EventEmitter that the SSE route consumes.
+ *
+ * When the orchestrator scales to >1 replicas, the in-process emitter
+ * must be replaced by a broker (NATS / Kafka). The persistence layer
+ * and signature chain remain unchanged.
+ */
+
+import { createHash, createHmac } from "crypto";
+import { EventEmitter } from "events";
+import { query } from "../db/postgres";
+import { logger } from "../logging/logger";
+
+/**
+ * Normalised event types — arch §7.2. Keep this list as the single
+ * source of truth so subscribers can exhaustively match on it.
+ */
+export const EVENT_TYPES = [
+  "transaction.created",
+  "participants.authorized",
+  "preconditions.satisfied",
+  "instrument.ready",
+  "payment.ready",
+  "transaction.prepared",
+  "instrument.dispatched",
+  "payment.dispatched",
+  "instrument.acknowledged",
+  "payment.accepted",
+  "payment.settled",
+  "transaction.validated",
+  "transaction.committed",
+  "transaction.aborted",
+  "transaction.unwind_initiated",
+] as const;
+
+export type EventType = (typeof EVENT_TYPES)[number];
+
+export interface EventRecord {
+  id: string;
+  plan_id: string;
+  type: EventType;
+  actor: string | null;
+  payload: Record<string, unknown>;
+  payload_hash: string;
+  prev_hash: string | null;
+  signature: string;
+  created_at: string;
+}
+
+export interface PublishInput {
+  planId: string;
+  type: EventType;
+  actor?: string;
+  payload?: Record<string, unknown>;
+}
+
+const emitter = new EventEmitter();
+emitter.setMaxListeners(0);
+
+function getSigningSecret(): string {
+  return (
+    process.env.EVENT_BUS_HMAC_SECRET ??
+    process.env.SESSION_SECRET ??
+    "dev-event-bus-secret-change-in-production"
+  );
+}
+
+function sha256(input: string): string {
+  return createHash("sha256").update(input).digest("hex");
+}
+
+function sign(
+  planId: string,
+  type: string,
+  payloadHash: string,
+  prevHash: string | null,
+): string {
+  const h = createHmac("sha256", getSigningSecret());
+  h.update(`${planId}|${type}|${payloadHash}|${prevHash ?? ""}`);
+  return h.digest("hex");
+}
+
+/**
+ * Publish a typed, signed, hash-chained event for a plan. Returns the
+ * persisted record (including id + signature) so callers can reference
+ * it from transition `source_event_id`.
+ */
+export async function publish(input: PublishInput): Promise<EventRecord> {
+  const payload = input.payload ?? {};
+  const payloadHash = sha256(JSON.stringify(payload));
+
+  const prev = await query<{ signature: string }>(
+    `SELECT signature
+       FROM events
+      WHERE plan_id = $1
+      ORDER BY created_at DESC, id DESC
+      LIMIT 1`,
+    [input.planId],
+  );
+  const prevHash = prev.length > 0 ? prev[0].signature : null;
+  const signature = sign(input.planId, input.type, payloadHash, prevHash);
+
+  const rows = await query<EventRecord>(
+    `INSERT INTO events (plan_id, type, actor, payload, payload_hash, prev_hash, signature)
+     VALUES ($1, $2, $3, $4::jsonb, $5, $6, $7)
+     RETURNING id, plan_id, type, actor, payload, payload_hash, prev_hash, signature, created_at`,
+    [
+      input.planId,
+      input.type,
+      input.actor ?? null,
+      JSON.stringify(payload),
+      payloadHash,
+      prevHash,
+      signature,
+    ],
+  );
+
+  const record = rows[0];
+  logger.info(
+    { planId: record.plan_id, type: record.type, eventId: record.id },
+    "[EventBus] published",
+  );
+
+  emitter.emit(`plan:${record.plan_id}`, record);
+  emitter.emit("plan:*", record);
+
+  return record;
+}
+
+/**
+ * Read the full event trail for a plan in chronological order.
+ */
+export async function getEventsForPlan(planId: string): Promise<EventRecord[]> {
+  return query<EventRecord>(
+    `SELECT id, plan_id, type, actor, payload, payload_hash, prev_hash, signature, created_at
+       FROM events
+      WHERE plan_id = $1
+      ORDER BY created_at ASC, id ASC`,
+    [planId],
+  );
+}
+
+/**
+ * Verify the full hash chain for a plan's events. Returns `{ ok: true }`
+ * when every signature matches and `prev_hash` forms a contiguous chain;
+ * otherwise returns the first index that fails with a reason.
+ */
+export async function verifyChain(planId: string): Promise<
+  { ok: true } | { ok: false; brokenAt: number; reason: string }
+> {
+  const events = await getEventsForPlan(planId);
+  let prevSig: string | null = null;
+  for (let i = 0; i < events.length; i++) {
+    const e = events[i];
+    if (e.prev_hash !== prevSig) {
+      return { ok: false, brokenAt: i, reason: "prev_hash mismatch" };
+    }
+    const expectedPayloadHash = sha256(JSON.stringify(e.payload));
+    if (expectedPayloadHash !== e.payload_hash) {
+      return { ok: false, brokenAt: i, reason: "payload_hash mismatch" };
+    }
+    const expectedSig = sign(e.plan_id, e.type, e.payload_hash, e.prev_hash);
+    if (expectedSig !== e.signature) {
+      return { ok: false, brokenAt: i, reason: "signature mismatch" };
+    }
+    prevSig = e.signature;
+  }
+  return { ok: true };
+}
+
+/**
+ * Subscribe to live events for a single plan. Returns an unsubscribe
+ * function. Used by the SSE route.
+ */
+export function subscribe(
+  planId: string,
+  callback: (record: EventRecord) => void,
+): () => void {
+  const channel = `plan:${planId}`;
+  emitter.on(channel, callback);
+  return () => emitter.off(channel, callback);
+}
+
+/** test-only emitter access, never import in prod code */
+export const __emitterForTests = emitter;
--- a/orchestrator/src/services/swift/camt.ts
+++ b/orchestrator/src/services/swift/camt.ts
@@ -0,0 +1,129 @@
+/**
+ * camt.025 (Receipt) and camt.054 (Bank-to-Customer Debit/Credit
+ * Notification) ingestion.
+ *
+ * Arch §4.3 + §9.2. These are the inbound settlement-confirmation
+ * messages that allow the VALIDATING phase to mark the payment leg
+ * as SETTLED. The parser is intentionally minimal — just enough to
+ * extract the fields the VALIDATING reconciliation compares against.
+ */
+
+export interface Camt025Receipt {
+  type: "camt.025";
+  messageId: string;
+  originalMessageId: string;
+  status: "ACCP" | "ACSC" | "ACSP" | "RJCT" | "PDNG" | string;
+  reasonCode?: string;
+  dateTime?: string;
+}
+
+export interface Camt054Notification {
+  type: "camt.054";
+  messageId: string;
+  creditDebitIndicator: "CRDT" | "DBIT";
+  amount: number;
+  currency: string;
+  endToEndId?: string;
+  valueDate?: string;
+  bookingDate?: string;
+}
+
+export type CamtMessage = Camt025Receipt | Camt054Notification;
+
+function extractTag(xml: string, tag: string): string | undefined {
+  const re = new RegExp(`<${tag}[^>]*>([^<]*)</${tag}>`);
+  const m = re.exec(xml);
+  return m ? m[1].trim() : undefined;
+}
+
+function extractAmountWithCcy(xml: string, tag: string): { amount: number; currency: string } | undefined {
+  const re = new RegExp(`<${tag}[^>]*Ccy="([A-Z]{3})"[^>]*>([^<]*)</${tag}>`);
+  const m = re.exec(xml);
+  return m ? { currency: m[1], amount: Number(m[2]) } : undefined;
+}
+
+/**
+ * Parse a camt.025 Receipt. Only fields used by the orchestrator are
+ * surfaced; everything else stays in the raw XML.
+ */
+export function parseCamt025(xml: string): Camt025Receipt {
+  if (!/xmlns="urn:iso:std:iso:20022:tech:xsd:camt\.025/.test(xml)) {
+    throw new Error("camt.025: xmlns marker not found");
+  }
+  const messageId = extractTag(xml, "MsgId") ?? "";
+  const originalMessageId = extractTag(xml, "OrgnlMsgId") ?? "";
+  const status = (extractTag(xml, "Cd") ?? extractTag(xml, "ConfSts") ?? "PDNG") as Camt025Receipt["status"];
+  const reasonCode = extractTag(xml, "PrtryStsRsn") ?? extractTag(xml, "Rsn");
+  const dateTime = extractTag(xml, "CreDtTm");
+  if (!messageId) throw new Error("camt.025: missing MsgId");
+  if (!originalMessageId) throw new Error("camt.025: missing OrgnlMsgId");
+  return { type: "camt.025", messageId, originalMessageId, status, reasonCode, dateTime };
+}
+
+/**
+ * Parse a camt.054 Credit/Debit Notification.
+ */
+export function parseCamt054(xml: string): Camt054Notification {
+  if (!/xmlns="urn:iso:std:iso:20022:tech:xsd:camt\.054/.test(xml)) {
+    throw new Error("camt.054: xmlns marker not found");
+  }
+  const messageId = extractTag(xml, "MsgId") ?? "";
+  const cdtDbt = (extractTag(xml, "CdtDbtInd") ?? "CRDT") as "CRDT" | "DBIT";
+  const amt = extractAmountWithCcy(xml, "Amt");
+  if (!amt) throw new Error("camt.054: missing Amt");
+  const endToEndId = extractTag(xml, "EndToEndId");
+  const valueDate = extractTag(xml, "ValDt");
+  const bookingDate = extractTag(xml, "BookgDt");
+  if (!messageId) throw new Error("camt.054: missing MsgId");
+  return {
+    type: "camt.054",
+    messageId,
+    creditDebitIndicator: cdtDbt,
+    amount: amt.amount,
+    currency: amt.currency,
+    endToEndId,
+    valueDate,
+    bookingDate,
+  };
+}
+
+/**
+ * Dispatch on the xmlns marker. Throws if the document is neither
+ * camt.025 nor camt.054.
+ */
+export function parseCamt(xml: string): CamtMessage {
+  if (/xmlns="urn:iso:std:iso:20022:tech:xsd:camt\.025/.test(xml)) return parseCamt025(xml);
+  if (/xmlns="urn:iso:std:iso:20022:tech:xsd:camt\.054/.test(xml)) return parseCamt054(xml);
+  throw new Error("camt: unsupported or missing xmlns (expected camt.025 or camt.054)");
+}
+
+/**
+ * Reconcile a camt.054 credit notification against an expected
+ * (amount, currency, endToEndId). Returns the list of mismatches so
+ * VALIDATING can feed them into Data.valueMismatch().
+ */
+export interface ReconcileExpected {
+  amount: number;
+  currency: string;
+  endToEndId?: string;
+}
+
+export function reconcileCamt054(
+  msg: Camt054Notification,
+  expected: ReconcileExpected,
+): Array<{ field: string; expected: unknown; actual: unknown }> {
+  const mismatches: Array<{ field: string; expected: unknown; actual: unknown }> = [];
+  if (msg.creditDebitIndicator !== "CRDT") {
+    mismatches.push({ field: "creditDebitIndicator", expected: "CRDT", actual: msg.creditDebitIndicator });
+  }
+  if (msg.currency !== expected.currency) {
+    mismatches.push({ field: "currency", expected: expected.currency, actual: msg.currency });
+  }
+  if (msg.amount !== expected.amount) {
+    mismatches.push({ field: "amount", expected: expected.amount, actual: msg.amount });
+  }
+  if (expected.endToEndId && msg.endToEndId && msg.endToEndId !== expected.endToEndId) {
+    mismatches.push({ field: "endToEndId", expected: expected.endToEndId, actual: msg.endToEndId });
+  }
+  return mismatches;
+}
--- a/orchestrator/src/services/swift/index.ts
+++ b/orchestrator/src/services/swift/index.ts
@@ -0,0 +1,36 @@
+/**
+ * SWIFT gateway — public surface (arch §4.2 + §4.3).
+ *
+ * Outbound generators:
+ *   - generateMt760   : issuance of SBLC (Cat-7 FIN)
+ *   - generatePacs009 : FI-to-FI credit transfer (ISO 20022 XML)
+ *   - generateMt202   : FIN equivalent of pacs.009 for non-migrated
+ *                       corridors
+ *
+ * Inbound parsers:
+ *   - parseCamt025    : receipt / status of a prior instruction
+ *   - parseCamt054    : bank-to-customer credit/debit notification
+ *   - reconcileCamt054: diff a camt.054 against the expected amount,
+ *                       currency, and end-to-end id
+ *
+ * Channel selection (arch §9.2 accepted !== settled):
+ *   - pacs.008 remains the customer-initiated PSP channel (existing
+ *     `services/iso20022.ts`). COMMIT must not fire on pacs.008
+ *     "acceptance" alone.
+ *   - pacs.009 / MT202 is the interbank settlement channel; COMMIT
+ *     requires either camt.025 ACSC or camt.054 CRDT evidence here.
+ */
+
+export { generateMt760, messageHash, type Mt760Message } from "./mt760";
+export { generatePacs009, type Pacs009Options, type Pacs009Result } from "./pacs009";
+export { generateMt202, type Mt202Options, type Mt202Message } from "./mt202";
+export {
+  parseCamt,
+  parseCamt025,
+  parseCamt054,
+  reconcileCamt054,
+  type Camt025Receipt,
+  type Camt054Notification,
+  type CamtMessage,
+  type ReconcileExpected,
+} from "./camt";
--- a/orchestrator/src/services/swift/mt202.ts
+++ b/orchestrator/src/services/swift/mt202.ts
@@ -0,0 +1,78 @@
+/**
+ * MT202 COV — General Financial Institution Transfer (cover method).
+ *
+ * Arch §4.3. FIN equivalent of pacs.009 used on SWIFT networks that
+ * have not yet migrated to ISO 20022. Generated alongside pacs.009
+ * during transitional period — settlement confirmation can arrive on
+ * either channel.
+ */
+
+import type { Plan, PlanStep } from "../../types/plan";
+
+export interface Mt202Options {
+  transactionReference: string;
+  relatedReference?: string;
+  valueDate: string;           // YYYY-MM-DD
+  sendingInstitution: string;  // BIC
+  receivingInstitution: string;// BIC
+  beneficiaryInstitution: string; // BIC
+  orderingInstitution?: string;// BIC
+}
+
+export interface Mt202Message {
+  sender: string;
+  receiver: string;
+  fin: string;
+  fields: Record<string, string>;
+}
+
+function yyMMdd(iso: string): string {
+  const m = /^(\d{4})-(\d{2})-(\d{2})$/.exec(iso);
+  if (!m) throw new Error(`MT202: valueDate must be YYYY-MM-DD, got '${iso}'`);
+  return `${m[1].slice(2)}${m[2]}${m[3]}`;
+}
+
+function bicCheck(bic: string, field: string): void {
+  if (!/^[A-Z0-9]{8}([A-Z0-9]{3})?$/.test(bic)) {
+    throw new Error(`MT202: ${field} must be a valid BIC, got '${bic}'`);
+  }
+}
+
+function findPayStep(plan: Plan): PlanStep {
+  const step = plan.steps.find((s) => s.type === "pay");
+  if (!step) throw new Error("MT202: plan must contain a 'pay' step");
+  return step;
+}
+
+export function generateMt202(plan: Plan, opts: Mt202Options): Mt202Message {
+  bicCheck(opts.sendingInstitution, "sendingInstitution");
+  bicCheck(opts.receivingInstitution, "receivingInstitution");
+  bicCheck(opts.beneficiaryInstitution, "beneficiaryInstitution");
+  if (opts.orderingInstitution) bicCheck(opts.orderingInstitution, "orderingInstitution");
+
+  const payStep = findPayStep(plan);
+  const ccy = (payStep.asset ?? "USD").toUpperCase();
+  const amount = payStep.amount.toFixed(2).replace(".", ",");
+  const field32A = `${yyMMdd(opts.valueDate)}${ccy}${amount}`;
+
+  const fields: Record<string, string> = {
+    "20": opts.transactionReference,
+    "21": opts.relatedReference ?? opts.transactionReference,
+    "32A": field32A,
+    "52A": opts.orderingInstitution ?? opts.sendingInstitution,
+    "57A": opts.receivingInstitution,
+    "58A": opts.beneficiaryInstitution,
+  };
+
+  const block1 = `{1:F01${opts.sendingInstitution.padEnd(12, "X")}0000000000}`;
+  const block2 = `{2:I202${opts.receivingInstitution.padEnd(12, "X")}N}`;
+  const block4 = Object.entries(fields).map(([t, v]) => `:${t}:${v}`).join("\n");
+  const block4Wrapped = `{4:\n${block4}\n-}`;
+
+  return {
+    sender: opts.sendingInstitution,
+    receiver: opts.receivingInstitution,
+    fin: `${block1}${block2}${block4Wrapped}`,
+    fields,
+  };
+}
--- a/orchestrator/src/services/swift/mt760.ts
+++ b/orchestrator/src/services/swift/mt760.ts
@@ -0,0 +1,112 @@
+/**
+ * MT760 — Issue of a Demand Guarantee / Standby Letter of Credit
+ * (arch §4.2 Banking Instrument Layer + §6 Instrument Terms Hash).
+ *
+ * SWIFT FIN message. This is the issuance leg of the two-phase
+ * commit. Output is deterministic so the planHash anchored on-chain
+ * can be reproduced by any party with access to the InstrumentTerms.
+ *
+ * Reference: SWIFT FIN Category 7 User Handbook, MT760 format;
+ * Emirates Islamic Bank beneficiary-format SBLC template.
+ */
+
+import { createHash } from "crypto";
+import type { InstrumentTerms } from "../../types/plan";
+
+export interface Mt760Message {
+  sender: string;
+  receiver: string;
+  messageReference: string;
+  fin: string;
+  fields: Record<string, string>;
+}
+
+function formatAmount(amount: number, currency: string): string {
+  // SWIFT FIN amount: 3-letter currency + 15n,2d (max), decimal comma.
+  if (amount < 0) throw new Error("MT760: amount must be non-negative");
+  return `${currency}${amount.toFixed(2).replace(".", ",")}`;
+}
+
+function yyMMdd(iso: string): string {
+  // Accept YYYY-MM-DD and return YYMMDD.
+  const m = /^(\d{4})-(\d{2})-(\d{2})$/.exec(iso);
+  if (!m) throw new Error(`MT760: expiryDate must be YYYY-MM-DD, got '${iso}'`);
+  return `${m[1].slice(2)}${m[2]}${m[3]}`;
+}
+
+/**
+ * Render an MT760 from an InstrumentTerms record. Uses the
+ * block-structured FIN format (Block 1/2/4/5). Tag codes:
+ *
+ *   :20:   Transaction reference number
+ *   :23:   Further identification
+ *   :27:   Sequence of total (here: 1/1)
+ *   :30:   Date of issue
+ *   :40C:  Applicable rules (URDG 758, UCP 600)
+ *   :31D:  Date and place of expiry
+ *   :50:   Applicant
+ *   :52A:  Issuing bank (BIC)
+ *   :59:   Beneficiary name + account
+ *   :32B:  Amount
+ *   :77C:  Details of guarantee
+ *   :72Z:  Sender to receiver info
+ */
+export function generateMt760(
+  terms: InstrumentTerms,
+  opts: { transactionReference: string; issueDate: string },
+): Mt760Message {
+  const sender = terms.issuingBankBIC;
+  const receiver = terms.beneficiaryBankBIC;
+  const field32B = formatAmount(terms.amount, terms.currency);
+  const field31D = `${yyMMdd(terms.expiryDate)}${terms.placeOfPresentation.toUpperCase()}`;
+
+  const fields: Record<string, string> = {
+    "20": opts.transactionReference,
+    "23": "ISSUE OF STANDBY LETTER OF CREDIT",
+    "27": "1/1",
+    "30": yyMMdd(opts.issueDate),
+    "40C": terms.governingLaw,
+    "31D": field31D,
+    "50": terms.applicant,
+    "52A": terms.issuingBankBIC,
+    "59": [terms.beneficiaryName, terms.beneficiaryAccount].filter(Boolean).join("\n"),
+    "32B": field32B,
+    "77C": [
+      `TEMPLATE/${terms.templateRef}`,
+      `TEMPLATE_HASH/${terms.templateHash}`,
+      `TENOR/${terms.tenor}`,
+    ].join("\n"),
+    "72Z": `GOVLAW/${terms.governingLaw}`,
+  };
+
+  // Build FIN block 4 body with :tag:value sequences.
+  const block4 = Object.entries(fields)
+    .map(([tag, value]) => `:${tag}:${value}`)
+    .join("\n");
+
+  const block1 = `{1:F01${sender.padEnd(12, "X")}0000000000}`;
+  const block2 = `{2:I760${receiver.padEnd(12, "X")}N}`;
+  const block4Wrapped = `{4:\n${block4}\n-}`;
+  const block5 = `{5:{CHK:${checksum(block4)}}}`;
+
+  const fin = `${block1}${block2}${block4Wrapped}${block5}`;
+
+  return { sender, receiver, messageReference: opts.transactionReference, fin, fields };
+}
+
+/**
+ * Deterministic SHA-256 over the canonical field list. Matches
+ * InstrumentTerms.templateHash when all 11 required fields are filled
+ * in with the SBLC template values.
+ */
+export function messageHash(msg: Mt760Message): string {
+  const canonical = Object.entries(msg.fields)
+    .sort(([a], [b]) => a.localeCompare(b))
+    .map(([k, v]) => `${k}=${v}`)
+    .join("\n");
+  return createHash("sha256").update(canonical).digest("hex");
+}
+
+function checksum(block4Body: string): string {
+  return createHash("sha256").update(block4Body).digest("hex").slice(0, 12).toUpperCase();
+}
--- a/orchestrator/src/services/swift/pacs009.ts
+++ b/orchestrator/src/services/swift/pacs009.ts
@@ -0,0 +1,94 @@
+/**
+ * pacs.009 — Financial Institution Credit Transfer (ISO 20022).
+ *
+ * Arch §4.3 Payment Messaging / Settlement Layer. Used for
+ * **bank-to-bank** credit transfers (the interbank leg); pacs.008 is
+ * for **customer-to-bank** PSP-initiated transfers. The gap-analysis
+ * flagged that ExecutionCoordinator was generating pacs.008 for what
+ * is actually a FI-to-FI settlement leg — this module fixes that.
+ *
+ * Reference: ISO 20022 Payments Maintenance 2019 / 2022,
+ * pacs.009.001.08 schema.
+ */
+
+import type { Plan, PlanStep } from "../../types/plan";
+
+export interface Pacs009Options {
+  messageId: string;
+  creationDateTime?: string;
+  instructingAgentBIC: string;
+  instructedAgentBIC: string;
+  debtorAgentBIC: string;
+  creditorAgentBIC: string;
+  endToEndId?: string;
+}
+
+export interface Pacs009Result {
+  messageId: string;
+  endToEndId: string;
+  xml: string;
+}
+
+function bicCheck(bic: string, field: string): void {
+  if (!/^[A-Z0-9]{8}([A-Z0-9]{3})?$/.test(bic)) {
+    throw new Error(`pacs.009: ${field} must be a valid BIC, got '${bic}'`);
+  }
+}
+
+function findPayStep(plan: Plan): PlanStep {
+  const step = plan.steps.find((s) => s.type === "pay");
+  if (!step) throw new Error("pacs.009: plan must contain a 'pay' step");
+  return step;
+}
+
+/**
+ * Render a pacs.009.001.08 XML message for the interbank leg of the
+ * plan's `pay` step.
+ */
+export function generatePacs009(plan: Plan, opts: Pacs009Options): Pacs009Result {
+  bicCheck(opts.instructingAgentBIC, "instructingAgentBIC");
+  bicCheck(opts.instructedAgentBIC, "instructedAgentBIC");
+  bicCheck(opts.debtorAgentBIC, "debtorAgentBIC");
+  bicCheck(opts.creditorAgentBIC, "creditorAgentBIC");
+
+  const payStep = findPayStep(plan);
+  const messageId = opts.messageId;
+  const endToEndId = opts.endToEndId ?? `E2E-${plan.plan_id ?? messageId}`;
+  const creDtTm = opts.creationDateTime ?? new Date().toISOString();
+  const ccy = (payStep.asset ?? "USD").toUpperCase();
+  const amount = payStep.amount.toFixed(2);
+  const settleDate = creDtTm.split("T")[0];
+
+  const xml = `<?xml version="1.0" encoding="UTF-8"?>
+<Document xmlns="urn:iso:std:iso:20022:tech:xsd:pacs.009.001.08">
+  <FICdtTrf>
+    <GrpHdr>
+      <MsgId>${escapeXml(messageId)}</MsgId>
+      <CreDtTm>${escapeXml(creDtTm)}</CreDtTm>
+      <NbOfTxs>1</NbOfTxs>
+      <SttlmInf><SttlmMtd>INGA</SttlmMtd></SttlmInf>
+      <InstgAgt><FinInstnId><BICFI>${opts.instructingAgentBIC}</BICFI></FinInstnId></InstgAgt>
+      <InstdAgt><FinInstnId><BICFI>${opts.instructedAgentBIC}</BICFI></FinInstnId></InstdAgt>
+    </GrpHdr>
+    <CdtTrfTxInf>
+      <PmtId>
+        <InstrId>${escapeXml(messageId)}</InstrId>
+        <EndToEndId>${escapeXml(endToEndId)}</EndToEndId>
+        <TxId>${escapeXml(messageId)}</TxId>
+      </PmtId>
+      <IntrBkSttlmAmt Ccy="${ccy}">${amount}</IntrBkSttlmAmt>
+      <IntrBkSttlmDt>${settleDate}</IntrBkSttlmDt>
+      <Dbtr><FinInstnId><BICFI>${opts.debtorAgentBIC}</BICFI></FinInstnId></Dbtr>
+      <DbtrAgt><FinInstnId><BICFI>${opts.debtorAgentBIC}</BICFI></FinInstnId></DbtrAgt>
+      <CdtrAgt><FinInstnId><BICFI>${opts.creditorAgentBIC}</BICFI></FinInstnId></CdtrAgt>
+      <Cdtr><FinInstnId><BICFI>${opts.creditorAgentBIC}</BICFI></FinInstnId></Cdtr>
+    </CdtTrfTxInf>
+  </FICdtTrf>
+</Document>`;
+
+  return { messageId, endToEndId, xml };
+}
+
+function escapeXml(s: string): string {
+  return s.replace(/[<>&"']/g, (c) => ({ "<": "&lt;", ">": "&gt;", "&": "&amp;", '"': "&quot;", "'": "&apos;" }[c]!));
+}
--- a/orchestrator/tests/unit/eventBus.test.ts
+++ b/orchestrator/tests/unit/eventBus.test.ts
@@ -0,0 +1,149 @@
+import { describe, it, expect, beforeEach, jest } from "@jest/globals";
+
+type Row = {
+  id: string;
+  plan_id: string;
+  type: string;
+  actor: string | null;
+  payload: Record<string, unknown>;
+  payload_hash: string;
+  prev_hash: string | null;
+  signature: string;
+  created_at: string;
+};
+
+const rows: Row[] = [];
+let idSeq = 0;
+
+jest.mock("../../src/db/postgres", () => ({
+  query: async (sql: string, params: unknown[] = []) => {
+    if (sql.startsWith("SELECT signature")) {
+      const planId = params[0] as string;
+      const matches = rows.filter((r) => r.plan_id === planId);
+      if (matches.length === 0) return [];
+      return [{ signature: matches[matches.length - 1].signature }];
+    }
+    if (sql.startsWith("INSERT INTO events")) {
+      const [plan_id, type, actor, payloadJson, payload_hash, prev_hash, signature] =
+        params as [string, string, string | null, string, string, string | null, string];
+      const rec: Row = {
+        id: `evt-${++idSeq}`,
+        plan_id,
+        type,
+        actor,
+        payload: JSON.parse(payloadJson),
+        payload_hash,
+        prev_hash,
+        signature,
+        created_at: new Date(Date.now() + idSeq).toISOString(),
+      };
+      rows.push(rec);
+      return [rec];
+    }
+    if (sql.startsWith("SELECT id, plan_id")) {
+      const planId = params[0] as string;
+      return rows.filter((r) => r.plan_id === planId);
+    }
+    return [];
+  },
+}));
+
+import { publish, getEventsForPlan, verifyChain, EVENT_TYPES } from "../../src/services/eventBus";
+
+describe("Event Bus", () => {
+  beforeEach(() => {
+    rows.length = 0;
+    idSeq = 0;
+  });
+
+  it("EVENT_TYPES covers all arch §7.2 categories", () => {
+    expect(EVENT_TYPES).toContain("transaction.created");
+    expect(EVENT_TYPES).toContain("transaction.committed");
+    expect(EVENT_TYPES).toContain("transaction.aborted");
+    expect(EVENT_TYPES).toContain("payment.settled");
+    expect(EVENT_TYPES).toContain("instrument.dispatched");
+    expect(EVENT_TYPES.length).toBe(15);
+  });
+
+  it("publish persists with payload_hash, prev_hash=null, and signature", async () => {
+    const rec = await publish({
+      planId: "p-1",
+      type: "transaction.created",
+      actor: "coordinator",
+      payload: { foo: 1 },
+    });
+    expect(rec.id).toMatch(/evt-/);
+    expect(rec.prev_hash).toBeNull();
+    expect(rec.payload_hash).toMatch(/^[0-9a-f]{64}$/);
+    expect(rec.signature).toMatch(/^[0-9a-f]{64}$/);
+    expect(rec.payload).toEqual({ foo: 1 });
+  });
+
+  it("prev_hash chains consecutive events for the same plan", async () => {
+    const a = await publish({ planId: "p-1", type: "transaction.created" });
+    const b = await publish({ planId: "p-1", type: "participants.authorized" });
+    const c = await publish({ planId: "p-1", type: "preconditions.satisfied" });
+    expect(a.prev_hash).toBeNull();
+    expect(b.prev_hash).toBe(a.signature);
+    expect(c.prev_hash).toBe(b.signature);
+  });
+
+  it("events are isolated per plan_id", async () => {
+    const a1 = await publish({ planId: "p-1", type: "transaction.created" });
+    const b1 = await publish({ planId: "p-2", type: "transaction.created" });
+    expect(a1.prev_hash).toBeNull();
+    expect(b1.prev_hash).toBeNull();
+  });
+
+  it("verifyChain returns ok for an untampered chain", async () => {
+    await publish({ planId: "p-1", type: "transaction.created" });
+    await publish({ planId: "p-1", type: "transaction.prepared" });
+    await publish({ planId: "p-1", type: "transaction.committed" });
+    const result = await verifyChain("p-1");
+    expect(result.ok).toBe(true);
+  });
+
+  it("verifyChain detects payload tampering", async () => {
+    await publish({ planId: "p-1", type: "transaction.created", payload: { amount: 100 } });
+    await publish({ planId: "p-1", type: "transaction.committed" });
+    rows[0].payload = { amount: 999_999 }; // tamper
+    const result = await verifyChain("p-1");
+    expect(result.ok).toBe(false);
+    if (!result.ok) {
+      expect(result.brokenAt).toBe(0);
+      expect(result.reason).toBe("payload_hash mismatch");
+    }
+  });
+
+  it("verifyChain detects signature tampering", async () => {
+    await publish({ planId: "p-1", type: "transaction.created" });
+    await publish({ planId: "p-1", type: "transaction.committed" });
+    rows[1].signature = "0".repeat(64); // tamper
+    const result = await verifyChain("p-1");
+    expect(result.ok).toBe(false);
+    if (!result.ok) {
+      expect(result.brokenAt).toBe(1);
+    }
+  });
+
+  it("verifyChain detects broken prev_hash link", async () => {
+    await publish({ planId: "p-1", type: "transaction.created" });
+    await publish({ planId: "p-1", type: "transaction.committed" });
+    rows[1].prev_hash = "0".repeat(64);
+    const result = await verifyChain("p-1");
+    expect(result.ok).toBe(false);
+    if (!result.ok) {
+      expect(result.reason).toBe("prev_hash mismatch");
+    }
+  });
+
+  it("getEventsForPlan returns events in chronological order", async () => {
+    await publish({ planId: "p-1", type: "transaction.created" });
+    await publish({ planId: "p-1", type: "transaction.prepared" });
+    const events = await getEventsForPlan("p-1");
+    expect(events.map((e) => e.type)).toEqual([
+      "transaction.created",
+      "transaction.prepared",
+    ]);
+  });
+});
--- a/orchestrator/tests/unit/swift.test.ts
+++ b/orchestrator/tests/unit/swift.test.ts
@@ -0,0 +1,169 @@
+import { describe, it, expect } from "@jest/globals";
+import {
+  generateMt760,
+  messageHash,
+  generatePacs009,
+  generateMt202,
+  parseCamt025,
+  parseCamt054,
+  parseCamt,
+  reconcileCamt054,
+} from "../../src/services/swift";
+import type { InstrumentTerms, Plan } from "../../src/types/plan";
+
+const TERMS: InstrumentTerms = {
+  applicant: "ACME TRADING FZE",
+  issuingBankBIC: "EBILAEAD",
+  beneficiaryBankBIC: "EMBKAEAD",
+  beneficiaryName: "BLUE OCEAN SHIPPING LLC",
+  beneficiaryAccount: "AE070260001015104203701",
+  amount: 1_500_000,
+  currency: "USD",
+  tenor: "365D",
+  expiryDate: "2027-04-18",
+  placeOfPresentation: "DUBAI",
+  governingLaw: "URDG 758",
+  templateRef: "EIB-SBLC-2024-01",
+  templateHash: "a".repeat(64),
+};
+
+const PLAN: Plan = {
+  plan_id: "11111111-2222-3333-4444-555555555555",
+  creator: "0xabc",
+  steps: [{ type: "pay", asset: "USD", amount: 1_500_000 }],
+};
+
+describe("SWIFT gateway — MT760", () => {
+  it("renders all 12 required tags", () => {
+    const msg = generateMt760(TERMS, { transactionReference: "TXN1", issueDate: "2026-04-18" });
+    expect(msg.sender).toBe("EBILAEAD");
+    expect(msg.receiver).toBe("EMBKAEAD");
+    expect(msg.fields["20"]).toBe("TXN1");
+    expect(msg.fields["30"]).toBe("260418");
+    expect(msg.fields["32B"]).toBe("USD1500000,00");
+    expect(msg.fields["31D"]).toBe("270418DUBAI");
+    expect(msg.fin).toContain("{1:F01EBILAEADXXXX0000000000}");
+    expect(msg.fin).toContain("{2:I760EMBKAEADXXXXN}");
+    expect(msg.fin).toContain(":32B:USD1500000,00");
+  });
+
+  it("rejects malformed expiry date", () => {
+    expect(() =>
+      generateMt760({ ...TERMS, expiryDate: "not-a-date" }, { transactionReference: "T", issueDate: "2026-04-18" }),
+    ).toThrow(/YYYY-MM-DD/);
+  });
+
+  it("rejects negative amount", () => {
+    expect(() =>
+      generateMt760({ ...TERMS, amount: -1 }, { transactionReference: "T", issueDate: "2026-04-18" }),
+    ).toThrow(/non-negative/);
+  });
+
+  it("messageHash is deterministic", () => {
+    const a = generateMt760(TERMS, { transactionReference: "T", issueDate: "2026-04-18" });
+    const b = generateMt760(TERMS, { transactionReference: "T", issueDate: "2026-04-18" });
+    expect(messageHash(a)).toBe(messageHash(b));
+    expect(messageHash(a)).toMatch(/^[0-9a-f]{64}$/);
+  });
+});
+
+describe("SWIFT gateway — pacs.009", () => {
+  const opts = {
+    messageId: "MSG-1",
+    creationDateTime: "2026-04-18T10:00:00Z",
+    instructingAgentBIC: "EBILAEAD",
+    instructedAgentBIC: "EMBKAEAD",
+    debtorAgentBIC: "EBILAEAD",
+    creditorAgentBIC: "EMBKAEAD",
+  };
+
+  it("emits well-formed pacs.009.001.08 XML", () => {
+    const result = generatePacs009(PLAN, opts);
+    expect(result.messageId).toBe("MSG-1");
+    expect(result.xml).toContain("urn:iso:std:iso:20022:tech:xsd:pacs.009.001.08");
+    expect(result.xml).toContain("<IntrBkSttlmAmt Ccy=\"USD\">1500000.00</IntrBkSttlmAmt>");
+    expect(result.xml).toContain("<BICFI>EBILAEAD</BICFI>");
+    expect(result.xml).toContain("<BICFI>EMBKAEAD</BICFI>");
+    expect(result.endToEndId).toBe(`E2E-${PLAN.plan_id}`);
+  });
+
+  it("rejects invalid BIC", () => {
+    expect(() => generatePacs009(PLAN, { ...opts, instructingAgentBIC: "BAD" })).toThrow(/BIC/);
+  });
+
+  it("requires a pay step", () => {
+    expect(() =>
+      generatePacs009({ ...PLAN, steps: [{ type: "borrow", amount: 1, asset: "USD" }] }, opts),
+    ).toThrow(/pay/);
+  });
+});
+
+describe("SWIFT gateway — MT202", () => {
+  it("renders the 6 required tags", () => {
+    const msg = generateMt202(PLAN, {
+      transactionReference: "TXN-1",
+      valueDate: "2026-04-18",
+      sendingInstitution: "EBILAEAD",
+      receivingInstitution: "EMBKAEAD",
+      beneficiaryInstitution: "EMBKAEAD",
+    });
+    expect(msg.fields["20"]).toBe("TXN-1");
+    expect(msg.fields["32A"]).toBe("260418USD1500000,00");
+    expect(msg.fields["58A"]).toBe("EMBKAEAD");
+    expect(msg.fin).toContain(":20:TXN-1");
+  });
+});
+
+describe("SWIFT gateway — camt parsers", () => {
+  it("parseCamt025 extracts status + ids", () => {
+    const xml = `<?xml version="1.0"?><Document xmlns="urn:iso:std:iso:20022:tech:xsd:camt.025.001.05"><Rct><MsgId>R1</MsgId><OrgnlMsgId>MSG-1</OrgnlMsgId><Cd>ACSC</Cd><CreDtTm>2026-04-18T10:01:00Z</CreDtTm></Rct></Document>`;
+    const r = parseCamt025(xml);
+    expect(r.type).toBe("camt.025");
+    expect(r.originalMessageId).toBe("MSG-1");
+    expect(r.status).toBe("ACSC");
+  });
+
+  it("parseCamt054 extracts credit amount + endToEndId", () => {
+    const xml = `<?xml version="1.0"?><Document xmlns="urn:iso:std:iso:20022:tech:xsd:camt.054.001.08"><BkToCstmrDbtCdtNtfctn><MsgId>N1</MsgId><Ntfctn><Ntry><Amt Ccy="USD">1500000.00</Amt><CdtDbtInd>CRDT</CdtDbtInd><BookgDt><Dt>2026-04-18</Dt></BookgDt><ValDt><Dt>2026-04-18</Dt></ValDt><NtryDtls><TxDtls><Refs><EndToEndId>E2E-plan-1</EndToEndId></Refs></TxDtls></NtryDtls></Ntry></Ntfctn></BkToCstmrDbtCdtNtfctn></Document>`;
+    const r = parseCamt054(xml);
+    expect(r.type).toBe("camt.054");
+    expect(r.creditDebitIndicator).toBe("CRDT");
+    expect(r.amount).toBe(1_500_000);
+    expect(r.currency).toBe("USD");
+    expect(r.endToEndId).toBe("E2E-plan-1");
+  });
+
+  it("parseCamt dispatches on xmlns marker", () => {
+    const xml025 = `<Document xmlns="urn:iso:std:iso:20022:tech:xsd:camt.025.001.05"><Rct><MsgId>R</MsgId><OrgnlMsgId>O</OrgnlMsgId><Cd>ACSC</Cd></Rct></Document>`;
+    expect(parseCamt(xml025).type).toBe("camt.025");
+  });
+
+  it("parseCamt rejects unknown xmlns", () => {
+    expect(() => parseCamt('<Document xmlns="urn:other"/>')).toThrow(/unsupported/);
+  });
+
+  it("reconcileCamt054 returns empty array when everything matches", () => {
+    const msg = {
+      type: "camt.054" as const,
+      messageId: "N1",
+      creditDebitIndicator: "CRDT" as const,
+      amount: 1_500_000,
+      currency: "USD",
+      endToEndId: "E2E-1",
+    };
+    expect(reconcileCamt054(msg, { amount: 1_500_000, currency: "USD", endToEndId: "E2E-1" })).toEqual([]);
+  });
+
+  it("reconcileCamt054 reports amount + currency + direction mismatches", () => {
+    const msg = {
+      type: "camt.054" as const,
+      messageId: "N1",
+      creditDebitIndicator: "DBIT" as const,
+      amount: 1_400_000,
+      currency: "EUR",
+      endToEndId: "E2E-2",
+    };
+    const result = reconcileCamt054(msg, { amount: 1_500_000, currency: "USD", endToEndId: "E2E-1" });
+    expect(result.map((m) => m.field).sort()).toEqual(["amount", "creditDebitIndicator", "currency", "endToEndId"]);
+  });
+});