diff --git a/package-lock.json b/package-lock.json
index 53a1d09fb49..f16699ff667 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -5750,6 +5750,10 @@
       "resolved": "shared-libs/bulk-docs-utils",
       "link": true
     },
+    "node_modules/@medic/bulk-operations": {
+      "resolved": "shared-libs/bulk-operations",
+      "link": true
+    },
     "node_modules/@medic/calendar-interval": {
       "resolved": "shared-libs/calendar-interval",
       "link": true
@@ -44275,6 +44279,11 @@
       "version": "1.0.0",
       "license": "Apache-2.0"
     },
+    "shared-libs/bulk-operations": {
+      "name": "@medic/bulk-operations",
+      "version": "1.0.0",
+      "license": "Apache-2.0"
+    },
     "shared-libs/calendar-interval": {
       "name": "@medic/calendar-interval",
       "version": "1.0.0",
diff --git a/shared-libs/bulk-operations/package.json b/shared-libs/bulk-operations/package.json
new file mode 100644
index 00000000000..24d1de4831d
--- /dev/null
+++ b/shared-libs/bulk-operations/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "@medic/bulk-operations",
+  "version": "1.0.0",
+  "description": "Shared document model for the CHT-Core bulk operation framework (delete, move, merge)",
+  "main": "src/index.js",
+  "scripts": {
+    "test": "nyc --nycrcPath='../nyc.config.js' mocha ./test"
+  },
+  "author": "",
+  "license": "Apache-2.0"
+}
diff --git a/shared-libs/bulk-operations/src/index.js b/shared-libs/bulk-operations/src/index.js
new file mode 100644
index 00000000000..d84078cce83
--- /dev/null
+++ b/shared-libs/bulk-operations/src/index.js
@@ -0,0 +1,98 @@
+const { v7: uuid } = require('uuid');
+
+/**
+ * Document model for the bulk operation framework.
+ *
+ * A bulk operation is recorded with two kinds of document:
+ *  - a single LOG document (stored in medic-logs) that tracks overall status and is read by the polling endpoint.
+ *  - one ACTION document per action type (stored in medic-sentinel) that Sentinel processes in batches.
+ *
+ * Delete, move and merge all express their work as a set of these actions.
+ */
+
+const LOG_ID_PREFIX = 'bulk-operation:';
+const ACTION_ID_PREFIX = 'bulk-operation-action:';
+
+const ACTIONS = {
+  ARCHIVE: 'archive',
+  SET_CONTACT: 'set-contact',
+  DELETE_USER: 'delete-user',
+};
+
+const STATUSES = {
+  QUEUED: 'queued',
+  COMPLETED: 'completed',
+  FAILED: 'failed',
+};
+
+// The per-item params for each action live in an attachment rather than inline, so updating the
+// action document's cursor as Sentinel works through the batches does not rewrite the whole list.
+const OPERATIONS_ATTACHMENT = 'operations';
+const OPERATIONS_CONTENT_TYPE = 'application/json';
+
+const getOperationUuid = (operationId) => operationId.slice(LOG_ID_PREFIX.length);
+
+const generateOperationId = () => `${LOG_ID_PREFIX}${uuid()}`;
+
+const generateActionId = (operationId) => `${ACTION_ID_PREFIX}${getOperationUuid(operationId)}:${uuid()}`;
+
+const encodeOperations = (operations) => ({
+  content_type: OPERATIONS_CONTENT_TYPE,
+  data: Buffer.from(JSON.stringify(operations)).toString('base64'),
+});
+
+const decodeOperations = (attachment) => JSON.parse(Buffer.from(attachment.data, 'base64').toString());
+
+const buildActionDoc = (operationId, action, operations) => ({
+  _id: generateActionId(operationId),
+  bulk_operation_id: operationId,
+  action,
+  cursor: 0,
+  total: operations.length,
+  _attachments: {
+    [OPERATIONS_ATTACHMENT]: encodeOperations(operations),
+  },
+});
+
+const buildLogAction = (action, totalChangesCount, date) => ({
+  status: STATUSES.QUEUED,
+  action,
+  updated_date: date,
+  total_changes_count: totalChangesCount,
+});
+
+/**
+ * Builds the documents that make up a single bulk operation.
+ * @param {Array<{action: string, operations: Object[]}>} actionOperations - one entry per action type, each holding
+ *   its list of per-item params
+ * @param {Date} date - the operation start date, also the initial updated_date of every action
+ * @returns {{log: Object, actions: Object[]}} the log document (for medic-logs) and the action documents
+ *   (for medic-sentinel); the log's `actions` map is keyed by each action document's `_id`
+ */
+const buildBulkOperation = (actionOperations, date) => {
+  const operationId = generateOperationId();
+  const actions = actionOperations.map(({ action, operations }) => buildActionDoc(operationId, action, operations));
+
+  const logActions = {};
+  actions.forEach((actionDoc) => {
+    logActions[actionDoc._id] = buildLogAction(actionDoc.action, actionDoc.total, date);
+  });
+
+  const log = {
+    _id: operationId,
+    start_date: date,
+    actions: logActions,
+  };
+
+  return { log, actions };
+};
+
+module.exports = {
+  LOG_ID_PREFIX,
+  ACTION_ID_PREFIX,
+  ACTIONS,
+  STATUSES,
+  OPERATIONS_ATTACHMENT,
+  buildBulkOperation,
+  decodeOperations,
+};
diff --git a/shared-libs/bulk-operations/test/index.js b/shared-libs/bulk-operations/test/index.js
new file mode 100644
index 00000000000..c4fc5074008
--- /dev/null
+++ b/shared-libs/bulk-operations/test/index.js
@@ -0,0 +1,100 @@
+const chai = require('chai');
+const { validate: isUuid } = require('uuid');
+
+const service = require('../src/index');
+
+const expect = chai.expect;
+
+describe('bulk-operations document model', () => {
+  describe('constants', () => {
+    it('exposes the action types', () => {
+      expect(service.ACTIONS).to.deep.equal({
+        ARCHIVE: 'archive',
+        SET_CONTACT: 'set-contact',
+        DELETE_USER: 'delete-user',
+      });
+    });
+
+    it('exposes the statuses', () => {
+      expect(service.STATUSES).to.deep.equal({
+        QUEUED: 'queued',
+        COMPLETED: 'completed',
+        FAILED: 'failed',
+      });
+    });
+
+    it('exposes the document id prefixes', () => {
+      expect(service.LOG_ID_PREFIX).to.equal('bulk-operation:');
+      expect(service.ACTION_ID_PREFIX).to.equal('bulk-operation-action:');
+    });
+  });
+
+  describe('buildBulkOperation', () => {
+    const date = new Date('2026-06-29T12:00:00.000Z');
+
+    it('builds a log document with a uuid-v7 operation id', () => {
+      const { log } = service.buildBulkOperation([{ action: 'archive', operations: [{ id: 'a' }] }], date);
+
+      expect(log._id.startsWith('bulk-operation:')).to.equal(true);
+      expect(isUuid(log._id.slice('bulk-operation:'.length))).to.equal(true);
+      expect(log.start_date).to.equal(date);
+    });
+
+    it('builds one action document per action type, linked back to the operation', () => {
+      const groups = [
+        { action: 'archive', operations: [{ id: 'person' }, { id: 'report' }] },
+        { action: 'set-contact', operations: [{ id: 'place', current_contact_id: 'person' }] },
+        { action: 'delete-user', operations: [{ id: 'org.couchdb.user:chw' }] },
+      ];
+
+      const { log, actions } = service.buildBulkOperation(groups, date);
+
+      expect(actions).to.have.length(3);
+      actions.forEach((actionDoc, i) => {
+        expect(actionDoc._id.startsWith('bulk-operation-action:')).to.equal(true);
+        // the action id embeds the operation's uuid, so the two ids stay parseable together
+        expect(actionDoc._id).to.include(log._id.slice('bulk-operation:'.length));
+        expect(actionDoc.bulk_operation_id).to.equal(log._id);
+        expect(actionDoc.action).to.equal(groups[i].action);
+        expect(actionDoc.cursor).to.equal(0);
+        expect(actionDoc.total).to.equal(groups[i].operations.length);
+        expect(service.decodeOperations(actionDoc._attachments.operations)).to.deep.equal(groups[i].operations);
+      });
+    });
+
+    it('stores the operation params in a base64 json attachment', () => {
+      const operations = [{ id: 'place', current_contact_id: 'person' }];
+      const { actions } = service.buildBulkOperation([{ action: 'set-contact', operations }], date);
+
+      const attachment = actions[0]._attachments.operations;
+      expect(attachment.content_type).to.equal('application/json');
+      expect(attachment.data).to.be.a('string');
+      expect(service.decodeOperations(attachment)).to.deep.equal(operations);
+    });
+
+    it('cross-links each action document to its entry in the log', () => {
+      const groups = [
+        { action: 'archive', operations: [{ id: 'person' }] },
+        { action: 'set-contact', operations: [{ id: 'place' }, { id: 'place2' }] },
+      ];
+
+      const { log, actions } = service.buildBulkOperation(groups, date);
+
+      expect(Object.keys(log.actions)).to.deep.equal(actions.map(actionDoc => actionDoc._id));
+      actions.forEach((actionDoc) => {
+        const logAction = log.actions[actionDoc._id];
+        expect(logAction.status).to.equal('queued');
+        expect(logAction.action).to.equal(actionDoc.action);
+        expect(logAction.updated_date).to.equal(date);
+        expect(logAction.total_changes_count).to.equal(actionDoc.total);
+      });
+    });
+
+    it('generates a distinct operation id on each call', () => {
+      const first = service.buildBulkOperation([{ action: 'archive', operations: [] }], date);
+      const second = service.buildBulkOperation([{ action: 'archive', operations: [] }], date);
+
+      expect(first.log._id).to.not.equal(second.log._id);
+    });
+  });
+});