diff --git a/package-lock.json b/package-lock.json
index dc0a0ca..5acedb9 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@fullfabric/public-api",
-  "version": "1.7.0",
+  "version": "1.7.1",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "@fullfabric/public-api",
-      "version": "1.7.0",
+      "version": "1.7.1",
       "license": "MIT",
       "dependencies": {
         "assert": "^2.0.0",
diff --git a/package.json b/package.json
index 2bb97e0..1041de3 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@fullfabric/public-api",
-  "version": "1.7.0",
+  "version": "1.7.1",
   "description": "Function wrappers for the FullFabric public API.",
   "type": "module",
   "browser": "dist/index.js",
diff --git a/spec/utils/getPageDigest.spec.js b/spec/utils/getPageDigest.spec.js
new file mode 100644
index 0000000..29e170d
--- /dev/null
+++ b/spec/utils/getPageDigest.spec.js
@@ -0,0 +1,64 @@
+import getPageDigest from '../../src/utils/getPageDigest'
+
+describe('utils.getPageDigest(opts)', () => {
+  let oldUserAgent
+
+  beforeAll(() => {
+    oldUserAgent = navigator.userAgent
+
+    Object.defineProperty(navigator, 'userAgent', {
+      configurable: true,
+      value:
+        'Mozilla/5.0 (darwin) AppleWebKit/537.36 (KHTML, like Gecko) jsdom/20.0.3'
+    })
+  })
+
+  afterAll(() => {
+    Object.defineProperty(navigator, 'userAgent', {
+      configurable: true,
+      value: oldUserAgent
+    })
+  })
+
+  describe('when no request-id meta element is available', () => {
+    it('returns null', async () => {
+      expect(await getPageDigest()).toBeNull()
+    })
+
+    it('can use a given requestId', async () => {
+      expect(await getPageDigest({ requestId: '12345' })).toEqual(
+        '7f1c12a5c58c6f29bcaeaf5c6382fef305660da38f2d0919deac9fc4a58705d4'
+      )
+    })
+  })
+
+  describe('when a request-id meta element is available', () => {
+    beforeEach(() => {
+      document.head.innerHTML = `
+        <meta name="request-id" content="12345">
+      `
+    })
+
+    it("uses the request-id meta element's content", async () => {
+      expect(await getPageDigest()).toEqual(
+        '7f1c12a5c58c6f29bcaeaf5c6382fef305660da38f2d0919deac9fc4a58705d4'
+      )
+    })
+
+    it('can use a given requestId instead', async () => {
+      expect(await getPageDigest({ requestId: '54321' })).toEqual(
+        '0b3adfbef9370498eb8a03f99fba9e86a41b89d1beef6499646d20090db0739b'
+      )
+    })
+
+    it("can suffix the digest with another digest of a source's type and ID", async () => {
+      expect(
+        await getPageDigest({ sourceType: 'form', sourceId: '12345' })
+      ).toEqual(
+        '7f1c12a5c58c6f29bcaeaf5c6382fef305660da38f2d0919deac9fc4a58705d4' +
+          ':' +
+          '0daba4f5e1a46e9e2be8bd4aac8651a020267a7da81690be4f093abe635b6aa1'
+      )
+    })
+  })
+})
diff --git a/src/utils/getPageDigest.js b/src/utils/getPageDigest.js
new file mode 100644
index 0000000..e8c8a2b
--- /dev/null
+++ b/src/utils/getPageDigest.js
@@ -0,0 +1,44 @@
+/**
+ * Generates a digest for anti-spam purposes.
+ *
+ * This algorithm should match the backend's exactly, otherwise the requests
+ * will be unauthorized.
+ *
+ * By default, each digest is unique to a page load. When there are multiple
+ * submissions possible in the same page, e.g. via multiple forms, a source can
+ * be passed to generate a digest unique to it.
+ *
+ * @param {String} [requestId] ID of the request, pass if originating from an API request.
+ * @param {String} [sourceType] Type of source for the digest, should match backend.
+ * @param {String} [sourceId] ID of source for the digest, should match backend.
+ * @returns {String} The generated digest.
+ */
+export default async function getPageDigest({
+  requestId,
+  sourceType,
+  sourceId
+} = {}) {
+  requestId ||= document.querySelector("meta[name='request-id']")?.content || ''
+
+  // If there's no requestId, no point generating a digest, won't ever match
+  // the backend. Same if we can't access the crypto API.
+  if (!requestId || !crypto?.subtle?.digest) return null
+
+  let digest = await makeDigest(`${navigator.userAgent}:${requestId}`)
+
+  if (sourceType && sourceId) {
+    const suffix = `${sourceType}:${sourceId}`
+    digest += `:${await makeDigest(suffix)}`
+  }
+
+  return digest
+}
+
+async function makeDigest(str) {
+  const message = new TextEncoder().encode(str)
+  const digestRaw = await crypto.subtle.digest('SHA-256', message)
+
+  return Array.from(new Uint8Array(digestRaw))
+    .map((b) => b.toString(16).padStart(2, '0'))
+    .join('')
+}
diff --git a/src/utils/index.js b/src/utils/index.js
index e0c3f89..087a944 100644
--- a/src/utils/index.js
+++ b/src/utils/index.js
@@ -1,3 +1,4 @@
+export { default as getPageDigest } from './getPageDigest'
 export { default as checkResponse } from './checkResponse'
 export { default as extractHeaders } from './extractHeaders'
 export { default as url } from './url'