diff --git a/README.md b/README.md
index 24ef9be..34bc3f3 100644
--- a/README.md
+++ b/README.md
@@ -160,3 +160,12 @@ In cooperation with https://github.com/wgroeneveld/serve-my-jams
 Calls the get webmention endpoint, sorts by date, adds metadata such as relative date (`x days ago`, property `publishedFromNow`), and returns data. Could be written in a `data` folder for Hugo to parse, for example. 
 
 Parameters: just one, the `domain`.
+
+#### 5.1 `send`
+
+Calls the set webmention endpoint using a `PUT`. Based on the RSS feed located at `/index.xml`, see the [serve-my-jams](github.com/wgroeneveld/serve-my-jams) README. 
+
+Parameters: just two:
+
+1. `domain` (see 5.1)
+2. `configfile` location where an ISO-formatted datetime property is kept. 
diff --git a/package.json b/package.json
index 429b4d3..04c3d0d 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "jam-my-stack",
-  "version": "1.0.11",
+  "version": "1.0.12",
   "repository": {
     "url": "https://github.com/wgroeneveld/jam-my-stack",
     "type": "git"
diff --git a/src/index.js b/src/index.js
index 95c436c..5bd8a18 100644
--- a/src/index.js
+++ b/src/index.js
@@ -2,7 +2,9 @@ const { parseMastoFeed } = require('./mastodon/feed-parser')
 const { widgetify } = require('./goodreads/widgetify.js')
 const { buildIndex } = require('./lunr/index-builder.js')
 const { howlong } = require('./howlongtobeat/howlong.js')
+
 const { getWebmentions } = require('./webmention/get.js')
+const { sendWebmentions } = require('./webmention/send.js')
 
 module.exports = {
 	mastodon: {
@@ -18,6 +20,7 @@ module.exports = {
 		howlong: howlong
 	},
 	webmention: {
-		getWebmentions: getWebmentions
+		getWebmentions: getWebmentions,
+		send: sendWebmentions
 	}
 };
diff --git a/src/webmention/send.js b/src/webmention/send.js
new file mode 100644
index 0000000..f994abb
--- /dev/null
+++ b/src/webmention/send.js
@@ -0,0 +1,36 @@
+
+const got = require('got')
+const config = require('../config')
+const fsp = require('fs').promises
+
+const dayjs = require('dayjs')
+
+async function getSince(configfile) {
+	let since = ''
+	try {
+		const fileContent = await fsp.readFile(configfile, 'utf8')
+		since = JSON.parse(fileContent.toString()).since
+	} catch(err) {
+		// console.log(err)
+		// we assume the file doesn't exist. See https://nodejs.org/api/fs.html#fs_fs_access_path_mode_callback
+	}
+	return since	
+}
+
+async function updateSince(configfile) {
+	const since = new Date().toISOString()
+	await fsp.writeFile(configfile, JSON.stringify({ since }, null, 2), 'utf-8')
+}
+
+async function sendWebmentions(domain, configfile) {
+	const since = await getSince(configfile)
+	const url = `${config.serveMyJamEndpoint}/webmention/${domain}/${config.serveMyJamToken}?since=${since}`
+
+	// this is an async call and will return 202 to say "started sending them out".
+	const result = await got.put(url)
+	await updateSince(configfile)
+}
+
+module.exports = {
+	sendWebmentions	
+}
diff --git a/test/__mocks__/got.js b/test/__mocks__/got.js
index e39c26f..99ed3ba 100644
--- a/test/__mocks__/got.js
+++ b/test/__mocks__/got.js
@@ -14,4 +14,10 @@ async function got(url) {
 	return result
 }
 
+async function gotPutMock(url, opts) {
+	
+}
+
+got.put = gotPutMock
+
 module.exports = got
diff --git a/test/webmention/send.test.js b/test/webmention/send.test.js
new file mode 100644
index 0000000..c286784
--- /dev/null
+++ b/test/webmention/send.test.js
@@ -0,0 +1,52 @@
+const MockDate = require('mockdate')
+const dayjs = require('dayjs')
+
+
+describe("webmention send serve-my-jam tests", () => {
+
+	const fs = require('fs');
+	const fsp = require('fs').promises;
+	const { rmdir } = require('./../utils')
+
+	const got = require('got')
+	
+
+	const { sendWebmentions } = require('./../../src/webmention/send')
+	const domain = "brainbaking.com"
+	const dumpdir = `${__dirname}/dump`
+
+	beforeEach(() => {
+		MockDate.set(dayjs('2021-03-11T19:00:00').toDate())
+		got.put = jest.fn()
+
+		if(fs.existsSync(dumpdir)) {
+			rmdir(dumpdir)
+		}
+		fs.mkdirSync(dumpdir)
+	});
+
+
+	test("sendWebmentions without a config creates a file with current date as since", async() => {
+		await sendWebmentions('brainbaking.com', `${dumpdir}/send.json`)
+
+		const config = (await fsp.readFile(`${dumpdir}/send.json`)).toString()
+		const since = JSON.parse(config).since
+
+		expect(got.put).toHaveBeenCalledWith("https://jam.brainbaking.com/webmention/brainbaking.com/miauwkes?since=")
+		expect(since).toBe(dayjs('2021-03-11T19:00:00').toDate().toISOString())
+	})
+
+	test("sendWebmentions with a previous since sets that since as a query parameter", async() => {
+		const sinceSetup = dayjs('2020-01-01T20:00:00').toDate().toISOString()
+		await fsp.writeFile(`${dumpdir}/send.json`, JSON.stringify({ since: sinceSetup }), 'utf-8')
+
+		await sendWebmentions('jefklakscodex.com', `${dumpdir}/send.json`)
+
+		const config = (await fsp.readFile(`${dumpdir}/send.json`)).toString()
+		const since = JSON.parse(config).since
+
+		expect(got.put).toHaveBeenCalledWith(`https://jam.brainbaking.com/webmention/jefklakscodex.com/miauwkes?since=${sinceSetup}`)
+		expect(since).toBe(dayjs('2021-03-11T19:00:00').toDate().toISOString())
+	})
+
+})