---
title: "Klaviyo helped design the protocol that could let AI agents bypass its emails; insiders sold $200 million"
description: "Sierra and Meta's draft Personal Agent Protocol would let consumers' AI agents buy, return and rebook directly with brands, past the marketing messages Klaviyo sells. Klaviyo joined the design table as insiders net-sold $199.9 million of its stock over 12 months."
publisher: "The Inference"
section: "Platforms"
published: 2026-10-12T15:24:54.043Z
modified: 2026-10-12T15:24:54.043Z
canonical: https://theinference.org/article/klaviyo-helped-design-the-protocol-that-could-let-ai-agents-bypass-its-emails-insiders-sold-200-million
language: en
keywords: "AI Agents, Agentic Commerce, Klaviyo, Insider Selling, Sierra"
---

# Klaviyo helped design the protocol that could let AI agents bypass its emails; insiders sold $200 million

> Sierra and Meta's draft Personal Agent Protocol would let consumers' AI agents buy, return and rebook directly with brands, past the marketing messages Klaviyo sells. Klaviyo joined the design table as insiders net-sold $199.9 million of its stock over 12 months.

Ed Hallen co-founded [Klaviyo](https://theinference.org/markets/companies/klaviyo) and still serves as a director and ten-percent owner, per the filing. On October 7 he sold 97,482 shares at a weighted average of $17.40, about $1.7 million, and gifted 17,885 more to a donor-advised fund the next day [1].

[The Form 4, the SEC filing that discloses insider trades](https://www.sec.gov/Archives/edgar/data/1835830/000147083126000934/0001470831-26-000934-index.htm), landed on October 9, in the same week [Sierra](https://theinference.org/markets/companies/sierra), the agent company co-founded by Bret Taylor, published [a draft of the Personal Agent Protocol](https://theinference.org/article/sierra-built-the-agent-front-door-and-the-detector-shopify-s-30-8-billion-rally-needs-the-gates-open) naming Klaviyo among 35 design partners, beside [PayPal](https://theinference.org/markets/companies/paypal), Visa and messaging rival OneSignal [2][3]. The sale ran under a Rule 10b5-1 plan, a trading schedule set months in advance and adopted on June 1 [1], so its timing is not a reaction to the draft.

## One agent session instead of the inbox

Sierra [announced the draft, called Poppy, on October 6](https://sierra.ai/blog/poppy) with eight launch partners: [Meta](https://theinference.org/markets/companies/meta), Genesys, Instinct, NiCE, Rocket, [Shopify](https://theinference.org/markets/companies/shopify), Stripe and Walmart [2]. Poppy would let a consumer's personal agent identify itself, carry the customer's permission and finish a return, a rebooking or a purchase through a brand's website, APIs or its own agent [2].

The draft's stated goal is that a brand "sees the whole journey instead of disconnected fragments" [2]. Klaviyo, with [more than 205,000 paying customers by its own count](https://www.businesswire.com/news/home/20260908135080/en/Klaviyo-Goes-Headless-Opening-Its-Platform-to-Agents-and-Marketers-Wherever-They-Work), sells those fragments: the email, SMS and push flows brands pay it to run [4].

## Insiders net-sold $199.9 million as growth halved

Insiders sold $200.2 million of Klaviyo stock over the 12 months to early October and bought $0.3 million, a net $199.9 million out the door [5]. The company [cut roles in design and product on October 1](https://www.bizjournals.com/boston/news/2026/10/01/klaviyo-cuts-roles-in-design-product.html) [6]. Revenue still grows, just more slowly each year: 47.5% year over year in Q3 2023, 26.4% in Q2 2026, and the street models 22.2% for the quarter due on November 4 at a $379.87 million consensus [7][8].

*Chart: **Klaviyo's growth has halved in three years; the street models 22% for Q3** Line chart showing Klaviyo's year-over-year revenue growth slowing from 47.5% in Q3 2023 to 26.4% in Q2 2026, with the Q3 2026 street consensus marked as an estimate at 22.2%.*

*Year-over-year revenue growth by calendar quarter. Q3 2023 through Q2 2026 from Klaviyo's SEC filings [7]; Q3 2026E is MarketBeat consensus revenue of $379.87M versus $310.88M a year earlier, as of October 9, 2026 [8]. [7][8]*

The shares closed at $17.41 on October 7, down from a 52-week high of $33.36, against a $27.14 average brokerage target [5][8]. [GuruFocus](https://www.gurufocus.com/news/9114412/a-look-at-klaviyo-inc-kvyo-after-49-gain-gf-value-4308-vs-price-1741) puts fair value at $43.08; the same service scores Klaviyo's growth outlook 0 of 10 and its financial strength 8 of 10 [5].

*Chart: **Klaviyo trades at $17.41, roughly half the $43.08 fair value GuruFocus models** Bar chart comparing Klaviyo's $17.41 closing share price on October 7 with its $33.36 52-week high, its $27.14 average brokerage target and GuruFocus's $43.08 fair-value estimate.*

*Share price is the October 7 close. The 52-week high and GuruFocus GF Value are as of October 7; the average brokerage target is as of October 9. Sources: GuruFocus [5]; MarketBeat [8]. [5][8]*

## Klaviyo is selling both sides of the shift

The bull case is not hollow. [In September Klaviyo went headless](https://theinference.org/article/chatgpt-s-agents-can-read-klaviyo-but-can-t-run-it): 260-plus tools built on MCP, the Model Context Protocol, and 490-plus APIs now open its platform to Claude, ChatGPT or any other agent, and its own Customer Agent has exchanged more than 1.3 million messages with shoppers [4]. It sells brands the messages that reach customers and the agents that serve them, and it took a seat at the protocol's design table rather than fight the rails.

The rails are also early. [Amazon](https://theinference.org/markets/companies/amazon) and [Anthropic](https://theinference.org/markets/companies/anthropic) are absent from the founding group, [OpenAI](https://theinference.org/markets/companies/openai) appears on the design list but not among the founders, and [survey data cited by Forkast puts the share of US adults who trust AI agents to complete purchases at 3%](https://forkast.news/sierra-and-metas-personal-agent-protocol-gives-commerce-a-common-front-door-for-those-willing-to-open-it/) [9][2].

## Two dates will price it

The v0.1 specification and a reference implementation are due by the end of October [3]. [Earnings follow on November 4](https://www.marketbeat.com/earnings/reports/2026-11-4-klaviyo-inc-stock/) [8]. Klaviyo is betting that knowing the customer outearns reaching them, and Poppy is the first priced test of that bet.

## Takeaway

Sierra and Meta's draft Personal Agent Protocol would route shoppers' AI agents straight to brands, past the email flows Klaviyo sells; Klaviyo joined the design table as insiders net-sold $199.9 million and growth halved to 26.4%.

## Sources

1. [SEC Form 4, Klaviyo, Inc., reporting owner Ed Hallen, filed 9 October 2026](https://www.sec.gov/Archives/edgar/data/1835830/000147083126000934/0001470831-26-000934-index.htm)
2. [Sierra blog, Sharing a draft of Personal Agent Protocol, October 2026](https://sierra.ai/blog/poppy)
3. [PYMNTS, Meta and Sierra Build Standard for How Personal Agents Interact With Businesses, 6 October 2026](https://www.pymnts.com/news/artificial-intelligence/2026/meta-and-sierra-build-standard-for-how-personal-agents-interact-with-businesses/)
4. [Business Wire, Klaviyo Goes Headless, Opening Its Platform to Agents and Marketers Wherever They Work, September 2026](https://www.businesswire.com/news/home/20260908135080/en/Klaviyo-Goes-Headless-Opening-Its-Platform-to-Agents-and-Marketers-Wherever-They-Work)
5. [GuruFocus, A Look at Klaviyo Inc (KVYO) After 4.9% Gain, GF Value $43.08 vs Price $17.41, 7 October 2026](https://www.gurufocus.com/news/9114412/a-look-at-klaviyo-inc-kvyo-after-49-gain-gf-value-4308-vs-price-1741)
6. [Boston Business Journals, Klaviyo cuts roles in design, product, 1 October 2026](https://www.bizjournals.com/boston/news/2026/10/01/klaviyo-cuts-roles-in-design-product.html)
7. [Klaviyo, quarterly figures from its SEC filings, retrieved 12 October 2026](https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001835830)
8. [MarketBeat, Klaviyo Q3 2026 Earnings Date and Estimates, collected 9 October 2026](https://www.marketbeat.com/earnings/reports/2026-11-4-klaviyo-inc-stock/)
9. [Forkast, Sierra and Meta's Personal Agent Protocol Gives Commerce a Common Front Door, 6 October 2026](https://forkast.news/sierra-and-metas-personal-agent-protocol-gives-commerce-a-common-front-door-for-those-willing-to-open-it/)


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Klaviyo helped design the protocol that could let AI agents bypass its emails; insiders sold $200 million — The Inference. Canonical: https://theinference.org/article/klaviyo-helped-design-the-protocol-that-could-let-ai-agents-bypass-its-emails-insiders-sold-200-million