AgentMail vs LangChain: who uses which
Customers, public proof and the companies that use both.
On usedby, 13 companies use AgentMail and 35 use LangChain. 2 companies use both, including Factory and Clay. LangChain leads among the DevTools & Infrastructure companies on usedby that use either tool.Latest check Oct 25, 2026: 48 of 48 public lines checked. Counts include every proof level, job-post signals included. A company on both tools counts at any proof level, and a job post on one side is marked as such.
Who uses AgentMail, LangChain, or both
Every company with a public proof for at least one of the two tools.
11
listed for AgentMail only
2
companies use both
33
listed for LangChain only
On usedby, 11 companies are listed for AgentMail only, 33 are listed for LangChain only and 2 use both, out of the 46 companies listed for at least one. An absent listing does not prove non-use.
Who uses both
Companies with a public line on both tools, at any proof level: the strongest proofs come first, and a job post is marked.
| Company | First public proof, LangChain |
|---|---|
 Factory | On or before Dec 2024 |
 Clay | On or before Jun 2025 |
Side by side
Facts from our data and from each vendor's public pages. Each line says where it comes from.
AgentMail
LangChainQuestions about AgentMail and LangChain
Which is used more, AgentMail or LangChain?
LangChain has more customers on usedby: 35 against 13 for AgentMail.
Do companies use both AgentMail and LangChain?
Yes. 2 companies use both on usedby, including Factory and Clay.
Who uses AgentMail?
13 companies on usedby, each with the public page that shows it. See who uses AgentMail.
Who uses LangChain?
35 companies on usedby, each with the public page that shows it. See who uses LangChain.
How does usedby count customers?
A company counts when a public page shows it: a vendor's customer page, a case study, a press release or a job post, most saved with a dated capture. Every line is a customer, at one of four proof levels: confirmed, declared by the company itself, observed or signal (a job post, the weakest). A company counts as using both tools when it has a line on each, at any level; the list shows the strongest proofs first and marks job posts.