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Resend

INFRA · APIS
Velocity6.3

Email API for developers to send transactional and marketing email

resend.com ↗

The developer email API is rebuilding itself as something agents log into, not just call

email-apimcpoauthagent-nativedeveloper-platformdistribution
◆Current state
Resend shipped at a near-weekly pace through July and almost all of it points one direction. A hosted MCP server with built-in OAuth, a one-click Claude connector, and a Codex plugin bundling the MCP server and every Resend skill all landed within three weeks, sitting on OAuth 2.1 with PKCE that arrived alongside them. The rest is platform hygiene: Message-ID exposed on webhooks and email endpoints, CSV contact import at scale, suppression management, and automatic revocation of API keys leaked to GitHub.
◆Where it's heading
Resend is moving from a service you hold an API key for to one a third party or an agent authenticates into on a user's behalf. That is why OAuth and the secret scanner arrived in the same window as the agent surfaces — delegated auth is the thing that makes agent access safe, and long-lived static keys are the thing that makes it dangerous. Distribution is following the same logic, with Resend showing up in the Vercel marketplace, the Claude connector directory, and the Codex plugin marketplace rather than waiting to be integrated.
◆Prediction
Expect the MCP surface to widen past sending into contacts, domains, and analytics, and more of these one-click listings wherever agent tools keep directories. The terse changelog entries make it unclear how much of the OAuth work is generally available versus early access.

◆Recent moves

  1. 2d ago

    Email Suppressions

    Suppressed addresses become manageable from both the dashboard and the API. Deliverability plumbing that a sending platform is expected to expose once customers are large enough to have suppression lists worth auditing.

    View source ↗
  2. 8d ago

    Resend Plugin for Codex

    Resend lists in the official Codex plugin marketplace, shipping its MCP server and full skill set as a single install. The third agent-surface distribution point in a month, after the Claude connector and the hosted MCP server itself.

    View source ↗
  3. 14d ago

    GitHub Secret Scanner

    Leaked Resend keys found on GitHub are detected, revoked, and reported to the team automatically. Static API keys are the weak point in a product being wired into agent tools, and this narrows the window an exposed one stays live.

    View source ↗
  4. 17d ago

    OAuth Support

    ⚡ SPARK

    OAuth 2.1 with PKCE lets third parties build authenticated experiences on Resend instead of asking users for an API key. It is the primitive the hosted MCP server, the Claude connector, and the Codex plugin all depend on, which is why they arrived within days of each other.

    View source ↗
  5. 19d ago

    Resend Connector for Claude

    Resend appears in Claude's connector directory as a one-click install. Distribution rather than capability, but it puts sending in reach of anyone using Claude without a developer in the loop.

    View source ↗
  6. 22d ago

    Email Threading with Message-ID

    Message-ID now comes back on every email webhook and GET endpoint, which is what threading replies to a sent message requires. A small field with outsized effect for anyone building two-way email on top of Resend.

    View source ↗