MyMX (now Primitive)

Apparently renamed: MyMX seems to be Primitive (primitive.dev)

The old domain mymx.dev now answers with an HTTP 307 redirect to https://www.primitive.dev/ (checked 2026-10-02). Primitive is a Y Combinator company (listed on ycombinator.com/companies/primitive; search results 2026-10-05 describe it as launched in Spring 2026 and led by founder Ethan Byrd), a San Francisco company building “email infrastructure for AI agents”. A search summary of the Primitive Python SDK says it still accepts the retired MyMX-Signature header for older deliveries, which is consistent with a rename, but no Primitive page we could fetch states the rename explicitly. The original inbound-only “MyMX” offer (and npm package mymx) appears to be superseded by the Primitive product described below.

MyMX / Primitive

Overview

MyMX (as described in an earlier version of this note; the original pages could not be re-fetched) turned inbound email into structured, signed JSON webhooks: point a domain’s MX record at the service and every email arrives at your HTTP endpoint with parsed headers, text/HTML body, attachments (with SHA-256 hashes and download URLs), SMTP envelope data and SpamAssassin scores. Tagline then: “Email was always an API in disguise.” It was described as inbound-only and beta; whether it was free is not verified. The earlier draft’s npm install mymx examples, payload version 2025-12-14 and MYMX_CONFIRMED_HEADER are historical; npm page could not be fetched (403), so the package status is unverified.

Primitive today (2026-10-02, primitive.dev)

• Positioning: email infrastructure for AI agents; one HTTP call to send and receive (POST /v1/send-mail, long-polling for messages), SPF/DKIM/DMARC handled.
• primitive chat: send a message and wait for the threaded reply; agent-to-agent email without SMTP credentials.
• Managed inboxes: every account gets a *.primitive.email subdomain that runs hosted JavaScript Functions on each inbound email; custom domains supported; webhooks are signed.
• Extras: MCP integration (usable from ChatGPT and Claude), “Primitive Memories” persistent state, x402 USDC payments over email (Python SDK), agent skills for Claude Code, Cursor and others.
• SDKs/CLI: Node.js (@primitivedotdev/sdk), Python (primitivedotdev, v1.34.0 released 2026-09-29, MIT), Go, CLI, GitHub Actions.
• Plans (primitive.dev/pricing.md): Developer (free, with a small usage credit; 5 GB storage, 1 global webhook, 25 recipient routes); Power (unlimited webhooks/routes); Platinum (50 GB storage). Each paid plan includes a usage credit; usage-metered beyond credit; enterprise via contact. Current prices: see https://www.primitive.dev/pricing.md.
• Team (about page): Ethan Byrd (CEO and founder), Benjamin Poile, Ashley Ha, Vivian Sarratt.

Why it matters for agents

Email is a universal, addressable channel: an agent with an inbox can receive tasks, notify humans and talk to other agents. Event-driven webhooks fit serverless agent stacks. Compare other agent-email services such as AgentMail (YC S25; raised USD 6M, TechCrunch 2026-03-10) and general providers like resend-style APIs; for workflow triggers see n8n.

Related

• ai-agentic-systems, openclaw (assistants often use email as a channel), n8n

Open items

• Rename MyMX to Primitive rests on the domain redirect and a search summary; no first-party statement found. Confirm with the vendor or YC page.
• Primitive’s YC batch not stated on fetched pages.
• npm mymx package status and whether the old free tier persists: unverified.

Sources (accessed 2026-10-02)

• https://www.mymx.dev/ (307 redirect to primitive.dev)
• https://www.primitive.dev/ , https://www.primitive.dev/about , https://www.primitive.dev/pricing.md
• https://docs.primitive.dev/docs
• https://github.com/primitivedotdev
• https://pypi.org/project/primitivedotdev/
• https://www.ycombinator.com/companies/primitive (via search, 2026-10-05)
• https://techcrunch.com/2026/03/10/agentmail-raises-6m-to-build-an-email-service-for-ai-agents/