Pricing, limits, and integration
Both the REST API and the MCP server are part of the Sequenzy platform rather than a separate product, and Sequenzy leads with a free plan, so programmatic and agent access is reachable without an enterprise contract. Paid pricing scales by volume from a $19 Scale tier up to a custom Enterprise plan (1.2M+ emails).
Authentication is the same API key for both paths: generate it under Settings, API Keys, pass it as a Bearer-style key to the REST API, or set it as SEQUENZY_API_KEY for the @sequenzy/mcp server. The MCP server uses stdio transport, so it runs locally alongside the client rather than as a hosted OAuth endpoint.
Operational limits are lightly documented: rate-limit thresholds are not published, so build in backoff. There are framework guides for Node.js (Express, Next.js), Bun and SMTP, plus outbound webhooks, but no full set of standalone language SDKs, so outside the Node ecosystem you integrate against the REST API directly. The MCP tools carry readOnly/destructive/openWorld annotations, which is a genuine plus for safe agent use.
How much does the Sequenzy API actually cost?
Sequenzy publishes an API, but per-tier gating wasn't extracted automatically.
- Most likely scenario: API access is either included in all paid plans, or it's gated to higher tiers and we need to verify on the live docs page.
- Until verified, treat the question "which plan unlocks the API" as open. Don't budget on the assumption it's free with the cheapest paid plan.
API at a glance
Webhooks: Full webhook management through both the API and the MCP: create, update, delete, test, list deliveries, and replay. Wire events into n8n, Slack, or your own endpoint.
Which AI clients can read Sequenzy data?
Not every AI assistant supports MCP natively. Here's the per-client picture for Sequenzy specifically.
| Client | Support | Notes |
|---|---|---|
| Claude (Desktop/Web) | Native MCP | Add the @sequenzy/mcp server to your Claude Desktop config with SEQUENZY_API_KEY. |
| Claude Code | Native MCP | Runs the @sequenzy/mcp stdio server; full 113-tool access. |
| Codex | Native MCP | Supported MCP client per Sequenzy docs. |
| Cursor | Native MCP | Add the stdio MCP server with your API key. |
| Windsurf | Native MCP | Listed as a supported MCP client. |
Sequenzy also has an MCP server
If you're wiring Sequenzy into Claude / Cursor / Codex, the MCP server is usually less code than the REST API.
See Sequenzy MCP pageWhat you can build with the Sequenzy API
Three personas, three different shapes of build. Pick the row that matches how you actually ship.
Glue Sequenzy into your daily workflow
- Pull a digest of campaign performance into your morning Slack
- Trigger a one-off backfill when something looks off
- Pipe data into your own SQLite for ad-hoc queries
Sell Sequenzy reporting at scale
- White-label Sequenzy data into client-branded dashboards
- Run scheduled multi-account reports without logging into the Sequenzy UI
- Cross-reference with the rest of the client's stack (CRM, analytics, ad spend)
Production pipelines for Sequenzy
- Real-time sync into your warehouse via webhooks
- Custom alerts the dashboard's built-in alerting can't express
- Backfill + idempotency handling for Sequenzy data older than the dashboard exposes
Quickstart template
# Starter template — endpoint paths and SDK package names come from # the Sequenzy API docs: https://docs.sequenzy.com curl -X GET "https://api.sequenzy.com/<your-endpoint>" \ -H "Authorization: Bearer $YOUR_API_KEY" \ -H "Accept: application/json" | jq .
Template only. Endpoint paths, exact base URL, and auth header format come from docs.sequenzy.com.
Limits and gotchas
- No OpenAPI spec — you write typed clients by hand or use a third-party generator on the docs HTML.
- Webhooks available — react to Sequenzy events in real time instead of polling.
- No official SDK detected. Plan on hitting the API directly with your HTTP client of choice.
- Rate limits: always read the docs page before scaling — the published limit is usually lower than the practical one and overages can be expensive.
- Structured JSON outputs — agent-friendly, no scraping required.
Agent-readiness verdict
Solid, well-documented API with webhooks and API-key auth. No OpenAPI spec or official SDK yet, so expect hand-rolled HTTP unless you drive it through the MCP.
Strong agent fit, top tier for an email tool. Sequenzy ships an official MCP server exposing 120 tools on its own domain, offered both as a hosted Streamable HTTP endpoint (api.sequenzy.com/v1/mcp) and a local stdio server (npx @sequenzy/mcp). Every tool carries structured outputs (outputSchema plus readOnlyHint, destructiveHint and openWorldHint annotations), so an agent gets typed, safe results instead of raw JSON. Webhooks (create, test, replay) and a documented REST API with an llms.txt index round it out, authenticated by API key. The only gaps versus a perfect score are a published OpenAPI spec and an official REST SDK, and the 120-tool MCP already covers most of what those would give you.
Sequenzy API FAQ
Does Sequenzy have a public API?+
What auth does the Sequenzy API use?+
Does Sequenzy support webhooks?+
Should I use the API or the MCP server for Claude / Cursor / Codex?+
Sources
- Sequenzy official site: https://www.sequenzy.com
- API docs: https://docs.sequenzy.com
- MCP server: https://api.sequenzy.com/v1/mcp
10+ years in digital marketing. I review marketing software for AI-stack fit: real pricing, MCP and API support, and how cleanly each tool drops into an AI agent workflow, cross-checked against verified data and real user feedback.