Reflow

Reflow runs email workflows that survive restarts, long waits, and retries.

You describe the flow. An MCP agent (or you, via CLI) creates templates, saves a graph, publishes it, and enrolls contacts. Temporal keeps each enrollment alive. Resend sends the mail.

There is no operator dashboard. CLI and MCP use the same operations.

What you need

• Node.js 22+

• pnpm 11+

• Docker Compose (Postgres + Temporal)

• A Resend API key if you want real email (optional for validate/simulate)

Related MCP server: Nitrosend

1. Start the stack locally

cp .env.dev.example .env
pnpm install --frozen-lockfile
make dev-infra
pnpm migrate
umask 077
openssl rand -base64 18 > /tmp/reflow-admin-password
pnpm setup -- --email admin@example.com --name Admin --password-file /tmp/reflow-admin-password

Start three host processes (keep each terminal open):

pnpm dev              # API :3000
pnpm dev:worker       # Temporal worker
pnpm dev:dispatcher   # Outbox / webhook side work

Local ports:

Stop infra with make dev-infra-down.

For production Compose with TLS, see docs/DEPLOYMENT.md.

2. Sign in

pnpm build
pnpm link --global   # once, so `reflow` is on your PATH

export REFLOW_URL=http://localhost:3000
reflow auth login --email admin@example.com --password-file /tmp/reflow-admin-password
reflow workspace use
rm /tmp/reflow-admin-password

Your session is stored under ~/.config/reflow/. Later accounts need an admin (account.create). Open signup stays off unless ALLOW_REGISTRATION=true.

3. Send email (Resend)

Put your key in .env.local (do not commit it):

printf '%s\n' 'RESEND_API_KEY=re_...' >> .env.local
chmod 600 .env.local

Add to .env.local:

RESEND_API_KEY=re_...
REFLOW_FROM="Reflow <onboarding@resend.dev>"

Restart pnpm dev and pnpm dev:worker so they reload the key.

With Resend’s test sender (onboarding@resend.dev), you can only send to the email on your Resend account. Use a verified domain for other recipients. See the complete Resend setup guide for domain verification, webhooks, and safe test addresses.

4. Email templates (React Email)

Author .tsx locally. The CLI renders with react-email render and uploads HTML + plain text. The API/worker never execute TSX; they only interpolate {{contact.*}} / {{variables.*}} at send time. Local templates can import whatever you need.

reflow template init                 # creates emails/welcome.tsx
reflow template preview              # React Email viewer on :3030
reflow template push emails/welcome.tsx \
  --name Welcome \
  --subject "Welcome, {{contact.firstName}}"
# Re-running with the same --name revises the draft and publishes a new version (no duplicate rows).
reflow template list

React Email 6 needs both react-email (components + CLI) and @react-email/ui (preview app) in the project that owns emails/. This repo already lists them. In another project, install matching versions (pnpm add react-email@6.9.5 @react-email/ui@6.9.5). Saying yes to the preview prompt only installs @react-email/ui; templates still import from react-email.

Add Component.PreviewProps on each template so template preview has sample data. push renders locally, creates + publishes, and prints templateVersionId. Pin that id on each email.send node.

workflow.validate / workflow.publish fail with TEMPLATE_REFERENCE_INVALID (plus hint + details.nextSteps) if a node points at a missing template. template.archive fails with TEMPLATE_IN_USE while any workflow draft or published version still pins it, and archived templates cannot be republished.

5. First project: welcome + nudge

Follow examples/welcome-nudge/README.md:

1. reflow template preview / reflow template push for the two .tsx emails

2. Pin the version ids in workflow.template.json

3. workflow.validate → workflow.create → workflow.publish

4. contact.upsert → enrollment.create

6. Day-to-day commands

reflow call system.capabilities
reflow call workflow.actions
reflow template list
reflow call workflow.list --input '{"workspaceId":"YOUR_WORKSPACE_ID"}'
reflow call message.list --input '{"workspaceId":"YOUR_WORKSPACE_ID"}'

MCP clients talk to http://localhost:3000/mcp with a session token or API key. Cursor can use .cursor/mcp.json.

Mental model

Installed actions today: email.send, contact.update. See docs/OPERATIONS.md.

Checks

make check

Docs