Resend CLI

1. choose the right Resend primitive,
2. choose the right CLI command,
3. run it in a deterministic non-interactive way,
4. detect the important CLI coverage gaps before it gets stuck, and
5. fall back to MCP/API only when the CLI genuinely does not cover the job.

Start here

• references/agent-operating-model.md

  — the default decision process for live Resend work

• references/install-auth-and-profiles.md

  — install methods, auth priority, profiles, config paths

• references/subprocess-contract.md

  — how agents should invoke

  resend

  safely and parse output

• references/command-selection.md

  — fast routing from user intent to the right command(s)

• references/sending-scheduling-and-batch.md

  — transactional sends, schedules, tags, attachments, batch limits

• references/domains-dns-and-deliverability.md

  — domain creation, verification, receiving, TLS, tracking, 403/domain mismatch

• references/webhooks-and-listeners.md

  — webhook creation, update, signature handling, temporary local listeners

• references/inbound-receiving-and-threading.md

  — inbound list/get/attachments/forward/listen flows

• references/contacts-topics-segments-and-broadcasts.md

  — subscription modelling, targeting, campaigns

• references/templates-and-coverage-gaps.md

  — template lifecycle and the important current CLI gaps

• references/diagnostics-and-fallbacks.md

  — debug order, CLI quirks, when to fall back to MCP/API

• references/recipes.md

  — short end-to-end playbooks

• references/sources.md

  — first-party source manifest and refresh notes

• assets/command-catalog.json

  — command index with detail levels (

  source_inspected

  ,

  readme_confirmed

  ,

  tree_confirmed

  )

• assets/task-router.json

  — route common tasks to command sequences

• assets/error-map.json

  — fast-fail diagnosis hints

• assets/coverage-gaps.json

  — current CLI limitations and ambiguities that matter to agents

• assets/subprocess-contract.json

  — deterministic invocation defaults

• assets/scaffold-index.json

  — reusable command/file scaffolds

• assets/source-manifest.json

  — authoritative URLs used to build this skill

• scripts/resend_cli.py

  — agent wrapper for probing, routing, scaffolding, batch linting, diagnosis, and safe subprocess execution

Core operating rules

1) Prefer the official CLI for live Resend work

1. Official Resend CLI for live terminal/CI/agent operations
2. Official Resend MCP server if the environment already exposes it and the CLI is unavailable
3. Official SDK when editing app code inside an existing integration
4. Raw REST only for stack-neutral examples, protocol debugging, or feature gaps

2) For agents, stay non-interactive by default

• pass all required flags explicitly
• use global

  --json -q

• prefer

  RESEND_API_KEY

  or a stored profile over typing secrets interactively
• set

  RESEND_NO_UPDATE_NOTIFIER=1

  for deterministic output
• capture both stdout and stderr defensively

3) Run

doctor

early when the environment is unknown

resend --json -q doctor

• CLI availability/version
• whether an API key is being resolved
• whether verified domains exist
• whether the machine looks like an AI-agent environment

4) Choose the primitive before the command

• One logical transactional email →

  emails send

• Up to 100 distinct transactional emails in one request →

  emails batch

• Scheduled transactional email mutation →

  emails update

  /

  emails cancel

• Campaign to a segment →

  broadcasts create

  /

  broadcasts send

• Reusable hosted content →

  templates *

• Sender or receiving setup →

  domains *

• Inbound processing →

  emails receiving *

  +

  webhooks *

• Scoped credentials →

  api-keys *

• Recipient data and preferences →

  contacts

  ,

  contact-properties

  ,

  topics

  ,

  segments

• Local dev event loop →

  webhooks listen

  or

  emails receiving listen

5) Know the current CLI gaps

• Template send gap: the CLI manages templates, but the current

  emails send

  command surface does not expose a direct

  --template-id

  /template-vars flow.
• Domain capability update gap:

  domains update

  exposes TLS/open/click tracking, but not an explicit sending/receiving capability toggle, while inbound help text references such a toggle.
• Stream commands are special:

  webhooks listen

  and

  emails receiving listen

  are long-running and should be treated as NDJSON/event streams in agent mode.
• JSON error channel discrepancy: the README promises machine JSON on stdout only, but the current source writes JSON errors with

  console.error

  , so wrappers must parse stderr too.

6) Keep IDs and file paths

• domain IDs
• email IDs
• webhook IDs
• topic IDs
• segment IDs
• template IDs/aliases
• API key IDs
• the file paths it generated for HTML or batch JSON

The mutation ladder

1. classify the task
2. confirm the command sequence
3. make any needed file assets (

   .html

   , batch JSON)
4. run with

   --json -q

5. verify with

   get

   ,

   list

   , or a follow-up check
6. persist returned IDs and next-step context
7. only then continue to the next mutation

Bundled helper script

scripts/resend_cli.py

• probe

  — find the CLI, report install hints, and show environment basics

• catalog

  — list known commands from the bundled catalogue

• info

  — inspect one command and its notes/gaps

• recommend

  — route a free-text task to the best CLI sequence

• scaffold

  — print or materialise sample commands/files

• lint-batch

  — statically validate an

  emails batch

  JSON file

• doctor

  — explain likely causes of common CLI/API failures

• run

  — execute the official CLI with deterministic defaults and tolerant JSON parsing

python3 scripts/resend_cli.py probe
python3 scripts/resend_cli.py catalog --resource emails
python3 scripts/resend_cli.py info "emails send"
python3 scripts/resend_cli.py recommend "send 70 different shipment notifications"
python3 scripts/resend_cli.py scaffold batch-send --write-dir ./tmp
python3 scripts/resend_cli.py lint-batch ./tmp/batch-emails.json
python3 scripts/resend_cli.py doctor --command "emails send" --status 403 --message "1010 forbidden"
python3 scripts/resend_cli.py run -- emails list --limit 5

Response shape this skill should produce

1. the exact Resend primitive,
2. the exact CLI command or command sequence,
3. any file scaffolding the user needs,
4. the operational caveats that matter here,
5. the verification step,
6. the fallback path if the CLI does not currently cover the flow.

Example prompts this skill should handle

• “Use the Resend CLI to send a scheduled password reset email”
• “Should I use

  emails send

  ,

  emails batch

  , or

  broadcasts create

  ?”
• “Create a sending + receiving domain in

  eu-west-1

  ”
• “Set up local webhook listening with ngrok”
• “Why is my batch file failing?”
• “How do I manage multiple Resend accounts from one agent?”
• “Can the CLI send a hosted template directly?”
• “How should my agent parse

  resend

  output safely?”