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io.github.spruikco/send16-mcp

NPM · SEND16-MCP · 2 COMPONENTS · SCANNED SEP 21

Email for AI agents: send mail, manage contacts, automations & webhooks. Zero-DNS first send.

0 this week 82 Trust /100
Trust breakdown (7 categories)

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. How we score → Why this is hard to score →

Supply Chain Security98
  • No malware found by supply-chain analysis.Pass
  • No known CVEs affecting this package version or its production dependencies.Pass
  • No install/post-install scripts declared.Pass
  • 31 of 95 dependencies flagged as unhealthy. View diagnostics → Partial
Provenance & Transparency45
Schema Quality & AI Usability81
  • AI-judged instruction clarity (excellent).Pass
  • Tool/resource definitions use about 6302 tokens (~79/item across 79 items; 79 tools + 0 resources), lean.Pass
  • Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management93
  • Stability observed for 28 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage95
  • 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
  • 84% of tool parameters carry a description.Partial
Tool Safety75
  • No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
  • 0 of 14 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation; "send_email" implies "send" and declares no destructiveHint at all, which the MCP spec reads as destructive by default. See how to fix → Fail
  • An AI judge read all 79 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
  • Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Install

How do I install the io.github.spruikco/send16-mcp server?

io.github.spruikco/send16-mcp runs locally as an npm package, launched with npx -y send16-mcp. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

npm · send16-mcp

# add to Claude Code
claude mcp add spruikco-send16-mcp -- npx -y send16-mcp
// .cursor/mcp.json
{
  "mcpServers": {
    "spruikco-send16-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "send16-mcp"
      ]
    }
  }
}
// .vscode/mcp.json
{
  "servers": {
    "spruikco-send16-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "send16-mcp"
      ]
    }
  }
}
# add to Codex CLI
codex mcp add spruikco-send16-mcp -- npx -y send16-mcp
// opencode.json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "spruikco-send16-mcp": {
      "type": "local",
      "command": [
        "npx",
        "-y",
        "send16-mcp"
      ],
      "enabled": true
    }
  }
}
# add to OpenClaw
openclaw mcp add spruikco-send16-mcp --command npx --arg -y --arg send16-mcp
# ~/.hermes/config.yaml
mcp_servers:
  spruikco-send16-mcp:
    command: "npx"
    args: ["-y", "send16-mcp"]
// ~/.netclaw/config/netclaw.json
{
  "McpServers": {
    "spruikco-send16-mcp": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "send16-mcp"
      ]
    }
  }
}
# add to Vellum
assistant mcp add spruikco-send16-mcp -t stdio -c npx -a -y send16-mcp
// mcp.json
{
  "mcpServers": {
    "spruikco-send16-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "send16-mcp"
      ]
    }
  }
}
Changelog

Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.

  • 20 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 87 to 90. That category is still filling its 30-day observation window: 26 days of observed history at the previous scan, 27 at this one. The score rises as the window fills, whether or not the server changes.

  • 18 Sept 26 −2
    • Stability: pass → 0.83 functional
  • 17 Sept 26 0
    • Stability: 0.97 → pass security
  • 16 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 93 to 97. That category is still filling its 30-day observation window: 28 days of observed history at the previous scan, 29 at this one. The score rises as the window fills, whether or not the server changes.

  • 14 Sept 26 +1
    • Security disclosure: unverified → fail functional
  • 13 Sept 26 0
    • Security disclosure: fail → unverified functional
  • 12 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 80 to 83. That category is still filling its 30-day observation window: 24 days of observed history at the previous scan, 25 at this one. The score rises as the window fills, whether or not the server changes.

  • 11 Sept 26 0
    • Security disclosure: unverified → fail functional
Diagnostics

Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.

Captured 21 Sept 2026 · Analysed npm/send16-mcp@0.5.8

Provenance No attestation

The registry publishes no build provenance for this version, so there is nothing to verify.

Result No attestation
Ecosystem npm

Background: How many MCP packages publish verified provenance →

Dependencies 95 packages
Packages resolved 95
Stale 31
Tree resolution Complete

Background: SBOMs and build attestations, explained →

MCP tools · 79 exposed · ~6,302 tokens

The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →

Tool Tokens
list_topics ~70

List subscription topics. Topics are granular categories contacts can subscribe to (e.g. 'product-updates', 'weekly-digest'). Campaigns and automations can be gated to subscribers of a specific topic.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)

No output schema declared.

No examples provided.

list_webhooks ~56

List configured outgoing webhooks (your endpoints that Send16 POSTs delivery events to). Outgoing webhooks are a plan feature.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)

No output schema declared.

No examples provided.

list_workspaces ~44

List workspaces the authenticated user has access to (owner or member).

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)

No output schema declared.

No examples provided.

mark_convo_read ~51

Mark a conversation as read for the current viewer.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
convoIdstringyesConversation ID

No output schema declared.

No examples provided.

pause_automation ~56

Pause an automation. Existing enrollments freeze in place; no new contacts enroll.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
automationIdstringyesAutomation ID

No output schema declared.

No examples provided.

pause_campaign ~55

Pause a sending campaign. Already-sent messages are unaffected; remaining sends halt.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
campaignIdstringyesCampaign ID

No output schema declared.

No examples provided.

pre_send_review ~101

Run an AI pre-send review on an email's HTML before sending. Surfaces tone issues, broken links, missing alt text, spam triggers, and accessibility problems.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
audiencestringShort description of the audience (helps tone analysis)
htmlstringyesFull HTML body to review
subjectstringyesEmail subject line

No output schema declared.

No examples provided.

preview_campaign_recipients ~58

Preview the recipient set for a campaign before sending. Returns count + sample list.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
campaignIdstringyesCampaign ID

No output schema declared.

No examples provided.

preview_segment ~49

Preview the contacts that match a segment without sending.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
segmentIdstringyesSegment ID

No output schema declared.

No examples provided.

regenerate_webhook_secret ~60

Rotate the HMAC signing secret for an outgoing webhook endpoint. Returns the new secret once.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
webhookIdstringyesWebhook ID

No output schema declared.

No examples provided.

remove_contact_from_audience ~59

Remove a contact from an audience.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
audienceIdstringyesAudience ID
contactIdstringyesContact ID

No output schema declared.

No examples provided.

remove_suppression ~59

Remove an email from the suppression list. Use only when you've confirmed the recipient wants to receive mail again.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
emailstringyes

No output schema declared.

No examples provided.

render_email_content ~108

Compile an EmailContent JSON object (the shape used by the Send16 builder + templates) into HTML using the platform's authoritative renderer. Returns the exact HTML the API would send. Useful for previews and post-processing.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
contentobjectyesEmailContent JSON (from get_template or the builder)
variablesobjectVariable replacements (e.g. {firstName:'Alice'})

No output schema declared.

No examples provided.

resume_campaign ~44

Resume a paused campaign.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
campaignIdstringyesCampaign ID

No output schema declared.

No examples provided.

schedule_campaign ~99

Schedule (or send immediately) an existing draft campaign to an audience/segment/topic.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
audienceIdstring
campaignIdstringyesCampaign ID
scheduleAtstringISO-8601 future datetime; omit to send immediately
segmentIdstring
topicIdstring

No output schema declared.

No examples provided.

screener_decide ~83

Decide a pending screener conversation (first-time sender). 'allow' lets future emails through, 'reject' blocks, 'cold' marks as cold outreach.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
convoIdstringyesConversation ID
decisionstringyesScreener decision

No output schema declared.

No examples provided.

search_contacts ~90

Search contacts by email address or name. Returns matching contacts with their tags and subscription status.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
pageintegerPage number
pageSizeintegerResults per page (max 100)
querystringyesSearch query (matches against email, first name, last name)

No output schema declared.

No examples provided.

send_broadcast ~224

One-shot broadcast: create a campaign and immediately schedule it to send. Mirrors Resend's one-call broadcast API. Pass either an audienceId, segmentId, topicId, or fully-qualified filter. Provide html OR templateSlug.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
audienceIdstringSend to all contacts in this audience
fromEmailstringyesMust be a verified domain
fromNamestringyes
htmlstringFull HTML body (one of html/templateSlug required)
namestringyesInternal campaign name
previewTextstring
replyTostring
scheduleAtstringISO-8601 future datetime; omit to send immediately
segmentIdstringSend to all contacts matching this segment
subjectstringyes
templateSlugstringWorkspace template slug to use
topicIdstringSend to all subscribers of this topic

No output schema declared.

No examples provided.

send_campaign_test ~79

Send a test email for an existing campaign to preview how it will look in recipients' inboxes.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
campaignIdstringyesCampaign ID to send test for
testEmailstringyesEmail address to send the test to

No output schema declared.

No examples provided.

send_email ~275

Send a transactional email through Send16. Provide `html`, `text`, or both (text-only is fine for OTPs/receipts/alerts). `from_email` must belong to a domain that is verified in the workspace — call `whoami` for the account and `list_domains` to see which senders are allowed; a send from an unverified domain returns a clear error, not a silent failure. For a zero-setup first send, use from_email `onboarding@send16.com` — the sandbox sender delivers with no DNS, but only to your own account email.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
from_emailstringSender email address (must be from a verified domain)
from_namestringSender display name (e.g. "Acme Co")
htmlstringHTML body content
reply_tostringReply-to email address
subjectstringyesEmail subject line
templatestringTransactional template slug to use instead of inline content
textstringPlain text body content
toyesRecipient email address or array of addresses (max 50)
variablesobjectTemplate variables for merge tags

No output schema declared.

No examples provided.

send_event ~163

Fire a custom event for a contact. Automations whose trigger is `{type:'custom_event', eventName:'<name>'}` will enroll the contact and start running. Payload is exposed to condition steps as `event.<key>`.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
contactEmailstringContact email (provide either this or contactId)
contactIdstringContact UUID (provide either this or contactEmail)
namestringyesEvent name (e.g. 'trial_started', 'order.placed')
occurredAtstringISO-8601 timestamp; defaults to now
payloadobjectArbitrary JSON metadata available to automation conditions

No output schema declared.

No examples provided.

send_reply ~94

Reply to an inbox conversation. The reply is sent from the original recipient address (the alias the convo arrived on) and threaded back to the contact.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
convoIdstringyesConversation ID
htmlstringHTML body of the reply
textstringPlain text body of the reply

No output schema declared.

No examples provided.

update_action ~99

Update an Action (toggle enabled, change template, change event name).

NameTypeReqDescription
actionIdstringyesAction ID
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
delaySecondsinteger
enabledboolean
eventNamestring
namestring
sendOnceboolean
templateSlugstring

No output schema declared.

No examples provided.

update_brand ~128

Update workspace brand settings. The designSpec field is a Markdown DESIGN.md document fed into AI generation system prompts — use it to encode voice, do/don't lists, and visual rules.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
designSpecstringMarkdown DESIGN.md spec for AI generation
fontFamilystring
logoUrlstring
primaryColorstringHex color (e.g. '#4F46E5')
secondaryColorstringHex color

No output schema declared.

No examples provided.

update_campaign ~109

Update a draft campaign's content, subject, preview text, or sender info.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
campaignIdstringyesCampaign ID
fromEmailstring
fromNamestring
htmlstring
previewTextstring
replyTostring
subjectstring
templateSlugstring

No output schema declared.

No examples provided.

update_contact ~84

Update a contact's profile fields, custom fields, or subscription state.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
contactIdstringyesContact ID
customFieldsobject
firstNamestring
lastNamestring
subscribedboolean

No output schema declared.

No examples provided.

update_convo ~100

Update conversation state (open/closed/snoozed/spam/trash), star, or assignee.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
assigneeIdstring|nullWorkspace member ID, or null to unassign
convoIdstringyesConversation ID
starredbooleanStar/unstar
statestringNew state

No output schema declared.

No examples provided.

update_topic ~72

Update a subscription topic (name, description, default).

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)
descriptionstring
isDefaultboolean
namestring
topicIdstringyesTopic ID

No output schema declared.

No examples provided.

whoami ~78

Verify the API key and return the authenticated workspace: name, plan, email quota (used/limit), and owner. Call this first to confirm the key works before sending. Pair with list_domains to see which `from` addresses are allowed.

NameTypeReqDescription
apiKeystringSend16 API key (overrides SEND16_API_KEY env var)

No output schema declared.

No examples provided.

Common questions

What is the io.github.spruikco/send16-mcp server?

io.github.spruikco/send16-mcp is listed in the public MCP registry as io.github.spruikco/send16-mcp. Email for AI agents: send mail, manage contacts, automations & webhooks. Zero-DNS first send. This page covers its npm package (send16-mcp).

Is the io.github.spruikco/send16-mcp server safe to use?

io.github.spruikco/send16-mcp scores 82 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 21 September 2026. It declares no install or post-install scripts. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

What tools does the io.github.spruikco/send16-mcp server expose?

io.github.spruikco/send16-mcp exposes 79 tools: whoami, send_email, send_campaign_test, create_campaign, design_email_template, and 74 more. Their descriptions and schemas cost roughly 6,302 tokens of context every time the server is loaded.

Is the io.github.spruikco/send16-mcp server still maintained?

io.github.spruikco/send16-mcp is still listed as active in the MCP registry. We last reached this channel on 21 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

What licence is the io.github.spruikco/send16-mcp server under?

io.github.spruikco/send16-mcp declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.