Cold Email

MachFive - AI Cold Email Generator

Generate personalized cold email sequences from lead data. MachFive uses AI to research prospects and craft unique, relevant outreach - not templates.

Setup

1. Get your API key at https://app.machfive.io/settings (Integrations → API Keys)
2. Set MACHFIVE_API_KEY in your environment

Campaign ID

Every generate request needs a campaign ID in the URL: /api/v1/campaigns/{campaign_id}/generate (or /generate-batch).

• If the user has not provided a campaign name or ID: Call GET /api/v1/campaigns (see below) to list campaigns in their workspace, then ask them to pick one by name or ID before running generate.
• Where to get it manually: https://app.machfive.io/campaigns → open a campaign → copy the ID from the URL or settings.
• No default: The skill does not assume a campaign. The user (or agent config) must provide one. Agents can store a default campaign ID for the workspace if the user provides it (e.g. "use campaign X for my requests").

Endpoints

List Campaigns (discover before generate)

List campaigns in the workspace so the agent can ask the user which campaign to use when they haven't provided a name or ID.

GET https://app.machfive.io/api/v1/campaigns
Authorization: Bearer {MACHFIVE_API_KEY}

Or use X-API-Key: {MACHFIVE_API_KEY} header.

Optional query: ?q=search or ?name=search to filter by campaign name.

Response (200):

{
  "campaigns": [
    { "id": "cb1bbb14-e576-4d8f-a8f3-6fa929076fd8", "name": "SaaS Q1 Outreach", "created_at": "2025-01-15T12:00:00Z" },
    { "id": "a1b2c3d4-...", "name": "Enterprise Leads", "created_at": "2025-01-10T08:00:00Z" }
  ]
}

If no campaign name or ID was given, call this first, then ask the user: "Which campaign should I use? [list names/IDs]."

Single Lead (Sync)

Generate an email sequence for one lead (3–5 emails per lead). Waits for completion, returns the sequence directly. The request can take 3–5 minutes (AI research + generation); use a client timeout of at least 300 seconds (5 min) or 600 seconds (10 min). Do not use a 120s timeout or the response will be cut off.

POST https://app.machfive.io/api/v1/campaigns/{campaign_id}/generate
Authorization: Bearer {MACHFIVE_API_KEY}
Content-Type: application/json

Or use X-API-Key: {MACHFIVE_API_KEY} header.

{
  "lead": {
    "name": "John Smith",
    "title": "VP of Marketing",
    "company": "Acme Corp",
    "email": "john@acme.com",
    "company_website": "https://acme.com",
    "linkedin_url": "https://linkedin.com/in/johnsmith"
  },
  "options": {
    "list_name": "Q1 Outreach",
    "email_count": 3,
    "email_signature": "Best,\nYour Name",
    "approved_ctas": ["Direct Meeting CTA", "Lead Magnet CTA"]
  }
}

Response (200):

{
  "lead_id": "lead_xyz789",
  "list_id": "uuid",
  "sequence": [
    { "step": 1, "subject": "...", "body": "..." },
    { "step": 2, "subject": "...", "body": "..." },
    { "step": 3, "subject": "...", "body": "..." }
  ],
  "credits_remaining": 94
}

Recovery: The response includes list_id. If the request times out or the response is truncated, you can still get the result: call GET /api/v1/lists/{listid} to confirm status, then GET /api/v1/lists/{listid}/export?format=json to retrieve the sequence.

Batch (Async)

Generate email sequences for multiple leads (one list; each lead gets a sequence). Returns immediately (202) with list_id; processing runs in the background. To get results: poll list status, then call export.

POST https://app.machfive.io/api/v1/campaigns/{campaign_id}/generate-batch
Authorization: Bearer {MACHFIVE_API_KEY}
Content-Type: application/json

Or use X-API-Key: {MACHFIVE_API_KEY} header.

{
  "leads": [
    { "name": "John Smith", "email": "john@acme.com", "company": "Acme Corp", "title": "VP Marketing" },
    { "name": "Jane Doe", "email": "jane@beta.com", "company": "Beta Inc", "title": "Director Sales" }
  ],
  "options": {
    "list_name": "Q1 Outreach Batch",
    "email_count": 3
  }
}

Response (202):

{
  "list_id": "uuid",
  "status": "processing",
  "leads_count": 2,
  "message": "Batch accepted. Poll list status or open in UI."
}

List lead lists

List lead lists in the workspace. Optional query: campaign_id, status (pending | processing | completed | failed), limit (default 50, max 100), offset.

GET https://app.machfive.io/api/v1/lists
GET https://app.machfive.io/api/v1/lists?campaign_id={campaign_id}&status=completed&limit=20
Authorization: Bearer {MACHFIVE_API_KEY}

Response (200): { "lists": [ { "id", "campaign_id", "custom_name", "processing_status", "created_at", "completed_at" }, ... ] }. Order is created_at desc.

List status (poll)

Poll until the list is done. Use the list_id from generate or generate-batch.

GET https://app.machfive.io/api/v1/lists/{list_id}
Authorization: Bearer {MACHFIVE_API_KEY}

Response (200): id, campaign_id, custom_name, processing_status (pending | processing | completed | failed), created_at, updated_at. When processing_status === 'completed': leads_count, emails_created, completed_at. When failed: failed_at. 404 if list not found or not in workspace.

Poll every 10–30 seconds until processing_status === 'completed' or failed. If failed, the list cannot be exported; retry by submitting a new batch.

List export (get results)

After status is completed, fetch the processed output. CSV (default) or JSON.

GET https://app.machfive.io/api/v1/lists/{list_id}/export?format=csv
GET https://app.machfive.io/api/v1/lists/{list_id}/export?format=json
Authorization: Bearer {MACHFIVE_API_KEY}

• format=csv (default): Returns the processed CSV (same as UI download), with Content-Disposition: attachment; filename="MachFive-{list_id}.csv".
• format=json: Returns { "leads": [ { "email": "...", "sequence": [ { "step": 1, "subject": "...", "body": "..." }, ... ] }, ... ] }. Each lead may include optional name, company, title when present, e.g. { "email": "john@acme.com", "name": "John Smith", "company": "Acme Corp", "title": "VP Marketing", "sequence": [ ... ] }.
• 409 if list is not yet completed (poll GET /lists/:id first). 404 if list not found or not in workspace.

Batch flow: POST generate-batch → 202 + list_id → poll GET /lists/:id until processing_status === 'completed' → GET /lists/:id/export?format=csv or json → return result to user.

Lead Fields

Each lead must include a valid email; it is used to map the lead through processing and to match generated sequences back to the lead in exports (same as the app UI). All other fields are optional but improve personalization.

| Field | Required | Description | |-------|----------|-------------| | email | Yes | Lead's email address; used to map the lead through processing and in exports | | name | No | Full name or first name (improves personalization) | | company | No | Company name (improves personalization) | | title | No | Job title (improves personalization) | | company_website | No | Company URL for research | | linkedin_url | No | LinkedIn profile for deeper personalization |

Options

| Option | Type | Default | Description | |--------|------|---------|-------------| | list_name | string | Auto | Display name for this list in MachFive UI | | email_count | number | 3 | Emails per lead (1-5) | | email_signature | string | None | Signature appended to emails | | campaign_angle | string | None | Context for personalization | | approved_ctas | array | From campaign | CTAs to use (omit to use campaign defaults) |

Limits

• Single lead (sync): Request can take 5–10 minutes; use a client timeout of at least 300s (5 min) or 600s (10 min).
• Batch (async): Returns 202 immediately; poll GET /api/v1/lists/{list_id} every 10–30s until processing_status is completed or failed. Workspaces have a concurrent batch limit; if you get 429, retry later.
• List lists: Query param limit default 50, max 100; offset for pagination.

Errors

| Code | Error | Description | |------|-------|-------------| | 400 | BADREQUEST | Invalid JSON, missing lead/leads, or missing/invalid lead email; or campaign has no vector store | | 401 | UNAUTHORIZED | Invalid or missing API key | | 402 | INSUFFICIENTCREDITS | Out of credits | | 403 | FORBIDDEN | Campaign not in your workspace | | 404 | NOTFOUND | Campaign or list doesn't exist | | 409 | NOTREADY | Export called before list completed (poll GET /lists/:id first) | | 429 | WORKSPACE_LIMIT | Too many concurrent batch jobs; try again later |

Usage Examples

"Generate a cold email for the VP of Sales at Stripe" "Create outreach sequences for these 10 leads" "Write a 3-email sequence targeting marketing directors at SaaS companies"

Pricing

• Free: 100 credits/month
• Starter: 2,000 credits/month
• Growth: 5,000 credits/month
• Enterprise: Custom credits/month
• 1 credit = 1 lead processed

Get started: https://machfive.io

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Bluecraft-AI
• Source: Bluecraft-AI/machfive-skills
• License: MIT
• Homepage: https://machfive.io

Install and usage instructions live in the source repository linked above.