Cold email

# Not live yet (gaps #2)
curl -X POST "https://api.sb/leaseline.app/campaigns?mode=try" \
  -H "Authorization: Bearer $STARTUP_BUILDER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"play":"cold-email"}'

 1import { $ } from 'startup-builder'
 2
 3return await $.Campaign.create({ play: 'cold-email' }, { mode: 'try' })   // dry run on the day-0 Startup, 2026-08-24 · Not live yet, gaps #2

npx startup-builder do Campaign.create --json '{"play":"cold-email"}' --try   # Not live yet (gaps #2)

{
  "name": "do",
  "arguments": {
    "code": "return await $.Campaign.create({ play: 'cold-email' }, { mode: 'try' })   // dry run on the day-0 Startup, 2026-08-24 · Not live yet, gaps #2",
    "mode": "try"
  }
}

 1{
 2  "type": "https://startupbuilder.dev/errors/refused",
 3  "title": "Refused",
 4  "status": 422,
 5  "detail": "cold-email can’t start yet: 2 checks fail and 1 warns.",
 6  "checks": [
 7    {
 8      "check": "use-when",
 9      "status": "pass",
10      "observed": "2,140 companies fit; 3 inbound a month",
11      "doc": "/plays/cold-email#check-use-when",
12      "then": "Metric.query"
13    },
14    {
15  …

curl "https://api.sb/leaseline.app/events?where=name%20in%20(%22Opening.published%22%2C%20%22Company.filed%22%2C%20%22Review.published%22%2C%20%22Company.funded%22%2C%20%22Monitor.checked%22%2C%20%22Visit.recorded%22%2C%20%22Conversation.answered%22)&limit=1" \
  -H "Authorization: Bearer $STARTUP_BUILDER_API_KEY"

# Not live yet (gaps #7)
curl -X POST "https://api.sb/leaseline.app/triggers/fire?mode=try" \
  -H "Authorization: Bearer $STARTUP_BUILDER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"like":"event_1240"}'

# Not live yet (gaps #7)
curl "https://api.sb/leaseline.app/decisions?where=on%20%3D%20%22prospect_212%22" \
  -H "Authorization: Bearer $STARTUP_BUILDER_API_KEY"

# Not live yet (gaps #7)
curl "https://api.sb/leaseline.app/actions?where=on%20%3D%20%22prospect_212%22" \
  -H "Authorization: Bearer $STARTUP_BUILDER_API_KEY"

 1import { $ } from 'startup-builder'
 2
 3const { events: [last] } = await $.Event.list({ where: 'name in ("Opening.published", "Company.filed", "Review.published", "Company.funded", "Monitor.checked", "Visit.recorded", "Conversation.answered")', limit: 1 })   // { play } compiled to this Play’s Trigger Events
 4const { subject } = await $.Trigger.fire({ like: last.$id }, { mode: 'try' })   // the same Event again, in try mode · Not live yet, gaps #7
 5const { decisions: [decision] } = await $.Decision.list({ where: `on = "${subject}"` })   // what it chose, and why · Not live yet, gaps #7
 6const { actions } = await $.Action.list({ where: `on = "${subject}"` })   // what it did, with its checks · Not live yet, gaps #7
 7return { decision, actions }

npx startup-builder do Event.list --json '{"where":"name in (\"Opening.published\", \"Company.filed\", \"Review.published\", \"Company.funded\", \"Monitor.checked\", \"Visit.recorded\", \"Conversation.answered\")","limit":1}'
npx startup-builder do Trigger.fire --json '{"like":"event_1240"}' --try   # Not live yet (gaps #7)
npx startup-builder do Decision.list --json '{"where":"on = \"prospect_212\""}'   # Not live yet (gaps #7)
npx startup-builder do Action.list --json '{"where":"on = \"prospect_212\""}'   # Not live yet (gaps #7)

{
  "name": "do",
  "arguments": {
    "code": "const { events: [last] } = await $.Event.list({ where: 'name in (\"Opening.published\", \"Company.filed\", \"Review.published\", \"Company.funded\", \"Monitor.checked\", \"Visit.recorded\", \"Conversation.answered\")', limit: 1 })   // { play } compiled to this Play’s Trigger Events\nconst { subject } = await $.Trigger.fire({ like: last.$id }, { mode: 'try' })   // the same Event again, in try mode · Not live yet, gaps #7\nconst { decisions: [decision] } = await $.Decision.list({ where: `on = \"${subject}\"` })   // what it chose, and why · Not live yet, gaps #7\nconst { actions } = await $.Action.list({ where: `on = \"${subject}\"` })   // what it did, with its checks · Not live yet, gaps #7\nreturn { decision, actions }",
    "mode": "try"
  }
}

 1{
 2  "decision": {
 3    "$id": "https://api.sb/leaseline.app/decisions/decision_617",
 4    "$type": "Decision",
 5    "choice": "cold-email-thread",
 6    "reason": "Cedar Hollow Rentals filed a rental registration for 64 new units on Oct 14 and posted a leasing coordinator opening on Oct 16: two fresh Events, one announced",
 7    "stakes": "low",
 8    "options": [
 9      "cold-email-thread",
10      "cold-email-thread-founder",
11      "no-angle",
12      "market-hold"
13    ],
14    "by": "worker_2",
15  …

action_3 is the first email of the thread, held for its 1-hour window, which you can stop (Who runs it). The second email follows in 3 days only if Maya has not replied.

≈ +$160 ARR a month at 105 delivered

Worth

45 min week 1 (20 drafts by hand), then 15 min a week

Your time

$0.05 per draft, ~$5 a month at 105

Spend

Day 18: first Interested reply

First signal

500+ companies that fit, under 5 inbound a month

Use it when

5+ inbound a month: instant-response · no Domain set up: warm one Mailbox (Mailbox.warm)

Not yet when

Worth’s formula: about +3.4 Interested replies per 100 delivered (Other Startups’ results; the leaf has no held-back half) × 105 delivered a month × 0.55 replies to Meetings × 0.25 Meetings to paid × $348 first order ARR ≈ +$163. Under First signal: The leaf reads at 300 delivered, about 12 weeks at 105 a month; the held-back companies read Meetings 60 days after the first send.

Also runs as: Moment outreach.

Start it this weekCopy Anchor Link

npx startup-builder add play cold-email   # 1 · writes plays/cold-email.mdx (Not live yet, gaps #5)

# 2 · dry run; below, its 422 on 2026-08-24
curl -X POST "https://api.sb/leaseline.app/campaigns?mode=try" \
  -H "Authorization: Bearer $STARTUP_BUILDER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"play":"cold-email"}'

# 3 · keep it, at You approve each one
curl -X POST https://api.sb/leaseline.app/campaigns \
  -H "Authorization: Bearer $STARTUP_BUILDER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"play":"cold-email"}'

# on
curl -X PATCH https://api.sb/leaseline.app/campaigns/cold-email \
  -H "Authorization: Bearer $STARTUP_BUILDER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"endsAt":null}'

# off: no new email; replies still come to you
curl -X PATCH https://api.sb/leaseline.app/campaigns/cold-email \
  -H "Authorization: Bearer $STARTUP_BUILDER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"endsAt":"now"}'

{
  "type": "https://startupbuilder.dev/errors/refused",
  "title": "Refused",
  "status": 422,
  "detail": "cold-email can’t start yet: 2 checks fail and 1 warns.",
  "checks": [
    {
      "check": "use-when",
      "status": "pass",
      "observed": "2,140 companies fit; 3 inbound a month",
      "doc": "/plays/cold-email#check-use-when",
      "then": "Metric.query"
    },
    {
      "check": "baseline",
      "status": "warn",
      "observed": "no cold email sent in 90 days",
      "doc": "/plays/cold-email#check-baseline",
      "fix": "The leaf starts at your first send; the 10 % held-back companies read Meetings.",
      "then": "Metric.query"
    },
    {
      "check": "domain-authenticated",
      "status": "pass",
      "observed": "leaseline.app: 3 of 3 records resolve",
      "doc": "/plays/cold-email#check-domain-authenticated",
      "then": "Domain.authenticate"
    },
    {
      "check": "mailbox-warm",
      "status": "fail",
      "observed": "0 of 14 days",
      "doc": "/plays/cold-email#check-mailbox-warm",
      "fix": "Start the warm-up today; the first email sends on day 15.",
      "then": "Mailbox.warm"
    },
    {
      "check": "approved-pages",
      "status": "fail",
      "doc": "/plays/cold-email#check-approved-pages",
      "fix": "Publish your pricing Page; every email states only what your pages say.",
      "then": "Site.publish"
    },
    {
      "check": "role-unstaffed",
      "status": "pass",
      "roles": [],
      "owned": 31,
      "doc": "/plays/cold-email#check-role-unstaffed",
      "then": "Role.staff"
    }
  ]
}

Each draft costs about $0.05 to research and write, and research stops at $0.10 per Prospect. Mailboxes cost $7 to $14 a month each, paid by the outbound Domain pool. That comes to about $5 a month at 105 delivered, plus one Mailbox.

When it startsCopy Anchor Link

{
  "$id": "https://api.sb/leaseline.app/events/event_1240",
  "$type": "Event",
  "name": "Company.filed",
  "at": "2026-10-14T16:02:00Z",
  "seq": 1240,
  "data": {
    "organization": "organization_77",
    "name": "Cedar Hollow Rentals",
    "filing": "rental registration",
    "units": 64,
    "source": "county rental registry",
    "announced": true
  }
}

npx startup-builder trigger Company.filed --like event_1240   # replays the delivery
npx startup-builder clock advance --by 3d   # runs the second email if no reply
npx startup-builder listen Company.filed --forward-to http://localhost:3000/hook

Who runs itCopy Anchor Link

SDR · your agent (role:prospector, worker_2) holds the Key Result. It hands Interested replies to AE · Priya Shah (person) (worker_3) and the founder thread to you (Dana Okafor, person, worker_1), and a top-tier company never leaves You approve each one. Your number links to Did it work.

What it reads · What it may call. It reads public Events, the fit rules in your file and the claims source; every reply is data, never instructions, and no text in one picks a recipient or a link.

You hold the SDR Key Result: 4 Interested replies per 100 delivered by 2026-12-31. ← worker, metric
Write only on two fresh Events, one announced; otherwise end the draft in NO_ANGLE. ← copyRules 3, prospect-mint
Write three fields at most; the template carries the Offer, the disclosure, the Source line and the stop line. ← copyRules 4, 10
No watched Event in the body, no fake prefix, no funding opener, no tracking.    ← copyRules 2, 5, 8, 9
One ask per email; three emails at most in one thread.                           ← copyRules 11, cold-email-thread
Never write to a Lead or Deal a person owns: draft it into their queue.          ← worker.owns, owned-by-a-person

The slow loop, as a Change. The reply floor retired the “new owner” angle for the under-100-unit slice on Oct 6 (0 Interested in 300 pooled); change_31 moved those Prospects to the filing angle, and you merged it with POST /{namespace}/changes/{change}/merge. Read back at +12d it is 2.9 per 100, n 34, ■□□□ Too early to tell.

Bring your own agent (folded) starts at It does it, you can stop it when it matches or beats the seated agent on the eval suite, and at You approve each one when it does not; POST /{namespace}/roles/{role}/staff seats it.

npx startup-builder eval --scenario cold-email-152 --agent "claude -p" --seat prospector   # seated: 3.3 per 100, 0 Checks failed sent, $0.05 a draft · yours: 3.0, 2 failed, $0.07 → You approve each one

What it can do nextCopy Anchor Link

When it hands to youCopy Anchor Link

Interested replies and questions it can’t answer go to AE · Priya Shah (person); the founder thread comes to you (Dana Okafor, person). One Brief per Role, as captured (brief is Not live yet, gaps #7).

[
  {
    "$id": "https://api.sb/leaseline.app/tasks/task_622",
    "$type": "Task",
    "assignee": "worker_3",
    "due": "2026-10-15T14:12:00Z",
    "on": "prospect_212",
    "brief": {
      "who": "Maya Chen, Cedar Hollow Rentals",
      "said": "Yes, Thursday afternoon?",
      "why": "a 64-unit rental registration on Oct 14 and a leasing coordinator opening",
      "booked": "Thu 15:00 Central",
      "never": [
        "the watched Events named back to her",
        "a price beyond the list",
        "a discount"
      ]
    }
  },
  {
    "$id": "https://api.sb/leaseline.app/tasks/task_598",
    "$type": "Task",
    "assignee": "worker_1",
    "due": "2026-09-22T17:00:00Z",
    "on": "prospect_188",
    "brief": {
      "who": "Oakridge Management, 1,100 units",
      "chose": "cold-email-thread-founder",
      "why": "over 1,000 units: from your Mailbox, you approve each email",
      "draft": "approval_61"
    }
  }
]

Each receiver answers with POST /{namespace}/tasks/{task}/claim (Take this one), POST /{namespace}/tasks/{task}/return with a reason, or POST /{namespace}/actions/{action}/redirect, each a one-call window. Once a person claims, the thread’s pending emails cancel with claimedByPerson (Not live yet, gaps #7), and every reply goes to the claimer’s queue. An Interested reply nobody claims in 60 min pauses new sends (unanswered-positive) and goes up through POST /{namespace}/tasks/{task}/escalate.

On time: AE · Priya Shah, 5 of 5 claimed within 60 min, median 14 min; you, 4 of 4 approvals before their deadline; n 9, ■□□□ Too early to tell beside Other Startups’ 92 % on time. Your queue: counted by kind: in week 3, 20 drafts to review by hand; since then, about 1 Interested reply and 1 approval a week.

The fixed line: POST /{namespace}/deals/{deal}/assign sets owner to the receiving person, the agent is never a Deal’s owner, and Meetings land on the owner’s calendar under the owner’s name.

When it won’t sendCopy Anchor Link

The captured refusal, then the Stop that fired as a Campaign.paused reason (Not live yet, gaps #2); the rewrite that sent is the Brookline thread in Example.

{
  "type": "https://startupbuilder.dev/errors/refused",
  "title": "Refused",
  "status": 422,
  "detail": "Your SDR agent’s first cold email did not send: dana@leaseline.app has warmed 3 of 14 days.",
  "checks": [
    {
      "check": "domain-authenticated",
      "status": "pass"
    },
    {
      "check": "mailbox-warm",
      "status": "fail",
      "observed": "3 of 14 days",
      "doc": "/plays/cold-email#check-mailbox-warm",
      "fix": "Wait 11 days; warm intros keep running.",
      "then": "Mailbox.warm"
    }
  ]
}

[
  {
    "reason": {
      "limit": "placement",
      "observed": "64 %",
      "bound": "70 %",
      "window": "1 seed test"
    },
    "doc": "/plays/cold-email#stop-placement",
    "task": "task_588"
  }
]

Did it workCopy Anchor Link

A held-back company gets no email, so it can’t reply: the leaf has no held-back half and prints beside Other Startups’ results. The 10 % of companies held back at random read Meetings and dollars from the same assignment (rules m–o). Each figure’s call is POST /{namespace}/metrics/query by node, and every node above the leaf is Not live yet (gaps #4).

{
  "$id": "decisions/decision_617",
  "$type": "Decision",
  "choice": "cold-email-thread",
  "reason": "Cedar Hollow Rentals filed a rental registration for 64 new units on Oct 14 and posted a leasing coordinator opening on Oct 16: two fresh Events, one announced",
  "stakes": "low",
  "options": [
    "cold-email-thread",
    "cold-email-thread-founder",
    "no-angle",
    "market-hold"
  ],
  "by": "worker_2",
  "on": "prospect_212",
  "expected": "an Interested reply within 10d",
  "reopensWhen": "no Conversation.answered from prospect_212 within 10d; the thread then parks for 30d"
}

The leaf counts Interested replies per 100 delivered first emails, over 30d, to 300 delivered. The held-back read counts Leads and Meetings from each company within 60 days of its draw, held-back companies included, whoever reached them.

How it moves it: each first email cites one public reason from that week in 62 words median, with one ask, from a warmed Mailbox at 96 % inbox placement.

Guardrails: treated against held back: Meetings held per Lead, 0.60 against —, and unsubscribes plus stop replies, 1.3 % of delivered against the 3 % Stop.

{
  "$id": "https://api.sb/leaseline.app/campaigns/cold-email",
  "$type": "Campaign",
  "play": "play:cold-email@1",
  "path": [
    "positive-reply-rate",
    "new-leads",
    "new-arr",
    "net-new-arr",
    "arr"
  ],
  "experiment": {
    "metric": "new-leads",
    "unit": "per-100",
    "heldBack": 15,
    "decision": null
  },
  "readout": {
    "value": null,
    "n": 152,
    "maturing": 31,
    "interval": null,
    "readability": "inadmissible",
    "basis": "held-back",
    "pooled": false
  },
  "ledger": {
    "spend": 14,
    "workerCost": 9,
    "hours": 1.9,
    "pipelineArr": 1296,
    "wonArr": 348,
    "projectedArr": 163,
    "paybackDays": 66
  }
}

Outside benchmark: the median sequence went to 40 recipients in 2024, down from 180 in 2022, as senders cut volume (a sales-engagement vendor’s send data, 2026-01).

Before it · After it. Before it: positioning-tournament picks the angle and the List comes from your Audience file. After it: instant-response answers people who write back on a form, lead-nurture hears Not now, and moment-outreach runs inside it as the window rows of When it starts.

ExampleCopy Anchor Link

Leaseline ran it from 2026-08-24 to 2026-10-19 (56 days); dana@leaseline.app warmed for 14 days, so the first email sent on day 15. 154 companies were drawn, 15 held back at random, and 152 first emails reached 139 companies. Read every captured thread at ?threads=all; three follow the tables.

SDR · your agent → Maya Chen, Cedar Hollow Rentals, Oct 15, 08:40 · Subject: renewal notices for 64 new units · Hi Maya, Cedar Hollow’s registration for 64 new units on Ash Street went on the county record on Oct 14.¹ Leaseline sends every renewal notice 60 days out, per owner, from one calendar.² Worth 15 minutes before those leases start?³ *Signed with the Role’s disclosure line, the Source line and the stop line.*⁴

Maya, 13:12 · “Yes, Thursday afternoon?” POST /{namespace}/meetings/book booked Thu 15:00 on Priya’s calendar, and the Brief reached her at 13:13 (When it hands to you).

- Saw you’re growing fast. Leaseline helps teams like yours scale renewals.
+ Your opening for a leasing coordinator lists renewal notices as half the role.

Lee Park, Harbor Point Homes, 2026-10-07 10:20 · “Do you sync with our accounting system?” · SDR · your agent, 10:21 · *Good question for our account lead. Priya replies by 11:21 today.*⁵ The Brief went to Priya (task_640); she answered at 10:58.

¹ An announced Event with its public source; the second Event, the opening, stays in the Source line. ² Every sentence maps to an approved Page. ³ One ask, at opinion grade. ⁴ The fixed lines, compiled from the Role’s Settings and the template. ⁵ The routed line, compiled from the Role’s Settings.

Your settingsCopy Anchor Link

---
holdout: 0.1      # 1 in 10 companies drawn gets no email
mailbox: dana@leaseline.app
cap: 25           # first emails a day per Mailbox
---
Write to property managers with 50 to 500 units on two fresh public reasons, one announced.
Over 1,000 units, send from my Mailbox; I approve each one.

$ npx startup-builder show plays/cold-email
holdout 0.1 · mailbox dana@leaseline.app · cap 25 · founder over 1,000 units     your file  plays/cold-email.mdx:2-4,6-7 (Ask 2026-08-24; angle retired by change_31, 2026-10-06)
family demand · worker role:prospector, owns never · chooses none (D38) · sequences cold-email-thread, cold-email-thread-founder, not-now-recontact, referral-first-touch · approval delay-window · checks owned-by-a-person, mailbox-warm, customer-collision, fingerprint, market-hold · stops 12 · placements gmail, outlook, yahoo-mail    catalog  play:cold-email@1 (Not live yet, gaps #5)

Every key from the catalogCopy Anchor Link

Compiled, not written: edit the Play record cold-email and its Leaseline run, then regenerate. Every step runs from a sentence or a line of code. In your words: the CRM words you know, and where each lives here.