The proven open-source GTM framework
Ostack by o11 is the open source GTM framework we use internally to book 6+ meetings per BDR. It’s completely free.
Your calendar
Booked this week 0
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9 AM10 AM11 AM12 PM1 PM2 PM3 PM4 PM5 PM
Works with 
Claude Code
Gmail
HubSpot
Codex
Outlook
Salesforce
Cursor
Google Sheets
Attio
Gemini
Slack
Pipedrive
LinkedIn
Lightfield
Google Calendar
Airtable
Superhuman
Close
Notion
Apollo
Zoho CRM
Calendly
Clay
Folk
Excel
Twenty
Cal.com
monday CRM
Affinity
Copper
Fastmail
Claude CodeGmailHubSpotCodexOutlookSalesforceCursorGoogle SheetsAttioGeminiSlackPipedriveLinkedInLightfieldGoogle CalendarAirtableSuperhumanCloseNotionApolloZoho CRMCalendlyClayFolkExcelTwentyCal.commonday CRMAffinityCopperFastmailWhat it does
Outbound that runs every day, the way your team sells.
Finds the right people
New leads every morning, checked against your rules.
Writes like you
Short, specific drafts from your template and voice.
Follows up and books
Answers replies and puts meetings on your calendar.
One setup for the team
Set it up once. Everyone sends from their own inbox.
Priya
Sam
Jordan How it works
1Paste the prompt
Into Claude Code, Codex or Cursor.
2Answer a few questions
Who you sell to, your voice and your tools.
3Approve the drafts
Nothing sends until you say so.
4It runs every day
Finds, writes, follows up and books.
Open source
Free to use
MIT licensed
Drafts until you say send
$1 of free credit
Leads stay in your CRM
Questions
Open-source playbooks your coding agent runs every day. GTM, the first, runs your outbound. o11 is the account it runs on: sign-in, your team’s setup, run history and the data it pays for.
No. Paste one prompt into your agent and answer its questions in plain words.
Only after you switch it to send. Until then it leaves drafts in your inbox for you to approve.
Ostack is free. Finding companies, people and emails is paid from your o11 wallet at catalog prices. New accounts get $1 of credit.
An admin sets it up once. Teammates sign in and add only their mailbox and signature. Every run shows up on the team’s Ostack page.
Leads stay in your CRM, sheet or CSV, and messages go through your own mailbox. o11 keeps your team’s notes, settings and run history.
Run outbound with the agent you already use.
Free and open source. One prompt sets it up.
Outbound activity
Weekdays only · inside your hours
New replies
Dana · Ledgerly “Thursday at 2 works.”
Marco · Finchpay “Send me the deck, looping in our CTO.”
Lena · Brightwire “Good timing. Free Tuesday?”
Since setup
- Meetings booked
- 7
- Replies
- 23
- Sent from your inbox
- 412