Comparison
Build vs buy an AI SDR: the plumbing a prototype leaves out
A prototype AI SDR is a language model, a prompt and a LinkedIn or email connection. A system you can leave running also needs opt out handling, a suppression check before every send, daily limits, approval control, machine mail filtering and erasure. Build if outreach is your product or you need something unusual. Buy if outreach is a job you want done.
Published by Sellinger AI. Numbers and settings checked on 19 October 2026 against the fact register. Report an error.
What you would have to build, and what Sellinger does
| You would have to build | What Sellinger does today |
|---|---|
| Opt out detection in several languages | When a contact replies with an opt out such as STOP or unsubscribe, in English, Bulgarian or German among other forms, the contact goes on the team's suppression list, the agent stops and the lead is closed out. A weak or unclear phrase never writes the permanent record: the agent stops and a person decides |
| A send gate that refuses suppressed contacts | Before every send on email, LinkedIn and WhatsApp, the platform checks the team's suppression list and refuses the send when the contact is on it or when the check cannot be completed |
| Per account pacing and quiet hours | Every connected account has daily limits that the agent cannot exceed, set per account. LinkedIn defaults are 20 invitations a day and 150 a week. Email defaults to 50 sends a day per mailbox, with an optional warm up that starts at 5 a day and doubles every 3 days up to the limit |
| Approval and human takeover | A campaign can run in approval mode, where every message waits for a person to approve it, or send automatically. A person can take over any conversation, and the agent stops on its own when it cannot answer, for example a price it has no answer for |
| Filtering of automatic mail | Automatic replies from helpdesks, no reply senders, satisfaction surveys and empty messages are marked as machine mail. They never count as a human reply, the agent does not answer them, and the lead is sent to a person with a named reason |
| Erasure on request | An erasure function takes an email address, phone number or LinkedIn address, anonymizes the matching leads in the workspace and adds the identifiers to the suppression list so the person cannot be imported and contacted again |
| API keys and rate limits | API keys are stored only as SHA-256 hashes, can be revoked or set to expire, and carry per minute and per day limits |
Each statement is a fact register entry with its code source and check date, on the facts page.
The middle path: buy the engine, build on top
A REST API with webhooks (from the Full Stack bundle up) and a hosted MCP connector with 43 tools for Claude and ChatGPT. Teams that want a custom workflow can call the API or work through an assistant, and keep the sending, limits and opt out handling in the product. See the MCP recipes.
Choose by what outreach is to you
Build if
- outreach automation is your product,
- you need a channel or a rule no vendor supports,
- you have engineers to maintain it for years,
- you are willing to own the compliance and account safety risk.
Buy if
- outreach is a job to be done, not a product,
- you want opt outs, limits and approvals handled and audited,
- you want to be live within a day,
- you would rather spend engineering time on your own product.
Common questions
How long does it take to build an AI SDR?
Can I use my own language model?
What about data protection?
Is buying lock in?
Sources and method
Each row is a fact register entry with its source file in the product code, checked 19 October 2026.
Related: fact register, security, MCP connector, AI SDR vs human SDR.
