# AI Growth Agent vs Building Your Own: Build or Buy?

> Should an engineer-founder build their own AI growth agent or use Revnu? What you'd have to build, what Revnu's API does and doesn't expose, and when building wins.

Canonical: https://revnu.com/comparisons/ai-growth-agent-vs-building-your-own
Published October 15, 2026 by Art Freebrey, Co-founder, Revnu

**The short answer.** Build your own growth agent if you need one channel, want to own the data and the sending, and are happy running inbox warm-up and LinkedIn pacing yourself. Use Revnu if you would rather keep shipping product and approve the work. You can also do both: Revnu has a REST API, a CLI and an MCP server, so your own tools can drive it. What none of them do is hand you Revnu's lead search or sending as raw parts.

If you write code for a living, "build it" is the honest first instinct. You have Claude Code open in another tab. A loop that reads your site, finds companies and drafts an email to each one looks like a weekend project, and for the writing part it is. This page is about the rest: what a growth agent needs around the writing, what Revnu exposes to an engineer, and the cases where building wins.

## What would I have to build myself?

The writing is the easy part. These are the pieces that take longer, and each one is something Revnu already runs.

| Piece | What it involves | What Revnu does |
| --- | --- | --- |
| Lead data | Companies and the right person at each, with work emails, and a record of why each one was picked | Searches its own database of companies and people, researches each company on public pages, and shows a Why Now, source links and a fit score on every lead ([what's on a lead](/docs/lead-details)) |
| Verification | Checking every email address before it's used, so bounces don't damage your domain | Checks every address before it sends |
| Sending infrastructure | Lookalike domains, inboxes, mail records, days to weeks of warm-up, weekday sending windows | Buys and warms [sending inboxes](/docs/sending-inboxes) after you approve the cost, or sends from your own Gmail or Outlook |
| Pacing | Per-inbox daily caps, a LinkedIn ramp with daily and hourly limits, pausing when LinkedIn pushes back, a block list on every first touch | Enforced in code. On Pro, Revnu sends up to 50 emails a day and 20 an hour from each Gmail or Outlook inbox you connect. See [LinkedIn limits](/docs/linkedin-limits) |
| Approvals | A queue for what waits, and rules for what may go out alone | Your first sequence always waits for your yes. After that, Settings > Agent decides what asks first. Replies to prospects, spend, budgets, booking links and new inboxes always wait. ([what Revnu asks before it acts](/docs/approvals)) |
| Guardrails | Claims your agent must never make, checked on every send and post | A Never Say list in [Memory](/docs/memory), enforced on every send and post |
| Measurement | Opens, clicks, replies, bounces, ad spend per platform, search and AI-answer visibility, conversions sent back to ad platforms | Tracks all of it and reports outcomes to your ad channels through the [Revnu Tag](/docs/revnu-tag) |

None of these is hard in isolation. Together they are the difference between a script that sends email and a growth loop you can leave running. The sending infrastructure is the slowest to stand up, because new inboxes can't be rushed: they warm up over days to weeks before they send cold email.

## What does Revnu's API give an engineer?

The same controls a customer has in the dashboard, from code. With a personal `rvp_` token and the right scopes, your software can:

- message Revnu and read its replies, so your agent can ask for work in plain words
- read and approve the review queue, under the same cards the dashboard shows
- read results and leads, and set labels on leads
- keep the block list, for example from your CRM
- read one person's LinkedIn connection state and messages
- run workflows, the standing jobs Revnu does on a schedule
- set up a new account, and [preview a website](/docs/preview) with no account at all

The REST API lives at `https://revnu.com/api/v1`, with an OpenAPI document at `https://revnu.com/openapi.json`. The [CLI](/docs/cli) (`npx @revnu/cli setup`) and the [MCP server](/docs/mcp) at `https://revnu.com/api/mcp` are thin layers over it: every subcommand and MCP tool maps to one route. Inbound [webhooks](/docs/webhooks) let your backend hand Revnu an event, such as a new sign-up.

## What doesn't the API give you?

Revnu's tools stay inside its agent. There is no route for:

- searching for companies or people, or looking up contact details
- verifying an email address
- sending an email or LinkedIn message you wrote, or publishing a post you wrote
- creating or changing ad campaigns directly
- changing settings, approval rules or connections
- receiving events, since there are no outbound webhooks

Your agent reaches all of that by asking Revnu. "Find 20 fintechs in Berlin with 50 to 200 staff" sent as a message returns researched leads you read back with the leads route. If what you want is raw lead search and a send endpoint to wire into your own agent, Revnu's API isn't that, and it is better to know now. [API, CLI, MCP or chat](/docs/api-cli-mcp-or-chat) has the full capability list.

## When is building your own the right call?

Building wins in a few clear cases:

- **You need one channel.** If cold email to a list you already own is the whole plan, a script and a sending tool may be all you need.
- **You want to own the data and the sending.** Some teams need leads and mail to live in their own systems. Revnu has no CSV export and no CRM sync; leads come out through the API.
- **You enjoy the plumbing.** Warm-up schedules, bounce handling and LinkedIn limits are real work that never ends. If that is interesting to you, it is a fine project.
- **Your channel is somewhere Revnu doesn't go.** Revnu doesn't publish organic social posts for you (it drafts them and sends a share link), doesn't connect to CRMs or analytics tools, and can't find private individuals to contact.

Revnu wins when you would rather the loop ran without you. It runs outbound, LinkedIn, ads, search pages and AI-answer visibility as one system, and a lesson in one channel changes what happens in the next. Building that across several channels is where a weekend project turns into a quarter.

## Can I build on top of Revnu instead?

Yes, and for many engineers it is the best of both. Keep Revnu doing the sending, the lead research and the tracking, and build what you care about on its API:

- a [review screen](/docs/build-a-review-screen) in your admin, in Slack or on a wall display
- [reporting](/docs/pull-results-into-reporting) that pulls Revnu's results into your own dashboards
- block-list sync from your CRM, so customers never get cold email
- an agent in Claude, ChatGPT or Cursor that asks Revnu for work over MCP

## What it costs

Revnu Pro is from $99 a month, with lead data included, and Revnu pays up to $100 a month for the sending inboxes it buys. Ad spend is billed by each platform to your own ad account. Managed adds a growth engineer from our team and is priced on a call ([book one](/book)). A home-built agent costs your hours plus the data, inboxes and model calls you pay for separately.

## Where this leaves you

Write down which channels you need in the next three months. If it is one, and you like infrastructure, build it. If it is more than one, or you'd rather spend your hours on the product, let Revnu run the loop and build your own review screen or reports on its API. If you're still comparing, [one AI growth agent vs a stack of point tools](/comparisons/ai-growth-agent-vs-point-tools) covers the middle option, and [AI growth agent vs hiring a growth marketer](/comparisons/ai-growth-agent-vs-growth-hire) covers the human one. To see what Revnu does with your product, [start with your website](/sign-up).

## Frequently asked questions

### Can I build my own AI growth agent with Claude Code or a raw model API?

Yes. Writing emails and posts with a model is a weekend of work. The longer parts sit around the writing: sending domains and inboxes that need warming up, lead data with verified email addresses, per-inbox and LinkedIn pacing, a queue for what needs approval, and tracking what worked across channels. Revnu comes with all of it running across email, LinkedIn, search and ads.

### Does Revnu have an API for lead search, email verification or sending?

Through Revnu's agent: your code asks Revnu in a message, for example to find 20 fintechs in Berlin, and reads the researched leads back from the API. Revnu runs the search, email verification, sending and publishing itself, with your approval settings applied.

### Can my own agent drive Revnu?

Yes. The REST API, the @revnu/cli CLI and the MCP server let software do what a customer does in the dashboard: message Revnu and read its replies, read results and leads, approve or answer review cards, keep the block list and run workflows. Inbound webhooks let your backend hand Revnu an event, such as a new sign-up. Settings, approval rules and connections stay in the dashboard.

### Does Revnu send events to my servers?

Revnu's API is pull-based: poll the results, leads or review queue routes for what changed. Inbound webhooks work the other way: your systems can wake Revnu, up to 60 events an hour for each hook.

### How much does Revnu cost next to building it myself?

Revnu Pro is from $99 a month, with lead data included, and Revnu pays up to $100 a month for the sending inboxes it buys. Ad spend is billed by each platform to your own ad account. Managed adds a growth engineer from our team and is priced on a call. Building your own costs your time plus whatever you pay for data, inboxes and model calls.