MCP server / for mobile apps

Find the leak.Ship the fix.Prove the lift.

Add mob to your coding agent. It reads your Mixpanel, RevenueCat and Superwall, finds where users drop off before they pay, and runs an in-app experiment against a holdout. Nothing ships until you approve it.

simulated session · illustrative data

~/code/my-app — claude

One loop. Four tools.

Your agent calls them in order, and the output of each one is the input to the next.

diagnose() → Leak[]

Reads your analytics and subscription data. Returns leaks ranked by impact, each with evidence, a hypothesis and a suggested experiment.

instrument(leak) → PR

Finds the events a leak needs that you don't track yet and proposes them as a pull request. You merge it.

run_flow(leak) → Experiment

Drafts one in-app message for the leak's segment, with a holdout. It waits for your explicit approval before anyone sees it.

measure(exp) → Verdict

Lift on the one metric the experiment targeted, against the holdout, with confidence. Then keep, kill or iterate.

↻ then it runs diagnose again.

What you need

mob doesn't replace your stack. It reads and writes through the services you already use. Here's what each tool needs.

ToolRequiredOptional

diagnose

Required

Mixpanelraw event export, read through the data connectors of JJ, Ninefold's analytics agent

Optional

RevenueCatsubscription charts, for churn evidence
Superwallpaywall views to purchases

instrumentthe tool comes later; this is the in-app setup today

Required

MobSur SDKFlutter 2.1+, in your app
Your app forwards its analytics events and sets is_subscribed and days_since_install

Optionalnothing else

run_flow

Required

MobSurdraft, approval, and the experiment with its holdout
MobSur SDKshows the message in your app
Superwalloryour own paywall: the button opens a paywall placement

Copy: one of these

NinaNinefold's content agent writes the message, if configured
Claude APIwrites it otherwise

measure

Required

MobSurwho saw what, per arm
Mixpanelwho converted, joined on your user id

Optionalnothing else

nextcoming soon

Planned

Superwalla second place to run experiments: run_flow and measure on paywall campaigns, through Superwall's API

Statusnot built yet

Third-party service names are plain labels, and mob isn't affiliated with them. Nina and JJ are Ninefold's own agents.

Built with guardrails

Your agent proposes the experiments and you approve each one. Every experiment keeps a holdout, so the number you get at the end is lift you can defend.

There's no dashboard to learn and no campaign builder. mob works from any MCP client, such as Claude Code, Codex or Cursor, and it returns text and JSON your agent can act on.

# invariants
holdout    always on, random by user id
approval   explicit, per experiment
surface    in-app messages first
reads      mixpanel · revenuecat · superwall
writes     PRs you review, drafts you approve
ui         none. your agent is the interface

Find the leak.Ship the fix.Prove the lift.

One loop. Four tools.

What you need

Built with guardrails

Your agent already writes the code.Let it find the money.

Your agent already writes the code.
Let it find the money.