Vibe coding ideas · Sep 2026

Vibe coding ideas developers are already asking for

31 things to build with or for your coding agent. Each one comes from real Reddit threads, not a brainstorm.

~/next-project
claude "what should I build next?"
reading r/ClaudeAI, r/ClaudeCode, r/codex…
58 threads · ▲ 21k upvotes
5 build surfaces · 4 agents
31 ideas with proof, 11 weekend-sized
31
ideas, each linked to its threads
21k
upvotes on the source threads
11
can be built in a weekend
11
subreddits read

Pick your agent

Ideas that work with each tool

Or pick what to build

Extension points people are asking for

Build time vs. demand

Bar length = upvotes on the Reddit threads behind each idea

All 31 ideas

Open a card for build steps, stack and the source threads

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2.7k
4 Reddit threads
App

Usage limit radar

A menu bar app that shows what's left of your Claude Code, Codex and Cursor limits before a task dies mid-run.

Claude Code logo>_Cursor logo1 to 2 weeks$5/mo
How to build it
  1. 1Read the session logs each agent writes locally and count tokens per usage window.
  2. 2Show the remaining budget per tool in the menu bar, with a warning at 80%.
  3. 3Charge for history and team views once the single-user app is solid.
Tauri or SwiftLocal session logsOS notificationsBuyer: Max, Pro and Ultra subscribers

The Reddit threads

2.6k
2 Reddit threads
CLI tool

Command output compressor

A proxy that trims noisy test and build output before it floods the agent's context.

Claude Code logo>_Cursor logo1 to 2 weeksFree core, $8/mo rule packs
How to build it
  1. 1Wrap test runners, builds and git log so only failures and summaries pass through.
  2. 2Count tokens saved per session so the value is obvious.
  3. 3Sell filter packs per framework and language.
Rust or GoShell wrapperPer-command filtersBuyer: Heavy agent users on usage caps

The Reddit threads

2.3k
1 Reddit thread
MCP server

Agent-to-agent chat bridge

A shared channel where Claude Code and Codex pass work to each other instead of you copy-pasting.

Claude Code logo>_Cursor logo1 to 2 weeksFree, paid hosted rooms
How to build it
  1. 1Expose post_message and read_messages tools over MCP.
  2. 2Give each agent a role so handoffs stay in order.
  3. 3Add a web view so you can watch the thread and step in.
MCP serverWebSocketSQLiteBuyer: Developers pairing two agents

The Reddit threads

1.8k
1 Reddit thread
App

Spreadsheet cleanup app for ChatGPT

Turns a messy CSV into a clean, editable table right inside the ChatGPT conversation.

ChatGPT logo1 to 2 weeks$12/mo
How to build it
  1. 1Build an MCP server with tools to load, clean and export a table.
  2. 2Render an editable grid inside the chat with the Apps SDK.
  3. 3Charge for large files and saved cleanup recipes.
Apps SDKMCP serverReact grid widgetBuyer: Ops and finance people living in spreadsheets

The Reddit threads

1.8k
4 Reddit threads
SaaS

Pre-launch security scan

Checks a vibe-coded app for open databases, leaked keys and missing auth rules before launch.

Claude Code logo>_Cursor logoA month$29 per scan
How to build it
  1. 1Crawl the live app and test Firebase and Supabase rules for public reads and writes.
  2. 2Scan the client bundle for API keys that should never ship.
  3. 3Return fixes written as prompts the founder can paste into their agent.
Next.jsFirebase and Supabase rule checksHeadless browserBuyer: Non-technical founders before launch

The Reddit threads

1.6k
3 Reddit threads
SaaS

Skills and plugins directory

A searchable index of Claude Code skills and plugins with install commands, activity and safety notes.

Claude Code logo>_1 to 2 weeksFree, paid featured listings
How to build it
  1. 1Crawl GitHub for SKILL.md and marketplace.json files.
  2. 2Show install commands, stars, last update and which tools each one can run.
  3. 3Charge authors for featured spots and teams for private catalogs.
Next.jsGitHub APIScheduled crawlerBuyer: Skill authors and teams

The Reddit threads

1.5k
3 Reddit threads
Skill

Launch checklist skill

Walks the agent through auth, rate limits, backups and secrets before anything goes live.

Claude Code logo>_Weekend$19 one-time
How to build it
  1. 1Turn a production checklist into a SKILL.md with one section per risk.
  2. 2Bundle scripts that catch public database rules and committed secrets.
  3. 3Sell it as a one-time download with free updates.
SKILL.mdCheck scriptsMarkdown reportBuyer: Vibe coders about to launch

The Reddit threads

1.3k
2 Reddit threads
SaaS

Per-developer AI spend

Splits Cursor, Claude and Codex team bills by developer and repo, with alerts on spikes.

Claude Code logo>_Cursor logo1 to 2 weeks$4/seat/mo
How to build it
  1. 1Pull usage from each vendor's admin API every day.
  2. 2Map accounts to people and repos, then chart spend per week.
  3. 3Alert in Slack when someone spends 3x their normal day.
Vendor admin APIsPostgresSlack alertsBuyer: Engineering managers

The Reddit threads

1.3k
2 Reddit threads
Hook

Token budget guard

A hook that stops a runaway loop before it burns through your plan or your API bill.

Claude Code logoWeekendFree, paid team policies
How to build it
  1. 1On every PreToolUse event, sum the session's token use from its log.
  2. 2Exit with code 2 and a clear message once the session passes its budget.
  3. 3Sell shared budgets and Slack alerts to teams.
PreToolUse hookNode or BashSession JSONL logsBuyer: Teams on API billing

The Reddit threads

1.1k
3 Reddit threads
SaaS

Month-3 prototype rescue

Fixed-price cleanup for stalled vibe-coded apps: tests, structure and a real deploy pipeline.

Claude Code logo>_Cursor logoWeekend$1,500 per rescue
How to build it
  1. 1Sell a fixed-scope audit: architecture map, test coverage and top 10 risks.
  2. 2Have subagents write tests before any refactor starts.
  3. 3Upsell a monthly maintenance plan.
Claude CodeTest runnerGitHub ActionsBuyer: Non-technical founders stuck at month 3

The Reddit threads

1.1k
4 Reddit threads
App

Phone approvals for agents

A push notification when an agent needs you, with approve and deny right from the lock screen.

Claude Code logo>_1 to 2 weeks$6/mo
How to build it
  1. 1Use a Claude Code Notification hook to push when a session waits for input.
  2. 2Send the answer back through a small relay the session polls.
  3. 3Add Codex through its notify setting.
Notification hookPush relayReact NativeBuyer: Developers who leave agents running

The Reddit threads

1k
2 Reddit threads
Subagent

Test-first subagent

Writes a failing test that reproduces the bug before the main agent is allowed to fix it.

Claude Code logoWeekendFree, paid framework packs
How to build it
  1. 1Define a subagent that may only touch test files.
  2. 2Have it reproduce the bug as a failing test and hand back the test name.
  3. 3Use a Stop hook to confirm the test passes before the task closes.
.claude/agentsTest runnerStop hookBuyer: Vibe coders whose fixes keep breaking things

The Reddit threads

The loudest threads

Most upvoted posts behind these ideas

Which agent each idea works with

Top 12 by upvotes. Filled dot = works with that agent

BID MCP server

Ask your agent what to build next

Connect Business Ideas Database to Claude Code, Codex or Cursor and search validated ideas, Reddit proof and keyword data without leaving the terminal.

# Claude Code
claude mcp add --transport http bid \
https://businessideasdb.com/api/mcp \
--header "Authorization: Bearer $BID_KEY"
✓ Connected: search_ideas, get_idea
# then just ask
find me a dev tool idea with real demand

Questions

What is vibe coding?

Vibe coding means building software by describing what you want to an AI coding agent such as Claude Code, Codex or Cursor and steering the result, instead of writing most of the code by hand. Andrej Karpathy coined the term in February 2025.

What should I build with Claude Code?

Start with a problem other developers already complain about. The most upvoted requests on this page are Usage limit radar, Command output compressor, Agent-to-agent chat bridge. 11 of the 31 ideas are small enough to build in a weekend.

Where do these ideas come from?

Each idea is based on public Reddit threads in communities like r/ClaudeAI, r/ClaudeCode, r/codex, r/cursor, where developers describe a problem or ask for a tool. Every card links to its threads so you can read them yourself. Upvote counts are a September 2026 snapshot and change over time.

Your next idea is already validated.

You just haven't seen it yet.