Opportunities › AI-assisted mainframe and COBOL development › Proposed app
Spoolside
Review and approve AI-run COBOL changes, JCL jobs and spool results in a browser
- Score
- 30
- confidence 38
- Evidence
- 4
- items on the page
- Rivals
- 2
- named in sources
- First version
- 45 d
- estimate
- Type
- Desktop and mobile
- PWA: on computers and phones alike
- Market since
- 2023
- Emerging market · AI estimate
ScreensConcept
Desktop and mobile: Developers write and patch code at a desk, but approve sensitive changes and review agent progress from anywhere on a phone. Sample screens on a computer and a phone, in the proposed brand. Their numbers are sample data.
Run PAYCALC fix
Paused for approvalStep 6 of 9
About this appAI proposal
Spoolside runs the repetitive loop of mainframe work for you: find the source member, check the copybooks, patch fixed-width lines, submit the JCL, read the spool, and try again. An agent does each step against your z/OS system and shows every step as a plain timeline you can read.
Nothing sensitive happens unseen. Edits show as column-aware diffs, and job submissions, dataset writes and deletes wait for a named approver. You can approve from a browser on your phone or desk, without holding a terminal session open.
It is built for developers and systems programmers on COBOL estates in banks, insurers, airlines and government. It works from the real jobs, datasets and output rather than a chat window beside a terminal, and keeps a record of what it did.
- Tagline
- The mainframe change loop, run by an agent and approved by you.
- Voice
- PreciseCalmPlain
- Why this name
- Spool is where job output lands on z/OS; side means the agent works beside you, in view, not behind your back.
In the first version
Members say which features they would use. It tells PWAS what people want; it changes no score.
Change loop agent
Finds members, reads copybooks, edits source, submits JCL and reads results, then retries within limits you set.
No member yet
Approval gates
Submits, writes, deletes and promotions pause for a named approver. Read-only steps run freely.
No member yet
Column-safe diffs
Shows fixed-width COBOL changes with column rulers, so an edit never slips into the sequence area or past column 72.
No member yet
Spool explainer
Turns abend codes, return codes and compiler messages into the likely cause and the line to check, linked to the output.
No member yet
Brand identityAI proposal
Check the name against trademark registers before using it.
Palette
#F4F1EALedger Paper · surface#1F2A24Ink Green · text#1F5C4ACore Green · primary#D98E04Amber Lamp · accent#2F5D8ASpool Blue · data
Typography
Aa
Spoolside
ABCDEFGHIJKLMNOPQRSTUVWXYZ 0123456789
The mainframe change loop, run by an agent and approved by you.
PricingAI proposal
The material gives no competitor prices. Tiers follow the per-developer or enterprise licensing in the opportunity; amounts are left open to test with buyers.
Team
Contact us
- Per-developer seats
- Approval gates and run timeline
- Shareable run reports
Enterprise
Contact us
- Single sign-on and audit export
- Scope rules per team
- Self-hosted gateway option
- Support agreement
What it could be worthEstimate
What a software business making this much sells for today, from real deals. Pick a monthly revenue.
If it makes
Worth about
$190,000
Sale range $132,000 to $263,000
$120,000 a year in revenue
From 87 software businesses listed and sold on Empire Flippers in the last year, revenue vetted by the broker: they sell for about 19× their monthly revenue, most between 13× and 26×.
Measured on profit, the middle deal is 32× monthly net profit: about 2.7 years of profit.
An estimate, not an offer or financial advice. A real price depends on profit, growth, churn, how much of the work is the owner's, and the buyer.
How it would growAI proposal
How the product would reach new customers through its own use, and how the first ones would be found. A plan to test, not a result.
- Built-in loop
- Shared outputs. Developers send a run report link, with diff, job results and approvals, to a reviewer or change manager who may not use Spoolside, to get a change signed off.
- Do they become customers?
- Reviewers see the product name on each report and could become buyers, but most are not purchasers. Test whether report links lead reviewers to request seats or a trial.
- First customers
- Mainframe application teams of 5 to 30 COBOL developers at one mid-size regional bank or insurer, starting with the team lead who owns delivery speed.
- Where to reach them
- Mainframe communities: Share worked examples of fixing a compile error with approvals in mainframe forums and Hacker News threads.
- Direct outreach: Contact COBOL team leads and modernization managers at banks and insurers with a live demo on a test system.
- Consultancies: Offer pilots to firms that staff COBOL contracts and want faster delivery for clients.
- First milestone
- Three paid pilots at financial institutions, each running 20 or more agent changes through approval on a test system.
Why people already pay for this
- VerifiedHacker News post received 97 points and 51 comments
- Public claimMainframes run critical infrastructure at banks, insurance, airlines, government, and logistics firms, processing enormous transaction volumes with decades-old systems.
- Public claimCOBOL development workflows are repetitive and well-defined, with many manual steps like finding source, checking copybooks, submitting jobs, and interpreting output—making them suitable for agentic automation.
- Public claimThe existing TN3270 and ISPF environment was designed for human experts, not AI agents, limiting automation potential.
Tech stack
Every proposal builds on the same PWA base, installable from the browser on any phone or computer. Dashed boxes are what this app adds.
- AppNext.js and TypeScript
- PWAManifest and service worker
- UITailwind CSS
- Data and authSupabase Postgres
- PaymentsStripe
- EmailResend
- HostingVercel
- This app · Mainframe gatewaySmall agent service run inside the customer networkBanks will not expose z/OS to the internet; the gateway makes outbound calls and talks to z/OS over its supported interfaces.
- This app · Terminal accessTN3270 client library for screen-only tasksSome tasks exist only in ISPF panels, so the agent needs a way to drive them.
RisksAI inference
- CommercialBanks and insurers buy slowly and need security review before any agent touches a mainframe; the sales cycle may outlast a small team's runway.
- TechnicalReaching z/OS from a cloud app needs an in-network gateway, and each site differs in security setup, panels and job rules.
- AIThe agent may write a plausible but wrong edit, or misread an abend. Approval gates reduce harm but add review work.
- CommercialA competitor already offers an agentic mainframe environment with its own terminal; Spoolside must win on review and control.
- DataSource code and spool output are sensitive; sending them to a hosted model may be forbidden by customer policy.
Everything marked AI proposal or AI inference was written by a model from the evidence on the opportunity page. The proposed name must be checked against trademark registers before it is used.