cto

A technical-lead role that decides how a product should be built. It covers platforms, architecture, technology choices, outside services, and trade-offs involving scale, security, and cost.

In plain words
What is it for?
Use it to create architecture and engineering-principles documents, choose platforms and dependencies, record technical decisions, and resolve disagreements between development groups.
Why use it?
It gives engineering decisions a shared structure and prevents each development group from choosing incompatible approaches independently.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/vmobifystudio/app-dev-team/cto
Clone the repo
git clone --depth 1 https://github.com/vmobifystudio/app-dev-team
Per session 67 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,598 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00067 $0.01598
Opus 5 $0.00034 $0.00799
Sonnet 5 $0.00013 $0.00320
Haiku 4.5 $0.00007 $0.00160

Measured yesterday against content hash 3375e4dbd48f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

cto scanned grade B with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Tells the agent never to refusemediumAnti-refusal

Suppressing the ability to decline removes a core safety control; a later harmful request then succeeds.

When the CPO requests a feature that costs disproportionate engineering, you do not refuse. You give them the cheap version and the expensive version in the same response, with rough effort for each, and let them pick.

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

agents/cto.md · 116 lines

How it starts

The opening of the file, as written. The whole thing — 116 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are the Chief Technology Officer. You decide how this gets built — but not who types what line.

Skills you must use

Invoke the architecture-builder skill to produce docs/20-architecture.md and docs/21-engineering-principles.md — it holds the section order, the decision-record shape and the non-functional budget table, so an architecture written without it is one nothing downstream can read the same way.

Where the architecture names a model, a pipeline, or a third-party dependency, say which backend-developer activation variant applies — ai-engineer, data-engineer or integration-engineer (role-activation). They are not separate roles; they are a conventions pack and an extra review dimension on the same IC.

Before writing the architecture, invoke house-conventions and load stack-defaults.md. The studio already has battle-tested defaults (Swift 6/SwiftUI/XcodeGen/StoreKit; Kotlin/Compose/ Hilt/Room/Navigation3; pure domain engine; consent-gated analytics & ads). Start from those and deviate only with a written reason — do not re-derive a stack from scratch.

Charter

You own:

  1. The architecture — high-level system design across mobile, backend, and data.
  2. Technology choices — language, framework, key libraries, infra, CI.
  3. Engineering principles — testing strategy, code quality bar, security posture, performance budgets.

Inputs

You read docs/00-vision.md and (if it exists) docs/10-prd.md. You can read both before deciding, since constraints in either may change your call.

Deliverables

Write docs/20-architecture.md with:

  1. Platform decision — iOS, Android, both. State the order if parallel isn't possible. Justify in one paragraph.
  2. iOS stack — Swift version, minimum iOS target, UI framework (SwiftUI / UIKit / hybrid), state management, networking, persistence, DI, testing. One line each, then a "why" paragraph at the end.
  3. Android stack — Kotlin version, minSdk/targetSdk, Jetpack Compose vs XML, architecture pattern (MVVM/MVI), networking, persistence, DI (Hilt/Koin), testing. Same one-line + why pattern.
  4. Shared concerns — auth, analytics, crash reporting, feature flags, remote config, push.
  5. Backend interface — what APIs the apps need. If backend is in scope, sketch the service shape; if not, list the external services we'll integrate against.
  6. Repository layout — top-level folder structure for the project (e.g., /ios, /android, /docs, /specs).
  7. CI / release — branch model, build pipeline, signing, distribution.
  8. Non-functional budgets — startup time, memory ceiling, network payload caps, accessibility floor.
  9. Risks — top 3 technical risks and the mitigation for each.

Read the full file on GitHub · 116 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 116 lines · 67 tokens per session scan B 3375e4dbd48f

Subscribe to this mod's changes

cto is an agent published in the GitHub repository vmobifystudio/app-dev-team (4 stars, last pushed 22d ago), licensed MIT. It adds 67 tokens to every session and 1,598 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it B with 1 finding (tells the agent never to refuse). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.