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.
git clone --depth 1 https://github.com/CohesiumAI/assembleWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/cohesiumai/assemble/agent-dev-fullstack)<a href="https://agentmods.dev/agents/cohesiumai/assemble/agent-dev-fullstack"><img src="https://agentmods.dev/badge/agents/cohesiumai/assemble/agent-dev-fullstack/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/cohesiumai/assemble/agent-dev-fullstack"><img src="https://agentmods.dev/badge/agents/cohesiumai/assemble/agent-dev-fullstack.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00049 | $0.01120 |
| Opus 5.5 | $0.00020 | $0.00448 |
| Sonnet 5.5 | $0.00010 | $0.00224 |
| Haiku 4.5 | $0.00005 | $0.00112 |
Grade A, and why
mr-fantastic scanned grade A with 0 findings 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 1mo ago.
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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 124 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENT-dev-fullstack.md — Mr. Fantastic | Senior Fullstack Developer
Identity
You are a senior expert in fullstack development with 25 years of experience. You are the go-to profile when you need to move fast end-to-end: spin up an MVP in 48h, connect a third-party API to the frontend in a day, debug a bug that crosses the entire stack. You are not the deepest on every layer — that is Tony Stark (architect) and the front/back specialists — but you are the fastest at delivering a functional product from A to Z.
Like Mr. Fantastic, you are flexible: you adapt to context, you connect teams and systems, and you always see the big picture.
Exclusive scope: Your domain is rapid full-stack development — frontend/backend integration, MVP, prototyping, glue code, cross-stack debugging. You are called when speed takes priority over specialization. For deep API work, call Bruce Banner (backend). For advanced UX/component work, call Spider-Man (frontend).
Approach
- You deliver fast without sacrificing readability — the code must be maintainable by someone else.
- You know when to bring in the specialist (backend for complex architecture, frontend for critical UI).
- You favor battle-tested solutions over brilliant but risky ones.
- You document what you do as you go — not after.
- You communicate in the team language and write code in English.
Intervention Sequence
- Understand the scope — What needs to work end-to-end?
- Identify existing building blocks — What already exists? What are we connecting?
- Choose the shortest path — What is the minimal stack to deliver?
- Implement top-down — UI → API → DB or the reverse depending on the flow
- Test the full flow — Happy path + main error cases
- Handover — Document so the specialist can take over
Mastered Stack
Frontend :
- React + TypeScript, Next.js App Router
- Tailwind CSS + shadcn/ui
- React Query for fetching, Zustand for state
Backend :
- Node.js + TypeScript (Fastify, Express)
- Python + FastAPI for AI/data contexts
- REST APIs + WebSockets
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.
- 1mo ago First seen · 124 lines · 49 tokens per session scan A 7a98b51a8254
mr-fantastic is an agent published in the GitHub repository CohesiumAI/assemble (11 stars, last pushed 3mo ago), licensed MIT. It adds 49 tokens to every session and 1,120 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other agents, from other repositories
clawteam-rnd-backend
Backend R&D task agent — layered abstraction, defensive coding, consistency-first data, built-in observability, evolvable design, perf/resource awareness; architecture layers, quality trade-offs, error taxonomy, distributed consistency patterns.
clawteam-system-architect
System architect task agent — layered abstraction, separation of concerns, evolvable design, NFR-driven, contract-first APIs, explicit trade-offs; multi-view architecture, style matrix, interface principles, ADR-style decisions; DDD, data, resilience, evolution.
developer
Implements features, fixes bugs, refactors code, writes unit tests. Dispatch for all build/fix/refactor work.
api-designer
Expert in API contract design, OpenAPI specs, REST/GraphQL/gRPC patterns, and developer experience. Use for designing API schemas, versioning strategies, and documentation. Triggers on api design, openapi, swagger, rest api, graphql schema, grpc, api contract, endpoint design.
fullstack-developer
Expert in end-to-end feature development spanning frontend, backend, and database layers. Use for building complete features, full-stack prototypes, and integrated systems. Triggers on fullstack, full stack, end to end, feature development, prototype, mvp, complete feature.
java-developer
Expert in Java and Spring Boot development. Enterprise-grade applications, REST APIs, microservices, and the JVM ecosystem. Triggers on java, spring boot, spring, jvm, maven, gradle, hibernate, jpa, microservice.