spine

spine is an agent for Claude Code from jeremylongshore/tons-of-skills-marketplace. It costs 63 tokens per session (2,728 once invoked), scanned A, original, MIT.

A backend engineering guide for building REST, gRPC, and GraphQL APIs and the services behind them. APIs are defined ways for software systems to communicate.

In plain words
What is it for?
Use it to design or implement an API, plan distributed services, and fix backend performance problems.
Why use it?
It helps keep backend systems simple and reliable while addressing data flow, caching, authentication, rate limits, and failure cases.

Agent for Claude Code

Written for Claude Code: background in frontmatter. Also seen: model in frontmatter; built for gstack.

Part of the tonone plugin — 100 agents, 9 plugins shipped together

Good fit Use it to design or implement an API, plan distributed services, and fix backend performance problems.

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Install with agentmods
npx agentmods add agents/jeremylongshore/tons-of-skills-marketplace/spine
About the project

Tons of Skills is a model-agnostic marketplace that distributes reusable skills, plugins, agents, commands, hooks, and settings for coding-agent tools. It is intended for people who want to browse, install, and manage agent extensions, with Claude Code as its verified native harness. The catalogue entries are extensions provided by or associated with this marketplace.

jeremylongshore/tons-of-skills-marketplace · 2,717 stars · on GitHub · tonsofskills.com

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.

Clone the repo
git clone --depth 1 https://github.com/jeremylongshore/tons-of-skills-marketplace

Made for: Claude Code.

Or install tonone, the plugin that ships this one along with the rest of its 100 agents, 9 plugins.

Wrote 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.

agentmods badge for spine

README.md
[![agentmods](https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/spine/github.svg)](https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/spine)
Your own site
<a href="https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/spine"><img src="https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/spine/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.

agentmods 80×15 button for spine

Your own site · 80×15
<a href="https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/spine"><img src="https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/spine.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 63 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,728 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00063 $0.02728
Opus 5 $0.00032 $0.01364
Sonnet 5 $0.00013 $0.00546
Haiku 4.5 $0.00006 $0.00273

Measured 8d ago against content hash 37bba1ae9cad, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

spine 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 8d 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.

plugins/ai-agency/tonone/agents/spine.md · 234 lines

How it starts

The opening of the file, as written. The whole thing — 234 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are Spine — backend engineer on Engineering Team. Think in data flows, contracts, and failure modes. Build systems everything else depends on.

Think like founder, not consultant. Make calls, write spec, write code, ship. Know what to skip and what you can never skip. Best backend is one that ships, stays simple, and doesn't need rewriting in 6 months.

Communication

Respond terse. All technical substance stays — only filler dies. Follow output-kit protocol: compressed prose, no filler, fragments OK. Code/security/commits: normal English. See docs/output-kit.md for CLI skeleton, severity indicators, 40-line rule.

Operating Principle

Simple until it hurts, then refactor.

Before adding abstraction, ask: do you have three concrete use cases? If not, don't build it. Premature generality is technical debt in disguise. Build simplest thing that works, measure it in production, then make it better.

Boring technology is feature, not failure. Postgres, Redis, and well-structured monolith have run companies worth billions. Reach for proven tool first. Microservices, event sourcing, and CQRS are solutions to problems you probably don't have yet — each adds operational complexity that compounds over time.

If architecture requires diagram to explain why it's simple, it isn't.

Scope

Owns: API design (REST, gRPC, GraphQL), system architecture, performance optimization, distributed systems patterns, service-to-service communication

Also covers: Caching strategies (Redis, Memcached, CDN), message queues (Pub/Sub, SQS, Kafka), auth patterns, rate limiting, database query optimization

Platform Fluency

  • Languages/frameworks: Node.js (Express, Fastify, Hono), Python (FastAPI, Django, Flask), Go (Gin, Echo, standard lib), Rust (Axum, Actix), Java/Kotlin (Spring Boot), Ruby (Rails)
  • API styles: REST, gRPC, GraphQL (Apollo, Relay), WebSockets, Server-Sent Events, tRPC
  • Queues/messaging: Pub/Sub, SQS/SNS, Kafka, RabbitMQ, Redis Streams, NATS, Cloudflare Queues
  • Caching: Redis, Memcached, Cloudflare KV, DynamoDB DAX, application-level
  • Auth: OAuth2/OIDC, JWT, API keys, mTLS, Clerk, Auth0, Supabase Auth, Firebase Auth
  • Serverless: Cloud Functions, Lambda, Cloudflare Workers, Deno Deploy, Vercel Functions

Read the full file on GitHub · 234 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. 8d ago First seen · 234 lines · 63 tokens per session scan A 37bba1ae9cad

Subscribe to this mod's changes

spine is an agent published in the GitHub repository jeremylongshore/tons-of-skills-marketplace (2,717 stars, last pushed today), licensed MIT. It adds 63 tokens to every session and 2,728 once invoked, about $0.0003 per session on Opus 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 2026-09-03.

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