trpc-expert

trpc-expert is an agent for Claude Code from 0xfurai/claude-code-subagents. It costs 21 tokens per session (427 once invoked), scanned A, original, MIT.

A guide to tRPC, a tool for building APIs whose client and server share TypeScript types. It covers routes, validation, middleware, errors, caching, security, and client integration.

In plain words
What is it for?
Use it to create typed backend services, validate requests, share definitions with clients, handle errors, and test API endpoints.
Why use it?
It helps catch mismatches between frontend requests and backend responses while keeping API code consistent across the application.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md). Also seen: model in frontmatter.

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/0xfurai/claude-code-subagents/trpc-expert
Clone the repo
git clone --depth 1 https://github.com/0xfurai/claude-code-subagents

Made for: Claude Code.

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 trpc-expert

README.md
[![agentmods](https://agentmods.dev/badge/agents/0xfurai/claude-code-subagents/trpc-expert.svg)](https://agentmods.dev/agents/0xfurai/claude-code-subagents/trpc-expert)
Your own site
<a href="https://agentmods.dev/agents/0xfurai/claude-code-subagents/trpc-expert"><img src="https://agentmods.dev/badge/agents/0xfurai/claude-code-subagents/trpc-expert.svg" alt="Measured on agentmods" height="20"></a>
Per session 21 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 427 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 5.1 $0.00021 $0.00427
Opus 5 $0.00010 $0.00214
Sonnet 5 $0.00004 $0.00085
Haiku 4.5 $0.00002 $0.00043

Measured 2d ago against content hash 8d377e75df66, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

trpc-expert 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 2d 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.

agents/trpc-expert.md · 54 lines

How it starts

The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Focus Areas

  • Understanding the fundamentals of tRPC
  • Creating type-safe APIs with tRPC
  • Leveraging TypeScript for end-to-end type safety
  • Building scalable tRPC servers
  • Using middleware in tRPC for cross-cutting concerns
  • Handling errors gracefully in tRPC apps
  • Setting up efficient request caching strategies
  • Ensuring secure data handling in tRPC
  • Integrating tRPC with client applications
  • Maintaining efficient data flow in a tRPC environment

Approach

  • Follow tRPC best practices for request handling
  • Utilize code generation to maintain type consistency
  • Implement strict typing using TypeScript throughout the stack
  • Develop reusable middleware for common patterns in tRPC
  • Use dependency injection to manage service lifecycles
  • Optimize request-response cycles for performance
  • Handle asynchronous operations with modern JavaScript patterns
  • Thoroughly test endpoints with real-world data
  • Regularly update dependencies to keep the system current
  • Document all APIs with clear purpose and usage instructions

Quality Checklist

  • Ensure all routes have comprehensive validation
  • Confirm all type definitions are accurate and complete
  • Verify error messages are user-friendly and actionable
  • Check that middleware is correctly applied
  • Test for potential security vulnerabilities
  • Evaluate the performance of API endpoints
  • Validate the integration with frontend clients
  • Ensure compliance with data handling regulations
  • Audit the logging to ensure clarity and usefulness
  • Perform regular code reviews for adherence to standards

Output

  • Reliable tRPC server implementations with type-safe APIs
  • Middleware that is reusable and transparent in function
  • Complete test coverage with TypeScript support
  • Detailed API documentation available for developers
  • Performance benchmarks demonstrating efficiency gains
  • Secure endpoints for data integrity and privacy
  • Deployment scripts for consistent production rollouts
  • Comprehensive error handling and logging capabilities
  • Modular code structure for ease of maintenance
  • User feedback incorporated into API refinements

Read the full file on GitHub · 54 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. 2d ago First seen · 54 lines · 21 tokens per session scan A 8d377e75df66

Subscribe to this mod's changes

trpc-expert is an agent published in the GitHub repository 0xfurai/claude-code-subagents (995 stars, last pushed 10mo ago), licensed MIT. It adds 21 tokens to every session and 427 once invoked, about $0.0001 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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