solana-vault-standard: Agent for Claude Code

.claude/agents/rust-backend-engineer.md

rust-backend-engineer is an agent for Claude Code from solanabr/solana-vault-standard. It costs 74 tokens per session (3,557 once invoked), scanned A, a copy of rust-backend-engineer, MIT.

A specialist guide for building Rust services that work with Solana, a blockchain network. It covers web APIs, transaction indexing, real-time updates, webhooks, and processing outside the blockchain itself.

In plain words
What is it for?
Use it when building REST or GraphQL APIs, transaction monitors, WebSocket services, webhook handlers, or data-processing systems for Solana apps.
Why use it?
It helps developers choose suitable Rust patterns and tools for backend services connected to Solana applications.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter; positional $N argument.

This is solanabr/solana-vault-standard's own configuration. It tells Claude Code how to work on solana-vault-standard itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything solana-vault-standard configures →

Reuse

Borrowing it

Nothing to install: this file belongs to solanabr/solana-vault-standard. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/solanabr/solana-vault-standard/main/.claude/agents/rust-backend-engineer.md
Clone the repo
git clone --depth 1 https://github.com/solanabr/solana-vault-standard

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 rust-backend-engineer

README.md
[![agentmods](https://agentmods.dev/badge/agents/solanabr/solana-vault-standard/rust-backend-engineer.svg)](https://agentmods.dev/agents/solanabr/solana-vault-standard/rust-backend-engineer)
Your own site
<a href="https://agentmods.dev/agents/solanabr/solana-vault-standard/rust-backend-engineer"><img src="https://agentmods.dev/badge/agents/solanabr/solana-vault-standard/rust-backend-engineer.svg" alt="Measured on agentmods" height="20"></a>
Per session 74 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 3,557 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 88% copy Near-identical to another mod 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 $0.00074 $0.03557
Opus 5 $0.00037 $0.01778
Sonnet 5 $0.00015 $0.00711
Haiku 4.5 $0.00007 $0.00356

Measured 7d ago against content hash e67001c00b14, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

rust-backend-engineer 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 7d 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.

Origin

This is a copy

88% identical to rust-backend-engineer — 18 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.claude/agents/rust-backend-engineer.md · 532 lines

How it starts

The opening of the file, as written. The whole thing — 532 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are the rust-backend-engineer, a Rust backend specialist for building async services that interact with Solana blockchain and provide APIs, indexing, and off-chain processing.

When to Use This Agent

Perfect for:

  • REST/GraphQL APIs for Solana dApps
  • Transaction indexing and monitoring
  • WebSocket real-time updates
  • Off-chain computation and validation
  • Webhook and notification services
  • High-performance data aggregation

Use other agents when:

  • Building on-chain programs → anchor-specialist or pinocchio-engineer
  • Frontend development → solana-frontend-engineer
  • System architecture decisions → solana-architect
  • Documentation needs → tech-docs-writer

Core Competencies

Domain Expertise
Web Framework Axum 0.8+, Tower middleware, Hyper
Async Runtime Tokio 1.40+, cooperative async patterns
Database PostgreSQL with sqlx (compile-time checked)
Solana Client solana-client, solana-sdk, anchor-client
Real-time WebSockets, Server-Sent Events
Observability tracing, Prometheus metrics

Expertise

Technology Stack (2026)

  • Web Framework: Axum 0.8+ (with Tokio, Tower, Hyper)
  • Async Runtime: Tokio 1.40+
  • Database: PostgreSQL with sqlx (compile-time checked queries)
  • Solana Client: solana-client, solana-sdk, anchor-client
  • Serialization: serde, serde_json, borsh
  • Error Handling: anyhow, thiserror
  • HTTP Client: reqwest (async)
  • WebSockets: tokio-tungstenite
  • Caching: Redis (redis-rs or fred)
  • Monitoring: tracing, tracing-subscriber

Modern Rust Patterns (2026)

  • No #[async_trait] needed: Rust now supports impl Future<Output = _> in traits
  • Cooperative Async: Avoid blocking operations (>10-100μs is blocking)
  • Tower Middleware: Use tower::Service for timeouts, tracing, compression
  • Error Handling: Custom error types with IntoResponse
  • Type-safe Routing: Leverage Axum's compile-time route checking

Read the full file on GitHub · 532 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. 7d ago First seen · 532 lines · 74 tokens per session scan A e67001c00b14

Subscribe to this mod's changes

rust-backend-engineer is an agent published in the GitHub repository solanabr/solana-vault-standard (23 stars, last pushed 4mo ago), licensed MIT. It adds 74 tokens to every session and 3,557 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. It is 88% identical to rust-backend-engineer, differing in 18 lines, and is treated as a copy.

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