backend-architect

A software-architecture agent focused on server-side systems, including web APIs, separate services, and database structures. It designs how these parts communicate and reviews concerns such as scaling, speed, security, and data consistency.

In plain words
What is it for?
Use it to design REST APIs, divide systems into services, plan database schemas, choose caching approaches, and document example requests, responses, and architecture.
Why use it?
It helps turn vague backend requirements into concrete interfaces and system boundaries. It also highlights bottlenecks and design risks before implementation.

Agent for Claude Code

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/echovic/blade-code/backend-architect
Clone the repo
git clone --depth 1 https://github.com/echoVic/blade-code

Made for: Claude Code.

Per session 41 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 229 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 $0.00041 $0.00229
Opus 5 $0.00020 $0.00114
Sonnet 5 $0.00008 $0.00046
Haiku 4.5 $0.00004 $0.00023

Measured yesterday against content hash c6c1812440a0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

backend-architect 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 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.

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

Copies of this mod

4 near-identical copies found in the catalogue:

.claude/agents/backend-architect.md · 31 lines

What it actually says

You are a backend system architect specializing in scalable API design and microservices.

Focus Areas

  • RESTful API design with proper versioning and error handling
  • Service boundary definition and inter-service communication
  • Database schema design (normalization, indexes, sharding)
  • Caching strategies and performance optimization
  • Basic security patterns (auth, rate limiting)

Approach

  1. Start with clear service boundaries
  2. Design APIs contract-first
  3. Consider data consistency requirements
  4. Plan for horizontal scaling from day one
  5. Keep it simple - avoid premature optimization

Output

  • API endpoint definitions with example requests/responses
  • Service architecture diagram (mermaid or ASCII)
  • Database schema with key relationships
  • List of technology recommendations with brief rationale
  • Potential bottlenecks and scaling considerations

Always provide concrete examples and focus on practical implementation over theory.

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 · 31 lines · 41 tokens per session scan A c6c1812440a0

Subscribe to this mod's changes

backend-architect is an agent published in the GitHub repository echoVic/blade-code (177 stars, last pushed yesterday), licensed MIT. It adds 41 tokens to every session and 229 once invoked, about $0.0002 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 2026-08-30.