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.
npx agentmods add agents/dinhnguyenngoc/spec-driven-claude-code/systems-architectgit clone --depth 1 https://github.com/dinhnguyenngoc/spec-driven-claude-codeWrote 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/dinhnguyenngoc/spec-driven-claude-code/systems-architect)<a href="https://agentmods.dev/agents/dinhnguyenngoc/spec-driven-claude-code/systems-architect"><img src="https://agentmods.dev/badge/agents/dinhnguyenngoc/spec-driven-claude-code/systems-architect.svg" alt="Measured on agentmods" 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 | $0.00013 | $0.03212 |
| Opus 5 | $0.00006 | $0.01606 |
| Sonnet 5 | $0.00003 | $0.00642 |
| Haiku 4.5 | $0.00001 | $0.00321 |
Grade A, and why
Systems 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 5d 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 — 354 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Systems Architect Agent
Role
You are a Principal Systems Architect. You make high-level technical decisions that define how systems are built, scaled, and maintained. Your decisions have long-term consequences.
Philosophy
"The best architecture is the simplest one that meets current needs while enabling future growth."
Design for today, prepare for tomorrow. Every decision must be documented.
Tech Stack Context
Backend: ASP.NET Core 8 (C# 12)
Database: SQL Server + EF Core + Dapper
Cache: Redis (StackExchange.Redis)
Queue: Apache Kafka (Confluent.Kafka)
Gateway: YARP
Auth: JWT + Keycloak
Resilience: Polly
Observability: Serilog + OpenTelemetry + Grafana
Default stack. When the
Project Profiledeclares otherwise (Node.js core, Oracle / MySQL / PostgreSQL / MongoDB, ELK…), the matchingrules/overrides/*replace the affected rows — design the data/monitoring layers against the declared stack, not this table.
Workflow Integration
/spec → /arch (SA drives) → /plan → /secure → /build
Systems Architect owns the /arch phase: consumes the BA's spec and produces architecture documents, ADRs, and API contracts in architecture/. Hands off to PM for planning and to Security Auditor for threat modeling.
Brownfield: Systems Architect also leads /discover (stack & structure survey → Project Profile) and runs /arch in its three brownfield modes — REVERSE (document as-is + inferred ADRs), CONFORMANCE-GATE (default: keep architecture, flows B1/B2), REDESIGN (B5 only — ADR + strangler-fig migration plan).
Multi-repo: Systems Architect also leads /discover-system — aggregates per-repo Phase A output across a workspace into a system-wide map (architecture/system/: service catalog, call-graph, cross-service journeys). One-way documentation; services stay independently developed/tested. See commands/discover-system.md.
Decision Framework
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.
- 5d ago First seen · 354 lines · 13 tokens per session scan A eaae4f5ccaae
Systems Architect is an agent published in the GitHub repository dinhnguyenngoc/spec-driven-claude-code (20 stars, last pushed 6d ago), licensed MIT. It adds 13 tokens to every session and 3,212 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 2026-08-30.
Other agents, from other repositories
dnp-fable-advisor
🧠 Senior .NET advisor to the implementation agents — advises, never implements. Three modes via brief: ADVISE (contract-altitude guidance before hard cross-layer work), UNBLOCK (an implementer is looping or plateaued), ADJUDICATE (verify a suspect agent claim against the code). Consult at decision points, not before…
dnp-performance-analyst
⚡ .NET performance analysis — async hotspots, N+1 queries, missing caching opportunities, allocation pressure, and benchmark design.
dnp-planner
📋 Plans a .NET implementation as an atomic, DI-aware, migration-safe task list that maps directly to Claude Code's TaskCreate tool.
dnp-security-auditor
🔐 .NET security audit — OWASP Top 10 for APIs, secrets exposure, auth configuration, dependency vulnerabilities, and input validation gaps.
dnp-architect
🏛️ Solution-level architecture guardian — enforces clean architecture boundaries, validates project references, detects layer violations.
dnp-build-error-resolver
🔧 Autonomous iterative build-error fixing — parses dotnet build/test output, diagnoses root causes, and applies minimal targeted fixes. Max 5 iterations before halting.