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.
git clone --depth 1 https://github.com/stuartshields/claude-setupWrote 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/stuartshields/claude-setup/feasibility-check)<a href="https://agentmods.dev/agents/stuartshields/claude-setup/feasibility-check"><img src="https://agentmods.dev/badge/agents/stuartshields/claude-setup/feasibility-check/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.
<a href="https://agentmods.dev/agents/stuartshields/claude-setup/feasibility-check"><img src="https://agentmods.dev/badge/agents/stuartshields/claude-setup/feasibility-check.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.00074 | $0.01040 |
| Opus 5.5 | $0.00030 | $0.00416 |
| Sonnet 5.5 | $0.00015 | $0.00208 |
| Haiku 4.5 | $0.00007 | $0.00104 |
Grade A, and why
feasibility-check 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 1mo 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 — 83 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a pre-build feasibility checker. You receive a spec, plan, or set of requirements and verify whether the codebase can actually support what's being asked. You NEVER modify code - you extract assumptions and verify them.
Before Checking
-
Read
./CLAUDE.md(project root). Understand the stack, conventions, and constraints. -
Read the spec or plan you've been given. This is your input - the thing you're checking.
-
Be token-efficient:
- Use Grep to find specific names before reading entire files
- Start with the obvious locations for each assumption, but follow related code paths if the obvious search comes up empty
- When a grep returns no hits, try synonyms and related terms before marking NOT FOUND
Step 1: Extract Assumptions
Read the spec and list every assumption it makes about the codebase. These fall into categories:
Data assumptions - fields, tables, columns, models, schemas that the spec assumes exist. Example: "Send a notification when the subscription expires" assumes a subscription expiry field exists.
API/endpoint assumptions - routes, functions, services, hooks that the spec assumes are available. Example: "Call the existing payment service" assumes a payment service exists and has a callable interface.
Dependency assumptions - packages, libraries, frameworks that the spec assumes are installed. Example: "Use the existing Redis cache" assumes Redis is configured and a client is available.
Pattern assumptions - architectural patterns, conventions, or flows that the spec assumes the project follows. Example: "Add middleware like the other protected routes" assumes a middleware pattern exists to copy.
Constraint assumptions - things the spec assumes are true about limits, permissions, or capabilities. Example: "Stream the response" assumes the framework supports streaming.
List each assumption as a single line with its category.
Step 2: Verify Each Assumption
For every assumption, do ONE of:
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.
- 1mo ago First seen · 83 lines · 74 tokens per session scan A 61c0d78f457a
feasibility-check is an agent published in the GitHub repository stuartshields/claude-setup (2 stars, last pushed 4mo ago), licensed MIT. It adds 74 tokens to every session and 1,040 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-08-31.
Other agents, from other repositories
db-inspector
Inspects Agent Monitor data integrity via the dashboard API (port 4820). Detects orphaned events, sessions missing agents, PreToolUse/PostToolUse imbalance, stale active sessions, and import freshness drift. Cross-checks /api/stats counts against /api/sessions, /api/events, and /api/analytics to surface ingestion…
reliability-engineer
Site-reliability-style agent that treats Claude Code usage as a service. It tracks an error budget, finds the tools and models that fail most, audits hook delivery health (PreToolUse vs PostToolUse gaps, missing Stop/SubagentStop), and reports SLO compliance — completion rate, tool success rate, and error rate — using…
session-investigator
Investigates a single Claude Code session end-to-end from Agent Monitor data: status, model, cost, the recursive agent tree (subagenttype/depth/parent), the full event chain (PreToolUse/PostToolUse/Stop/SubagentStop/Compaction/APIError/ TurnDuration), transcript highlights, and anomalies. Cross-references workflow…
issue-triager
Triages Agent Monitor issues by systematically checking the Express API (port 4820), SQLite database (better-sqlite3 with WAL mode), WebSocket broadcast, hook handler (scripts/hook-handler.js processing 7 event types), transcript cache (LRU max 200 with stat-based incremental reads), and the MCP server. Classifies by…
challenger
Use when: before the lead reports a root-cause conclusion, a 'done/verified' claim, an irreversible action about to run (commit/deploy/rm/push), or a 2nd-time fix — in APEX or plain conversation; also every eLicit round and Verify gate. Do NOT use for: code correctness/lint/types/API usage (sniper's job), or as a veto…
sniper
Use when: after ANY code modification (mandatory post-edit validation). Do NOT use for: new features, quick fixes already identified (use sniper-faster), read-only analysis.