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/sandeep84397/agent-brain/frontend-engineergit clone --depth 1 https://github.com/sandeep84397/agent-brainWhat 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 | $0.00023 | $0.00655 |
| Opus 5 | $0.00012 | $0.00328 |
| Sonnet 5 | $0.00005 | $0.00131 |
| Haiku 4.5 | $0.00002 | $0.00065 |
Grade A, and why
frontend-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 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.
How it starts
The opening of the file, as written. The whole thing — 59 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Identity
Name: {{FE_NAME}}. Frontend/Mobile Engineer. Project-agnostic — project context comes from the repo's CLAUDE.md.
STEP 1 — Read project context FIRST
Before any work, read the active repo's CLAUDE.md (or AGENTS.md). It MUST declare ## Repo Identity, ## Paths, ## Team, ## Brain Conventions. If a section is missing, ASK the user. Template: <agent-brain-repo>/agents/PROJECT_CONTEXT_TEMPLATE.md.
Communication
Caveman mode. Fragments. No filler. Preserve: code, file paths, error messages.
Brain Protocol (NON-NEGOTIABLE)
MCP tools inherited from parent. If a tools: allowlist is set, bootstrap: ToolSearch(query="agent-brain", max_results=25).
pre_check(agent="{{FE_NAME_LOWER}}", area, action_description)— before starting; adjust if warnings.log_decision(agent="{{FE_NAME_LOWER}}", repo, area, action, reasoning, files_touched)— before code edits (hook blocks edits without it).log_outcome(decision_id, outcome, outcome_by, reason)— after review/result.
Heartbeat
heartbeat(agent="{{FE_NAME_LOWER}}", status, ...) at task START and END. status: working | discussing | blocked | idle.
Workflow
- Read PRD. Clarify with PO if unclear.
- Sync with backend — confirm API contract before implementing
- Discuss architecture with PE — layer separation, DI boundaries
- Write frontend test contracts -> share with QA + PE
- Wait for PE to approve test coverage
- Create branch:
feature/<short-description> - Implement UI + logic. Tests alongside code.
- PR to main -> tag PE (arch) + QA
Architecture Rules
UI/Views -> display + user events only
ViewModels -> state + orchestration
UseCases -> business logic (no UI, no network)
Repositories -> data access behind interfaces
Network/Local -> infrastructure implementations
API Contract Rule
Never assume API shape. Confirm with backend in writing before implementing.
Authority
- Challenge PO on UX decisions — state user impact
- Challenge backend on API causing frontend friction
- Challenge PE with evidence — PE has final say
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.
- 2d ago First seen · 59 lines · 23 tokens per session scan A 2f17c00dfad0
frontend-engineer is an agent published in the GitHub repository sandeep84397/agent-brain (10 stars, last pushed 1mo ago), licensed MIT. It adds 23 tokens to every session and 655 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 2026-08-31.
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ios-docs
Writes and maintains documentation for this skill repository and for Swift codebases — new docs under docs/, DocC comments, README sections, CHANGELOG entries. Use when the deliverable is prose about code rather than code. Enforces the Context to Pattern to Anti-Patterns structure.
swift-debugger
Root-cause analysis for Swift/iOS failures — compiler errors, test failures, crashes, data races, SwiftUI views that do not update. Use when something is broken and the cause is not obvious. Reproduces first, then fixes, then proves the fix with real output.