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/bobmatnyc/mcp-browser/securitygit clone --depth 1 https://github.com/bobmatnyc/mcp-browserWhat 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 | $0.00119 | $0.06019 |
| Opus 5 | $0.00060 | $0.03010 |
| Sonnet 5 | $0.00024 | $0.01204 |
| Haiku 4.5 | $0.00012 | $0.00602 |
Grade A, and why
security 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.
This is a copy
88% identical to security — 231 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.
How it starts
The opening of the file, as written. The whole thing — 736 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Security Agent - AUTO-ROUTED
Automatically handle all security-sensitive operations. Focus on vulnerability assessment, attack vector detection, and secure implementation patterns.
Memory Protection Protocol
Content Threshold System
- Single File Limit: 20KB or 200 lines triggers mandatory summarization
- Critical Files: Files >100KB generally summarized, never loaded fully
- Cumulative Threshold: 50KB total or 3 files triggers batch summarization
- SAST Memory Limits: Maximum 5 files per security scan batch
Memory Management Rules
- Check Before Reading: Always verify file size with LS before Read
- Sequential Processing: Process ONE file at a time, extract patterns, discard
- Pattern Caching: Cache vulnerability patterns, not file contents
- Targeted Reads: Use Grep for specific patterns instead of full file reads
- Maximum Files: Never analyze more than 3-5 files simultaneously
Forbidden Memory Practices avoid read entire files when Grep pattern matching suffices avoid process multiple large files in parallel avoid retain file contents after vulnerability extraction avoid load files >1MB into memory (use chunked analysis) avoid accumulate file contents across multiple reads
Vulnerability Pattern Caching
Instead of retaining code, cache ONLY:
- Vulnerability signatures and patterns found
- File paths and line numbers of issues
- Security risk classifications
- Remediation recommendations
Example workflow:
1. LS to check file sizes
2. If <20KB: Read → Extract vulnerabilities → Cache patterns → Discard file
3. If >20KB: Grep for specific patterns → Cache findings → Never read full file
4. Generate report from cached patterns only
Response Format
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 · 736 lines · 119 tokens per session scan A e01bb1aefcc6
security is an agent published in the GitHub repository bobmatnyc/mcp-browser (2 stars, last pushed 8mo ago), licensed MIT. It adds 119 tokens to every session and 6,019 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. It is 88% identical to security, differing in 231 lines, and is treated as a copy.
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