GBrain is a memory and retrieval layer for AI agents that searches, connects, and synthesizes information from stored sources. It is used to give coding agents and autonomous agents access to knowledge beyond their current code, including shared company information with access controls. The catalogue add-ons help agents operate GBrain and connect it to agent workflows.
Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/garrytan/gbrainnpx agentmods add skills/garrytan/gbrain/schema-authorWrote 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/skills/garrytan/gbrain/schema-author)<a href="https://agentmods.dev/skills/garrytan/gbrain/schema-author"><img src="https://agentmods.dev/badge/skills/garrytan/gbrain/schema-author/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/skills/garrytan/gbrain/schema-author"><img src="https://agentmods.dev/badge/skills/garrytan/gbrain/schema-author.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Snyk pass
- NVIDIA SkillSpector warn
SkillSpector: 5 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Rogue Agent · line 47 Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
- medium Agent Snooping · line 65 Skill enumerates or reads other installed skills. Access to other skills' SKILL.md files or the skills directory reveals prompt instructions, capabilities, and secrets that should be invisible to peer skills.Fix: Remove all code or instructions that list or read other skills' files or directories. Skills should operate independently; cross-skill access is a privilege escalation.
- medium Agent Snooping · line 68 Skill enumerates or reads other installed skills. Access to other skills' SKILL.md files or the skills directory reveals prompt instructions, capabilities, and secrets that should be invisible to peer skills.Fix: Remove all code or instructions that list or read other skills' files or directories. Skills should operate independently; cross-skill access is a privilege escalation.
- medium Rogue Agent · line 250 Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
- medium Excessive Agency · line 260 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 | $0.00067 | $0.03557 |
| Opus 5 | $0.00034 | $0.01778 |
| Sonnet 5 | $0.00013 | $0.00711 |
| Haiku 4.5 | $0.00007 | $0.00356 |
Grade A, and why
schema-author 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- schema-author — 95% identical, 20 lines differ
How it starts
The opening of the file, as written. The whole thing — 306 lines — stays where its author put it; the contents beside it link to each section on GitHub.
schema-author — evolve your schema pack
Non-goals (use these other skills instead)
This skill AUTHORS the schema pack (adds page types, link verbs, prefixes, flags). For these adjacent jobs, route elsewhere:
- Filing one specific page →
skills/brain-taxonomist/SKILL.md. Brain- taxonomist routes at WRITE TIME ("where does this note go?"). schema-author changes the rules at AUTHORING TIME ("what types and prefixes exist?"). - Schema-check as part of EIIRP iteration →
skills/eiirp/SKILL.mdalready has a schema-check phase. Don't duplicate. - Just looking up a type's settings →
gbrain schema explain <type>directly. This skill is for CHANGING the pack, not READING from it. - Querying who knows about X →
gbrain whoknows <topic>directly. schema-author makes a type expert-routable; it does not run the query.
Convention
Convention: see conventions/brain-first.md for the lookup chain (search → query → get_page → external).
Convention: see conventions/schema-evolution.md for "when to add a type vs alias vs prefix" — the heuristic.
When to invoke
Invoke when the user (or a sibling skill) says any of:
- "Add a
researchertype to my schema" - "I have 4000 untyped pages under
meetings/" - "My brain doesn't know that
journal-articleis a type" - "Set
paperto be extractable" - "Propose types from what I've ingested"
- "Sync the new types to backfill existing pages"
DON'T invoke for "where does THIS note go" (use brain-taxonomist) or
"who knows about X" (use expert-routing / gbrain whoknows).
Tutorial + vision
- Why this matters:
docs/what-schemas-unlock.md— 7 killer use cases (4000 invisible meetings made queryable, founder ops brain, research brain, legal brain, team brain, agent-as-co-curator) plus the structural argument for why types matter at query time. Read this before pitching schema authoring to a user — it's the doc that explains the difference between a pile of notes and a brain with structure. - 5-minute walkthrough:
docs/schema-author-tutorial.md— fork the bundled pack, add a researcher type, sync, prove the T1.5 wiring viagbrain whoknows. Use placeholder pages so it runs against any brain without affecting real content.
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 · 306 lines · 67 tokens per session scan A 1dd11a44dabc
schema-author is a skill published in the GitHub repository garrytan/gbrain (29,751 stars, last pushed yesterday), licensed MIT. It adds 67 tokens to every session and 3,557 once invoked, about $0.0003 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 2026-09-03.
Other skills, from other repositories
create-pr
Creates a GitHub PR with a Linear-ticket-prefixed title and a decision-led, narrative description for prisma-next. Use when the user wants to create a pull request, open a PR, or submit changes for review.
schema-exploration
Lists tables, describes columns and data types, identifies foreign key relationships, and maps entity relationships in a database. Use when the user asks about database schema, table structure, column types, what tables exist, ERD, foreign keys, or how entities relate.
ha-data-stores
Map of Hope Agent's local data stores and safe read-only query workflow. Use when the user asks where Hope Agent stores data, wants to inspect sessions/messages/memory/logs/background jobs/knowledge indexes/settings, asks the model to query local app data, or debugging requires checking persisted state. Trigger…
supabase
Supabase / PostgREST Row-Level-Security playbook — pull the anon (or leaked servicerole) key out of the frontend JS, map tables from the auto-generated OpenAPI spec, test anonymous RLS READ disclosures (PII/secret leaks), and anonymous RLS WRITE abuse (insert/update/delete — e.g. forging…
nornicdb-cypher-queries
Pick fast, predictable Cypher query shapes in NornicDB — point lookups, batch retrieval, pagination, search, traversal, batched UNWIND/MERGE writes, cleanup, multi-tenant isolation. Use when writing or reviewing Cypher whose latency or throughput matters; maps user intent to the executor's hot-path query templates.
dsql
Build with Aurora DSQL — manage schemas, execute queries, handle migrations, diagnose query plans, diagnose cluster performance, load data, and develop applications with a serverless, distributed SQL database. Covers IAM auth, multi-tenant patterns, MySQL-to-DSQL and PostgreSQL-to-DSQL schema conversion, foreign key…