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 skills add proyecto26/system-design-skills --skill blob-storegit clone --depth 1 https://github.com/proyecto26/system-design-skillsWrote 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/proyecto26/system-design-skills/blob-store)<a href="https://agentmods.dev/skills/proyecto26/system-design-skills/blob-store"><img src="https://agentmods.dev/badge/skills/proyecto26/system-design-skills/blob-store/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/proyecto26/system-design-skills/blob-store"><img src="https://agentmods.dev/badge/skills/proyecto26/system-design-skills/blob-store.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 | $0.00147 | $0.03048 |
| Opus 5 | $0.00073 | $0.01524 |
| Sonnet 5 | $0.00029 | $0.00610 |
| Haiku 4.5 | $0.00015 | $0.00305 |
Grade A, and why
blob-store 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 10d 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 — 196 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Blob store
Store large, immutable, unstructured objects — images, video, backups, model weights, document blobs — in a flat namespace keyed by a string, replicated for durability and served by direct download. Getting it wrong means stuffing multi-megabyte blobs into a row-oriented database (where they bloat the working set, wreck cache locality, and cap throughput) or hand-rolling a file server that loses data on the first disk failure.
When to reach for this
Objects are large (KB to GB), written once and read many times, and you only ever
fetch them whole by key — never query inside them. Photo/video stores, user
uploads, backups, data-lake/ML datasets, static-site assets, log archives. The
access pattern is PUT key → GET key, durability matters, and the total volume is
too large or too cold to sit in a primary database.
When NOT to
Small structured records you query, filter, sort, or join — that is data-storage.
Data that needs transactions, secondary indexes, or partial updates (blobs are
replace-whole, not edit-in-place). Low-latency reads of tiny values (a KV cache or
caching wins). A few files on one box that never grow — the local filesystem is
fine; a blob store is operational overhead you do not need yet (YAGNI). Naming
"object storage" for a workload that is really a database is failure mode #2.
Clarify first
- Object size distribution — average and p99 size? (Decides chunking, multipart
thresholds, and whether reads stream or buffer.) →
back-of-the-envelope. - Read:write ratio and access recency — write-once/read-many? How fast does data go cold? (Drives tiering and CDN fronting.)
- Durability and availability target — how many nines of durability? Can a read briefly fail or must it always succeed? (Replication vs erasure coding, multi-region.)
- Access control — public, private, or time-limited per-object grants? (Signed URLs.)
- Mutability and history — do objects change? Must old versions be retained (compliance, undo)? (Versioning + lifecycle.)
- Egress profile — who reads, from where, how often? (CDN offload, egress cost.)
What ships with it
5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 10d ago First seen · 196 lines · 147 tokens per session scan A 97399360eda6
blob-store is a skill published in the GitHub repository proyecto26/system-design-skills (69 stars, last pushed 3mo ago), licensed MIT. It adds 147 tokens to every session and 3,048 once invoked, about $0.0007 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.
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