kora-s3

kora-s3 is a skill for Claude Code from kora-projects/kora-skills. It costs 60 tokens per session (3,624 once invoked), scanned A, original, Apache-2.0.

A Kora integration for storing files and other binary data in S3-compatible object storage, such as AWS S3 or MinIO.

In plain words
What is it for?
Use it for images, files, and other stored objects, including multipart uploads, streaming, path-based object keys, and presigned download URLs.
Why use it?
It provides Kora-specific ways to save, retrieve, list, delete, and upload large objects without treating them like ordinary database records.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: mentions AGENTS.md.

Needs its repository: it reads a path above its own folder, which exists only inside the repository. The line is **Kora sub-skill — obey the [kora-v1 meta rules](../../SKILL.md) on every task:** **R0** ensure `.kora-agent/` docs+examples are cloned · **R1** read this sub-s.

Part of the kora-v1 plugin — 41 skills shipped together

Good fit Use it for images, files, and other stored objects, including multipart uploads, streaming, path-based object keys, and presigned download URLs.

Compare 6 skills from other repositories ↓
Install

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.

Clone the repo
git clone --depth 1 https://github.com/kora-projects/kora-skills
agentmods
npx agentmods add skills/kora-projects/kora-skills/kora-s3

Made for: Claude Code.

Or install kora-v1, the plugin that ships this one along with the rest of its 41 skills.

Wrote 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.

agentmods badge for kora-s3

README.md
[![agentmods](https://agentmods.dev/badge/skills/kora-projects/kora-skills/kora-s3/github.svg)](https://agentmods.dev/skills/kora-projects/kora-skills/kora-s3)
Your own site
<a href="https://agentmods.dev/skills/kora-projects/kora-skills/kora-s3"><img src="https://agentmods.dev/badge/skills/kora-projects/kora-skills/kora-s3/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.

agentmods 80×15 button for kora-s3

Your own site · 80×15
<a href="https://agentmods.dev/skills/kora-projects/kora-skills/kora-s3"><img src="https://agentmods.dev/badge/skills/kora-projects/kora-skills/kora-s3.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 60 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,624 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00060 $0.03624
Opus 5 $0.00030 $0.01812
Sonnet 5 $0.00012 $0.00725
Haiku 4.5 $0.00006 $0.00362

Measured 9d ago against content hash 7fd84da23870, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

kora-s3 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 9d 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.

plugins/kora-v1/skills/kora-s3/SKILL.md · 324 lines

How it starts

The opening of the file, as written. The whole thing — 324 lines — stays where its author put it; the contents beside it link to each section on GitHub.

kora-s3 — object storage

Kora sub-skill — obey the kora-v1 meta rules on every task: R0 ensure .kora-agent/ docs+examples are cloned · R1 read this sub-skill before writing code · R2 Kora APIs only — no Spring/Micronaut/Quarkus, no invented annotations or config keys · R3 journal any incorrect Kora usage. Add comments/Javadoc only if asked.

Read this first when:

  • adding S3-compatible storage (AWS S3, MinIO, Ceph) to a Kora app,
  • choosing between AWS SDK (s3-client-aws) and MinIO (s3-client-minio) implementations,
  • writing declarative @S3.Client interfaces vs using imperative S3KoraClient,
  • streaming large files via multipart uploads with S3Body.ofPublisher(),
  • modeling S3 key templates with {argName} path substitutions,
  • handling S3-specific responses (GetObjectResponse, ListObjectsV2Response, presigned URLs).

Pick an implementation

Aspect AWS SDK MinIO
Artifact ru.tinkoff.kora.experimental:s3-client-aws ru.tinkoff.kora.experimental:s3-client-minio
Module AwsS3ClientModule (ru.tinkoff.kora.s3.client.aws) MinioS3ClientModule (ru.tinkoff.kora.s3.client.minio)
Native client classes S3Client (sync), S3AsyncClient (async), S3AsyncClient @Tag(MultipartUpload.class) (batch uploads) MinioClient (sync), MinioAsyncClient (async)
HTTP transport Any kora-client HTTP module (required) Auto-creates OkHttp; or use the OkHttp module
Best for AWS S3 itself, deep S3 feature use (versioning, ACL, etc.), AWS Java SDK ecosystem MinIO server, simpler API surface, smaller dependency footprint

Plug exactly one. Both expose Kora's common S3KoraClient / S3KoraAsyncClient API on top, so declarative @S3.Client interfaces are portable between them — switching implementations changes only the module on @KoraApp and a few config keys.

implementation "ru.tinkoff.kora.experimental:s3-client-aws"
implementation "ru.tinkoff.kora:http-client-async"             // any kora-client HTTP module

Read the full file on GitHub · 324 lines

Files

What ships with it

7 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.

Changes

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.

  1. 9d ago First seen · 324 lines · 60 tokens per session scan A 7fd84da23870

Subscribe to this mod's changes

kora-s3 is a skill published in the GitHub repository kora-projects/kora-skills (1 stars, last pushed 9d ago), licensed Apache-2.0. It adds 60 tokens to every session and 3,624 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 2026-08-31.

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