feat: add upstash-redis skill 🤖🤖🤖

[CahidArda]

Pull Request Checklist

• I have read and followed the CONTRIBUTING.md guidelines.
• I have read and followed the Guidance for submissions involving paid services.
• My contribution adds a new instruction, prompt, agent, skill, workflow, or canvas extension file in the correct directory.
• The file follows the required naming convention.
• The content is clearly structured and follows the example format.
• I have tested my instructions, prompt, agent, skill, workflow, or canvas extension with GitHub Copilot.
• I have run npm start and verified that README.md is up to date.
• I am targeting the main branch for this pull request.

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Description

Adds one skill:

• skills/upstash-redis/SKILL.md — caching (cache-aside with TTL), session storage, and rate limiting from serverless/edge runtimes using @upstash/redis (HTTP-based Redis client) and @upstash/ratelimit (fixed window, sliding window, token bucket). Includes a Next.js route-handler example that returns 429 with Retry-After, notes on pending/waitUntil for edge runtimes, and a "when not to use" section (TCP Redis clients, in-process caches).

The skill states requirements and limitations (hosted service, env vars, per-command HTTP cost) and links only to documentation and source repositories.

docs/README.skills.md was regenerated with npm start; npm run skill:validate and npx @microsoft/vally-cli lint pass for the new folder.

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Type of Contribution

• New instruction file.
• New prompt file.
• New agent file.
• New plugin.
• New skill file.
• New agentic workflow.
• New canvas extension.
• Update to existing instruction, prompt, agent, plugin, skill, workflow, or canvas extension.
• Other (please specify):

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Additional Notes

Affiliation disclosure: I work at Upstash, the company that operates the service this skill covers. The content is written as neutral, practical guidance per Discussion #968; the same material is maintained in the open at https://github.com/upstash/skills. Happy to revise wording or trim anything that reads as promotional.

Validated with npm run skill:validate, npm start, and npx @microsoft/vally-cli lint on the folder; code samples were checked against the current SDK APIs (@upstash/redis 1.38, @upstash/ratelimit 2.0).

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By submitting this pull request, I confirm that my contribution abides by the Code of Conduct and will be licensed under the MIT License.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[github-actions]

🔒 PR Risk Scan Results

Scanned 1 changed file(s).

Severity	Count
🔴 High	0
🟠 Medium	0
ℹ️ Info	0

✅ No matching risk patterns were detected in changed files.

This is an automated soft-gate report. Findings indicate review targets and do not block merge by themselves.

[github-actions]

🔍 Vally Lint Results

✅ All checks passed

Scope	Checked
Skills	1
Agents	0
Total	1

Severity	Count
❌ Errors	0
⚠️ Warnings	0
ℹ️ Advisories	0

Summary

Level	Finding
ℹ️	✅ upstash-redis (2/2 checks passed)
ℹ️	✓ [spec-compliance] All 1 skill(s) are spec-compliant.
ℹ️	✓ spec-compliance: All spec checks passed.
ℹ️	✓ [valid-refs] All file references across 1 skill(s) are valid.
ℹ️	✓ valid-refs: All file references resolve to existing files within the skill directory.
ℹ️	1 skill(s) linted, 1 passed

Full linter output

### Linting skills/upstash-redis
✅ upstash-redis (2/2 checks passed)
    ✓ [spec-compliance] All 1 skill(s) are spec-compliant.
        ✓ spec-compliance: All spec checks passed.
    ✓ [valid-refs] All file references across 1 skill(s) are valid.
        ✓ valid-refs: All file references resolve to existing files within the skill directory.

1 skill(s) linted, 1 passed

[Copilot]

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