Messages API

Q: What is a Claude Code skill and how does the Messages API skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Messages API is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Content category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Content · Sub-category: translation · Last updated: 2026-07-21

ai:claude

Reference for the Anthropic Messages API (/v1/messages) as a third-party compatibility protocol — the 7 inference servers that implement it natively (vLLM, SGLang, llama.cpp, Ollama, mistral.rs, Llama Stack/OGX, Lemonade), gateways that adapt it (LiteLLM, Bifrost, Superagent Gateway), client behavior (Claude Code, opencode anthropic provider), Messages ↔ Chat Completions translation, the thinking-signature seam, stop_reason divergences, and streaming quirks. NOT for official Anthropic API usage (models, pricing, SDK) — that is the claude-api skill.

Security AStatic scan found no risk patternsHow grading works ›

From the source SKILL.md

The Anthropic Messages API (POST /v1/messages) is now the second open compatibility surface after Chat Completions: every major local inference server serves it natively (verified by source examination 2026-07-19 — vLLM, SGLang, llama.cpp, Ollama, mistral.rs, Llama Stack/OGX, Lemonade), and gateways (LiteLLM, Bifrost, Superagent Gateway) adapt it to everything else. Claude Code is the driving client; Ollama, Lemonade, and Superagent all ship Claude Code-specific affordances.

What this skill does

Messages API is a community-contributed Claude Code skill in the translation sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/messages-api/ and loads when your prompt matches the skill's trigger.

Who uses this skill

The Messages API Claude Code skill is built for content creators, marketers, copywriters, SEO professionals, and editorial teams. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 156,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/messages-api
curl -L https://claudskills.com/skills/messages-api/SKILL.md \
  -o ~/.claude/skills/messages-api/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/messages-api/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/messages-api/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\messages-api\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Messages API Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/messages-api/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Messages API skill do?

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Messages API skill?

Use Messages API when your Claude Code task falls under the Content category — specifically in the translation area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Messages API" or describe the task and let Claude pick). Browse related skills at /category/content/.

What is a Claude Code skill and how does the Messages API skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Messages API is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Content category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/air-gapped/skills/blob/HEAD/.claude/skills/messages-api/SKILL.md
License: MIT
Author: air-gapped

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

air-gapped. (2026). Messages API [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/messages-api/

BibTeX

@misc{messages-api-2026,
  author    = {air-gapped},
  title     = {Messages API [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/messages-api/}
}

Embed this skill

Promote, attribute, or link this skill from your own README, blog post, or documentation. All three snippets are free to use — no sign-up, no API key. More distribution surfaces →

Badge

[![ClaudSkills](https://claudskills.com/badge/messages-api.svg)](https://claudskills.com/skills/messages-api/?utm_source=badge&utm_medium=readme&utm_campaign=skill_badge)

Security scan

Grade A · scanned 2026-07-21 — free static scan against the OWASP Agentic Skills Top 10.

No risk patterns were found in any of the ten OWASP-aligned categories. How grading works ›

✓ Prompt injection
✓ Data exfiltration
✓ Supply chain
✓ Reverse shell
✓ Credentials
✓ Execution
✓ Filesystem
✓ Persistence
✓ Obfuscation
✓ Network

Show this grade on your repo (click to copy):

[![Security: A](https://img.shields.io/badge/Security-A-2e7d32)](https://claudskills.com/skills/messages-api/#security)