The JapanFold skill¶

To fold and design from your AI agent instead of writing HTTP calls, install the JapanFold skill: a single SKILL.md built on the open Agent Skills standard. It teaches your agent the API, so you can ask in plain language.

The repo exposes it at two paths. The npx skills installer and anyone downloading the raw file take the root SKILL.md; the Claude Code plugin marketplace loads plugins/japanfold/skills/japanfold/SKILL.md, which is a symlink to it, so the two cannot drift.

Install¶

Set your token in the terminal you start your agent from. Make one at japanfold.aiand.com/account/token, then:
```
export JAPANFOLD_API_KEY=jf_live_your_token
export JAPANFOLD_BASE_URL=https://api.japanfold.aiand.com
```
Never paste it into a chat. Chats are sent to the model provider.
Start your agent from that terminal and paste this:

Install the JapanFold skill: download https://japanfold.aiand.com/skill.md with curl (a web-fetch tool returns only a summary of it) and save it unchanged as your skill file, for Claude Code ~/.claude/skills/japanfold/SKILL.md.

Install it yourself¶

One command installs it into any compatible harness (Claude Code, Cursor, Codex, Gemini CLI, Cline, Windsurf, Copilot, Amp and more):

npx skills add japanfold/japanfold          # this project
npx skills add japanfold/japanfold -g       # global: every project / new chat

Target specific agents: -a claude-code, -a cursor, -a codex, -a '*' (all).
No installer? It is one file. Download it unchanged into your agent's skills directory, for Claude Code:
```
curl -fsSL --create-dirs -o ~/.claude/skills/japanfold/SKILL.md https://japanfold.aiand.com/skill.md
```
A web-fetch tool returns only a summary of the page, so an agent should use curl too.

Claude Code plugin marketplace¶

Install it as a managed plugin (auto-updates via /plugin marketplace update):

claude plugin marketplace add japanfold/japanfold
claude plugin install japanfold@japanfold

Restart Claude Code, then ask it to fold or design.

Claude Science¶

Manage skills in-app, no installer. Customize → Skills, add from the repo (or paste SKILL.md), and publish. If egress is sandboxed, approve the host api.japanfold.aiand.com.

Or connect the MCP server¶

Every MCP client (Claude Code, Claude Desktop, Cursor, Codex) can use JapanFold as tools instead of a skill. The server is https://api.japanfold.aiand.com/mcp and takes the same key:

claude mcp add --transport http japanfold https://api.japanfold.aiand.com/mcp \
  --header "Authorization: Bearer $JAPANFOLD_API_KEY"

In a client configured by JSON, give it the URL and the header Authorization: Bearer <your key>. The tools are generated from the API reference, so they take the same fields as the endpoints. When get_job reports a job succeeded it also hands back download, one shell command that fetches every result file.

Use¶

Once installed, ask in plain language:

"Fold this sequence with Boltz-2 and report the confidence: MKTAYIAK…"

"Co-fold this protein with aspirin and estimate the binding affinity."

"Design 10 nanobody binders against this target."

"Embed these sequences with ESMC-600M and save the pooled vectors."

Or invoke it explicitly where supported: /japanfold.

The API is public and self-describing, so you can also skip the skill entirely and tell your agent: "use the JapanFold API at api.japanfold.aiand.com to fold …".