AI Coding Skill

Use the Nevermined AI Skill to give your coding assistant deep knowledge of the Nevermined Payments SDK, the x402 payment protocol, and integration patterns for Express.js, FastAPI, Strands agents, MCP servers, and Google A2A. Instead of copy-pasting docs, you import the skill once and your AI assistant knows how to wire up payments for you.

Two skills, opposite directions

There are two, and which one you want depends on which side of the payment you’re on.

Skill	Your agent is…	Covers
`nevermined-payments`	receiving money, or buying a Nevermined plan	SDK integration, middleware, plans, credits — the rest of this page
`nevermined-router`	spending money at external services	Discovering services in the catalog, creating a spending Delegation, paying any x402 or MPP endpoint through the Nevermined Router, and the guardrails an autonomous buyer must respect

Installing both is fine — they don’t overlap. Every supported tool can now reach the Router:

Claude Code — install them as plugins, one command each. See the tab below.
Cursor, Windsurf, Cline, Amazon Q — swap nevermined-payments for nevermined-router in the paths below, or run the extra command shown in each tab.
Codex CLI and GitHub Copilot — AGENTS.md and .github/copilot-instructions.md are single files with no skill name to swap, so each one carries both halves: the payments guidance and a condensed Router section. Take the whole file. Codex can also install nevermined-router as a proper skill directory under .agents/skills/ — see its tab.

What’s Included

The skills provide your coding assistant with:

SDK initialization patterns for TypeScript and Python
Framework-specific middleware (Express.js, FastAPI, Strands, MCP, Google A2A)
x402 protocol flow — headers, verification, settlement
Payment plan registration and configuration
Client-side integration — ordering plans, generating tokens, calling protected APIs
Troubleshooting for common errors (402, -32003, -32002)

And, from the Router skill:

Service discovery in the public Agent Services Catalog
Spending Delegations — creating a capped budget and funding the buyer wallet
Paid calls over x402 and MPP through one endpoint, with the protocol auto-detected
Guardrails — every BCK.ROUTER.* code, what’s retryable, and why a refusal must not be worked around

Install the Skill

Choose your AI coding tool below for step-by-step installation instructions.

Claude Code

Install from the Nevermined plugin marketplace — two commands, and Claude Code keeps the skills up to date for you:

/plugin marketplace add nevermined-io/docs

/plugin install nevermined-payments@nevermined    # charging for your agent
/plugin install nevermined-router@nevermined      # buying from external services

Those are Claude Code commands — type them in Claude Code, not in a shell.Install either or both. The marketplace is named nevermined (that’s the @nevermined suffix); nevermined-io/docs is just the repository it’s served from.Claude Code loads each skill when it’s relevant to your work, and refreshes it in the background when we publish changes. To update by hand it takes two steps — /plugin marketplace update nevermined refreshes the catalogue, then /plugin update nevermined-router@nevermined updates the installed plugin itself (restart to apply).Alternative — copy the files directly. Use this if you’d rather take a snapshot you control, or you’re on a Claude Code build without plugin support:

mkdir -p ~/.claude/skills

tmpdir="$(mktemp -d)"
git clone --depth 1 --filter=blob:none --sparse https://github.com/nevermined-io/docs "$tmpdir"
cd "$tmpdir"
git sparse-checkout set skills/nevermined-payments skills/nevermined-router

cp -R skills/nevermined-payments ~/.claude/skills/
cp -R skills/nevermined-router ~/.claude/skills/    # buying through the Router

cd -
rm -rf "$tmpdir"

Claude Code discovers skills automatically from ~/.claude/skills/ (personal) and .claude/skills/ (project). Copied this way they’re a snapshot — you re-run the command to update.

ClawHub

Both skills are published to the ClawHub registry under the nevermined-io publisher, so any tool that reads a skills/ directory can pull them with one command:

npx clawhub install nevermined            # the payments skill
npx clawhub install nevermined-router     # buying through the Router

This writes to skills/<slug>/ in the current directory. --dir sets a different target — it’s a global flag, so it goes before the subcommand:

npx clawhub --dir ~/.claude/skills install nevermined-router

You don’t need an account to install. npx clawhub update --all pulls the latest published versions (the bare update errors — it wants a slug or --all), and npx clawhub inspect nevermined-router shows what you’d get without installing it.The install lock is per working directory, so if you installed with --dir, run the update from that same directory with the same flag: npx clawhub --dir ~/.claude/skills update --all.

Two ClawHub surprises worth knowing. The payments skill is published under the slug nevermined, not nevermined-payments (the Router skill’s slug matches its name). And the version clawhub inspect reports for the payments skill won’t match the Skill version in its own SKILL.md header — the registry assigns its own numbering. Trust the registry’s version for “is my copy current”, and the file’s for what changed.

Cursor

Option A — Remote rule import (recommended):

Open Cursor Settings (gear icon)
Navigate to Rules section
Click Add Remote Rule
Paste the GitHub repository URL: https://github.com/nevermined-io/docs
Cursor syncs the rules automatically

Option B — Copy rule files to your project:Download the rule file and add it to your project:

mkdir -p .cursor/rules
curl --fail -o .cursor/rules/nevermined-payments.mdc \
  https://raw.githubusercontent.com/nevermined-io/docs/main/.cursor/rules/nevermined-payments.mdc

# Buying from external x402 / MPP services through the Router
curl --fail -o .cursor/rules/nevermined-router.mdc \
  https://raw.githubusercontent.com/nevermined-io/docs/main/.cursor/rules/nevermined-router.mdc

The .cursor/rules/*.mdc format supports glob-based activation — the Nevermined rule auto-activates when you work with .ts, .js, or .py files.

Windsurf (Codeium)

Copy the rule file to your project’s Windsurf rules directory:

mkdir -p .windsurf/rules
curl --fail -o .windsurf/rules/nevermined-payments.md \
  https://raw.githubusercontent.com/nevermined-io/docs/main/.windsurf/rules/nevermined-payments.md

# Buying from external x402 / MPP services through the Router
curl --fail -o .windsurf/rules/nevermined-router.md \
  https://raw.githubusercontent.com/nevermined-io/docs/main/.windsurf/rules/nevermined-router.md

Windsurf automatically discovers rules from .windsurf/rules/ and applies them based on their activation mode.

Windsurf rules have a 6,000-character limit per file. The Nevermined rule file stays within this limit with the most essential patterns. For the full reference, point your assistant to the SKILL.md.

GitHub Copilot

Repository-wide instructions:Add the instructions file to your project:

mkdir -p .github
curl --fail -o .github/copilot-instructions.md \
  https://raw.githubusercontent.com/nevermined-io/docs/main/.github/copilot-instructions.md

Copilot reads .github/copilot-instructions.md automatically for every request within the repository.Path-specific instructions (optional):For more targeted activation, create a file at .github/instructions/nevermined.instructions.md:

---
applyTo: "**/*.ts,**/*.tsx,**/*.js,**/*.py"
---

When working with Nevermined payments, use the patterns from .github/copilot-instructions.md

OpenAI Codex CLI

Codex CLI reads AGENTS.md files for project context. Add it to your project:

curl --fail -o AGENTS.md \
  https://raw.githubusercontent.com/nevermined-io/docs/main/AGENTS.md

Codex CLI discovers AGENTS.md automatically by scanning from the current directory up to the repository root.Alternative — install as a Codex skill:

mkdir -p .agents/skills
cp -r skills/nevermined-payments .agents/skills/
cp -r skills/nevermined-router .agents/skills/    # buying through the Router

Codex CLI detects skills from .agents/skills/ and loads them when relevant.

Cline (VS Code)

Copy the rule file to your project:

mkdir -p .clinerules
curl --fail -o .clinerules/nevermined-payments.md \
  https://raw.githubusercontent.com/nevermined-io/docs/main/.clinerules/nevermined-payments.md

# Buying from external x402 / MPP services through the Router
curl --fail -o .clinerules/nevermined-router.md \
  https://raw.githubusercontent.com/nevermined-io/docs/main/.clinerules/nevermined-router.md

Cline discovers all .md files in the .clinerules/ directory and applies them based on the paths frontmatter. The Nevermined rule activates for .ts, .js, and .py files.You can also create rules through the Cline UI: click the + button in the Rules popover below the chat input.

Amazon Q Developer

Copy the rule file to your project:

mkdir -p .amazonq/rules
curl --fail -o .amazonq/rules/nevermined-payments.md \
  https://raw.githubusercontent.com/nevermined-io/docs/main/.amazonq/rules/nevermined-payments.md

# Buying from external x402 / MPP services through the Router
curl --fail -o .amazonq/rules/nevermined-router.md \
  https://raw.githubusercontent.com/nevermined-io/docs/main/.amazonq/rules/nevermined-router.md

Amazon Q automatically uses rules from .amazonq/rules/ as context. You can toggle rules on/off via the Rules button in the Amazon Q chat panel.

ChatGPT, Claude.ai, or any other assistant

Share the skill content directly with your assistant:

Open the SKILL.md file
Copy the contents
Paste into your assistant’s context, knowledge base, or system prompt

For a more concise version, use the AGENTS.md file instead.

Supported Tools at a Glance

<skill> is nevermined-payments or nevermined-router — install either or both.

Tool	Config File	Router available?	Auto-Activates
Claude Code	plugin, or `~/.claude/skills/<skill>/SKILL.md`	Yes	Yes — when relevant
Cursor	`.cursor/rules/<skill>.mdc`	Yes	Yes — on `.ts`, `.js`, `.py` files
Windsurf	`.windsurf/rules/<skill>.md`	Yes	Yes — model decides
GitHub Copilot	`.github/copilot-instructions.md`	Yes — condensed, in the same single file	Yes — always
Codex CLI	`AGENTS.md` or `.agents/skills/<skill>/`	Yes — condensed in `AGENTS.md`, in full via `.agents/skills/`	Yes — always or when relevant
Cline	`.clinerules/<skill>.md`	Yes	Yes — on `.ts`, `.js`, `.py` files
Amazon Q	`.amazonq/rules/<skill>.md`	Yes	Yes — always
Any (ClawHub)	`skills/<slug>/SKILL.md`	Yes	Depends on the tool

The Copilot and Codex files are condensed — they carry the buy loop, the money traps and every BCK.ROUTER.* retry decision, but not the full reference set: they omit 0004/0005, everything the Router refuses outright (MPP splits, internal targets, redirects, forged X-Router-*), and the relay limits. For the complete Router skill, install it as a directory (Claude Code plugin, ClawHub, or .agents/skills/).The IDE rule files also omit 0007. Windsurf’s copy additionally omits BCK.ROUTER.0012, because Windsurf truncates a rule file at 6,000 characters and drops the end — where the guardrails live — so the file cannot grow without displacing something. 0012 is a 400 whose non-retryable verdict the file already states as a rule (“only 0006 and 0007 are retryable”); BCK.ROUTER.0013 is kept because it is a 500, the one shape an agent retries by default. Cursor, Cline and Amazon Q carry both.

Example Prompts

After installing the skill, try prompts like:

Add payments to Express.js

“Add Nevermined x402 payment protection to my Express.js API. I want to charge 1 credit per request on the /ask endpoint.”

Protect a FastAPI endpoint

“Integrate Nevermined payments into my FastAPI app. Use dynamic credits based on the token count in the response.”

Build a paid MCP server

“Create an MCP server with Nevermined payments. Register a weather tool that costs 5 credits per call.”

Add payments to a Strands agent

“Protect my Strands agent tool with the @requires_payment decorator. Charge 2 credits per call.”

Alternative: Use the MCP Search Server

If you prefer real-time documentation search over a static skill, you can connect your coding assistant to the Nevermined MCP documentation server:

{
  "mcpServers": {
    "nevermined-docs": {
      "url": "https://nevermined.ai/docs/mcp"
    }
  }
}

This gives your assistant the ability to search the full Nevermined documentation on-demand. See Build Using Nevermined MCP for details.

Skill vs. MCP Server

Approach	Best For	Tradeoff
AI Skill (SKILL.md)	Fast, offline-capable, consistent patterns	Static — update when SDK changes
MCP Search Server	Always up-to-date, full doc coverage	Requires network, slower per-query

For the best experience, use both: install the skill for core patterns and connect the MCP server for edge cases.

Learn

Build

Payments

Nevermined Router

Solutions

Organizations

Integrations

Payment Patterns

Components

Specs

Two skills, opposite directions

What’s Included

Install the Skill

Claude Code

ClawHub

Cursor

Windsurf (Codeium)

GitHub Copilot

OpenAI Codex CLI

Cline (VS Code)

Amazon Q Developer

ChatGPT, Claude.ai, or any other assistant

Supported Tools at a Glance

Example Prompts

Add payments to Express.js

Protect a FastAPI endpoint

Build a paid MCP server

Add payments to a Strands agent

Alternative: Use the MCP Search Server

Skill vs. MCP Server

What’s Next?

5-Minute Setup

Express.js Integration

FastAPI Integration

MCP Integration

​Two skills, opposite directions

​What’s Included

​Install the Skill

​Claude Code

​ClawHub

​Cursor

​Windsurf (Codeium)

​GitHub Copilot

​OpenAI Codex CLI

​Cline (VS Code)

​Amazon Q Developer

​ChatGPT, Claude.ai, or any other assistant

​Supported Tools at a Glance

​Example Prompts

Add payments to Express.js

Protect a FastAPI endpoint

Build a paid MCP server

Add payments to a Strands agent

​Alternative: Use the MCP Search Server

​Skill vs. MCP Server

​What’s Next?

5-Minute Setup

Express.js Integration

FastAPI Integration

MCP Integration

Two skills, opposite directions

What’s Included

Install the Skill

Claude Code

ClawHub

Cursor

Windsurf (Codeium)

GitHub Copilot

OpenAI Codex CLI

Cline (VS Code)

Amazon Q Developer

ChatGPT, Claude.ai, or any other assistant

Supported Tools at a Glance

Example Prompts

Alternative: Use the MCP Search Server

Skill vs. MCP Server

What’s Next?