Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add san-npm/skills-ws --skill mcp-clientgit clone --depth 1 https://github.com/san-npm/skills-wsWrote 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.
[](https://agentmods.dev/skills/san-npm/skills-ws/mcp-client)<a href="https://agentmods.dev/skills/san-npm/skills-ws/mcp-client"><img src="https://agentmods.dev/badge/skills/san-npm/skills-ws/mcp-client/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.
<a href="https://agentmods.dev/skills/san-npm/skills-ws/mcp-client"><img src="https://agentmods.dev/badge/skills/san-npm/skills-ws/mcp-client.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00077 | $0.00740 |
| Opus 5.5 | $0.00031 | $0.00296 |
| Sonnet 5.5 | $0.00015 | $0.00148 |
| Haiku 4.5 | $0.00008 | $0.00074 |
Grade A, and why
mcp-client 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 2mo 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.
How it starts
The opening of the file, as written. The whole thing — 29 lines — stays where its author put it; the contents beside it link to each section on GitHub.
MCP Client — Consuming Model Context Protocol Servers
Transport policy (MCP spec): Use stdio for local subprocess servers and Streamable HTTP (
StreamableHTTPClientTransport, endpoint usually/mcp) for remote servers. The old HTTP+SSE transport was deprecated in spec revision2025-03-26and superseded by Streamable HTTP; keep it only as a legacy fallback for old servers (endpoint usually/sse). WebSocket transport was removed. As of Jun 2026 the latest spec revision is2025-11-25— verify at https://modelcontextprotocol.io/specification.
This skill makes an agent expert at being an MCP client: discovering a server's capabilities, calling its tools, reading its resources, using its prompts, and doing so safely with auth, timeouts, retries, and cost control. It is provider-agnostic; one specific public server (mcp.skills.ws) appears only as an optional worked example at the end.
For building the server side, see the sibling skill mcp-server-builder. For agent orchestration around these tool calls, see ai-agent-building. For wallet/payment flows (x402), see wallet-integration and defi-integration.
Reference guide
Read only the references needed for the current request:
- What this skill covers: references/what-this-skill-covers.md
- 1. Transports: references/1-transports.md
- 2. Programmatic client (official SDK): references/2-programmatic-client-official-sdk.md
- 3. Using server capabilities: references/3-using-server-capabilities.md
- 4. Configuring AI clients: references/4-configuring-ai-clients.md
- 5. Authentication: references/5-authentication.md
- 6. Robustness patterns: references/6-robustness-patterns.md
- 7. Cost control: references/7-cost-control.md
- 8. Pay-per-call (x402) — handle the challenge safely: references/8-pay-per-call-x402-handle-the-challenge-safely.md
- 9. Optional worked example —
mcp.skills.ws: references/9-optional-worked-example-mcp-skills-ws.md - 10. Troubleshooting: references/10-troubleshooting.md
- Quick reference: references/quick-reference.md
What ships with it
13 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.
- agents/openai.yaml 190 B
- references/1-transports.md 2.0 KB
- references/10-troubleshooting.md 1.4 KB
- references/2-programmatic-client-official-sdk.md 5.3 KB
- references/3-using-server-capabilities.md 7.0 KB
- references/4-configuring-ai-clients.md 3.8 KB
- references/5-authentication.md 4.1 KB
- references/6-robustness-patterns.md 3.2 KB
- references/7-cost-control.md 712 B
- references/8-pay-per-call-x402-handle-the-challenge-safely.md 2.9 KB
- references/9-optional-worked-example-mcp-skills-ws.md 2.7 KB
- references/quick-reference.md 1.5 KB
- references/what-this-skill-covers.md 924 B
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.
- 2mo ago First seen · 29 lines · 77 tokens per session scan A fd9603daea5f
mcp-client is a skill published in the GitHub repository san-npm/skills-ws (4 stars, last pushed 1mo ago), licensed MIT. It adds 77 tokens to every session and 740 once invoked, about $0.0003 per session on Opus 5.5. 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.
mcp-client compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| mcp-clientsan-npm/skills-ws | Skill | 4 | 1mo ago | MIT | A | 77 | Codex |
| mem0-oss-to-platformmem0ai/mem0 | Skill | 68k | 2d ago | Apache-2.0 | A | 217 | Claude Code, Codex |
| azure-mgmt-botservice-dotnetmicrosoft/skills | Skill | 3.2k | yesterday | MIT | A | 78 | Claude Code |
| fastapi-router-pymicrosoft/skills | Skill | 3.2k | yesterday | MIT | A | 46 | Claude Code |
| dev-runtimelangwatch/langwatch | Skill | 5.0k | yesterday | Apache-2.0 | A | 172 | Claude Code |
| api-designericrisco/rsc-harness | Skill | 503 | 2d ago | MIT | A | 105 | Claude Code, Codex |
| migrate-segw-to-raparc-mcp/arc-1 | Skill | 252 | yesterday | MIT | A | 106 | Claude Code |