MCP客户端

Sign a payment using the base64-encoded PAYMENT-REQUIRED header

mcpc x402 sign <base64-payment-required>

Install

Requires a JavaScript runtime — install the latest Node.js or Bun if you don't have one yet.

```bash npm install -g @apify/mcpc

Wallet setup

mcpc stores a single wallet in ~/.mcpc/wallets.json (file permissions 0600). You need to create or import a wallet before using x402 payments.

```bash

Quickstart

```bash

Usage

Usage: mcpc [<@session>] [<command>] [options]

Universal command-line client for the Model Context Protocol (MCP).

Commands:
  connect [<server>] [@session]  Connect to an MCP server and start a new named @session
  close <@session>               Close a session
  restart <@session>             Restart a session (losing all state)
  login <server>                 Interactively login to a server using OAuth and save profile
  logout <server>                Delete an OAuth profile for a server
  clean [resources...]           Clean up mcpc data (sessions, profiles, logs, all)
  grep <pattern>                 Search tools and instructions across all active sessions
  x402 [subcommand] [args...]    Configure an x402 payment wallet (EXPERIMENTAL)
  help [command] [subcommand]    Show help for a specific command

Options:
  --json                         Output in JSON format for scripting
  --verbose                      Enable debug logging
  --profile <name>               OAuth profile for the server ("default" if not provided)
  --timeout <seconds>            Request timeout in seconds (default: 300)
  --max-chars <n>                Truncate output to n characters (ignored in --json mode)
  --insecure                     Skip TLS certificate verification (for self-signed certs)
  -v, --version                  Output the version number
  -h, --help                     Display help

MCP session commands (after connecting):
  <@session>                   Show MCP server info, capabilities, and tools overview
  <@session> grep <pattern>    Search tools and instructions
  <@session> tools-list        List all server tools
  <@session> tools-get <name>  Get tool details and schema
  <@session> tools-call <name> [arg:=val ... | <json> | <stdin]
  <@session> prompts-list
  <@session> prompts-get <name> [arg:=val ... | <json> | <stdin]
  <@session> resources-list
  <@session> resources-read <uri>
  <@session> resources-subscribe <uri>
  <@session> resources-unsubscribe <uri>
  <@session> resources-templates-list
  <@session> skills-list
  <@session> skills-get <name> [--raw]
  <@session> tasks-list
  <@session> tasks-get <taskId>
  <@session> tasks-result <taskId>
  <@session> tasks-cancel <taskId>
  <@session> logging-set-level <level>
  <@session> ping
  <@session> logs [-n N] [--follow] [--since 1h]

Run "mcpc" without arguments to show active sessions and OAuth profiles.
Run "mcpc --json" to get the same data as `{ sessions: [...], profiles: [...] }`.

Use a local MCP server package (stdio) referenced from config file

mcpc connect ./.vscode/mcp.json:filesystem @fs mcpc @fs tools-list ```

Connect to a local server via config file entry

mcpc connect ~/.vscode/mcp.json:filesystem @fs mcpc @fs tools-list mcpc @fs tools-call list_directory path:=/

See [MCP feature support](#mcp-feature-support) for details about all supported MCP features and commands.

#### Command arguments

The `tools-call` and `prompts-get` commands accept arguments as positional parameters after the tool/prompt name:

Optionally protect proxy with bearer token for better security (stored in OS keychain)

mcpc connect mcp.apify.com @secure-relay --proxy 8081 --proxy-bearer-token secret123

Configuration

You can configure mcpc using a config file, environment variables, or command-line flags.

Precedence (highest to lowest):

1. Command-line flags (including --config option)
2. Environment variables
3. Built-in defaults

MCP server config file

mcpc supports the "standard" MCP server JSON config file, compatible with Claude Desktop, VS Code, and other MCP clients. Use the file:entry syntax to reference a server from a config file:

```bash

Open a session to a server specified in the Visual Studio Code config

mcpc connect .vscode/mcp.json:apify @my-apify mcpc @my-apify tools-list

`mcpc` also finds these files for you: run `mcpc connect` with no arguments to auto-discover config
files in standard locations and connect every server, or pass a file without an entry to connect all
of its servers. See [Server formats](#server-formats).

**Example MCP config JSON file:**

**Server configuration properties:**

For **Streamable HTTP servers:**

- `url` (required) - MCP server endpoint URL
- `headers` (optional) - HTTP headers to include with requests
- `timeout` (optional) - Request timeout in seconds

For **stdio servers:**

- `command` (required) - Command to execute (e.g., `node`, `npx`, `python`)
- `args` (optional) - Array of command arguments
- `env` (optional) - Environment variables for the process

> **Note:** Stdio servers inherit only a minimal env whitelist from the shell
> (`PATH`, `HOME`, `SHELL`, …). Other vars — `NODE_EXTRA_CA_CERTS`, `HTTPS_PROXY`,
> `SSL_CERT_FILE`, etc. — must be forwarded explicitly via the `env` block using
> `${VAR_NAME}`. Anything the server writes to stderr is captured to
> `~/.mcpc/logs/bridge-<session>.log` with a `[server stderr]` prefix, and the
> tail is appended to the error message if `mcpc connect` fails, so you can see
> why a stdio server failed to start.

**Environment variable substitution:**

Config files support environment variable substitution using `${VAR_NAME}` syntax:

Environment variables

• MCPC_HOME_DIR - Directory for session and authentication profiles data (default is ~/.mcpc)
• MCPC_VERBOSE - Enable verbose logging (set to 1, true, or yes, case-insensitive)
• MCPC_JSON - Enable JSON output (set to 1, true, or yes, case-insensitive)
• HTTPS_PROXY / https_proxy / HTTP_PROXY / http_proxy - Proxy URL for outbound connections (e.g. http://proxy.example.com:8080); HTTPS_PROXY takes precedence
• NO_PROXY / no_proxy - Comma-separated list of hostnames/IPs to bypass the proxy (e.g. localhost,127.0.0.1)

Nuclear option: remove everything

mcpc clean all # Delete all sessions, profiles, logs, and sockets ```

mcpc — a universal MCP CLI client

mcpc is a command-line client for the Model Context Protocol (MCP) that maps MCP operations to intuitive commands for interactive shell use, scripting, and AI agents.

mcpc is your new Swiss Army knife for MCP. It's great for manual inspection and debugging of MCP servers, as well as for agents to leverage all modern MCP capabilities through the most universal coding interface: the UNIX shell.

Key features:

• 🔧 Full MCP support - HTTP/stdio transports, instructions, tools, async tasks, resources, prompts, ...
• 🔄 Persistent sessions - Keep multiple stateful connections alive simultaneously.
• 🗺️ Progressive tool discovery - Find relevant MCP tools on the fly to save tokens and increase accuracy.
• 🔌 Code mode - JSON output composes with jq, xargs, and shell pipelines for MCP workflows as shell scripts.
• 🔒 Secure - Full OAuth 2.1 support with CMID and DCR, uses OS keychain for credentials storage.
• 🤖 AI sandboxing - Proxy MCP server connections to protect credentials from AI-generated code.
• 🪶 Lightweight - Minimal dependencies, works on Mac/Win/Linux, doesn't use LLMs on its own.
• 💸 Agentic payments - Experimental support for the x402 protocol on Base.

...now session name "@apify" is forgotten and available for future use

```

Bind to all interfaces (allows network access - use with caution!)

mcpc connect mcp.apify.com @relay --proxy 0.0.0.0:8080

Bind to specific interface

mcpc connect mcp.apify.com @relay --proxy 192.168.1.100:8080

When listing sessions, proxy info is displayed prominently:

@relay → https://mcp.apify.com (HTTP, OAuth: default) [proxy: 127.0.0.1:8080]

```

The session now automatically handles 402 responses using your preference

mcpc @apify tools-call expensive-tool query:="hello"

MCP CLI clients

Legend: ✅ = supported, ⚠️ = stale (no commits in 3+ months), Contrib / Commits = contributors / total commits, Tasks = async tasks, x402 = x402 payment protocol support, LLM = requires/uses an LLM.

Notes:

• thellimist/clihub is a code generator that compiles MCP tools into standalone CLI binaries, rather than a runtime client (HN discussion).
• knowsuchagency/mcp2cli also supports OpenAPI specs directly and uses a custom TOON encoding for token-efficient tool schemas.
• IBM/mcp-cli and mcp-client-cli integrate an LLM (Ollama, OpenAI, etc.) for chat-style interaction, while the other tools are pure CLI clients.

Troubleshooting

"Cannot connect to bridge"

• Bridge may have crashed. Try: mcpc @<session-name> tools-list to restart the bridge
• Check bridge is running: ps aux | grep -e 'mcpc-bridge' -e '[m]cpc/dist/bridge'
• Check socket exists: ls ~/.mcpc/bridges/

"Session not found"

• List existing sessions: mcpc
• Create new session if expired: mcpc @<session-name> close and mcpc connect <server> @<session-name>

"Authentication failed"

• List saved OAuth profiles: mcpc
• Re-authenticate: mcpc login <server> [--profile <name>]
• For bearer tokens: provide --header "Authorization: Bearer ${TOKEN}" again