MCP Sidecar

io.github.lsequeiraa/mcp-sidecarv0.3.2Other

Cross-platform MCP server for managing long-lived background processes from any MCP client

The current version, v0.3.2, was published to the official MCP registry on 2026-06-02. It is distributed as mcp-sidecar on npm, filed under Other by this index, and declares 8 environment variables. Removals and unreachable sources are measured across every server this index tracks, contract drift across the servers that answer in consecutive snapshots; the index's current counts put this record in context.

In-path gate · all MCP tools

Using MCP Sidecar in Claude, Cursor, Gemini CLI, Cline, or Zed?

MCP tool contracts can change remotely with no version bump. The mcpindex gate pins each contract and HOLDs the call when it drifts-before your agent acts. Zero credentials. This is not the package install for this server itself (use Install this server for that).

Install the mcpindex gate (one command)

Rewrites your MCP host config so each server launches behind the gate. Inspect first: curl -fsSL https://mcpindex.ai/install.sh | less

uv tool install mcpindex-gate && mcpindex-config-wire

Auditable install path →Watch it hold a drift →

Trust verdict · v1 advisory · method

REVIEWstatus: PARTIALfresh until 2026-09-08 01:19 UTC

screened 2026-07-24tier: scannedgranularity: description-levelsource: registry

Semantic screen found no manipulation pattern in the description. Conformance probe not yet run.

mcpindex.integrity.descriptionpassINFO

evidence“No malicious instructions found”via static_description

Limits of this verdict

- Semantic screen only - the deterministic conformance probe has not run on this server
- Confidence is reported but not yet calibrated (v1)
- Screen reads the tool description, not the live behavior
- advisory
- registry description only no input schema
- screen model 8b
- Still current: the description we screened is unchanged, re-checked against the registry

Semantic screen: an LLM judge reads the tool description for hidden instructions (status PARTIAL). A pass means the description is not lying, not that the tool is safe: a high-capability tool with an honest description still warrants caution. The deterministic conformance probe has not been run on this server yet, so the screen here is semantic-only. Posture: advisory. Confidences are reported but not yet calibrated (calibrated=false at v1). Full verdict history is not shown on this page.

Own this server? Screen its description →

That verdict was true at screening time (snapshot 2026-09-01).

Contracts can change after screening, with no version bump. The gate pins MCP Sidecar’s tool contracts on first sight and holds any silent change before your agent acts - the check that keeps being true on Tuesday.

See your first HOLD in 2 minutes →

Cite this record

People vet a server before wiring it in. One line on your project site or docs answers that with an independent record: screening verdict, registry provenance, contract drift history. It stays current as new screens and drift events land.

Markdown

[Independent trust record for MCP Sidecar](https://mcpindex.ai/server/io-github-lsequeiraa-mcp-sidecar) - screening verdict, registry provenance, and contract drift monitoring.

HTML

<a href="https://mcpindex.ai/server/io-github-lsequeiraa-mcp-sidecar">Independent trust record for MCP Sidecar</a> - screening verdict, registry provenance, and contract drift monitoring.

Embed this badge

A live verdict badge for your README or listing. It reflects the current screen, links back here, and updates when the verdict does.

Markdown

[![mcpindex](https://mcpindex.ai/api/v1/badge/io-github-lsequeiraa-mcp-sidecar)](https://mcpindex.ai/server/io-github-lsequeiraa-mcp-sidecar)

HTML

<a href="https://mcpindex.ai/server/io-github-lsequeiraa-mcp-sidecar"><img src="https://mcpindex.ai/api/v1/badge/io-github-lsequeiraa-mcp-sidecar" alt="mcpindex verdict" height="20" /></a>

Environment variables

SIDECAR_MAX_PROCESSES

Maximum number of concurrent managed processes (default: 10)

SIDECAR_BUFFER_SIZE

Output buffer size per stream in bytes (default: 1048576)

SIDECAR_KILL_TIMEOUT

Milliseconds to wait between graceful and forced termination (default: 5000)

SIDECAR_CLEANUP_AFTER

Seconds before exited processes are auto-removed. 0 disables cleanup (default: 1800)

SIDECAR_MAX_OUTPUT_SIZE

Global cap on bytes returned by the output tool. 0 means unlimited (default: 0)

SIDECAR_ALLOWED_EXECUTABLES

Comma-separated allowlist of executable names. When set, enables security mode with direct exec (no shell). Unset means security disabled.

SIDECAR_BLOCKED_PATTERNS

Comma-separated regex patterns to reject in commands. Only applies when security is enabled.

SIDECAR_AUDIT_LOG

Audit log destination. 'true' writes to cwd, 'temp' writes to OS temp dir, or a directory path. Unset disables audit logging.

MCP quality score · maturity, not trust · methodology

freshness

completeness

installability

documentation

stability

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Python Exec Sandbox

io.github.lu-zhengda/mcp-python-exec-sandbox

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Install this server

Claude Desktop (claude_desktop_config.json)

{
  "mcpServers": {
    "mcp-sidecar": {
      "command": "npx",
      "args": [
        "-y",
        "--",
        "mcp-sidecar"
      ],
      "env": {
        "SIDECAR_MAX_PROCESSES": "<sidecar_max_processes>",
        "SIDECAR_BUFFER_SIZE": "<sidecar_buffer_size>",
        "SIDECAR_KILL_TIMEOUT": "<sidecar_kill_timeout>",
        "SIDECAR_CLEANUP_AFTER": "<sidecar_cleanup_after>",
        "SIDECAR_MAX_OUTPUT_SIZE": "<sidecar_max_output_size>",
        "SIDECAR_ALLOWED_EXECUTABLES": "<sidecar_allowed_executables>",
        "SIDECAR_BLOCKED_PATTERNS": "<sidecar_blocked_patterns>",
        "SIDECAR_AUDIT_LOG": "<sidecar_audit_log>"
      }
    }
  }
}

Cursor (.cursor/mcp.json)

{
  "mcpServers": {
    "mcp-sidecar": {
      "command": "npx",
      "args": [
        "-y",
        "--",
        "mcp-sidecar"
      ],
      "env": {
        "SIDECAR_MAX_PROCESSES": "<sidecar_max_processes>",
        "SIDECAR_BUFFER_SIZE": "<sidecar_buffer_size>",
        "SIDECAR_KILL_TIMEOUT": "<sidecar_kill_timeout>",
        "SIDECAR_CLEANUP_AFTER": "<sidecar_cleanup_after>",
        "SIDECAR_MAX_OUTPUT_SIZE": "<sidecar_max_output_size>",
        "SIDECAR_ALLOWED_EXECUTABLES": "<sidecar_allowed_executables>",
        "SIDECAR_BLOCKED_PATTERNS": "<sidecar_blocked_patterns>",
        "SIDECAR_AUDIT_LOG": "<sidecar_audit_log>"
      }
    }
  }
}

Cline (cline_mcp_settings.json)

npx -y -- mcp-sidecar

Claude Code (claude mcp add)

claude mcp add --scope user mcp-sidecar -- npx -y -- mcp-sidecar

Gemini CLI (gemini mcp add)

gemini mcp add -s user mcp-sidecar npx -y -- mcp-sidecar

Verdict API

curl -s mcpindex.ai/api/v1/trust/server/io-github-lsequeiraa-mcp-sidecar

Free-tier verdict as JSON: decision + dimensions + severity. Call it from your agent before it invokes a tool it just discovered.

Details

version: v0.3.2
category: Other
verdict expires: 2026-09-08
quality: 80 / 100
operator: lsequeiraa

Listing

Listed from the official MCP registry. Unclaimed by its maintainer. Maintainer? Email us →

Provenance

Each verdict is bound to a hash of the exact description it judged, so a re-crawl that changes the text produces a new record rather than silently inheriting this one. Verdict history is hash-chained and anchored to Bitcoin via OpenTimestamps (latest confirmed at block 964,828). Verify it yourself.

Links

Repository →