MCP Sidecar
NPM · MCP-SIDECAR · SCANNED SEP 20
Cross-platform MCP server for managing long-lived background processes from any MCP client
Available components
How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. How we score → Why this is hard to score →
Supply Chain Security100
- No malware found by supply-chain analysis.Pass
- No known CVEs affecting this package version or its production dependencies.Pass
- No install/post-install scripts declared.Pass
- 0 of 5 dependencies flagged as unhealthy. View diagnostics → Pass
Provenance & Transparency97
- Source repository is publicly reachable at the declared URL. View diagnostics → Pass
- Cryptographically verified build provenance (signed, bound to lsequeiraa/mcp-sidecar). View diagnostics → Pass
- Clear OSI-approved license (MIT).Pass
- Actively maintained (last published 110 days ago).Pass
- Disclosure check failed: no security disclosure policy was found in the source repository. See how to fix → Fail
Schema Quality & AI Usability76
- AI-judged instruction clarity (good).Pass
- Tool/resource definitions use about 238 tokens (~39/item across 6 items; 6 tools + 0 resources), lean.Pass
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management90
- Stability observed for 27 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- All 2 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation.Pass
- An AI judge read all 6 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
How do I install the MCP Sidecar server?
MCP Sidecar runs locally as an npm package, launched with npx -y mcp-sidecar. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
npm · mcp-sidecar
claude mcp add lsequeiraa-mcp-sidecar -- npx -y mcp-sidecar
{
"mcpServers": {
"lsequeiraa-mcp-sidecar": {
"command": "npx",
"args": [
"-y",
"mcp-sidecar"
]
}
}
} {
"servers": {
"lsequeiraa-mcp-sidecar": {
"command": "npx",
"args": [
"-y",
"mcp-sidecar"
]
}
}
} codex mcp add lsequeiraa-mcp-sidecar -- npx -y mcp-sidecar
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"lsequeiraa-mcp-sidecar": {
"type": "local",
"command": [
"npx",
"-y",
"mcp-sidecar"
],
"enabled": true
}
}
} openclaw mcp add lsequeiraa-mcp-sidecar --command npx --arg -y --arg mcp-sidecar
mcp_servers:
lsequeiraa-mcp-sidecar:
command: "npx"
args: ["-y", "mcp-sidecar"] {
"McpServers": {
"lsequeiraa-mcp-sidecar": {
"Transport": "stdio",
"Command": "npx",
"Arguments": [
"-y",
"mcp-sidecar"
]
}
}
} assistant mcp add lsequeiraa-mcp-sidecar -t stdio -c npx -a -y mcp-sidecar
{
"mcpServers": {
"lsequeiraa-mcp-sidecar": {
"command": "npx",
"args": [
"-y",
"mcp-sidecar"
]
}
}
} Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 20 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 87 to 90. That category is still filling its 30-day observation window: 26 days of observed history at the previous scan, 27 at this one. The score rises as the window fills, whether or not the server changes.
- 18 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 80 to 83. That category is still filling its 30-day observation window: 24 days of observed history at the previous scan, 25 at this one. The score rises as the window fills, whether or not the server changes.
- 17 Sept 26 −3
- Stability: pass → 0.80 functional
- 16 Sept 26 0
- Stability: 0.97 → pass security
- 15 Sept 26 +1
- Security disclosure: unverified → fail ▼ functional
- 14 Sept 26 0
- Security disclosure: fail → unverified ▼ functional
- 13 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 87 to 90. That category is still filling its 30-day observation window: 26 days of observed history at the previous scan, 27 at this one. The score rises as the window fills, whether or not the server changes.
- 11 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 80 to 83. That category is still filling its 30-day observation window: 24 days of observed history at the previous scan, 25 at this one. The score rises as the window fills, whether or not the server changes.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 20 Sept 2026 · Analysed npm/mcp-sidecar@0.3.2
Provenance Verified
A signed build attestation was found and verified, binding this exact artifact to the source repository it claims to come from.
| Result | Verified |
|---|---|
| Ecosystem | npm |
| Reason | Verified |
| Discovered via | Registry attestation endpoint |
| Source repo | lsequeiraa/mcp-sidecar |
| Certificate issuer | https://token.actions.githubusercontent.com |
| Certificate SAN | https://github.com/lsequeiraa/mcp-sidecar/.github/workflows/release.yml@refs/tags/v0.3.2 |
| Rekor log index | 1699931668 |
| Predicate type | https://slsa.dev/provenance/v1 |
| Subject digest | sha512:27e9d2b290e08035f424a19c1735d67f8263469b3dc00ff60ca5bf27ba6eba79d5714fec6b1994edec5052e9d87136a3150586214ce57dcfff9ebe8be |
Background: How many MCP packages publish verified provenance →
Dependencies 5 packages
| Packages resolved | 5 |
|---|---|
| Tree resolution | Complete |
Background: SBOMs and build attestations, explained →
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
list ~12
List all managed processes
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
output ~73
Get buffered stdout and stderr of a process
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | Process ID |
| maxBytes | number | – | Max total bytes for stdout+stderr combined (0 = unlimited). Keeps the most recent output. Stderr is prioritized. |
| tail | number | – | Return only the last N lines (0 = all) |
No output schema declared.
No examples provided.
send ~40
Write to a process's stdin
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | Process ID |
| input | string | yes | Text to send (a trailing newline is added automatically) |
No output schema declared.
No examples provided.
start ~58
Spawn a background process
| Name | Type | Req | Description |
|---|---|---|---|
| command | string | yes | Shell command to execute |
| cwd | string | – | Working directory for the process |
| env | object | – | Additional environment variables |
| name | string | – | Human-friendly name for the process |
No output schema declared.
No examples provided.
status ~24
Get detailed state of a single process
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | Process ID |
No output schema declared.
No examples provided.
stop ~31
Terminate a managed process (graceful, then force)
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | Process ID to stop |
No output schema declared.
No examples provided.
What is the MCP Sidecar server?
MCP Sidecar is listed in the public MCP registry as io.github.lsequeiraa/mcp-sidecar. Cross-platform MCP server for managing long-lived background processes from any MCP client. This page covers its npm package (mcp-sidecar).
Is the MCP Sidecar server safe to use?
MCP Sidecar scores 94 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 20 September 2026. It declares no install or post-install scripts. Its build provenance is signed and verified. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the MCP Sidecar server expose?
MCP Sidecar exposes 6 tools: list, output, send, start, status, stop. Their descriptions and schemas cost roughly 238 tokens of context every time the server is loaded.
Is the MCP Sidecar server still maintained?
MCP Sidecar is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.
What licence is the MCP Sidecar server under?
MCP Sidecar declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.