Overwing
NPM · OVERWING-MCP · SCANNED SEP 25
Guardrails for LLM output: pass / fail / review verdicts with calibrated confidence in under 500 ms.
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 Security98
- 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
- 31 of 95 dependencies flagged as unhealthy. View diagnostics → Partial
Provenance & Transparency45
- Source repository is publicly reachable at the declared URL. View diagnostics → Pass
- Provenance check failed: no build-provenance attestation is published. See how to fix → View diagnostics → Fail
- Clear OSI-approved license (MIT).Pass
- Actively maintained (last published 0 days ago).Pass
- Disclosure check failed: no security disclosure policy was found in the source repository. See how to fix → Fail
Schema Quality & AI Usability83
- 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).Pass
- AI-judged instruction clarity (good).Pass
- Tool/resource definitions use about 1141 tokens (~81/item across 14 items; 13 tools + 1 resources), lean.Pass
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management7
- Stability observed for 2 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage79
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 36% of tool parameters carry a description.Partial
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 13 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 14 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 Overwing MCP server?
Overwing runs locally as an npm package, launched with npx -y overwing-mcp. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
npm · overwing-mcp
claude mcp add ai-overwing-mcp -- npx -y overwing-mcp
{
"mcpServers": {
"ai-overwing-mcp": {
"command": "npx",
"args": [
"-y",
"overwing-mcp"
]
}
}
} {
"servers": {
"ai-overwing-mcp": {
"command": "npx",
"args": [
"-y",
"overwing-mcp"
]
}
}
} codex mcp add ai-overwing-mcp -- npx -y overwing-mcp
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"ai-overwing-mcp": {
"type": "local",
"command": [
"npx",
"-y",
"overwing-mcp"
],
"enabled": true
}
}
} openclaw mcp add ai-overwing-mcp --command npx --arg -y --arg overwing-mcp
mcp_servers:
ai-overwing-mcp:
command: "npx"
args: ["-y", "overwing-mcp"] {
"McpServers": {
"ai-overwing-mcp": {
"Transport": "stdio",
"Command": "npx",
"Arguments": [
"-y",
"overwing-mcp"
]
}
}
} assistant mcp add ai-overwing-mcp -t stdio -c npx -a -y overwing-mcp
{
"mcpServers": {
"ai-overwing-mcp": {
"command": "npx",
"args": [
"-y",
"overwing-mcp"
]
}
}
} 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.
- 25 Sept 26 +1
- Stability: 0.03 → unverified ▼ security
- Tool safety: pass → unverified ▼ security
- Schema quality: 69 → 81 ▼ functional
- Capabilities: pass → unverified ▼ functional
- Tool coverage: 100 → unverified ▼ functional
- Schema quality: 100 → unverified ▼ functional
- Tool coverage: 26% → 36% ▲ functional
- Package version: 0.4.0 → 0.5.0 functional
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 24 Sept 26 +16
- Tool safety: pass → unverified ▼ security
- Malware scan: unverified → pass ▲ security
- Stability: Stability not yet verified: we do not have a sandbox capture of the MCP schema this version of the package serves yet. security
- Schema quality: 50 → 69 ▼ functional
- Capabilities: pass → unverified ▼ functional
- Tool coverage: 100 → unverified ▼ functional
- Schema quality: 100 → unverified ▼ functional
- Tool coverage: 18% → 26% ▲ functional
- Stability: unverified → 0.03 ▲ functional
- Package version: 0.3.0 → 0.4.0 functional
- 23 Sept 26 54
First indexed and scored.
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 25 Sept 2026 · Analysed npm/overwing-mcp@0.5.0
Provenance No attestation
The registry publishes no build provenance for this version, so there is nothing to verify.
| Result | No attestation |
|---|---|
| Ecosystem | npm |
Background: How many MCP packages publish verified provenance →
Dependencies 95 packages
| Packages resolved | 95 |
|---|---|
| Stale | 31 |
| 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 →
atlas_agents Search the agent registry (Overwing Atlas) ~166
Browse or search Overwing Atlas, the registry of AI crawlers, fetchers and browser agents: name, operator, user-agent tokens, Web Bot Auth key directory, robots.txt behaviour, and (with Atlas Pro or Team) purpose class, verification, evasion flags and traffic shares. Filter by free text, purpose (training, search, browser, coding), operator, or verification.
| Name | Type | Req | Description |
|---|---|---|---|
| limit | integer | – | – |
| operator | string | – | – |
| purpose | string | – | Purpose substring, e.g. training, search, browser, fetcher, coding |
| q | string | – | Free text over name, operator, user agents, description |
| verification | string | – | e.g. 'Web Bot Auth', 'spoofable', 'Unattributable' |
No output schema declared.
No examples provided.
atlas_lookup Identify a user agent (Overwing Atlas) ~142
Say what a User-Agent string claims to be and whether the claim can be trusted, from the Overwing Atlas registry of 241 AI crawlers, fetchers and browser agents. Returns the claimed agent, operator, purpose class, verification method (Web Bot Auth signature, user-agent string only, or unattributable) and a trust note. Metered per day by Atlas tier: free 100, Pro 10,000, Team 100,000. Use it when deciding whether to serve, block, or pay-gate a request, or to understand who is hitting a site.
| Name | Type | Req | Description |
|---|---|---|---|
| user_agent | string | yes | The User-Agent header value to identify |
No output schema declared.
No examples provided.
atlas_summary Agent traffic and spending summary (Overwing Atlas) ~72
Public numbers from Overwing Atlas: registry counts by purpose and verification, published browser-agent traffic shares, sector field-scan headlines (e.g. how many OSINT sites carry AI-crawler rules or any agent-payable surface), and the summary of the Agent Consumers report on what agents actually spend. No key needed.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
create_rule_set Create rule set ~121
Create a custom rule set with 1 to 25 rules. Each rule is a choice (pick one option), score (position on an ordered scale), or noul (yes/no) question with a fail condition, optional review threshold, weight, and action (block, redact, or review) that callers should take when it fails. Rule instructions may reference `context.*` fields that callers pass with each evaluation.
| Name | Type | Req | Description |
|---|---|---|---|
| description | string | – | – |
| name | string | yes | – |
| rules | array | yes | – |
| slug | string | yes | – |
No output schema declared.
No examples provided.
evaluate Evaluate text ~256
Score any text (typically an LLM's output) against an Overwing rule set. Returns an aggregate verdict of pass, fail, or review, a recommended_action (block, redact, review, or allow), and per-rule answers with probability, confidence, and the rule's action. Act on recommended_action: block means do not send, redact means remove the flagged content and resend, review means ask a human or a slower model, allow means proceed. Prebuilt sets: 'content-safety' (toxicity, PII, self-harm, sexual content, severity) and 'outbound-message', which also takes a context object (recipient, channel, owns_contact_info) so PII that the recipient already owns is not flagged.
| Name | Type | Req | Description |
|---|---|---|---|
| context | object | – | Facts the rules may reference: recipient, channel, whether you own the data, sender, purpose. Sent to the model alongside the text (max 8 KB). Use the 'outbound-message' rule set to have it honoured. |
| input | string | yes | The text to evaluate |
| metadata | object | – | Opaque data stored with the evaluation and echoed in webhooks (max 8 KB) |
| rule_set | string | – | Rule set slug |
No output schema declared.
No examples provided.
evaluate_batch Evaluate many texts ~112
Score up to 50 texts against one rule set in a single call. Each item counts as one evaluation. Returns a summary plus per-item verdicts; items can fail independently.
| Name | Type | Req | Description |
|---|---|---|---|
| context | object | – | Facts the rules may reference: recipient, channel, whether you own the data, sender, purpose. Sent to the model alongside the text (max 8 KB). Use the 'outbound-message' rule set to have it honoured. |
| items | array | yes | – |
| rule_set | string | – | – |
No output schema declared.
No examples provided.
get_evaluation Get evaluation ~32
Fetch a stored evaluation by id, including the original input and per-rule results.
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | – |
No output schema declared.
No examples provided.
get_rule_set Get rule set ~41
Fetch a rule set with its full rule definitions. Use 'content-safety' as a worked example when writing your own.
| Name | Type | Req | Description |
|---|---|---|---|
| slug | string | yes | – |
No output schema declared.
No examples provided.
get_usage Get usage ~27
Daily usage, remaining quota for today, and plan limits.
| Name | Type | Req | Description |
|---|---|---|---|
| days | integer | – | – |
No output schema declared.
No examples provided.
list_evaluations List evaluations ~60
List recent evaluations, newest first, with optional verdict and rule set filters. Use next_cursor to page.
| Name | Type | Req | Description |
|---|---|---|---|
| cursor | string | – | – |
| limit | integer | – | – |
| rule_set | string | – | – |
| verdict | string | – | – |
No output schema declared.
No examples provided.
list_plans List plans ~29
Public plan catalog: prices, daily limits, and per-minute burst limits. No API key needed.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
list_rule_sets List rule sets ~31
List the prebuilt and custom rule sets available to this organization.
| Name | Type | Req | Description |
|---|---|---|---|
| include_inactive | boolean | – | – |
No output schema declared.
No examples provided.
whoami Who am I ~26
Identify the organization and plan behind the configured API key, and whether billing is set up.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
What is the Overwing MCP server?
Overwing is an MCP server listed in the public MCP registry as ai.overwing/mcp. Guardrails for LLM output: pass / fail / review verdicts with calibrated confidence in under 500 ms. This page covers its npm package (overwing-mcp).
Is the Overwing MCP server safe to use?
Overwing scores 71 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 25 September 2026. It declares no install or post-install scripts. 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 Overwing MCP server expose?
Overwing exposes 13 tools: evaluate, evaluate_batch, list_rule_sets, get_rule_set, create_rule_set, and 8 more. Their descriptions and schemas cost roughly 1,115 tokens of context every time the server is loaded.
Is the Overwing MCP server still maintained?
Overwing is still listed as active in the MCP registry. We last reached this channel on 25 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 Overwing MCP server under?
Overwing declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.