ARBITER
REMOTE · API.GRIP.FYI · SCANNED SEP 28
Decision arbitration, action routing, workflow control, deployment remediation, persistent memory.
Available components
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →
Endpoint Security46
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation not fully verified: no authorisation is required to call this server, and 2 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe. See how to fix → View diagnostics → Unverified
- HTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement. View diagnostics → Unverified
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability76
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 363 tokens (~181/item across 2 items; 2 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management53
- Stability observed for 16 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
- We read all 2 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 2 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 ARBITER MCP server?
ARBITER is a hosted endpoint at https://api.grip.fyi/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · api.grip.fyi
claude mcp add --transport http fyi-grip-arbiter 'https://api.grip.fyi/mcp'
{
"mcpServers": {
"fyi-grip-arbiter": {
"url": "https://api.grip.fyi/mcp"
}
}
} {
"servers": {
"fyi-grip-arbiter": {
"type": "http",
"url": "https://api.grip.fyi/mcp"
}
}
} [mcp_servers.fyi-grip-arbiter] url = "https://api.grip.fyi/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"fyi-grip-arbiter": {
"type": "remote",
"url": "https://api.grip.fyi/mcp",
"enabled": true
}
}
} openclaw mcp add fyi-grip-arbiter --url 'https://api.grip.fyi/mcp' --transport streamable-http
mcp_servers:
fyi-grip-arbiter:
url: "https://api.grip.fyi/mcp" {
"McpServers": {
"fyi-grip-arbiter": {
"Transport": "http",
"Url": "https://api.grip.fyi/mcp"
}
}
} assistant mcp add fyi-grip-arbiter -t streamable-http -u 'https://api.grip.fyi/mcp'
{
"mcpServers": {
"fyi-grip-arbiter": {
"type": "http",
"url": "https://api.grip.fyi/mcp"
}
}
} The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.
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.
- 28 Sept 26 +1
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 26 Sept 26 +1
- Endpoint reachability: not serving MCP → reachable ▲ functional
- 25 Sept 26 +48
- 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 −47
- Endpoint reachability: reachable → not serving MCP ▼ security
- Stability: 0.37 → unverified ▼ security
- Tool safety: pass → unverified ▼ security
- Transport: pass → fail ▼ security
- Authorization: Authorisation not fully verified: no authorisation is required to connect, but we couldn't read the whole tool list to see what that exposes. security
- Capabilities: pass → unverified ▼ functional
- Tool coverage: 100 → unverified ▼ functional
- First check of Schema quality: unverified functional
- 22 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 30 to 33. That category is still filling its 30-day observation window: 9 days of observed history at the previous scan, 10 at this one. The score rises as the window fills, whether or not the server changes.
- 20 Sept 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 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 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.
- 17 Sept 26 +6
- Tool “arbiter_compare” rewrote its description, which is the text the model reads security
- Tool “arbiter_embed” rewrote its description, which is the text the model reads security
- Schema quality: 237 → 181 ▲ functional
- Tool coverage: 0% → 100% ▲ functional
- Schema quality: good → excellent functional
- “arbiter_compare” reworded the description of “candidates” cosmetic
- “arbiter_compare” reworded the description of “query” cosmetic
- “arbiter_compare” reworded the description of “top_k” cosmetic
- “arbiter_embed” reworded the description of “texts” cosmetic
- “arbiter_compare” dropped the optional parameter “use_freq” cosmetic
- “arbiter_embed” dropped the optional parameter “use_freq” cosmetic
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 28 Sept 2026 · Probed https://api.grip.fyi/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=grip.fyi | CN=WE1,O=Google Trust Services,C=US | 3 Aug 2026 | 1 Nov 2026 | ECDSA 256 | ECDSA-SHA256 | 66eec32d7b5f404313323b6de2b93b20 |
| SANs: grip.fyi, *.grip.fyi | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of api.grip.fyi. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| fyi. | present | 24340 | 8 | Verified |
| grip.fyi. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://api.grip.fyi/mcp | Verified | 200 | |
| http (plaintext) | http://api.grip.fyi/mcp | Inconclusive | 405 |
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 →
arbiter_compare ~215
Paid ARBITER finite-candidate measurement for contextual choice. Use when a caller already has an explicit candidate field and needs it ordered against a query, current state, intent, context, question, or perspective. query is the situation to measure. candidates is the finite caller-supplied field to order. top_k optionally limits returned results. Returns MCP text content containing the JSON result from POST /v1/compare with the supplied candidates ordered by measured coherence. Does not generate candidates or execute the selected action. Deterministic for identical inputs and engine state. Price: $0.01 USDC on Base per call. MCP identity: fyi.grip/arbiter.
| Name | Type | Req | Description |
|---|---|---|---|
| candidates | array | yes | Finite caller-supplied candidate field to order. ARBITER measures these candidates and does not generate them. |
| query | string | yes | Current state, context, intent, question, or perspective to measure against the candidate field. |
| top_k | integer | – | Optional maximum number of highest-ranked candidates to return. |
No output schema declared.
No examples provided.
arbiter_embed ~148
Paid ARBITER deterministic persistent machine representation. Use when a caller needs representations of supplied text for storage, indexing, retrieval, clustering, reuse, or later comparison. Use arbiter_compare instead when an explicit finite candidate field needs ordering now. texts is one or more supplied strings. Returns MCP text content containing the JSON result from POST /v1/embed. Does not store, retrieve, update, delete, or rank records. Deterministic for identical inputs and engine state. Price: $0.01 USDC on Base per call. MCP identity: fyi.grip/arbiter.
| Name | Type | Req | Description |
|---|---|---|---|
| texts | array | yes | One or more supplied text values to convert into deterministic persistent machine representations. |
No output schema declared.
No examples provided.
What is the ARBITER MCP server?
ARBITER is an MCP server listed in the public MCP registry as fyi.grip/arbiter. Decision arbitration, action routing, workflow control, deployment remediation, persistent memory. This page covers its hosted endpoint (https://api.grip.fyi/mcp).
Is the ARBITER MCP server safe to use?
ARBITER scores 68 out of 100 on VerifyMCP. 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 ARBITER MCP server expose?
ARBITER exposes 2 tools: arbiter_compare, arbiter_embed. Their descriptions and schemas cost roughly 363 tokens of context every time the server is loaded.
Does the ARBITER MCP server require authentication?
No. We connected to ARBITER without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the ARBITER MCP server still maintained?
ARBITER is still listed as active in the MCP registry. We last reached this channel on 28 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.