# gns_verify_chain

Verify the cryptographic integrity of an agent's breadcrumb chain. Returns { is_valid, block_count, issues[] } plus epoch Merkle roots. A valid chain proves no audit records have been tampered with.

Agent View of the PolicyLayer registry record for `gns_verify_chain`. HTML page: https://policylayer.com/tools/com-geiant-mcp-agentcore/gns-verify-chain

## Facts

- Tool: `gns_verify_chain`
- Server: Mcp Agentcore (`https://packagesmcp-perception-production.up.railway.app/mcp`) — https://policylayer.com/tools/com-geiant-mcp-agentcore.md
- Homepage: https://github.com/GNS-Foundation/geiant
- Risk category: Read (Low risk)
- Registry record: grade D, identity unverified
- Server auth posture: open
- Server rate-limited: no
- Parameters: 1
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `agent_pk` | string | no | Ed25519 public key (64 hex chars). Omit for own agent. |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "gns_verify_chain",
    "arguments": {}
  }
}
```

## Why gns_verify_chain is rated Low

gns_verify_chain is a cryptographic verification function that queries and validates the integrity of existing chain data. It has no side effects—it only inspects and reports on audit record integrity.

From the tool's own definition: "Tool performs verification and returns data ('Verify the cryptographic integrity', 'Returns { is_valid, block_count, issues[] }'); it reads and checks existing audit records without modifying, deleting, or executing external operations."

## Use case

AI agents call gns_verify_chain to retrieve information from Mcp Agentcore without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Mcp Agentcore:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "gns_verify_chain": {}
  }
}
```

## Other tools on Mcp Agentcore (7)

- `perception_classify` — Execute — https://policylayer.com/tools/com-geiant-mcp-agentcore/perception-classify.md
- `perception_embed` — Other — https://policylayer.com/tools/com-geiant-mcp-agentcore/perception-embed.md
- `gns_get_compliance_report` — Read — https://policylayer.com/tools/com-geiant-mcp-agentcore/gns-get-compliance-report.md
- `gns_get_trust_score` — Read — https://policylayer.com/tools/com-geiant-mcp-agentcore/gns-get-trust-score.md
- `perception_fetch_tile` — Read — https://policylayer.com/tools/com-geiant-mcp-agentcore/perception-fetch-tile.md
- `gns_roll_epoch` — Write — https://policylayer.com/tools/com-geiant-mcp-agentcore/gns-roll-epoch.md
- `perception_weather` — Write — https://policylayer.com/tools/com-geiant-mcp-agentcore/perception-weather.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=com-geiant-mcp-agentcore · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/com-geiant-mcp-agentcore