# KeeperHub Tab Anchor Verifier

> KeeperHub Tab Anchor Verifier is a paid API for AI agents from app.keeperhub.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-12).

Reads and verifies the on-chain anchor count for a given agent identifier (bytes32 hex) within a blockchain workflow automation context

## Facts

- Endpoint: POST https://app.keeperhub.com/api/mcp/workflows/tab-anchor-verifier/call?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/keeperhub-tab-anchor-verifier-72cab0af
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_q6mUDaQGVaOOPXVh4EVWM

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability keeperhub-tab-anchor-verifier-72cab0af -d '<json body>'
```

Example prompt: Check the tab anchor count on KeeperHub for agent ID 0x3a1b2c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a2b — I need to know how many anchors are currently recorded on-chain for that agent.

## When to prefer this

Use this endpoint when you need to programmatically verify how many on-chain tab anchors a specific KeeperHub blockchain automation agent has registered, especially as part of a pre-execution check, audit trail, or conditional workflow branch that depends on anchor state.

## Known failure modes

- Invalid or malformed agentId (not valid bytes32 hex) returns a 400-level error
- Agent ID not found on-chain returns empty or zero anchor count
- Payment failure (insufficient USDC balance) blocks the call with a 402 error
- Network or blockchain node unavailability causes timeout or 503 error
- Execution ID returned but underlying workflow fails asynchronously

## How this service works

Build powerful blockchain workflow automations with a visual, node-based editor. Built with Next.js and React Flow.

## Output

Returns a workflow execution status (e.g. 'running') and an execution ID (e.g. 'exec_abc123') that can be used to track or retrieve the actual anchor count result for the queried agent.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "agentId"
 ],
 "properties": {
  "agentId": {
   "type": "string",
   "description": "Agent identifier (bytes32 hex) whose anchor count to read"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "status": "running",
 "executionId": "exec_abc123"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/keeperhub-tab-anchor-verifier-72cab0af/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from app.keeperhub.com](https://www.zero.xyz/host/app.keeperhub.com/llms.txt)