# TD Agent Utility – State Put (Persistent Key-Value Store)

> TD Agent Utility – State Put (Persistent Key-Value Store) is a paid API for AI agents from tdagentutility.co.uk, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-16).

Stores a versioned key-value state entry with TTL metadata, returning a status record with timestamps, size, version, and result status.

## Facts

- Endpoint: POST https://tdagentutility.co.uk/v1/state-put?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/td-agent-utility-state-put-persistent-key-value-store-710d2346
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_m3DmmdC_zGbOIxoFAasy_

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 td-agent-utility-state-put-persistent-key-value-store-710d2346 -d '<json body>'
```

Example prompt: Save the deployment verification result for 'mysite.co.uk' under the key 'deploy-check-2024' using the state_put tool — I need it stored with a version number so I can retrieve it later and check whether it's still fresh.

## When to prefer this

Use this endpoint when an AI agent needs to persist intermediate state, checkpoint results, or share data across agent steps within the TD Agent Utility ecosystem — particularly when the stored data is related to website/deployment verification results and you need versioned, timestamped, expiry-aware storage billed per-call via x402 USDC micropayments.

## Known failure modes

- Missing or empty key returns validation error
- Payload too large exceeds size_bytes limit
- Payment failure (x402) blocks the write
- Malformed JSON body returns 400
- Key collision on version mismatch may return conflict error
- Expired or invalid USDC payment causes rejection

## How this service works

Independent website and deployment verification for AI agents: HTTP, DNS, TLS and Chromium screenshot evidence. Three deterministic tools, x402 V2 Base USDC.

## Output

Returns a JSON object with the stored key name, tool identifier ('state_put'), version number, size_bytes of the stored value, ISO-8601 checked_at timestamp, Unix integer created_at/updated_at/expires_at timestamps, a result_status string (e.g. 'PASS'), and a warnings array listing any non-fatal issues.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "key": "",
  "tool": "state_put",
  "version": 0,
  "warnings": [],
  "checked_at": "2026-10-15T00:00:00Z",
  "created_at": 0,
  "expires_at": 0,
  "size_bytes": 0,
  "updated_at": 0,
  "result_status": "PASS"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/td-agent-utility-state-put-persistent-key-value-store-710d2346/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from tdagentutility.co.uk](https://www.zero.xyz/host/tdagentutility.co.uk/llms.txt)