# Agent Long-Term Memory Write (Key-Value Store)

> Agent Long-Term Memory Write (Key-Value Store) is a paid API for AI agents from predator-ubuntu.taild9a745.ts.net, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-30).

Persists a key-value entry in a namespaced long-term memory store scoped to the calling agent's payer wallet, with optional TTL.

## Facts

- Endpoint: POST https://predator-ubuntu.taild9a745.ts.net/v1/memory/write?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-long-term-memory-write-key-value-store-8be39dd1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5ssW7uWJvABeUlZGx7zWT

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 agent-long-term-memory-write-key-value-store-8be39dd1 -d '<json body>'
```

Example prompt: Save a memory entry with the key 'user_preferences' and the value '{"theme":"dark","language":"en"}' to my agent's long-term memory store, and keep it for 90 days.

## When to prefer this

Use this endpoint when your agent needs to persist state, context, or data across sessions and wants it namespaced automatically to its payer wallet without managing a separate database. Ideal for lightweight agent memory (configs, preferences, intermediate results, research snapshots) up to 100KB per entry with a configurable TTL up to one year. Prefer this over general-purpose databases when you want zero-setup persistent memory billed per write with free reads/search.

## Known failure modes

- Key exceeds 256-character limit — rejected with validation error
- Value exceeds 100KB limit — rejected with payload-too-large error
- TTL outside 1–365 range — rejected with validation error
- Payment not settled or insufficient USDC balance — 402 Payment Required returned
- Tailnet host unreachable — connection timeout or network error

## How this service works

Long-term memory store for agents: write a key-value entry namespaced to your payer wallet (reads/search free)

## Output

A confirmation that the key-value entry has been written to the agent's wallet-namespaced memory store, including the key stored and the effective TTL. Reads and searches against this data are free; only writes incur the $0.01 USDC charge.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "key": {
   "type": "string",
   "maxLength": 256
  },
  "value": {
   "type": "string",
   "maxLength": 102400
  },
  "ttl_days": {
   "type": "integer",
   "maximum": 365,
   "minimum": 1
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-long-term-memory-write-key-value-store-8be39dd1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from predator-ubuntu.taild9a745.ts.net](https://www.zero.xyz/host/predator-ubuntu.taild9a745.ts.net/llms.txt)