# Synthex Forge x402 Memory Put

> Synthex Forge x402 Memory Put is a paid API for AI agents from x402.synthexforge.com, paid per call via x402, $0.1/call, status unknown (last checked 2026-10-23).

Writes a named key-value state entry into a per-agent memory slot, paid via x402 USDC micropayment on Base mainnet.

## Facts

- Endpoint: POST https://x402.synthexforge.com/v1/memory/put?utm_source=zero.xyz
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synthex-forge-x402-memory-put-07a44317
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rp1wibS0w5VtA7a6_VU3j

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 synthex-forge-x402-memory-put-07a44317 -d '<json body>'
```

Example prompt: Remember for agent 'planner-7' that the key 'current_budget' holds the value {remaining: 450, currency: 'USDC'} — store that in its memory slot now.

## When to prefer this

Choose this endpoint when an AI agent needs to persist structured state, preferences, or checkpoint data under a named key scoped to a specific agent identity, and when x402 micropayment via USDC on Base mainnet is acceptable. Prefer this over generic KV stores when operating within the Synthex Forge agent infrastructure ecosystem or when Ed25519-signed, governed storage is required.

## Known failure modes

- Missing required fields (key, owner, or value) returns a 400 error
- Payment not provided or insufficient returns HTTP 402 with x402 v2 payment-required envelope
- Invalid agent owner identifier may result in a 404 or 403
- Oversized value object exceeding budget cap returns an error without truncation
- Network or chain issues may cause intermittent 5xx errors

## How this service works

Synthex Forge x402 Receive: 41 paid verification, attestation and governance endpoints (Ed25519 + SHA-256 signed artifacts) plus free verify/public-key/standard sibling routes. Paid routes answer HTTP 402 with an x402 v2 `payment-required` envelope (atomic USDC on Base mainnet, chain ID 8453). Free routes are declared with `security: []` per the x402scan discovery spec.

## Output

Returns a simple JSON confirmation object {ok: true} indicating the key-value pair was successfully written to the agent's named memory slot.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "key": {
   "type": "string",
   "description": "Named memory slot to write."
  },
  "owner": {
   "type": "string",
   "description": "Agent identifier whose memory receives the state."
  },
  "value": {
   "type": "object",
   "description": "State to remember (budget-capped, NOT truncated)."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synthex-forge-x402-memory-put-07a44317/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.synthexforge.com](https://www.zero.xyz/host/x402.synthexforge.com/llms.txt)