# Mnemo Memory Write — POST /v1/memory/remember

> Mnemo Memory Write — POST /v1/memory/remember is a paid API for AI agents from memory.reversecaptcha.fun, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-29).

Writes a typed, tagged memory entry for a user that persists across agents, supporting optional client-side encryption (Tier B) and automatic deduplication.

## Facts

- Endpoint: POST https://memory.reversecaptcha.fun/v1/memory/remember?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mnemo-memory-write-post-v1-memory-remember-e9edfad5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_z4K6AUIO0wycZtolYAdj1

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 mnemo-memory-write-post-v1-memory-remember-e9edfad5 -d '<json body>'
```

Example prompt: Remember for me that I prefer dark mode in all apps and I'm lactose intolerant — store these as user preferences (kind: preference) with tags ['ui','dietary'] that never expire, using standard Tier A storage.

## When to prefer this

Use this endpoint when an AI agent needs to durably persist user-specific facts, preferences, instructions, decisions, or state that should survive across multiple agent sessions or different agents. Prefer Mnemo over ad-hoc in-context memory when the user's memory must be portable, owner-controlled, and retrievable via semantic search later. Choose Tier B if the content is sensitive and must remain opaque to the server.

## Known failure modes

- Missing or invalid Bearer token (mn_...) returns 401 Unauthorized
- Payment not settled via x402 returns 402 Payment Required
- Invalid 'kind' enum value returns 400 Bad Request
- Tier B write missing required ciphertext or blind_index fields returns 400
- TTL value is not a positive number returns 400
- Content field is empty or absent returns 400
- Server-side error during vector indexing returns 500

## How this service works

Memory that belongs to the user and follows them across agents. The agent pays per call (x402); the user authorizes the agent once: POST /v1/memory/delegate/challenge {user, agent} returns text the user signs (EIP-191), then POST /v1/memory/delegate {..., signature} returns a bearer token. Send Authorization: Bearer mn_... on every memory call. Start a session with GET /v1/memory/profile, write with POST /v1/memory/remember, retrieve with POST /v1/memory/recall (hybrid vector + keyword). When the user contradicts a memory, POST /v1/memory/conflict supersedes it with history kept. Tier B stores client-side ciphertext the server cannot read. Export and forget are always free.

## Output

Returns a JSON object containing a unique memory_id (e.g. 'mem_...') and a deduplicated boolean indicating whether the write was merged with an existing equivalent memory rather than creating a new entry.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "ttl": {
   "type": "number",
   "description": "seconds until the memory turns stale"
  },
  "kind": {
   "enum": [
    "fact",
    "preference",
    "instruction",
    "decision",
    "state"
   ]
  },
  "tags": {
   "type": "array",
   "items": {
    "type": "string"
   }
  },
  "tier": {
   "enum": [
    "A",
    "B"
   ]
  },
  "source": {
   "type": "string"
  },
  "content": {
   "type": "string"
  },
  "ciphertext": {
   "type": "string"
  },
  "confidence": {
   "type": "number"
  },
  "blind_index": {
   "type": "array",
   "items": {
    "type": "string"
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "memory_id": "mem_...",
  "deduplicated": false
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mnemo-memory-write-post-v1-memory-remember-e9edfad5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from memory.reversecaptcha.fun](https://www.zero.xyz/host/memory.reversecaptcha.fun/llms.txt)