Memory API

The simplest way to give your agent memory.

Hosted memory for LLM apps. MCP-native, REST-friendly, and ready in about 60 seconds. 14-day trial. Card required.

Try it

curl -X POST https://expert.maindex.io/v1/memories \
  -H "Content-Type: application/json" \
  -H "X-API-Key: YOUR_API_KEY" \
  -d '{
    "headline": "User prefers annual billing",
    "body": "Discussed in onboarding. Strong preference for annual with upfront discount.",
    "tags": ["pricing", "preferences"]
  }'

# Response: { "ok": true, "data": { "id": "mem-1jc4", "headline": "..." } }

import requests

resp = requests.post(
    "https://expert.maindex.io/v1/memories",
    headers={"X-API-Key": "YOUR_API_KEY"},
    json={
        "headline": "User prefers annual billing",
        "body": "Discussed in onboarding. Strong preference for annual with upfront discount.",
        "tags": ["pricing", "preferences"],
    },
)
print(resp.json())
# {"ok": true, "data": {"id": "mem-1jc4", "headline": "..."}}

const resp = await fetch("https://expert.maindex.io/v1/memories", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "X-API-Key": "YOUR_API_KEY",
  },
  body: JSON.stringify({
    headline: "User prefers annual billing",
    body: "Discussed in onboarding. Strong preference for annual with upfront discount.",
    tags: ["pricing", "preferences"],
  }),
});
const data = await resp.json();
// { ok: true, data: { id: "mem-1jc4", headline: "..." } }

{
  "mcpServers": {
    "maindex": {
      "type": "streamableHttp",
      "url": "https://expert.maindex.io/mcp"
    }
  }
}

// Add to .cursor/mcp.json, claude_desktop_config.json,
// or any MCP client. OAuth handles auth automatically.

Start your trial Card required. Cancel anytime.

Built for indie agent builders

Chatbots that remember each user across sessions

Scope memories per user. Your bot picks up where the last conversation left off.

GET /demo/expert/v1/search?q=alice+coffee

# Search returns memories tagged for that user

Coding agents that recall your architecture decisions

Tag decisions so your agent finds them by meaning, not filename.

GET /demo/expert/v1/search?q=database+choice

# Semantic search finds decisions by meaning

Multi-agent systems sharing one memory

One memory graph for every agent. Plan-step writes, execute-step reads. No glue code.

GET /demo/expert/v1/search?q=stripe+webhooks

# Full-body memories with linked decisions

Personal assistants with persistent context

One MCP config line. Your assistant remembers across every tool.

{
  "mcpServers": {
    "maindex": {
      "type": "streamableHttp",
      "url": "https://maindex.io/demo/expert/mcp"
    }
  }
}

Paste into any MCP client config (Claude Desktop, Cursor, Cline, Windsurf).

Hosted SaaS. You hit our API, we store, tag, link, and serve memories back. No infra to run. MCP server included.

Pricing

Expanding Brain

$14.99/mo

Generous monthly synapse quota
Join teams
Full MCP + API access

14-day trial · Card required

Galaxy Brain

$49.99/mo

Generous monthly synapse quota
20 collection locks
Unlimited owned teams
Full MCP + API access

14-day trial · Card required

What's a synapse? → FAQ

Built by Ian Maddox, ex-Google. One person, one product, real email: info@maindex.io. If something breaks, you'll hear back from me, usually within a day.

GitHub info@maindex.io

FAQ

What's a synapse, and will I really have enough?

A synapse is a single unit of memory usage. Every time your agent reads from or writes to your memory graph, the processing is measured in synapses. Expanding Brain includes generous monthly synapse quota. You can check your usage anytime in your dashboard. Full FAQ →

Is there a free tier?

No. Maindex offers a 14-day trial on every plan. A card is required up front. If it's not for you, cancel before the trial ends and you won't be charged.

How is this different from mem0 / Zep / Letta?

MCP-native from day one, fully hosted with no self-hosting requirement, structured memory with revision history, and you're set up in about 60 seconds. Same graph across REST and MCP.

Can I self-host?

No. Maindex is fully hosted SaaS. You don't run any infrastructure. For indie devs, that's the point: one fewer thing to maintain.

Is my data secure?

Yes. Every account is a fully isolated tenant with database-level row isolation. Data is encrypted at rest (AES-256) and in transit (TLS 1.2+). Authentication is OAuth-first via WorkOS (no passwords stored). Locked collections add passphrase-based access control on top. Full details →

What's the latency / SLA?

No formal SLA yet. Maindex is a one-person product and hasn't seen the load that would justify one. Request latency varies depending on which endpoint you're hitting and how much data you're writing or recalling. If your project needs a contractual SLA, this isn't the product for you yet.