store.blob-put

STORE: upload a file (any bytes) in a single paid call, scoped to YOUR wallet. Send the file base64-encoded in `data` with an optional contentType; we store it privately and key it to your payer address. Read it back with store.blob-get. Up to 3 MB per file (one-call limit); no per-wallet total cap. Kept on a rolling 90-day window that resets on every touch. There is NO public URL — only paid store.blob-get can read it, so your bytes are never fetchable without payment. No account or API key.

price
$0.0100 USDC per call
method
POST/api/store/blob-put
payment
x402 v2 · USDC on Base (EIP-3009) or Solana (SPL transfer)
auth
None. Sign the payment, retry with PAYMENT-SIGNATURE.

Overview

The blob put API is a pay-per-call store endpoint built for AI agents and autonomous software. STORE: upload a file (any bytes) in a single paid call, scoped to YOUR wallet.

There is no signup and no API key. An agent (or any HTTP client) hits the endpoint, receives an x402 "402 Payment Required" challenge, signs a sub-cent USDC payment on Base or Solana, and retries — the data comes back on the paid request. That makes it a drop-in blob put data source for an agent tool-use loop, an MCP host, or a backend that needs store data on demand without onboarding to yet another vendor portal.

Use cases

Parameters

NameTypeDescription
nsrequiredstringNamespace to group blobs, 1-64 chars of [A-Za-z0-9._:-]. e.g. "uploads".
keyrequiredstringKey within the namespace, up to 256 chars. e.g. "snapshot-42.json".
datarequiredstringThe file bytes, base64-encoded. Decoded size up to 3 MB.
min 1 chars
contentTypestringMIME type to return on read. e.g. "application/json", "image/png". Default application/octet-stream.
max 128 chars

Code samples

cURLbash
# 1. Probe the endpoint with no auth — receive 402 with PaymentRequirements
curl -sS -X POST 'https://2s.io/api/store/blob-put' \
  -H 'Content-Type: application/json' \
  -d '{"ns":"example","key":"example","data":"example","contentType":"example"}'

# 2. Sign the EIP-3009 transferWithAuthorization for the advertised price +
#    payTo from the 402 envelope, then retry with PAYMENT-SIGNATURE:
curl -sS -X POST 'https://2s.io/api/store/blob-put' \
  -H 'Content-Type: application/json' \
  -H 'PAYMENT-SIGNATURE: <base64-json-payload>' \
  -d '{"ns":"example","key":"example","data":"example","contentType":"example"}'

# Or just use the canonical runner — it handles the whole loop:
#   EVM_PRIVATE_KEY=0x... node --env-file=.env.local \
#     --experimental-strip-types scripts/x402-pay.ts \
#     'https://2s.io/api/store/blob-put'
TypeScript / Node — @2sio/sdktypescript
import { TwoS } from '@2sio/sdk'

const client = new TwoS({
  privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})

const result = await client.store.blobPut({
  "ns": "example",
  "key": "example",
  "data": "example",
  "contentType": "example"
})

console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)
Python — 2siopython
import os
from twosio import TwoS

client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])

result = client.store.blob_put(ns="example", key="example", data="example", contentType="example")

print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)
MCP — Claude Desktop / AgentKit / any MCP hostjson
// 1. Add @2sio/mcp to your MCP host config (Claude Desktop example below).
//    EVM_PRIVATE_KEY funds x402 payments per call.

// claude_desktop_config.json
{
  "mcpServers": {
    "2sio": {
      "command": "npx",
      "args": ["-y", "@2sio/mcp"],
      "env": { "EVM_PRIVATE_KEY": "0x..." }
    }
  }
}

// 2. Once the server is running, agents call this tool via standard MCP:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "store.blob-put",
    "arguments": {
      "ns": "example",
      "key": "example",
      "data": "example",
      "contentType": "example"
    }
  }
}

Response

FieldTypeDescription
okboolean
one of: true
itemsarray
totalintegerTotal matching rows upstream; null when unknown.
sourceobject
Example response datajson
{
  "ok": true,
  "items": [
    {
      "key": "example",
      "bytes": 1,
      "contentType": "example",
      "expiresAt": "example"
    }
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  }
}

FAQ

Do I need an API key to use the blob put API?
No. store.blob-put is x402-native — there is no signup and no API key. Your client makes the call, receives a 402 with payment requirements, signs a USDC payment, and retries. Funds come from a wallet you control.
How much does the blob put API cost?
$0.0100 USDC per call, charged per request. There are no monthly fees, seats, or minimums — you pay only for the calls you make.
Can I try the blob put API for free first?
Yes. Add ?trial=1 (or the header X-2s-Trial: 1) to get a free real call per endpoint per hour, so you can verify the response shape before wiring payment.
Which networks and tokens are supported?
USDC on Base (via EIP-3009 transferWithAuthorization) or Solana (SPL transfer), using the open x402 payment protocol.
How do I call store.blob-put from an AI agent or MCP host?
Use @2sio/sdk (TypeScript), 2sio (Python), or the @2sio/mcp server for any MCP host — each handles the probe → sign → retry loop for you. See the code samples on this page.

Discovery

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