{
  "format": "delx/intent-card/v1",
  "id": "payload-size-check-api",
  "intent": "Payload Size Check for an agent workflow",
  "title": "Payload Size Check API for agents",
  "description": "Measure payload byte size against soft and hard ceilings before paying — first-party local utility for agent preflight and proven micro-utils expansion. Returns deterministic machine-readable JSON for $0.001 USDC via x402 on Base. Execution is first-party, local-only, stateless, and memory-only with no paid upstream, no input retention, no web search, no live RPC, and no mediagen. Results are advisory; the caller owns authorization, budgets, and production controls. Sibling of Delx routes that already converted externally (random, hash, URL, FX families).",
  "keywords": [
    "Payload Size Check API",
    "Payload Size Check for agents",
    "pay per result API",
    "x402 API",
    "no API key"
  ],
  "updated_at": "2026-08-07",
  "canonical_url": "https://commerce.delx.ai/intents/payload-size-check-api",
  "machine_url": "https://commerce.delx.ai/intents/payload-size-check-api.json",
  "recommendation": {
    "tool_name": "util_payload_size_check",
    "service_name": "Delx Payload Size Check",
    "method": "POST",
    "resource": "https://api.delx.ai/api/v1/x402/payload-size-check",
    "price_usdc": "0.001",
    "payment_protocols": [
      "x402",
      "mpp"
    ],
    "input_schema": {
      "type": "object",
      "properties": {
        "payload": {
          "description": "Input field: payload.",
          "type": "object"
        },
        "soft_limit_bytes": {
          "description": "Input field: soft limit bytes.",
          "type": "integer"
        },
        "hard_limit_bytes": {
          "description": "Input field: hard limit bytes.",
          "type": "integer"
        }
      },
      "required": [
        "payload"
      ],
      "additionalProperties": true
    },
    "example_input": {
      "payload": {
        "hello": "world"
      },
      "soft_limit_bytes": 8192,
      "hard_limit_bytes": 65536
    },
    "example_output": {
      "schema": "delx/util-payload-size-check/v1",
      "bytes": 17,
      "chars": 17,
      "soft_limit_bytes": 8192,
      "hard_limit_bytes": 65536,
      "within_soft": true,
      "within_hard": true,
      "status": "ok",
      "recommend_truncate": false
    },
    "agentcash": {
      "buy": "npx agentcash@latest fetch https://api.delx.ai/api/v1/x402/payload-size-check -m POST -H 'x-delx-source: intent-card-payload-size-check-api' --max-amount 0.001 -b '{\"payload\":{\"hello\":\"world\"},\"soft_limit_bytes\":8192,\"hard_limit_bytes\":65536}'",
      "max_amount_usdc": "0.001"
    }
  },
  "attribution": {
    "header": "x-delx-source",
    "value": "intent-card-payload-size-check-api"
  },
  "evidence": {
    "paid_openapi": "https://api.delx.ai/openapi.x402.json",
    "governed_portfolio": "https://api.delx.ai/x402-portfolio.json",
    "live_contract": "https://api.delx.ai/api/v1/x402/payload-size-check"
  }
}