# Delx EVM Blob Fee Budget

> Delx EVM Blob Fee Budget is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Computes the total blob fee ceiling in wei given blob gas and max fee per blob gas, enabling EVM preflight cost checks without external calls.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/evm-blob-fee-budget
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-evm-blob-fee-budget-29f057fe
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0RjQhmTe08QWc55P2fqWU

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 delx-evm-blob-fee-budget-29f057fe -d '<json body>'
```

Example prompt: Before I submit my EIP-4844 transaction, calculate the blob fee ceiling in wei assuming blob gas of 131072 and a max fee per blob gas of 2 wei.

## When to prefer this

Choose this endpoint when an AI agent needs a fast, stateless, auditable computation of the EVM blob fee ceiling in wei before submitting an EIP-4844 blob transaction. It performs no external calls and retains no input data, making it ideal for preflight cost checks in automated blockchain workflows where privacy and determinism matter.

## Known failure modes

- Missing or invalid blob_gas integer causes validation error
- max_fee_per_blob_gas_wei exceeds maxLength of 8192 characters
- Non-numeric string passed for max_fee_per_blob_gas_wei
- Integer overflow if extremely large blob_gas or fee values are provided
- Malformed JSON body returns 400-level error

## How this service works

EVM Blob Fee Budget: EVM Blob Fee Budget calculates a worst-case blob fee from blob gas and fee cap from bounded caller-supplied values without an external provider. Call EVM Blob Fee Budget before signing, submitting, replacing, or accepting an EVM/Base transaction assembled from caller-owned data. Returns normalized transaction evidence, calculated budget or shape findings, and a fail-closed preflight status for EVM Blob Fee Budget as versioned deterministic JSON. Price: $0.001 USDC via x402…

## Output

Returns a JSON object containing the computed blob_fee_ceiling_wei (the maximum blob fee in wei), along with operation metadata including schema version, status, evidence of no data retention, input hash, and zero external calls made.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "blob_gas": {
   "type": "integer",
   "description": "Blob Gas supplied to EVM Blob Fee Budget; used only for this bounded calculation and processed in memory without retention."
  },
  "max_fee_per_blob_gas_wei": {
   "type": "string",
   "maxLength": 8192,
   "description": "Max Fee Per Blob Gas Wei supplied to EVM Blob Fee Budget; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "blob_fee_ceiling_wei": "262144"
  },
  "schema": "delx/util-evm-blob-fee-budget/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "452aa5227d3b7d47a78b8729ad6d09af441ba3bf8df5aa35b34a7f7e8c38965f",
   "external_calls": 0
  },
  "operation": "evm_preflight:evm_blob_fee_budget"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-evm-blob-fee-budget-29f057fe/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)