# EVM Base Fee Growth Ceiling Calculator

> EVM Base Fee Growth Ceiling Calculator 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 maximum base fee in wei that an EVM network could reach after a given number of blocks, given a fractional growth rate and starting base fee.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/evm-base-fee-growth-ceiling
- 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/evm-base-fee-growth-ceiling-calculator-7fcd6c3d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_1aclphhbsvt5dllyYiajS

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 evm-base-fee-growth-ceiling-calculator-7fcd6c3d -d '<json body>'
```

Example prompt: Calculate the EVM base fee growth ceiling starting from a current base fee of 1000000000 wei, with a growth fraction of 0.125, over 3 blocks — I need to know the worst-case fee ceiling before I submit my transaction batch.

## When to prefer this

Use this endpoint when you need a deterministic, in-memory computation of the EVM base fee ceiling with no external calls or data retention — ideal for agent preflighting before submitting EVM transactions, budgeting gas costs in DeFi bots, or modeling worst-case fee scenarios for smart contract workflows. Prefer this over off-chain estimates when you need a provable, auditable result with an input hash in the evidence block.

## Known failure modes

- Missing or invalid blocks integer — returns validation error
- Invalid growth_fraction (e.g. negative or >1 without clear context) — may return error or unexpected result
- current_base_fee_wei exceeds maxLength of 8192 characters — rejected at schema level
- Malformed JSON body — HTTP 400 or schema validation failure
- Payment not attached (x402 protocol) — returns HTTP 402 Payment Required

## How this service works

EVM Base Fee Growth Ceiling: EVM Base Fee Growth Ceiling compounds a caller growth fraction across future blocks from bounded caller-supplied values without an external provider. Call EVM Base Fee Growth Ceiling 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 Base Fee Growth Ceiling as versioned deterministic JSON.…

## Output

Returns a JSON object containing the computed fee_ceiling_wei (the maximum base fee in wei after the specified number of blocks), the number of blocks used in the calculation, the operation name, status (pass/fail), and an evidence block confirming no data was retained and no external calls were made.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "blocks": {
   "type": "integer",
   "description": "Blocks supplied to EVM Base Fee Growth Ceiling; used only for this bounded calculation and processed in memory without retention."
  },
  "growth_fraction": {
   "type": "number",
   "description": "Growth Fraction supplied to EVM Base Fee Growth Ceiling; used only for this bounded calculation and processed in memory without retention."
  },
  "current_base_fee_wei": {
   "type": "string",
   "maxLength": 8192,
   "description": "Current Base Fee Wei supplied to EVM Base Fee Growth Ceiling; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "blocks": 3,
   "fee_ceiling_wei": "1423828125"
  },
  "schema": "delx/util-evm-base-fee-growth-ceiling/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "e6331adf36b1a6016a316e2580f099fd04ebb97045f034d65e705d7114cceb67",
   "external_calls": 0
  },
  "operation": "evm_preflight:evm_base_fee_growth_ceiling"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-base-fee-growth-ceiling-calculator-7fcd6c3d/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)