# Delx EVM Replacement Fee Bump

> Delx EVM Replacement Fee Bump 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).

Checks whether a new EVM transaction fee (in wei) represents a sufficient bump over the old fee, given a minimum bump fraction threshold.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/evm-replacement-fee-bump
- 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-replacement-fee-bump-f22e82ba
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ViOs-_zF6K51ii6QnYsdD

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-replacement-fee-bump-f22e82ba -d '<json body>'
```

Example prompt: Check if bumping a stuck transaction from 1000000000 wei to 1125000000 wei satisfies a minimum bump fraction of 0.1 for EVM fee replacement.

## When to prefer this

Use this endpoint when an AI agent needs to programmatically verify that a replacement EVM transaction fee satisfies the network's replace-by-fee (RBF) minimum bump requirement before rebroadcasting. It is purpose-built for EVM fee bump preflight checks and returns structured, auditable results with no data retention — ideal for automated blockchain transaction management workflows.

## Known failure modes

- Missing required fields (new_fee_wei, old_fee_wei, or minimum_bump_fraction) may cause a 400 error
- Non-numeric or non-string wei values may cause parsing errors
- minimum_bump_fraction of 0 or negative values may produce unexpected results
- Extremely large wei strings beyond practical EVM values may be rejected

## How this service works

EVM Replacement Fee Bump: EVM Replacement Fee Bump checks proposed fee caps against a required replacement bump from bounded caller-supplied values without an external provider. Call EVM Replacement Fee Bump 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 Replacement Fee Bump as versioned deterministic JSON. Price:…

## Output

Returns a JSON object indicating whether the proposed fee bump is sufficient (sufficient_bump boolean), the proposed fee in wei, and the minimum required fee in wei to satisfy the bump fraction. Also includes audit evidence: input hash, retention status, and external call count.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "new_fee_wei": {
   "type": "string",
   "maxLength": 8192,
   "description": "New Fee Wei supplied to EVM Replacement Fee Bump; used only for this bounded calculation and processed in memory without retention."
  },
  "old_fee_wei": {
   "type": "string",
   "maxLength": 8192,
   "description": "Old Fee Wei supplied to EVM Replacement Fee Bump; used only for this bounded calculation and processed in memory without retention."
  },
  "minimum_bump_fraction": {
   "type": "number",
   "description": "Minimum Bump Fraction supplied to EVM Replacement Fee Bump; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "sufficient_bump": true,
   "proposed_fee_wei": "1125000000",
   "required_fee_wei": "1100000000"
  },
  "schema": "delx/util-evm-replacement-fee-bump/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "e26aad7e3411d7e56c828277122462cfbb1e33dd33e02d2a4747677195dc32fb",
   "external_calls": 0
  },
  "operation": "evm_preflight:evm_replacement_fee_bump"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-evm-replacement-fee-bump-f22e82ba/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)