How do I mock the Etherscan API locally?

Install stunt, add a one-service block to stunt.yaml (adapter: embedded:etherscan-style), and run stunt up. You get a local, stateful stand-in for Etherscan API 1.0 — 1 routes over rest — with no remote account, no network, and no bills.

Is the Etherscan API mock data synthetic?

Yes — entirely. The adapter returns generated data only; stunt's adapter lint rejects real-looking secrets and PII at build time. It simulates the shape and behavior of Etherscan API (routes, status codes, pagination, webhooks), never real records.

← all adapters

etherscan-style

simulates Etherscan API 1.0

restadapter v0.1.01 routes

verification

VMVM tier — no SDK suite yet· surface 1 · not implemented 3 · differs 2

use it

# add to stunt.yaml
services:
  etherscan:
    adapter: embedded:etherscan-style

# then
$ stunt up

The embedded: source extracts this adapter from the binary — no git clone, fully offline.

how to mock the Etherscan API locally

Install stunt, paste the service block above into stunt.yaml, run stunt up — then point your client at localhost instead of Etherscan API. It works offline, keeps state across requests and restarts, and every response is synthetic: the route shapes, status codes, pagination, and webhook delivery follow the real Etherscan API 1.0 surface — the data is fake, the behavior is real.

backing stores

accountstransactionscontractstoken_holders

api surface (1)

generated from the adapter manifest — exactly what boots, nothing more

1 routes

GET/api

VM-verified behaviors (6)

✓the apikey query parameter gates every module call
✓unknown modules and actions answer the NOTOK envelope over HTTP 200
✓balance reads the seeded ledger; unknown addresses default to "0"
✓txlist scopes by address then applies block filters, sort and paging
✓contract verification: ABI, source, and the unverified fallback
✓stats and token holders keep every number a decimal string

Not implemented (3)

No getLogs action (txlistinternal/tokentx are served, hard-coded empty)
No logs, proxy, or gastracker modules (gasoracle, eth_call passthrough)
No getminedblocks, getblocknobytime, or nodecount actions

Differs from the real API (2)

Auth accepts any non-empty apikey; only a missing key yields the error envelope
txlistinternal/tokentx/tokenbalance return hard-coded empty results

full scorecard →

want more of the Etherscan API surface? adapters are YAML + Starlark — the authoring guide covers adding routes, fixtures, and state machines. Open an issue for anything big first, or just file a PR — merged routes ship in the next release.