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TraceFast Proxy Contract Implementation History
x402
TraceFast Proxy Contract Implementation History is a paid API for AI agents from mpp.tracefast.xyz, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-19).
Returns the ordered history of implementation contracts a proxy has delegated to, detected via EIP-1167, EIP-1967, or OpenZeppelin v1 slots, with block ranges and replacement status.
Price / call$0.01
Success—
StatusUnknown
How this service works
TraceFast live Ethereum data: the implementations a proxy contract has been observed delegating to — from its EIP-1167 bytecode, its EIP-1967 implementation or beacon slot, or its OpenZeppelin v1 slot — newest first, each with the blocks it was seen at and whether it has since been replaced. Path address: The proxy contract address, `0x`-prefixed, 40 hex characters, any case. Docs: https://docs.tracefast.xyz/api/contract-proxy.md
Output
An ordered list (newest first) of implementation contract addresses the proxy has delegated to, each entry including the implementation address, the block numbers at which it was first and last observed, the proxy detection method used (EIP-1167 bytecode, EIP-1967 implementation slot, EIP-1967 beacon slot, or OpenZeppelin v1 slot), and a flag indicating whether that implementation has since been superseded by a newer one.
Example use cases
Audit upgradeable DeFi protocol
“Show me every implementation contract that 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 has ever delegated to on Ethereum, including which blocks each implementation was active and whether it's been replaced — I'm auditing this protocol's upgrade history.”
Detect proxy standard used by contract
“What proxy standard does 0x7d2768dE32b0b80b7a3454c06BdAc94A69DDc7A9 use — is it EIP-1167, EIP-1967, or OpenZeppelin v1 — and what implementation is it currently pointing to?”
Monitor contract for unexpected upgrades
“Has the proxy contract at 0xc3d688B66703497DAA19211EEdff47f25384cdc3 had its implementation changed recently? Give me its full delegation history with block numbers so I can check if anything changed in the last few weeks.”
Technical details
Endpoint
GEThttps://mpp.tracefast.xyz/api/v1/chains/1/contracts/:address/proxy?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need the full historical record of proxy delegations for a specific Ethereum contract address, including detection across multiple proxy standards (EIP-1167, EIP-1967 implementation/beacon, OpenZeppelin v1). Prefer this over static code analysis tools when you need live, on-chain observed data with block-level granularity. Ideal for security audits, protocol research, upgrade monitoring, and any workflow that needs to know not just the current implementation but the complete lineage of implementations a proxy has used.
Side effects
- Address is not a proxy contract — returns empty list or no-proxy indicator
- Invalid address format — returns 400 bad request
- Contract not indexed yet or very recent deployment — may return incomplete history
- Non-Ethereum chain ID — endpoint is scoped to chain ID 1 only
- Payment failure via x402 protocol — returns 402 Payment Required
- Network timeout on live chain data fetch — returns 503 or timeout error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| input | — |
Tags
x402
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