Definition: Sourcify is an open-source smart-contract source-code verification service and public repository. It checks whether submitted source files and compilation information can reproduce bytecode associated with a deployed contract on a specified chain and address. The result helps people inspect what code corresponds to a deployment; it does not assess whether that code is safe, lawful, or free of vulnerabilities.
How verification works
A developer supplies source code and the relevant compiler input or metadata. Sourcify compiles the submission with the stated settings and compares the result with on-chain bytecode. Compiler version, dependencies, optimization settings, source paths, and constructor or deployment details can all matter. A mismatch does not automatically mean the deployed contract is malicious; it means the submitted material did not produce the match Sourcify expected.
Full and partial matches
Sourcify distinguishes full matches from partial matches. A full match includes an exact match under the metadata and bytecode rules used by the service. A partial match can compare executable bytecode while excluding some metadata differences. The label and comparison details matter: a partial match is not identical evidence to a full match, and neither result is a security audit. Read the displayed match type and inspect the source rather than treating a verification badge as an endorsement.
Current service and practical limits
Sourcify supports multiple chains and smart-contract languages, but coverage depends on the current chain and compiler support. Its current documentation describes API v2 for verification and contract lookup; the documentation says the legacy API v1 was turned off on July 7, 2026. Sourcify also publishes a dataset for broader analysis. This makes the project useful to developers and explorers, but availability, API behavior, and verification results still depend on service infrastructure and the exact contract inputs.
Block explorers may offer their own verification flows and can integrate with Sourcify. These tools can complement each other; a verified source on one service should still be checked against the chain, address, match type, compiler details, and actual contract behavior.
Social Media Sentiment
One Ethereum Stack Exchange question asked July 9, 2023 described a Mumbai testnet contract verified on a block explorer but initially failing through Sourcify’s import path. A Sourcify contributor replied that it was probably a server hiccup and reported a successful import. When checked on October 22, 2026, the question showed 481 views and a score of 0; this is one resolved troubleshooting example, not a measure of the service’s overall reliability.
Last updated: 2026-10
Related Terms
See Also
- Why Smart Contract Audits Fail: What Post-Mortems Reveal About the Limits of Security Reviews
- What Are Zero-Knowledge Proofs — And Why Every Major Blockchain Is Building Around Them
- Does Ethereum TPS Include Layer 2 Transactions?
- Trade crypto with ChangeNOW
Sources
- Sourcify documentation: Introduction — The project documentation describes Sourcify’s verification service, supported languages, and public contract dataset.
- Sourcify documentation: Source-code verification — This guide explains bytecode comparison and warns that verification is not a security audit.
- Sourcify API documentation — Current API documentation states that API v1 is turned off and documents API v2 verification and lookup.
- Sourcify verification statistics — The live dashboard shows chain coverage and separates full-match from partial-match records.