Colibri: First Trustless Stateless Client

TL;DR
Colibri is a trustless, stateless, ultra-light Ethereum client that makes blockchain verification accessible everywhere — from browsers and mobile apps to IoT and AI systems. It removes the need to trust RPC endpoints by verifying all blockchain data locally through cryptographic proofs and zk-aggregated consensus verification.

Colibri transforms blockchain access from trust-based to proof-based.
It is the missing piece in Ethereum’s journey toward full statelessness and decentralization — an infrastructure layer that guarantees verifiable truth at every endpoint.
By making trustless verification possible on any device, Colibri expands the reach, security, and resilience of Web3 — ensuring that every wallet, every sensor, and every agent can independently verify the world it interacts with.

Most users and applications today access blockchains through centralized RPC providers.
While blockchains themselves are decentralized, the access layer is not.
When a wallet, dApp, or IoT device queries blockchain data, it typically asks a centralized service like Infura, Alchemy, or QuickNode. These providers can see, filter, or even manipulate the data being served. Users must trust that the answers are correct — yet this trust is unverifiable.
In recent years, multiple supply-chain and RPC hijack attacks have proven that this is not a theoretical risk.
A malicious provider can:

• Return fake balances or outdated state,
• manipulate transaction data before signing to redirect assets to attacker-controlled addresses,
• Manipulate smart contract reads (e.g., lending apps or governance votes),
• Silence or censor certain accounts or regions.

For end users, this means:
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• Wallets showing false information,
• Transactions being hijacked or front-run,
• IoT devices granting unauthorized access,
• AI systems making wrong autonomous decisions.

**
If this access-layer centralization continues, Web3’s decentralization becomes an illusion. We would end up with a decentralized core — but centralized control over how anyone interacts with it.

What Colibri Does
Colibri eliminates the need to *trust *RPCs at all.
It acts as a verifiable access layer — a stateless client that uses only cryptographic proofs to verify blockchain data locally.
This is done without any need for synchronization. Thus, colibri is a true stateless client. This minimizes both bandwidth requirements and energy consumption, which is the reason why “normal” light clients are not feasible for mobile devices.
When Colibri retrieves information (like account balances, contract state, or event logs), it also receives:

-** Execution proofs **(including EIP-1186 Merkle inclusions) verifying that the data truly belongs to a specific block, and

• Consensus proofs showing that the block itself is legitimate and signed by validators of the correct sync committee.

Together, these two layers ensure both what happened and that it really happened on Ethereum.

Colibri’s architecture:

• C-based core: ultra-light, fast, and portable — can run on embedded or mobile devices.
• SDK bindings for JS/TS, Python, Swift, and Kotlin/Java — making integration into wallets, browsers, or backend systems straightforward.
• zk-proof stack built on various zkVMs — recursively aggregates sync committee transitions into a single compact proof, minimizing bandwidth and compute needs. (work in progress)
  -** Local Transaction simulation**: Next to on-chain data verification, all transaction data can be simulated locally before signing based on proofs. (offered as SDK library function)

This means that even a sensor, phone, or AI agent can verify the Ethereum state independently — without syncing or trusting any third party.

Stage 1) For the first year and a bit we were self funded from the three founders to build a working product released on Main net and MVP for Gnosis and Optimism. Stage 2)As colibri is open source and a public good, we are now moving the the second stage, community-driven implementation into various ecosystems. Stage 3) For the future we plan to build products based on colibri for adjacent economies, like IoT, AI, Finance etc. and sell these to B2B to companies in the respective fields.

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