Covenant Language Support

Covenant is a privacy-first smart contract language that compiles to EVM bytecode. Write auditable, post-quantum-ready contracts with built-in access control, FHE, ZK proofs, and cryptographic amnesia — without writing Solidity.

Audited — OMEGA V4 full audit by Kairos Lab Security Research. 41 findings (5 Critical / 8 High / 8 Medium / 6 Low / 9 Info), all resolved. Public report →

Features

Syntax Highlighting

Full TextMate grammar covering every Covenant construct:

• Top-level constructs — module, record, token, ballot, counter, board, market, vault, registry, bridge, ceremony
• Privacy qualifiers — public, private, encrypted, sealed, hybrid, confidential
• Access control — only, when, given
• Types — amount, time, duration, hash, text, address, bool, ciphertext, map, shares, pq_key, …
• Control flow — match, let, return, if, else, for, each, try_action, catch, revert_with
• Annotations — @slot, @version, @selective_disclosure, …
• Comments — -- line comments
• Operators — full arithmetic, comparison, bitwise, assignment
• Literals — integers, hex (0x…), text strings, duration literals (30 days, 1 week)

Diagnostics

Real-time errors and warnings from the Covenant compiler, surfaced inline as you type. Covers:

• Parse errors
• Type mismatches
• Access control violations
• @slot annotation conflicts (E423)
• Unreachable code and dead assignments

Hover Documentation

Hover over any identifier to see its type, visibility, and declaration site. Works for fields, actions, views, events, and imported symbols.

Document Symbols

Full outline support — every record, token, action, view, event, and field appears in the VS Code Outline panel and breadcrumb.

Language Configuration

• Comment toggle (Ctrl+/ / Cmd+/) — adds/removes -- prefix
• Auto-close — {, [, (, " close automatically
• Smart indentation — increases inside { blocks, decreases on }
• Code folding — collapse any { } block

Requirements

Install the Covenant toolchain (compiler + language server):

# One-line installer — Linux / macOS
curl -sSL https://install.covenant-lang.org | sh

# Via cargo
cargo install covenant-cli

The extension automatically discovers covenant-lsp from your PATH. No manual server configuration needed.

Quick Start

1. Install the extension and the Covenant toolchain
2. Open or create a .cov file
3. Start writing — diagnostics, hover, and symbols activate immediately

-- hello.cov
record Hello {
    greeting: text

    action update(new_text: text) {
        greeting = new_text
    }

    view read returns text {
        greeting
    }
}

Language Samples

Token (ERC-20 equivalent)

token Coin {
    symbol:   "COIN"
    name:     "Covenant Coin"
    decimals: 18
    supply:   1_000_000 to deployer
}

Access Control

record Vault {
    private balance: amount
    owner: address

    only owner
    action deposit(value: amount) {
        balance += value
        emit Deposited(value)
    }

    when balance > 0
    action withdraw(value: amount) {
        balance -= value
        emit Withdrawn(value)
    }

    view total returns amount { balance }

    event Deposited(value: amount)
    event Withdrawn(value: amount)
}

Privacy + ZK

record PrivateVote {
    encrypted tally: map<address, choice>

    sealed
    action cast(encrypted vote: choice) {
        tally[caller] = vote
    }

    selective_disclosure
    view result returns choice {
        tally[caller]
    }
}

Post-Quantum

record PqBoard {
    pq_signed
    action submit(data: bytes) {
        emit Submitted(data)
    }

    event Submitted(data: bytes)
}

Extension Settings

Supported File Types

Roadmap

• [ ] Go-to-definition
• [ ] Find all references
• [ ] Auto-completion (fields, actions, types)
• [ ] Semantic tokens
• [ ] Code actions (quick fixes for common errors)
• [ ] Formatter integration (covenant fmt)
• [ ] Debugger adapter

Security & Audit

Covenant v0.6 was audited by Kairos Lab Security Research using the OMEGA V4 offensive methodology over 5 phases:

Key fixes: access control no-op (KSR-CVN-011), stale-memory precompile forgery (KSR-CVN-014), proxy initializer hijack (KSR-CVN-012), ceremony phase transition bypass (KSR-CVN-001).

Full public report: github.com/Valisthea/covenant-audits

Links

License

Apache-2.0 — see LICENSE