mero-sign

mero-sign is a CLI tool for Ed25519 key management and manifest signing. Every app bundle published to the Calimero registry must carry a valid Ed25519 signature — mero-sign is the tool that produces it.

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Installation

From crates.ioFrom source

cargo install mero-sign

git clone https://github.com/calimero-network/core
cd core
cargo install --path tools/mero-sign

Source: calimero-network/core/tools/mero-sign

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Generating a Key

Run once per developer. Keep this file outside your project directory.

mero-sign generate-key --output key.json

This writes a JSON file you use for all signing operations:

{
  "private_key": "PZbZ5yM9t63qOHMM-CCzExbNv8u79XTxZT9UW8GQJ60",
  "public_key":  "yuKE404BaldXazEIUC4XrVGFyXxxyoRVjrrGhcKk1P4",
  "signer_id":   "did:key:z6Mkt7Ejb12a1BxvRiUpd5YWkMrk8KVjaShW2vMt6trm7FGH"
}

Field	Description
private_key	Base64url-encoded 32-byte Ed25519 secret. Never share this.
public_key	Base64url-encoded 32-byte public key. Embedded in every signed manifest.
signer_id	did:key DID representation of the public key.

Key security

Store key.json outside your project directory and add it to .gitignore. Never commit private keys to version control.

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Signing a Manifest

mero-sign sign manifest.json --key key.json
# → writes signature block into manifest.json in-place

How signing works

  manifest.json  (signature field absent or empty)
       │
       ▼  Remove signature + all _* prefixed fields
       │
       ▼  RFC 8785 JSON Canonicalization
       │  (sorts all object keys recursively → deterministic bytes)
       │
       ▼  SHA-256 hash of canonical bytes
       │
       ▼  Ed25519 sign(hash, private_key)
       │
       ▼  Inject signature block into manifest:
          {
            "alg":      "ed25519",
            "pubkey":   "base64url-32-bytes",
            "sig":      "base64url-64-bytes",
            "signedAt": "ISO-8601"
          }

The registry re-runs this exact process on every upload and verifies the signature matches. A mismatch returns 400 invalid_signature.

Sign before packing

mero-sign operates on a standalone manifest.json file — not on a packed archive. Always sign first, then bundle.

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Team / Org Workflows

Org members each keep their own personal signing key — there is no shared org key. The registry validates org membership via the authenticated email, not by which key was used.

# Each developer generates their own key (one-time)
mero-sign generate-key --output my-key.json
echo "my-key.json" >> .gitignore

# Sign as usual — the registry validates org membership via your email
mero-sign sign manifest.json --key my-key.json

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Full Publishing Workflow

For a complete guide from build to publish see Publishing Apps.