Template Metadata

Tari Ootle supports off-chain template metadata with on-chain hash anchoring. This allows template consumers to verify authorship, discover templates by category, and audit provenance.

How it works

1. Template authors declare metadata in their Cargo.toml
2. A build.rs script encodes the metadata as CBOR and computes a SHA-256 multihash
3. The metadata hash is submitted on-chain alongside the WASM binary during publishing
4. Anyone can verify the off-chain metadata matches the on-chain hash

Metadata fields

Metadata is sourced from two sections of Cargo.toml:

Standard package fields

These come from the [package] section:

Field	Source
name	package.name
version	package.version
description	package.description
license	package.license
repository	package.repository

Template-specific fields

These go under [package.metadata.tari-template]:

Field	Type	Description
tags	string[]	Searchable tags
category	string	Template category
documentation	string	Documentation URL
homepage	string	Project homepage URL

Extra fields

Arbitrary key-value pairs can be added under [package.metadata.tari-template.extra]:

[package.metadata.tari-template.extra]
audit = "https://example.com/audit-report"

Setting up metadata

Interactive

tari template init ./my-template

Prompts for tags, category, documentation URL, and homepage.

Non-interactive (scripting)

tari template init ./my-template -y \
  --tags token,fungible,defi \
  --category token \
  --documentation https://docs.example.com \
  --homepage https://example.com

Automatic setup

When you create a new template with tari create, metadata generation is automatically configured. Use --skip-metadata to opt out.

Example Cargo.toml

[package]
name = "fungible-token"
version = "1.2.0"
description = "A standard fungible token"
license = "BSD-3-Clause"
repository = "https://github.com/example/fungible-token"

[package.metadata.tari-template]
tags = ["token", "fungible", "defi"]
category = "token"
documentation = "https://docs.example.com/fungible-token"
homepage = "https://example.com"

Inspecting metadata

After building, inspect the generated metadata:

# Human-readable table
tari template inspect

# JSON output (pipe-friendly)
tari template inspect --json

Hash verification

The metadata hash uses domain-separated SHA-256 encoded as a multihash (code 0x12, compatible with IPFS CIDv1):

SHA-256("com.tari.ootle.TemplateMetadata" || cbor_bytes)

This hash is anchored on-chain when you publish with tari template publish.