Soulbound tokens

Soulbound tokens (SBT) are a concept of non-transferable tokens: unlike ordinary tokens and NFTs, an SBT cannot be sold or transferred — it is 'bound' to a specific wallet (address). The idea is to represent things that by meaning should not be sold: reputation, achievements, diplomas/certificates, membership, participation. The concept was proposed recently (including by Vitalik Buterin) as a direction for Web3 identity. Honestly about the experimental nature, this is key: SBT is a very new and essentially experimental idea. Real, time-tested applications are few, standards and practices are still forming, infrastructure and support are immature. Implementing SBT now means working with an as-yet-unproven concept. It is justified only with a specific real task for non-transferability, not for following a trend. We honestly warn about this. Honestly about the inflexibility of non-transferability: the main property of SBT (cannot be transferred) is simultaneously its main limitation. A mistakenly or unfairly issued SBT is hard to 'revoke' (revocation mechanisms must be built in advance, and that is a compromise with the idea). Binding to a wallet means: changed/lost the wallet — and achievements/reputation are bound to the old address, transferring them is hard or impossible. This must be honestly designed. Honestly about privacy, this matters: a public blockchain is transparent. Binding reputation, achievements, membership to an address publicly reveals this information and links the activities of one address. For sensitive data (e.g. education, affiliation) this is a serious privacy question, not a plus. Honestly about 'an ordinary database is often simpler': for most reputation, badge, achievement or membership tasks an ordinary database under your control is simpler, more flexible (you can fix, revoke, manage privacy) and does not require wallets from users. SBTs are appropriate when public verifiability and independence from one platform are specifically needed. Honestly about the effect: for suitable scenarios SBTs give non-transferable, publicly verifiable credentials, but it is an immature concept with inflexibility and privacy questions. Honestly about access: a real task for non-transferability, a crypto audience with wallets are needed. An important boundary: this is SBT; ordinary NFTs (transferable) — 1074; DID — 1085; token gating — 1081. The base price starts from 70,000 ₽ (depends on the scenario).

• Non-transferable credentials (reputation, achievements, membership) are needed.
• Public verifiability independent of one platform matters.
• You want SBT as a new trend — but there is no real task for non-transferability.
• Inflexibility (revocation, wallet loss) and data publicity are not accounted for.

• SBT implementation for a specific scenario (non-transferable tokens, issuance, binding)
• Revocation/update mechanisms (a compromise with non-transferability) where needed
• An honest assessment: are SBTs needed or is an ordinary achievement DB simpler
• Accounting for privacy (a public blockchain reveals data)
• Honest boundaries (experimental/immature concept; inflexibility; wallet loss = SBT loss; privacy questions; an ordinary DB is often simpler)
• SBT smart-contract + code-review (see 1075)
• Documentation and handover
• Review with you

• Non-transferable, publicly verifiable credentials (for suitable tasks)
• Revocation/management mechanisms where built in
• An honest assessment: for most tasks an ordinary DB is simpler and more private
• Honest boundaries (immaturity; inflexibility; privacy; wallet loss = SBT loss)

• We assess the task: is non-transferability needed or is an ordinary DB enough
• We implement SBTs with revocation mechanisms and privacy accounting, review the contract
• We honestly set boundaries (maturity, inflexibility, privacy) and hand over to you

• SBT is a new trend, is it worth implementing?

  Only with a specific task, honestly: SBT is a very new, essentially experimental concept with few real applications; standards and infrastructure are immature. Implementing it to follow a trend is premature. It is justified when you genuinely need specifically non-transferable, publicly verifiable credentials. For most achievement/reputation tasks an ordinary database is simpler, more flexible and more private. We will honestly assess whether it is your case.

• Is SBT non-transferability only a plus?

  No, it is also the main limitation, honestly: a mistakenly or unfairly issued SBT is hard to revoke (mechanisms are needed in advance, and that is a compromise with the idea). Binding to a wallet means: lost/changed the wallet — achievements stayed on the old address, transferring is hard or impossible. This is inflexibility that must be honestly designed rather than passing non-transferability off as a pure advantage.

• Are SBTs safe for private data like education?

  This is a serious question, honestly: a public blockchain is transparent. Binding reputation, diplomas, membership to an address publicly reveals this information and links the activities of one address. For sensitive data this is a privacy risk, not a plus. Often an ordinary database under your control is both more private and more flexible. We honestly warn about the publicity rather than pass SBT off as a private solution.