Miden compatibility

Which Miden protocol line each Guardian release targets, what changed between lines, and what each upgrade does to stored data.

Guardian's own version and Miden's are not aligned. Guardian 0.16.x runs on Miden 0.15; Miden 0.16 arrives in Guardian 0.17.x. Read the matrix rather than matching the numbers.

This page is the single source of truth for those facts. Procedures live elsewhere and link here:

For	Read
Operator upgrade steps	PRODUCTION.md
Diagnosing a version-mismatch symptom	TROUBLESHOOTING.md
SDK contract pinning and release policy	MULTISIG_SDK.md

Support matrix

Guardian	Miden protocol	miden-protocol / miden-standards	miden-client (Rust)	@miden-sdk/miden-sdk (npm)
0.17.0	0.16	=0.16.1	=0.16.0	0.16.0 (exact)
0.16.x	0.15	0.15.3	0.15.0	^0.15.8
0.15.x	0.15	0.15.x	0.15.0	^0.15.0
0.14.x	0.14	n/a	0.14.x	^0.14.0
0.13.x	0.13	n/a	0.13.0	^0.13.0
0.12.x	0.12	n/a	0.12.5	^0.12.5

0.17.0 builds on the stable Miden 0.16 release. @miden-sdk/miden-sdk 0.16.0 embeds miden-client 0.16.0 and miden-protocol / miden-standards 0.16.1, which is why the Rust pins are 0.16.1 for the protocol crates and 0.16.0 for the client crates.

Pins are exact on the 0.16 line, and the Rust and npm pins must move together: nothing at build time verifies that the npm SDK's embedded miden-standards matches the Rust pin, so the CI parity gates are what catch drift. See MULTISIG_SDK.md.

Upgrading from 0.16.x (Miden 0.15) to 0.17.0 (Miden 0.16) is a protocol-line change: the guarded-multisig auth component now pays the transaction fee and transaction summaries bind the reference block, so nothing signed or stored on 0.15 verifies on 0.16. Stored Miden account data is reset by the embedded migration listed below, accounts must be recreated, and the Rust SDK's local miden-client SQLite store must be recreated (the browser IndexedDB store migrates in place). miden-client 0.16.0 also raises the MSRV to 1.98.1.

0.17.0-rc.1 to rc.3 were pre-releases on the Miden 0.16 release candidates, published to npm under the rc dist-tag. They are not supported. Every rc pinned a different auth_tx procedure root than 0.17.0 (0.16.1 factored the fee payment into miden::standards::auth::multisig::pay_bounded_fee), so an account created on an rc is rejected with UnsupportedContractVersion, and a proposal still pending from an rc cannot be reproduced: TransactionRequest serialization changed and the auth arg commitment moved. Execute or cancel every pending proposal on the rc version, have GUARDIAN drop any that cannot be executed, then recreate the account on 0.17.0. Recreating the account does not clear proposals served for the old one.

A Guardian server or SDK built on one protocol line rejects a node from another. Run a node matching the Miden protocol column.

Data resets

Guardian has twice been unable to migrate stored account data across a Miden line. Both resets are embedded migrations that run automatically at server startup, both are irreversible, and both scope the purge to Miden rows using account_metadata.network_config->>'kind' so EVM accounts survive.

Migration	Introduced in	Deletes	Preserves
2026-08-24-000001_miden_016_irreversible_reset	Guardian 0.17.x	Miden rows in delta_proposals, deltas, states, account_metadata; account_auth_state by cascade	EVM rows, admin_actions, auth_sessions, auth_challenges, storage_encryption_marker, worker_leases, keystore
2026-06-14-000001_v015_account_id_cutover	Guardian 0.15.x	pre-0.15 (v0 account ID) Miden rows in the same four tables	EVM rows, admin_actions

Both are Postgres-only. Filesystem-backed deployments reset by starting from empty storage and metadata directories, preserving the keystore directory.

A deployment upgrading across more than one line runs both migrations in the same startup; the newer reset subsumes the older one.

Guardian 0.17.x on Miden 0.16

Nothing stored under Miden 0.15 survives, because the account's on-chain surface moved in several independent ways:

• Procedure roots changed, so stored proposals no longer address the procedures they were signed against, and root-keyed storage reads (procedure_thresholds) miss.

• ECDSA-k256 public-key commitments changed in miden-crypto 0.28 to hash native affine-coordinate limbs (qx || qy as little-endian u32 limbs) instead of the compressed SEC1 bytes, so stored approver commitments no longer match their keys. Compressed SEC1 serialization is unchanged, which is why this fails as a commitment mismatch rather than a decode error.

• The signature advice ABI changed in miden-vm 0.29 to QX[8] || QY[8] || SIG_R[8] || SIG_S[8], and the recovery byte is no longer part of it, so stored signatures cannot be replayed into a transaction.

• Storage slot names moved from openzeppelin::* to miden::standards::*, so stored state cannot be read back by name.

• The transaction summary layout changed and now binds a chain anchor, so stored summaries cannot be recomputed or re-verified. Proposals carry a serialized ChainAnchor (wire field chain_anchor) and verification and execution pin to it.

• The custody account is now the upstream miden-standards AuthGuardedMultisig component rather than Guardian's local MASM, and guardianEnabled is gone: the guardian is always present.

• Transaction fees became the auth component's responsibility, and AuthGuardedMultisig now pays them. Its auth procedure calls miden::standards::auth::multisig::pay_bounded_fee before building the transaction summary, so the fee note and the vault withdrawal funding it fall inside what the cosigners sign rather than being appended afterwards.

  That makes the auth arg carry double duty. fee::load_conversion_info reads it as the commitment hash(CONVERSION_INFO || SALT) and looks the preimage up in the advice map; the same word then serves as the transaction summary salt. A bare salt still satisfies the salt role but not the fee role: the lookup misses, conversion info comes back empty, and fee payment aborts with ERR_FEE_CONVERSION_INFO_MISSING — though only once the computed fee is non-zero, so a zero-verification_base_fee chain never notices.

  Every typed create*Proposal path in both SDKs therefore commits native conversion info, at rate 1/1 under the chain's own fee faucet. This is the invariant change: a proposal's auth arg is no longer its salt.

  Cross-SDK reconstruction survives because the committed value is derived, not chosen. The faucet is read from the block the proposal is anchored at — the anchor travels with the proposal and is checked against the summary's block commitment before use — and the rate is fixed at 1/1. Both SDKs declare the stored proposal salt on their transaction request builders: fee_conversion_salt(salt) in Rust and withFeeConversionSalt(salt) in TypeScript. The pinned Miden clients then derive and commit the same native conversion info from the reference header used for execution.

  pay_bounded_fee then estimates the authentication cost and resolves the payment. It only accepts the chain-native fee faucet, and caps the payment at twice the computed fee so a fee increase while signatures are collected has bounded headroom.

  Two consequences follow:

  • The pinned Miden clients classify AuthGuardedMultisig as CallerChosenSalt. A request declares a salt, and the client commits the chain-native conversion info under that salt. Components that do not read fee conversion info still fail with TransactionRequestError::FeeConversionInfoUnsupported.
  • The built-in typed proposal paths always commit the chain-native asset at rate 1/1. On a fee-charging chain the guarded account needs that native asset in its vault or authentication aborts before the summary exists. Guardian- assisted recovery cannot route around this because it uses the same auth path. A custom request naming a different fee asset also aborts: the guarded multisig component enforces the native faucet itself.

  The exported builders always declare the fee conversion salt. A caller assembling a raw custom request can omit it, but the resulting request works only on a zero-fee chain. Typed proposal reconstruction always declares the stored salt_hex.

Data effect: full reset, see above. Operator steps: PRODUCTION.md.

Guardian 0.15.x and 0.16.x on Miden 0.15

Miden 0.15 invalidated account ID version 0: encoded version 0 is rejected, and every serialized AccountDelta or TransactionSummary embedding a v0 ID fails to deserialize. A v0 ID is a proof-of-work-derived commitment with no v1 equivalent, so there is no in-place migration. Addresses also moved to bech32m.

Guardian 0.16.x stayed on Miden 0.15 and required no reset; the changes in that release were Guardian-side only.

Data effect: the 0.15 cutover above, on the first 0.15 deploy.

Adding a line

When Guardian adopts a new Miden line:

1. Add a matrix row with the exact pins.
2. Add a per-line section stating what broke and what it does to stored data.
3. If data cannot be migrated, add the migration to the reset table and write the operator steps in PRODUCTION.md.
4. Leave the procedural and symptom docs pointing here rather than restating the version facts, so there is one place to update.