coin_ins not populated for spell inputs with empty charms

[AndeLabs]

Environment: Charms v8, charms-sdk 0.10.0

Observed behavior:
When a spell input has charms: {} (raw BTC without charms), tx.coin_ins is not populated. This results in coin_ins being empty/None even when BTC is present in the spell input.

Example spell input:

ins:
  - utxo_id: abc123...:0
    charms: {}  # Raw BTC, no charms attached

In the app contract, tx.coin_ins is empty for this input.

Expected behavior:
Unclear - is coin_ins expected to reflect all BTC inputs, or only those with charms?

Workaround:
Skip validation when coin_ins is not populated:

if btc_inputs > 0 && btc_inputs < required_amount {
    return Err(...);
}

Question:
Is this intentional behavior? What's the recommended pattern for validating BTC collateral in contracts when spell inputs have charms: {}?

Would appreciate clarification or documentation update on when coin_ins is populated.

[imikushin]

Is this still the case with v0.12.0 (on the main branch)?

[AndeLabs]

Hi @imikushin,

Thanks for the quick response! I can confirm I'm now using charms-sdk from the main branch (post v0.11.1) to get the coin_ins fix.

I've researched the codebase and documentation but couldn't find answers to a specific issue I'm experiencing with the prover (v8.charms.dev):

My situation:

• Deploying VaultManager contract on testnet4
• Getting "proof request is unexecutable" errors
• Same funding UTXO works once, then subsequent attempts fail with "duplicate funding UTXO spend with different spell"

What I understand from the code:

• VKs don't need pre-registration - the prover receives WASM in the binaries field
• The to_tx function in charms-client/src/lib.rs handles UTXO processing correctly

What I couldn't find documentation for:

• Is there a server-side cache for funding UTXOs?
• If so, what's the expiry time?
• Does changing the collateral UTXO (which changes the spell) invalidate previously cached funding UTXOs?

I have fresh UTXOs and want to ensure I use them correctly this time.

[AndeLabs]

Update: I just attempted deployment and got the error:

Proof request 0x7754e932ad98dce263ee13096a8356bd1a1b5e6e270292418afbd52cda0b10eb is unexecutable

Details:

• VK: 43e511d3868771d3cc569ba742e0669f974bff72d8a5f613dd9df426b7b1038f
• Wallet: tb1qr25l2p34sv4wnz4q0cuh4g9jd9qh2eua6y5awq
• Funding UTXO: d93540abec20ae20159f9f4de685975f17ad68004b970ae765d71bad42103649:1
• Collateral UTXO: da723ed8e69542b7c9552d3a461ff9c52b2fa8835970826bc6db9fbf71a832bd:1
• App contract satisfied locally ✅
• Using charms-sdk from main branch

The local validation passes but the prover rejects it. Is it possible to:

1. Check why this proof request is "unexecutable"?
2. Clear the cache for these UTXOs if needed?

Thanks!