Security fix for spark on devnet and testnet

[psolstice]

PR intention

Single-input Spark and Chaum v2 proof (a.k.a. H1/H2) HF blocks are set for devnet and testnet

[codeant-ai]

🤖 CodeAnt AI — Review Status

Status	Commit	Started (UTC)	Finished (UTC)
✅ Reviewed your PR	136cd9d	Sep 04, 2026 · 07:20	07:22

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No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Team

Run ID: d0abd98c-1dea-41a2-b688-6e9b494ede0f

📥 Commits

Reviewing files that changed from the base of the PR and between 4f0c771 and 136cd9d.

📒 Files selected for processing (1)

• src/chainparams.cpp

Included review availability: Your plan provides up to 4 included reviews per hour; 3 remain after this review.

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Summary by CodeRabbit

• New Features
  • Spark single-input spends are now active on testnet from block 210,700 and on devnet from block 3,600.
  • Chaum V2 spends are now active on testnet from block 210,800 and on devnet from block 3,700.
  • These network-specific activation heights enable consistent testing and validation of the updated spend capabilities.

Walkthrough

Testnet and devnet now activate Spark single-input and Chaum V2 spends at defined block heights instead of leaving both features disabled.

Changes

Spark activation

Layer / File(s)	Summary
Network activation heights src/chainparams.cpp	Testnet activates Spark single-input at 210700 and Chaum V2 at 210800. Devnet activates them at 3600 and 3700.

Estimated code review effort: 1 (Trivial) | ~2 minutes

Merge Risk: ⚪ Minimal · up to 136cd

Testnet and devnet will activate Spark single-input and Chaum V2 spends at their configured block heights. No current merge-blocking risk remains.

Suggested reviewers: levonpetrosyan93

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 2 functions across 1 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description check	✅ Passed	The description includes the mandatory PR intention and accurately states that H1/H2 activation blocks are set for devnet and testnet. The optional Code changes brief section is missing, but the descr…
Title check	✅ Passed	The title clearly identifies a security fix for Spark on devnet and testnet. It is concise and directly related to the hard-fork activation changes.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

• Fix all pre-merge checks with AI

✨ Finishing Touches 💡 1

📝 Generate docstrings 💡

• Create stacked PR
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🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch devnet-testnet-spark-fix

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User description

PR intention

Single-input Spark and Chaum v2 proof (a.k.a. H1/H2) HF blocks are set for devnet and testnet

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CodeAnt-AI Description

Activate Spark security upgrades on devnet and testnet

What Changed

• Devnet now enables single-input Spark proofs at block 3600 and Chaum v2 proofs at block 3700
• Testnet now enables single-input Spark proofs at block 210700 and Chaum v2 proofs at block 210800
• These network-specific activation heights replace the previous configuration that left both upgrades disabled

Impact

✅ Spark security fixes active on devnet
✅ Spark security fixes active on testnet
✅ Staged H1/H2 proof upgrades at defined block heights

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[reubenyap]

Reviewed head 136cd9d45348ab1ad0fdc87541ec95d80bb180c8. No additional actionable issues were found. I traced the testnet/devnet H1/H2 values through Spark transaction-format, mempool, and block-validation gates and confirmed the activation ordering remains valid; the four-line consensus diff is clean.