This Month in Forest - September 2026

[LesnyRumcajs]

This Month in Forest 🌲

Welcome to the September edition of This Month in Forest!

Highlights

NV29 Solstice

A couple of hours ago, the calibration network was successfully migrated to NV29 Solstice at epoch 4109133. Forest upgraded alongside the other implementations, and so far, it seems like a flawless upgrade. The mainnet upgrade will likely happen in a couple of weeks - watch Forest NV29 support discussion for updates!

New proof parameter hosting

ChainSafe is now the default proof parameter provider for Forest & Lotus; the files are available at filecoin-proofs.chainsafe.dev. Note that the old IPFS gateway now points there, so double-check if your fallback doesn't point to the default (if you're running an old Forest version, that'd be the case).

New releases

Two releases this month:

• v0.37.0 "Sharad Sampat": mandatory for calibnet node operators, as it brings NV29 support. It also contains breaking changes around proof parameter sources, so please read the CHANGELOG before upgrading.
• v0.36.1 "Kaaguy": non-mandatory, mostly RPC fixes (notably Filecoin.MpoolPending and Filecoin.ChainNotify).

A release supporting NV29 on mainnet will follow in the coming weeks.

Become a Filecoin Onchain Cloud Storage Provider in Five Minutes

FilOz released a guide on becoming a FOC provider in five minutes. Yes, the compose setup includes running a Forest node!

Development

fix n. & v. trans. [Latin figere "to attack with reproaches, to render immovable."] 1 n. A palliative shot in the system's arm, becoming less effective with each application 2 v. trans. To remove [a bug] by redefining the program specification in order to take advantage of an unexpected feature.
The Computer Contradictionary, Stan Kelly-Bootle

External dataset checks in CI

In July we started validating Forest's responses against chain.data.riba.plus, an independent dataset built by @ribasushi. Those checks now run in CI: on dispatch, on labelled PRs (#7509, #7570) and against both calibnet and mainnet (#7603), always picking a day for which the dataset is already published (#7621). The checker also gained a --probe mode (forest-iac#534).

EVM tooling

forest-cli can now talk to smart contracts directly, with no Lotus binary needed:

• forest-cli evm deploy and forest-cli evm call (#7582) deploy a contract and run read-only calls against it. Our own tests now use them in place of lotus evm deploy.
• forest-cli evm invoke (#7595) sends a state-changing transaction to a contract.
• forest-wallet send accepts --method and --params-hex (#7607), matching lotus send, so arbitrary actor methods can be invoked from the wallet.

Correctness

• eth_sendRawTransaction now returns the Ethereum transaction hash instead of the Filecoin message CID, and reports an error if storing the hash mapping fails (#7625). This unbreaks tooling such as forge script (solstice#57). Thanks to @wjmelements for the contribution! ❤️
• Filecoin.MpoolPending got three fixes: messages of a requested tipset that forks away from the pool's tipset are merged again, a missing BLS signature in the cache skips the message instead of failing the call, and a race that could list messages already applied by the reported tipset is gone (#7566).
• Filecoin.StateMinerInitialPledgeCollateral returns an error from NV29 on, matching Lotus, since under FIP-0118 a pre-commit no longer describes a pledge; use Filecoin.StateMinerInitialPledgeForSector instead (#7599). The pledge APIs also got test coverage based on the builtin-actors test vectors (#7626).
• Block production readiness. A missing guard in block message handling (#7651) and an under-estimated gas floor for secp messages (#7652) were fixed. Neither affects Forest today, but both would matter once Forest produces blocks on public networks.
• Snapshot GC no longer occasionally leaves a gap in the chain right above the exported snapshot, which made anything walking back past that point fail with tipset at epoch X not found (#7661).

Performance

A round of allocation trimming on paths every RPC call and message goes through:

• Computing a message's CBOR-encoded length no longer serialises it into a buffer, which is 30-50% faster, and message CIDs are hashed by streaming into Blake2b instead of buffering first (#7634).
• Conversions between the versioned Message types and their Lotus JSON form no longer allocate needlessly (#7646).
• A new benchmark validates tipsets over a snapshot and epoch ranges (#7583), useful for catching regressions (or wins) from, e.g., wasmtime updates in the FVM.

See the CHANGELOG for the full list of client-facing changes; the commit history has the rest. 🤓

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Individual reports

Disclaimer: This is for reporting purposes only.

@akaladarshi

Highlights

• Forest is ready for NV29 "Solstice" (FIP-0118), the next Filecoin network upgrade. Ported the upgrade's new actor code into the ChainSafe library Forest builds on and released it, added it to Forest together with the state migration that runs at the upgrade point, and confirmed that a Forest node ends up with the same post-upgrade state as Lotus on two test networks. The work shipped in Forest v0.37.0, released ahead of the calibration-network upgrade on 28 September (fil-actor-states#440, #7593, #7598, #7599, #7635, #7638, #7645, fil-actor-states#441, #7655, #7654, #7660, #7671).

• Forest's collection of smart-contract activity logs has its first restructured code. Turned last month's restructuring plan into a draft pull request for the team to review (#7608).

Wider ecosystem

A startup failure that blocked Forest's networking library upgrade on macOS is fixed upstream. The upgrade pulls in a DNS library that could not read some Macs' network settings; found this during review and got the fix merged into the library's release branch (hickory-dns#3940).

Full list of authored pull requests, September 2026.

@EclesioMeloJunior

Highlights

• External dataset checks on mainnet. Enabled the external dataset checks in CI to run against mainnet (#7603).
• forest-tool index backfill downloads proof parameters. Without them the backfill computed wrong state and receipt roots; it now also verifies that the recomputed roots match the child header's (#7588).
• Fetching drand beacon entries from gossipsub. Drand provides gossipsub topics that deliver new beacon entries, so Forest does not need to actively fetch them via HTTP. This is currently a work in progress (#7544).

Full list of authored pull requests, September 2026.

@LesnyRumcajs

Highlights

• Proof parameter hosting for the whole network. Coordinated with ChainSafe infra to host the full set of proof parameters (hundreds of GB) at filecoin-proofs.chainsafe.dev, usable by both Forest and Lotus; proofs.filecoin.io now points there. Moved Forest to it with an independent fallback (#7630, #7649).
• Fixes. A snapshot GC race that could leave a gap in the chain (#7661), and three Filecoin.MpoolPending bugs (#7566).
• Block production readiness. Fixed a missing guard in block message handling (#7651) and the secp message gas floor (#7652), both relevant once Forest produces blocks on public networks.
• Pledge API coverage for NV29. Tests for the pledge calculations based on builtin-actors test vectors (#7626).
• rust-libp2p 0.57 upgrade (#7617).

Full list of authored pull requests and filed issues, September 2026.

@sudo-shashank

Highlights

• EVM contracts from the Forest CLI, no Lotus needed. Implemented forest-cli evm deploy, call and invoke, mirroring their Lotus counterparts, and switched Forest's own tests from lotus evm deploy to them (#7582, #7595).
• forest-wallet send can call arbitrary actor methods. Added --method and --params-hex, matching lotus send (#7607).
• Fewer CBOR allocations. Computing a message's encoded length no longer serialises it (30-50% faster), and message CIDs are hashed by streaming (#7634).

Full list of authored pull requests, September 2026.