slv-pythnet

name

slv-pythnet

description

Run a self-hosted Pythnet RPC node — the application-specific Solana fork operated by Pyth's data providers. Pythnet RPC is what `slv-hermes` reads from for accumulator messages; running it locally completes a fully self-hosted Pyth price feed stack. Recipe handles disk mount, sysctl tuning, Solana 1.14 fork build (with cstdint workaround for modern GCC), identity gen, and systemd. Snapshot fetch + catch-up typically finishes in 10-20 minutes.

SLV Pythnet Skill

Ansible recipe + skill docs for running a self-hosted Pythnet RPC node — the application-specific Solana fork operated by Pyth's data providers.

What is Pythnet?

Pythnet is an application-specific blockchain operated by Pyth's data providers. This blockchain is a computation substrate to securely combine the data provider's prices into a single aggregate price for each Pyth price feed. Pythnet forms the core of Pyth's off-chain price feeds that serve all blockchains. — pyth-network/pythnet README

It's a Solana 1.14.17 fork. Running it as a no-voting RPC node lets you serve Pythnet HTTP+WS directly to a self-hosted Hermes (see slv-hermes), eliminating the dependency on public Pythnet endpoints (Triton, P2P, Blockdaemon, Figment).

Why self-host?

Pyth Network's documentation notes that running Pythnet RPC yourself is "discouraged due to the potential high cost and maintenance involved" — which is true relative to using a managed provider, but wildly overstated when compared to running a Solana mainnet RPC. Pythnet's traffic is tiny: only Pyth oracle operations, ~21 validators, no DeFi mints, no NFT spam. Ledger growth is ~10 GB/day. Catch-up from a fresh snapshot fetch finishes in 10-20 minutes (vs hours on mainnet).

If you already run Solana RPC infrastructure, Pythnet RPC is an order of magnitude smaller across every dimension.

Hardware target

Pythnet is light enough that mid-range commodity hardware suffices:

Resource	Recommended	Note
CPU	16-32 cores	Solana validator binary is multi-threaded but Pythnet TPS is bounded by Pyth oracle ops only
RAM	128 GB (256 GB safety margin)	AccountsDB + RocksDB block cache
Disk	2 TB NVMe (single)	Mainnet needs 4-8 TB RAID0; Pythnet doesn't
Network	1 Gbps	Mainnet needs 10 Gbps+; Pythnet doesn't
OS	Ubuntu 22.04 / 24.04	—

A second NVMe is optional — the recipe can format and mount it as /mnt/ledger if you set pythnet_format_disk=true, otherwise it uses whatever directory you point pythnet_ledger_mount at.

Directory Structure

ansible/
  mainnet-pythnet/  — playbooks (init.yml + supporting + lifecycle)
  cmn/              — shared common (create_user, fix_permissions, etc.)
jinja/
  mainnet-pythnet/  — start-pythnet.sh.j2 + pythnet.service.j2

CLI Command ↔ Playbook Mapping

The slv pythnet CLI commands map to these playbooks.

CLI Command	Playbook	Description
slv pythnet deploy	mainnet-pythnet/init.yml	Full Pythnet RPC deployment
slv pythnet start	mainnet-pythnet/start_node.yml	Start validator
slv pythnet stop	mainnet-pythnet/stop_node.yml	Stop validator
slv pythnet restart	mainnet-pythnet/restart_node.yml	Restart validator
slv pythnet update	mainnet-pythnet/update_pythnet.yml	Pull pythnet_ref, rebuild, restart

Network parameters (fixed by Pyth)

These are immutable network constants — verifiable via the public Pythnet RPC at any time:

curl -s https://pythnet.rpcpool.com -X POST -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"getGenesisHash"}'
# → GLKkBUr6r72nBtGrtBPJLRqtsh8wXZanX4xfnqKnWwKq

Constant	Value
expected_genesis_hash	GLKkBUr6r72nBtGrtBPJLRqtsh8wXZanX4xfnqKnWwKq
expected_shred_version	35891
feature_set	1435444185
Validator version	1.14.180 (Pyth-built; solana-v1.14.180 base)

Key Variables (extra_vars)

Variable	Default	Description
pythnet_repo	https://github.com/pyth-network/pythnet	Upstream
pythnet_ref	pyth-v1.14.17	Branch — currently the only supported one
pythnet_rust_toolchain	1.78.0	Bootstrap toolchain (build itself pins 1.60.0 via rust-toolchain)
pythnet_ledger_mount	/mnt/ledger	Where ledger/accounts/snapshots live
pythnet_ledger_device	/dev/nvme0n1	Disk to format if pythnet_format_disk=true
pythnet_format_disk	false	Set true to mkfs.xfs the secondary disk
pythnet_force_format	false	Required to wipe a device that already has a filesystem
pythnet_rpc_port	8899	JSON-RPC HTTP
pythnet_rpc_bind	0.0.0.0	Bind address
pythnet_dynamic_port_range	8000-8020	TPU/QUIC port range
pythnet_gossip_port	8001	Gossip port
pythnet_entrypoint	pythnet.rpcpool.com:8001	Boot peer for gossip+snapshot
pythnet_known_validators	(2 published Pyth validators)	--known-validator list
pythnet_genesis_hash	(constant above)	Sanity gate against wrong cluster
pythnet_shred_version	35891	Sanity gate against wrong cluster
pythnet_limit_ledger_size	50000000	Shred count cap

Usage

1. Write inventory

all:
  hosts:
    pythnet-1:
      ansible_host: "<bm-ip>"
      ansible_user: "solv"
      ansible_ssh_private_key_file: "~/.ssh/id_rsa"
  vars:
    pythnet_format_disk: true        # only if you want the recipe to mkfs nvme0n1
    pythnet_ledger_mount: "/mnt/ledger"

2. Deploy

slv pythnet deploy
# or:
ansible-playbook -i ~/.slv/inventory.mainnet.pythnet.yml \
  ~/.slv/mainnet-pythnet/init.yml

3. Watch catch-up

ssh solv@<bm-ip> 'tail -f /mnt/ledger/pythnet/log/validator.log | grep -E "snapshot|known validator|optimistic"'

4. Verify

curl -fsS http://<bm-ip>:8899 -X POST -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"getHealth"}'
# → {"jsonrpc":"2.0","result":"ok","id":1}

5. Point Hermes at it

In your hermes inventory:

    hermes_pythnet_http_addr: "http://<bm-ip>:8899"
    hermes_pythnet_ws_addr:   "ws://<bm-ip>:8900"

Then slv hermes restart.

Known gotchas

• --account-index program-id is mandatory on Pythnet — the validator panics on startup without it. The recipe sets this; if you customize the start script, do not remove it.
• rocksdb fails to build under GCC 13+ without CXXFLAGS="-include cstdint". The build playbook handles this; if you build by hand, copy that env var verbatim. Do not set CFLAGS with the same flag — blake3's build script uses cc to assemble .S files and -include cstdint corrupts the assembly source.
• sysctl rmem/wmem must be 128 MiB — the validator's startup self-check fails fast otherwise. The recipe writes /etc/sysctl.d/99-pythnet.conf to enforce this.
• Identity key has no monetary value — Pythnet RPC nodes run with --no-voting, the identity is just a gossip pubkey. Losing it costs nothing; the validator rejoins under a new pubkey on next start.
• Disk usage: expect ~10 GB/day ledger growth. With --limit-ledger-size 50000000 the ledger holds ~30 days of slots before rotation.