Document Timestamping API Comparison

Settlement network
Provncloud: Solana. Low transaction costs and fast finality. Economy tier settles in ~1 hour at no cost. Priority tier settles in under 2 seconds.
OpenTimestamps: Bitcoin. Uses OP_RETURN transactions. Settlement depends on Bitcoin network conditions — typically 10-60 minutes.
Self-hosted: Any chain with timestamping support (Ethereum, Solana, Bitcoin, private ledger). Full control over network choice.

Integration model
Provncloud: REST API with SDK support for Python, TypeScript, Rust, and Go. Submit hashes via HTTP, poll for confirmation. Simple curl-based integration for any language.
OpenTimestamps: Command-line client and Python library. Create timestamps locally, then submit to Bitcoin through the OTS calendar network.
Self-hosted: Requires building the submission pipeline internally. Full flexibility but significant engineering investment.

Verification model
Provncloud: Public verification endpoint — no authentication required. Merkle proof paths enable independent verification without trusting the API server. Solana transaction signatures can be verified on any block explorer.
OpenTimestamps: Verification is fully decentralized — the OTS client verifies against the Bitcoin blockchain directly. No third-party server dependency for verification.
Self-hosted: Verification depends on the chosen chain. Typically requires running a full node or querying an RPC provider.

Cost structure
Provncloud: Free tier (economy, ~1hr settlement). $19/mo standard tier with sub-minute settlement and higher throughput. $149/mo priority tier for high-volume, sub-second workflows.
OpenTimestamps: Free for local timestamp creation. Bitcoin transaction fees apply (~$0.50-2.00 per submission depending on network congestion). Calendar network nodes may have usage limits.
Self-hosted: Infrastructure costs (server, blockchain node or RPC access) plus per-transaction network fees. Predictable at scale but higher upfront investment.

Batch support
Provncloud: Native batch support. Submit multiple hashes in a single API call. Merkle tree aggregation provides individual proof-of-inclusion for each hash while settling one root on Solana.
OpenTimestamps: Each file or hash is timestamped individually. No native batching — batch aggregation requires custom tooling.
Self-hosted: Team builds the batching layer. Merkle tree aggregation is possible but requires implementation effort.

Operational overhead
Provncloud: Fully managed. No infrastructure to maintain. Monitor via health endpoint and batch status polling. Webhook notifications for confirmed batches.
OpenTimestamps: Low overhead for local use. Calendar network provides decentralized submission but has variable reliability. May need to run a personal calendar node for production workloads.
Self-hosted: Highest overhead. Team manages chain node or RPC access, builds submission pipeline, implements monitoring, and handles failure recovery.