Provider capability matrix

The provider profiles CapsuleDB supports (PostgreSQL, Bun SQLite, libSQL and Cloudflare D1) and the bounded atomic-batch contract D1 runs under.

Provider identity, SQL dialect, and execution capability are separate parts of the public contract. Select the profile that matches the host client and keep the same logical migration history across providers.

Profile	Dialect	Execution	Effect steps	Streaming	Notes
`SqliteBun.profile`	`sqlite`	Transactional	Supported	No	Host-owned Bun SQLite client; distinct provider identity.
`Libsql.profile`	`sqlite`	Transactional	Supported	No	Host-owned libSQL client; uses SQLite dialect defaults.
`Pg.profile`	`postgres`	Transactional	Supported	Yes	Host-owned PostgreSQL client; preparation serializes with an advisory lock.
`D1.profile`	`sqlite`	Atomic batch	Not supported	No	D1 identity with bounded atomic batches; no interactive transactions.

A profile’s capabilities._tag is its execution model; there is no separate field restating it. The table is derived from the profiles exported by capsuledb:

import { Provider } from "capsuledb";

for (const profile of Provider.providerCapabilityMatrix) {
  console.log(profile.provider, profile.dialect, profile._tag);
}

D1 runtime contract

D1 uses the binding’s atomic batch primitive. CapsuleDB compiles the unique ledger claim first and the rendered migration statements after it, then checks the complete batch before the first mutation. Cloudflare publishes per-statement limits for batch but no statement count, so the built-in profile sets its own bound: at most 16 statements per batch, 100,000 bytes per SQL statement, and 100 bound parameters per statement. The claim occupies one slot, leaving 15 rendered statements per runtime migration — enough for a declared table and its indexes.

D1 does not provide the transactional provider semantics used by SQLite, libSQL, or PostgreSQL. Effect migration steps, interactive transactions, savepoints, streaming, and multi-batch work are rejected. Keep long-running data transformations outside this migration seam and design small, static, bounded migrations.

Optional static artifacts

capsuledb d1 artifact projects the static D1 body from a validated manifest into an artifact.json index and deterministic .sql files. d1 check rebuilds the projection and compares the manifest fingerprint, order, metadata, and exact file contents. It rejects stale, edited, missing, reordered, and dynamic/unsupported projections.

bun run capsuledb -- d1 artifact \
  --module ./src/capsules.ts \
  --export capsule \
  --output ./d1-artifacts
bun run capsuledb -- d1 check \
  --module ./src/capsules.ts \
  --export capsule \
  --artifact ./d1-artifacts

Artifacts are deterministic deployment aids, not runtime authority. They do not contain the ledger claim, do not invoke Wrangler, and do not replace Registry.layer.