Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased]

[0.1.0] - 2026-07-04

Added

• Arcadic.Conn — pure-data connection handle (redacting Inspect) and Arcadic.connect/3 / Arcadic.with_database/2 to build and derive handles.
• Arcadic.query/4 + query!/4 (idempotent read endpoint) and Arcadic.command/4 + command!/4 (write endpoint), params-only ($name), Cypher-default with SQL/Gremlin/GraphQL/Mongo/SQLScript opt-in.
• Arcadic.command_async/4 — fire-and-forget write (server enqueues, returns :ok on HTTP 202).
• Session transactions: Arcadic.transaction/3 (commit on return, reraise on exception) and Arcadic.rollback/2 (intentional abort → {:error, reason}).
• Arcadic.Server — server admin: create_database/2 (+ !), drop_database/2 (+ !), database_exists?/2, list_databases/1, ready?/1.
• Arcadic.Error / Arcadic.TransportError — typed error taxonomy with boundary redaction (quarantined detail, value-free reasons).
• Arcadic.Transport — the transport behaviour seam, with the default Arcadic.Transport.HTTP (Req/Finch) implementation.
• Arcadic.Telemetry — value-free :telemetry.span/3 spans (no statement, params, values, or database name).
• Arcadic.Identifier — allowlist identifier validation.
• Migration runner: Arcadic.Migration (behaviour), Arcadic.MigrationRegistry (use + migrations [...]), and Arcadic.Migrator (migrate/2, status/2, rollback/3, reset/2, pending_migrations/2), tracking applied versions in _arcadic_migrations.
• Arcadic.Transport.Bolt — optional Bolt transport (Bolt v4, non-TLS scheme) via the optional boltx dependency; server admin remains HTTP-only.
• Arcadic.query_stream/4 — Bolt-only lazy Stream.t() of raw row maps, chunked over Bolt PULL/has_more (default chunk_size: 1000); a :timeout opt bounds each RUN/PULL receive (default :infinity), raising %Arcadic.TransportError{reason: :timeout} on breach; guarded off HTTP and inside transactions with a typed :not_supported.
• Arcadic.Transport.Bolt.setup/1 — single-source transport_options builder ([bolt: pool, bolt_opts: opts]).
• Arcadic.Telemetry.event/3 — allowlist-validated manual telemetry for lazy ops; [:arcadic, :query_stream, :start | :stop] events (value-free).

Fixed

• Arcadic.Transport.Bolt now threads conn.database into every Bolt RUN/BEGIN, so with_database/2 selects the database on Bolt (was hitting the connection default).
• Bolt transaction/3 maps a commit-failure to a typed %Arcadic.Error{reason: :transaction_error} instead of leaking DBConnection's bare :rollback atom.
• Arcadic.Transport.Bolt — a failed Bolt connect (wrong password, or a Bolt conn pointed at a non-Bolt port) no longer leaks a :gen_tcp socket. arcadic now owns the connect handshake and HELLO on both the per-stream connection and the DBConnection pool, closing the socket on every failure; a bad-password stream connect surfaces :unauthorized, and the connect HELLO is bounded by connect_timeout. Connect-time errors are redacted on both sites: a HELLO response arcadic's parser cannot classify returns a value-free :bolt_protocol_error instead of a raw exception carrying server bytes, and the DBConnection pool's connect error drops the server-supplied failure message (keeping the error code/class) so it cannot ride a connect-failure log line.