MCP Firebird 2.12.3 - Safe query diagnostics

MCP Firebird 2.12.3

October 17, 2026. Stable promotion of all changes from 2.13.0-alpha.1, released as 2.12.3 to continue the existing 2.12 stable line. No alpha installation is required. The historical alpha tag remains at 2.13.0-alpha.1; this release advances latest only.

Improvements since 2.12.2

• Real optimizer plans without query execution. get-execution-plan prepares the authorized, policy-adjusted SELECT in a read-only transaction and reads its legacy optimizer plan through a feature-detected driver API. It does not execute/fetch the SELECT, bind parameter values or read other sessions' monitoring data. Statement disposal and rollback are awaited; unavailable plans remain explicit errors with no execution fallback.
• Catalog-aware index advice. analyze-missing-indexes checks existing indexes, including system-generated primary-key/unique indexes and composite left prefixes, before suggesting DDL. It considers ordering direction, recommends reviewing inactive equivalents instead of creating duplicates, and does not assume partial/expression indexes provide general coverage. Inconsistent catalog segments are rejected. No index is created or activated automatically.
• Safe connection ownership. Retain lazy-send preparation/DROP coordination, asynchronous descriptor-parser error containment and pending-work cleanup before an attachment can be recycled or discarded.

Compatibility and limits

The production code is unchanged from the tested alpha. No driver/dependency upgrade, database migration or new flag is needed. Existing SQL/table/role policies, row filters, masking projection restrictions, audit requirements, quotas, deadlines, BLOB/transaction behavior and event support remain in force. Historical ISO/UTC dates remain the default; FIREBIRD_DATE_FORMAT=wall-clock is still explicitly optional. Advanced security controls remain opt-in. GitHub Actions remains disabled.

Plan retrieval supports statements beginning with SELECT, not WITH/CTEs or writes; parameter values do not influence a prepare-only plan. This is compilation strategy, not a runtime measurement. planDetails remains []. Index advice is a conservative single-table heuristic, not a complete optimizer or a performance guarantee. Unsupported shapes return an explanation, not an all-clear result. Review selectivity, the actual plan, key-size/collation limits, current metadata and write overhead before applying any DDL manually. See the English diagnostics guide and Spanish summary.

Install

npm install -g mcp-firebird@latest
# Or pin this stable release:
npm install -g mcp-firebird@2.12.3

For an existing npx launcher, change only its package argument to mcp-firebird@2.12.3. Keep database, transport, authentication and security configuration, then restart the MCP process/client. Node.js 20.19+ remains required.

Validation

The stable release repeats the local gate: typecheck, fresh build, lint error checks, 1,348 unit tests, 116 protocol/Node tests without skips and compiled security-runtime checks. The package is inspected and diagnostics exercised from the extracted artifact. Production dependency audit checks the unchanged lockfile for known advisories; it is not a guarantee against future vulnerabilities.

Live integration uses a new UUID-named disposable database on local Firebird 2.5.9 with the pure-JS driver. It retrieves real plans while an incrementing sequence remains unchanged, checks primary-key/composite/descending/inactive index handling without applying suggested DDL, and repeats existing BLOB/date/SQL-policy/audit/write/event/reconnect checks. The disposable database and audit file are removed afterwards.

Native API paths are covered using controlled adapters, not a live native addon. Live Firebird 3/4/5 and native-driver coverage is not claimed for this release. Validate against your deployed server/driver before a broad production rollout.

Full changelog · Diagnostics guide · Date compatibility