Microsoft Access VCS Project Guide

Rules and gotchas for programmatically editing Access objects exported by VCS 4.x. Violations cause silent corruption or Error 2128 on import via LoadComponentFromText.

Reference Files

Read the relevant reference file before working on a specific object type:

Project Overview

A VCS-exported Access project lives in <DatabaseName>.accdb.src/. The directory name must match the .accdb filename with .src appended.

File Pairing Rules

When deleting an object, delete ALL its associated files plus its entry in vcs-index.json.

Encoding

All JSON configuration files and .sql files use UTF-8 with BOM (byte order mark EF BB BF). The BOM must be preserved when editing. Binary text .bas files (forms, reports, macros) also use UTF-8 with BOM. .bas, .cls, and tbldef/relation .json files additionally use CRLF line endings (enforced via .gitattributes).

Creating a new file from scratch: standard write tools (including Claude's Write tool, echo, cat <<EOF) silently produce UTF-8 without BOM and use LF endings — this will corrupt the import. To create a new VCS file, emit the bytes explicitly:

printf '\xEF\xBB\xBF{\r\n  "Info": { ... }\r\n}\r\n' > path/to/new-file.json

Verify after writing: od -c -N 5 path/to/new-file.json should show 357 273 277 (the BOM) as the first three bytes, and the file should contain \r before each \n. Editing an existing file with Edit/Read preserves the original encoding — the BOM-stripping issue only applies to brand-new files created via Write.

Safe Deletion Checklist

Before deleting any Access object:

1. Search for references in all .cls, .bas, .sql files. Objects may be referenced by:
   • VBA code (DoCmd.OpenForm, DoCmd.OpenReport, DoCmd.OutputTo)
   • Query SQL (FROM tableName, subreport SourceObject)
   • Form RecordSource properties
   • DLookup expressions
2. Check for name collisions. Objects with similar names may serve completely different purposes (e.g., an active report and a dead integration table that share a prefix).
3. Delete all paired files (.bas + .sql, .bas + .cls + .json, etc.)
4. Remove from config files: vcs-index.json, db-connection.json, hidden-attributes.json
5. Renumber TabIndex values in any form/report section where a control was removed
6. Test import in Access after changes

Common Pitfalls

• Commented-out code referencing kept objects: Leave commented VBA lines alone if they reference objects you're keeping.
• db-connection.json: Must contain only one connection entry matching the canonical ODBC connection string used by all linked tables and pass-through queries. Never introduce plaintext passwords or user-specific credentials.