dcmassist

Turn an existing Snowflake database into a DCM project in seconds.

You've decided to manage your Snowflake schema with Declarative Change Management. Now you need a DEFINE TABLE … block for every table, view, schema, stage, sequence, file format, and tag you already have. Hand-writing thousands of these is the wrong way to start.

Point dcmassist at your database and it produces a complete, ready-to-commit DCM project — manifest.yml, Makefile, definitions, optional macros, the lot.

uvx dcmassist export --database MYDB --out-folder ./my-dcm-project

That's it. Commit, deploy, done.

Why dcmassist

• Zero-to-DCM in one command. No bespoke scripts, no copy-pasting from GET_DDL, no fixing up identifier quoting by hand.
• Multi-environment from day one. Database names are templated to {{ database }} automatically, so the same project deploys to dev, staging, and prod.
• Safe with secrets. Stage definitions are synthesized without credentials — credentials live on storage integrations, not in git. You won't accidentally commit AWS keys.
• Built for real Snowflake accounts. Paginates SHOW past the 10K-row cap. Quotes identifiers properly so leading-digit and lowercase names survive. Skips objects your role can't see instead of failing the run.
• Predictable output. Per-type files, deterministic ordering, automatic chunking when a type grows beyond a threshold. Diffs stay readable as your project evolves.
• Jinja macros by default. Every definition is a one-line macro invocation, so a column rename touches one file instead of hundreds. Pass --no-use-macros to emit raw DDL instead.
• Observable runs. Live status panel while it works; a per-run log file you can tail when something looks wrong.

What you get

my-dcm-project/
├── manifest.yml                # targets, configurations, templating defaults
├── Makefile                    # deploy, plan, sync, validate
├── dcmassist-export.log        # per-run log of options + per-object results
└── sources/
    ├── definitions/
    │   ├── schema.sql          # one file per type
    │   ├── table.sql           # auto-chunked into table2.sql, table3.sql … past the threshold
    │   ├── view.sql
    │   ├── sequence.sql
    │   ├── stage.sql           # synthesized — no credentials
    │   ├── file_format.sql
    │   └── tag.sql
    └── macros/                 # default; suppress with --no-use-macros
        └── <type>.sql

Run

Requires Python ≥ 3.10, uv, and a configured snow CLI connection.

dcmassist is a one-shot tool — you run it when you need a DCM project and rarely after that. The simplest way is uvx, which fetches and runs without a permanent install:

uvx dcmassist export --database MYDB

Pin a version for reproducibility:

uvx dcmassist@0.1.15 export --database MYDB

If you'd rather keep it installed:

uv tool install dcmassist
# or
pipx install dcmassist

Quick examples

The examples below use uvx; substitute dcmassist if you've installed it.

Just tables and views from one schema, into a custom folder:

uvx dcmassist export \
    --database MYDB \
    --schema PUBLIC \
    --include Table --include View \
    --out-folder ./project

Multi-environment manifest with templated configurations:

uvx dcmassist export \
    --database MYDB \
    --target dev --target prod \
    --configuration STAGING \
    --templating-default warehouse=COMPUTE_WH

Run uvx dcmassist export --help for every option.

Type support

Implemented: Schema, Table, View, Sequence, Stage, File format, Tag.

Recognized but not yet exported: Dynamic table, Task, Alert, SQL function, Data metric function, SQL procedure, Role, Database role, Grant, Authentication policy. Including these in --include is accepted (they pass validation) but they produce no output yet — contributions welcome.

Database is intentionally never exported: DCM rejects DEFINE DATABASE for the project's own parent database.

Configuration

Known limitations

• Pre-existing objects not owned by your role. dcmassist exports every object the running role can see, but snow dcm plan only succeeds for objects the running role owns. Visible-but-not-owned objects produce errors like File_format 'JSON' already exists, but current role has no privileges on it during snow dcm plan. The cleanest workaround is to run dcmassist export (and the resulting snow dcm plan) as a role that owns the objects you want to manage — typically ACCOUNTADMIN, or a custom role with ownership on the relevant schemas. Alternatively, prune the unwanted objects from the generated sources/definitions/*.sql files before deploying.

Project status

Pre-1.0. The output layout, CLI flags, and log format are stable enough to use; expect breaking changes between minor versions until 1.0. Issues and pull requests welcome at github.com/jamiekt/dcmassist.

License

MIT.