sqlc-gen-json

A sqlc plugin that writes the GenerateRequest sqlc would have passed to your codegen plugin out as a single JSON file.

Useful for:

• Debugging plugin pipelines — see exactly what schema, queries, settings, and plugin options sqlc parsed before invoking your generator.
• Prototyping new plugins — capture a real request, then iterate on a generator script offline against the saved JSON.
• Schema snapshots — keep a versioned JSON view of your database catalog alongside the SQL.

Installation

The plugin ships as a WASM artifact. Reference it from sqlc.yaml with the release URL and its sha256:

version: "2"plugins:
- name: jsonwasm:
url: https://github.com/sqlc-contrib/sqlc-gen-json/releases/download/v0.1.0/sqlc-gen-json.wasmsha256: <sha256 from the release assets>

Both the .wasm and a .wasm.sha256 sidecar are published with each release.

Configuration

sql:
- engine: postgresqlschema: db/schema.sqlqueries: db/queries.sqlcodegen:
- plugin: jsonout: ./genoptions:
filename: generate_request.json # optionalindent: ""# optional; "-" disables indentuse_proto_names: false # optionalemit_defaults: false # optional

Option	Type	Default	Description
filename	string	generate_request.json	Name of the emitted file.
indent	string	" " (two spaces)	Per-level indent string passed to protojson. Use the sentinel - to emit compact (single-line) JSON.
use_proto_names	boolean	false	When true, emit field names from the proto descriptor (snake_case) instead of protojson's default JSON names.
emit_defaults	boolean	false	When true, include scalar fields whose value is the zero value.

Unknown top-level options are rejected.

Output

The output is the full plugin.GenerateRequest from plugin-sdk-go serialized via protojson. A trimmed example for a single-table schema:

{
"settings": { "engine": "postgresql" },
"catalog": {
"defaultSchema": "public",
"schemas": [
{
"name": "public",
"tables": [
{
"rel": { "schema": "public", "name": "users" },
"columns": [
{ "name": "id", "type": { "name": "int4" }, "notNull": true },
{ "name": "email", "type": { "name": "text" }, "notNull": true }
]
}
]
}
]
},
"queries": [{ "name": "GetUser", "cmd": ":one" }],
"sqlc_version": "v1.30.0"
}

Note that plugin-sdk-go's proto descriptors do not consistently set json_name, so default output mixes camelCase (e.g. defaultSchema, notNull) and snake_case (e.g. sqlc_version). Set use_proto_names: true to force snake_case across the board.

Caveats

• Output is not byte-stable across runs.protojson.Marshal intentionally injects random whitespace to discourage byte-stable diffing. For diffs, use a JSON-aware tool (jq -S, diff <(jq -S . a) <(jq -S . b), etc.) rather than direct text comparison.
• No formatter_cmd. sqlc plugins cannot spawn subprocesses. If you want canonical formatting, run jq -S . generate_request.json | sponge generate_request.json (or similar) as a post-step.

Development

nix develop
go tool ginkgo run -r -coverprofile=coverage.out -covermode=atomic ./...

Build the WASM artifact locally:

nix build .#wasm
sha256sum result/bin/sqlc-gen-json.wasm

A native binary build is also exposed for convenience (used by the integration tests via gexec.Build):

nix build .# default == native build
./result/bin/sqlc-gen-json --help

License

MIT