30 Protocol Catalog

This appendix catalogs all 76 built-in protocols shipped with panproto. Each entry lists the protocol’s native format or file extension, its theory group assignment (A through E), and the parse and emit function names. The theory group determines which categorical structure underlies the protocol’s schema representation and governs which cross-format conversions are lossless.

30.1 Serialization protocols

Protocol	Native Format / Ext.	Theory Group	Parse Function	Emit Function
Protobuf	`.proto`	C	`parse_protobuf`	`emit_protobuf`
Avro	`.avsc`	C	`parse_avro`	`emit_avro`
Thrift	`.thrift`	C	`parse_thrift`	`emit_thrift`
Cap’n Proto	`.capnp`	C	`parse_capnproto`	`emit_capnproto`
FlatBuffers	`.fbs`	C	`parse_flatbuffers`	`emit_flatbuffers`
ASN.1	`.asn1`	C	`parse_asn1`	`emit_asn1`
Bond	`.bond`	C	`parse_bond`	`emit_bond`
MsgPack Schema	JSON	A	`parse_msgpack_schema`	`emit_msgpack_schema`

30.2 Data schema protocols

Protocol	Native Format / Ext.	Theory Group	Parse Function	Emit Function
JSON Schema	JSON	A	`parse_json_schema`	`emit_json_schema`
XML/XSD	`.xsd`	E	`parse_xsd`	`emit_xsd`
CSV/Table Schema	JSON	B	`parse_table_schema`	`emit_table_schema`
YAML Schema	YAML	A	`parse_yaml_schema`	`emit_yaml_schema`
TOML Schema	JSON	A	`parse_toml_schema`	`emit_toml_schema`
CDDL	`.cddl`	A	`parse_cddl`	`emit_cddl`
INI Schema	JSON	A	`parse_ini_schema`	`emit_ini_schema`
BSON Schema	JSON	A	`parse_bson_schema`	`emit_bson_schema`

30.3 API protocols

Protocol	Native Format / Ext.	Theory Group	Parse Function	Emit Function
GraphQL	`.graphql`	D	`parse_graphql`	`emit_graphql`
OpenAPI	YAML/JSON	A	`parse_openapi`	`emit_openapi`
AsyncAPI	YAML/JSON	A	`parse_asyncapi`	`emit_asyncapi`
RAML	`.raml`	A	`parse_raml`	`emit_raml`
JSON:API	JSON	A	`parse_jsonapi`	`emit_jsonapi`

30.4 Database protocols

Protocol	Native Format / Ext.	Theory Group	Parse Function	Emit Function
SQL	`.sql`	B	`parse_sql`	`emit_sql`
MongoDB	JSON	A	`parse_mongodb`	`emit_mongodb`
Cassandra	`.cql`	B	`parse_cassandra`	`emit_cassandra`
DynamoDB	JSON	B	`parse_dynamodb`	`emit_dynamodb`
Neo4j	Cypher	E	`parse_neo4j`	`emit_neo4j`
Redis	FT.CREATE	C	`parse_redis`	`emit_redis`

30.5 Type system protocols

Protocol	Native Format / Ext.	Theory Group	Parse Function	Emit Function
TypeScript	`.d.ts`	D	`parse_typescript`	`emit_typescript`
Python (Pydantic)	Pydantic	D	`parse_pydantic`	`emit_pydantic`
Rust Serde	`.rs`	D	`parse_rust_serde`	`emit_rust_serde`
Java	`.java`	D	`parse_java`	`emit_java`
Go	`.go`	D	`parse_go`	`emit_go`
Swift	`.swift`	D	`parse_swift`	`emit_swift`
Kotlin	`.kt`	D	`parse_kotlin`	`emit_kotlin`
C#	`.cs`	D	`parse_csharp`	`emit_csharp`

30.6 Web and document protocols

Protocol	Native Format / Ext.	Theory Group	Parse Function	Emit Function
ATProto	JSON	A	`parse_atproto`	`emit_atproto`
HTML	JSON	E	`parse_html`	`emit_html`
CSS	JSON	E	`parse_css`	`emit_css`
DOCX	JSON	E	`parse_docx`	`emit_docx`
ODF	JSON	E	`parse_odf`	`emit_odf`
Markdown	JSON	A	`parse_markdown`	`emit_markdown`
JSX/React	TSX	D	`parse_jsx`	`emit_jsx`
Vue	`.vue`	D	`parse_vue`	`emit_vue`
Svelte	`.svelte`	D	`parse_svelte`	`emit_svelte`
XML/XSD	`.xsd`	E	`parse_xsd`	`emit_xsd`

30.7 Data science protocols

Protocol	Native Format / Ext.	Theory Group	Parse Function	Emit Function
Parquet	JSON	B	`parse_parquet`	`emit_parquet`
Arrow	JSON	B	`parse_arrow`	`emit_arrow`
DataFrame	JSON	B	`parse_dataframe`	`emit_dataframe`

30.8 Domain protocols

Protocol	Native Format / Ext.	Theory Group	Parse Function	Emit Function
GeoJSON	JSON	A	`parse_geojson`	`emit_geojson`
FHIR	JSON	A	`parse_fhir`	`emit_fhir`
RSS/Atom	JSON	A	`parse_rss_atom`	`emit_rss_atom`
vCard/iCal	JSON	A	`parse_vcard_ical`	`emit_vcard_ical`
EDI X12	JSON	B	`parse_edi_x12`	`emit_edi_x12`
SWIFT MT	JSON	B	`parse_swift_mt`	`emit_swift_mt`

30.9 Config protocols

Protocol	Native Format / Ext.	Theory Group	Parse Function	Emit Function
HCL	`.tf`	C	`parse_hcl`	`emit_hcl`
K8s CRD	YAML	A	`parse_k8s_crd`	`emit_k8s_crd`
CloudFormation	JSON	A	`parse_cloudformation`	`emit_cloudformation`
Ansible	YAML	A	`parse_ansible`	`emit_ansible`

30.10 Theory groups

Each protocol is assigned to one of six theory groups. The group determines the categorical theory used internally to represent the protocol’s schema and governs how models migrate between protocols.

Group	Theory Combination	Description
A	`colimit(ThGraph, ThConstraint, ThMulti)` + `ThWType`	Constrained multigraph with W-types. Handles hierarchical, constraint-bearing schemas in JSON or YAML surface syntax. The most general setting.
B	`colimit(ThHypergraph, ThConstraint)` + `ThFunctor`	Hypergraph with functorial structure. Tabular and relational schemas where rows, columns, and foreign-key relationships are first-class.
C	`colimit(ThSimpleGraph, ThConstraint)` + `ThFlat`	Simple graph with flat structure. Binary wire formats and IDL-defined schemas lacking recursive or dependent types.
D	`colimit(ThGraph, ThConstraint, ThMulti, ThInterface)` + `ThWType`	Typed graph with interfaces and W-types. Host-language type systems supporting interfaces, generics, and recursive types.
E	`colimit(ThGraph, ThConstraint, ThMulti)` + `colimit(ThWType, ThMeta)`	Multigraph with W-types and meta-level structure. Document and markup formats where presentation, content, and schema interleave.

The theory group reflects the expressive requirements of a schema language, not its surface syntax. Two protocols with different surfaces may share a theory group if they require identical categorical structure.

30.11 Cross-format compatibility

Conversions between protocols in the same theory group are lossless: both parse and emit functors factor through the same internal representation, so no information is destroyed in round-trips. Migrating a schema from JSON Schema (Group A) to OpenAPI (Group A) to YAML Schema (Group A) and back yields the original schema up to syntactic normalization.

Conversions between different theory groups are lossy in general: the target theory may lack expressive capacity for structures definable in the source. The direction and degree of loss depend on how the two groups relate.

Source Group	Target Group	Typical Loss
A	B	Recursive and W-type structure flattens; only relational skeleton survives.
A	C	Constraints and multi-edges preserve; W-type recursion unrolls to fixed depth.
A	D	Lossless for schemas fitting typed-graph model; interfaces synthesized.
A	E	Lossless for schema content; meta-level presentation markup synthesized with defaults.
D	A	Interface and generic structure erases; remaining graph and W-type content survives.
D	C	Interface and W-type structure flattens; only simple-graph skeleton survives.
E	A	Meta-level markup strips; schema content survives.
B	A	Hyperedges decompose into binary edges; functorial structure encodes as constraints.
C	A	Flat structure embeds; W-type positions stay empty.

When a lossy conversion is required, panproto emits a diagnostic listing which structures were approximated and what information was discarded. Lossless conversions produce no diagnostics.

# Protocol Catalog {#sec-protocol-catalog .appendix} This appendix catalogs all 76 built-in protocols shipped with panproto. Each entry lists the protocol's native format or file extension, its theory group assignment (A through E), and the parse and emit function names. The theory group determines which categorical structure underlies the protocol's schema representation and governs which cross-format conversions are lossless. ## Serialization protocols | Protocol | Native Format / Ext. | Theory Group | Parse Function | Emit Function | |---|---|:---:|---|---| | Protobuf | `.proto` | C | `parse_protobuf` | `emit_protobuf` | | Avro | `.avsc` | C | `parse_avro` | `emit_avro` | | Thrift | `.thrift` | C | `parse_thrift` | `emit_thrift` | | Cap'n Proto | `.capnp` | C | `parse_capnproto` | `emit_capnproto` | | FlatBuffers | `.fbs` | C | `parse_flatbuffers` | `emit_flatbuffers` | | ASN.1 | `.asn1` | C | `parse_asn1` | `emit_asn1` | | Bond | `.bond` | C | `parse_bond` | `emit_bond` | | MsgPack Schema | JSON | A | `parse_msgpack_schema` | `emit_msgpack_schema` | ## Data schema protocols | Protocol | Native Format / Ext. | Theory Group | Parse Function | Emit Function | |---|---|:---:|---|---| | JSON Schema | JSON | A | `parse_json_schema` | `emit_json_schema` | | XML/XSD | `.xsd` | E | `parse_xsd` | `emit_xsd` | | CSV/Table Schema | JSON | B | `parse_table_schema` | `emit_table_schema` | | YAML Schema | YAML | A | `parse_yaml_schema` | `emit_yaml_schema` | | TOML Schema | JSON | A | `parse_toml_schema` | `emit_toml_schema` | | CDDL | `.cddl` | A | `parse_cddl` | `emit_cddl` | | INI Schema | JSON | A | `parse_ini_schema` | `emit_ini_schema` | | BSON Schema | JSON | A | `parse_bson_schema` | `emit_bson_schema` | ## API protocols | Protocol | Native Format / Ext. | Theory Group | Parse Function | Emit Function | |---|---|:---:|---|---| | GraphQL | `.graphql` | D | `parse_graphql` | `emit_graphql` | | OpenAPI | YAML/JSON | A | `parse_openapi` | `emit_openapi` | | AsyncAPI | YAML/JSON | A | `parse_asyncapi` | `emit_asyncapi` | | RAML | `.raml` | A | `parse_raml` | `emit_raml` | | JSON:API | JSON | A | `parse_jsonapi` | `emit_jsonapi` | ## Database protocols | Protocol | Native Format / Ext. | Theory Group | Parse Function | Emit Function | |---|---|:---:|---|---| | SQL | `.sql` | B | `parse_sql` | `emit_sql` | | MongoDB | JSON | A | `parse_mongodb` | `emit_mongodb` | | Cassandra | `.cql` | B | `parse_cassandra` | `emit_cassandra` | | DynamoDB | JSON | B | `parse_dynamodb` | `emit_dynamodb` | | Neo4j | Cypher | E | `parse_neo4j` | `emit_neo4j` | | Redis | FT.CREATE | C | `parse_redis` | `emit_redis` | ## Type system protocols | Protocol | Native Format / Ext. | Theory Group | Parse Function | Emit Function | |---|---|:---:|---|---| | TypeScript | `.d.ts` | D | `parse_typescript` | `emit_typescript` | | Python (Pydantic) | Pydantic | D | `parse_pydantic` | `emit_pydantic` | | Rust Serde | `.rs` | D | `parse_rust_serde` | `emit_rust_serde` | | Java | `.java` | D | `parse_java` | `emit_java` | | Go | `.go` | D | `parse_go` | `emit_go` | | Swift | `.swift` | D | `parse_swift` | `emit_swift` | | Kotlin | `.kt` | D | `parse_kotlin` | `emit_kotlin` | | C# | `.cs` | D | `parse_csharp` | `emit_csharp` | ## Web and document protocols | Protocol | Native Format / Ext. | Theory Group | Parse Function | Emit Function | |---|---|:---:|---|---| | ATProto | JSON | A | `parse_atproto` | `emit_atproto` | | HTML | JSON | E | `parse_html` | `emit_html` | | CSS | JSON | E | `parse_css` | `emit_css` | | DOCX | JSON | E | `parse_docx` | `emit_docx` | | ODF | JSON | E | `parse_odf` | `emit_odf` | | Markdown | JSON | A | `parse_markdown` | `emit_markdown` | | JSX/React | TSX | D | `parse_jsx` | `emit_jsx` | | Vue | `.vue` | D | `parse_vue` | `emit_vue` | | Svelte | `.svelte` | D | `parse_svelte` | `emit_svelte` | | XML/XSD | `.xsd` | E | `parse_xsd` | `emit_xsd` | ## Data science protocols | Protocol | Native Format / Ext. | Theory Group | Parse Function | Emit Function | |---|---|:---:|---|---| | Parquet | JSON | B | `parse_parquet` | `emit_parquet` | | Arrow | JSON | B | `parse_arrow` | `emit_arrow` | | DataFrame | JSON | B | `parse_dataframe` | `emit_dataframe` | ## Domain protocols | Protocol | Native Format / Ext. | Theory Group | Parse Function | Emit Function | |---|---|:---:|---|---| | GeoJSON | JSON | A | `parse_geojson` | `emit_geojson` | | FHIR | JSON | A | `parse_fhir` | `emit_fhir` | | RSS/Atom | JSON | A | `parse_rss_atom` | `emit_rss_atom` | | vCard/iCal | JSON | A | `parse_vcard_ical` | `emit_vcard_ical` | | EDI X12 | JSON | B | `parse_edi_x12` | `emit_edi_x12` | | SWIFT MT | JSON | B | `parse_swift_mt` | `emit_swift_mt` | ## Config protocols | Protocol | Native Format / Ext. | Theory Group | Parse Function | Emit Function | |---|---|:---:|---|---| | HCL | `.tf` | C | `parse_hcl` | `emit_hcl` | | K8s CRD | YAML | A | `parse_k8s_crd` | `emit_k8s_crd` | | CloudFormation | JSON | A | `parse_cloudformation` | `emit_cloudformation` | | Ansible | YAML | A | `parse_ansible` | `emit_ansible` | ## Theory groups Each protocol is assigned to one of six theory groups. The group determines the categorical theory used internally to represent the protocol's schema and governs how models migrate between protocols. | Group | Theory Combination | Description | |:---:|---|---| | A | `colimit(ThGraph, ThConstraint, ThMulti)` + `ThWType` | Constrained multigraph with W-types. Handles hierarchical, constraint-bearing schemas in JSON or YAML surface syntax. The most general setting. | | B | `colimit(ThHypergraph, ThConstraint)` + `ThFunctor` | Hypergraph with functorial structure. Tabular and relational schemas where rows, columns, and foreign-key relationships are first-class. | | C | `colimit(ThSimpleGraph, ThConstraint)` + `ThFlat` | Simple graph with flat structure. Binary wire formats and IDL-defined schemas lacking recursive or dependent types. | | D | `colimit(ThGraph, ThConstraint, ThMulti, ThInterface)` + `ThWType` | Typed graph with interfaces and W-types. Host-language type systems supporting interfaces, generics, and recursive types. | | E | `colimit(ThGraph, ThConstraint, ThMulti)` + `colimit(ThWType, ThMeta)` | Multigraph with W-types and meta-level structure. Document and markup formats where presentation, content, and schema interleave. | The theory group reflects the expressive requirements of a schema language, not its surface syntax. Two protocols with different surfaces may share a theory group if they require identical categorical structure. ## Cross-format compatibility Conversions between protocols in the same theory group are **lossless**: both parse and emit functors factor through the same internal representation, so no information is destroyed in round-trips. Migrating a schema from JSON Schema (Group A) to OpenAPI (Group A) to YAML Schema (Group A) and back yields the original schema up to syntactic normalization. Conversions between different theory groups are **lossy in general**: the target theory may lack expressive capacity for structures definable in the source. The direction and degree of loss depend on how the two groups relate. | Source Group | Target Group | Typical Loss | |:---:|:---:|---| | A | B | Recursive and W-type structure flattens; only relational skeleton survives. | | A | C | Constraints and multi-edges preserve; W-type recursion unrolls to fixed depth. | | A | D | Lossless for schemas fitting typed-graph model; interfaces synthesized. | | A | E | Lossless for schema content; meta-level presentation markup synthesized with defaults. | | D | A | Interface and generic structure erases; remaining graph and W-type content survives. | | D | C | Interface and W-type structure flattens; only simple-graph skeleton survives. | | E | A | Meta-level markup strips; schema content survives. | | B | A | Hyperedges decompose into binary edges; functorial structure encodes as constraints. | | C | A | Flat structure embeds; W-type positions stay empty. | When a lossy conversion is required, panproto emits a diagnostic listing which structures were approximated and what information was discarded. Lossless conversions produce no diagnostics.