Changed

• Payloads may nest. ClientEvent.payload, ClientIssue.payload, ClientMetaData.payload and ExtensionStat.payload changed from a map of primitives to a free-form JSON object — Record<string, unknown> in the generated TypeScript, the same type attachments has had since it stopped being a string. A payload value may now be an object, an array, or any nesting of the two, so a caller with structured context ({ device: { os: { name, version } } }) no longer has to flatten it into dotted keys or stringify it into one field and parse it back on the far side.

  In Avro the map’s values became AnyValue, a record that refers to itself through an objectValue map and an arrayValue array — the shape protobuf’s Struct/Value uses, and the only way Avro can describe unbounded nesting, since a union cannot contain another union and only a named type can recurse. Treat it as documentation of what may appear rather than as an encoding: Avro tags its union branches in JSON, so the .avsc has not described the codecs’ actual bytes since payloads stopped being strings in 3.5.0.

  Wire format: unchanged. Both codecs’ golden fixtures are byte-identical to 3.6.0 apart from the recorded version string. On the protobuf wire a payload was already a JSON string (proto3 can express neither the old union-valued map nor the new one), so nesting costs it nothing. In the JSON codec a payload is an opaque object written whole whenever it changes and never carried forward, which is what made nesting free there too — diffing into a payload would need a way to say “this key was removed”, which the format deliberately does not have. A 3.6.0 decoder reads a 3.7.0 stream and vice versa; only the TypeScript type moved.

  Upgrading: reading a payload value now needs narrowing. payload.role was boolean | string | number and is now unknown, so String(payload.role) or a type guard replaces a bare read. Writers need no change — everything that was valid before still is.

Fixed

• A non-finite number inside a payload or attachments no longer becomes null in silence. Both codecs copied opaque values with JSON.parse(JSON.stringify(v)), which turns NaN and Infinity into null without complaint — exactly the corruption the top-level finite check has always rejected, but it only ever saw the top level of a record. With payloads able to nest, a NaN several levels down was newly easy to reach, so the encode path now walks an opaque value before copying it and reports the path that was wrong (INVALID_VALUE). A bigint, which previously escaped as a bare TypeError from inside the codec, is rejected the same way, and a cycle is reported as MALFORMED_INPUT rather than by exhausting the stack. Both codecs use the same codes for the same inputs. Values JSON.stringify drops harmlessly — functions, symbols, undefined — are still dropped, and a value with its own toJSON, such as a Date, still serialises itself.

Internal

• TypeScript field-type overrides in the generator may now be scoped to one record, as Record.field, and a scoped key beats a bare one. The bare payload entry that gives the four client payloads their opaque type would otherwise also have caught SfuExtensionStats.payload, which is a genuine JSON string on the SFU wire; it keeps its string type through ['SfuExtensionStats.payload', 'string']. Field names are not unique across the schema set, so the mechanism now says which one it means.

Source: ObserveRTC schema changelog. Date verified from the schema version commit.