Case
aiosendspin -> sendspin-go
Start the server first, then the client. The server loads the PCM audio derived from almost_silent.flac, the client advertises a listener and FLAC as its only supported audio format, the server connects in, uses the SDK to encode the PCM into FLAC, streams it to the client, and the matrix compares the transported FLAC header and chunk bytes as received by the client.
Server
aiosendspin
Client
sendspin-go
Status
Passed
FLAC header and chunk bytes match exactly
Inspection
Summaries, logs, and builds
Matrix result
RAW{
"case_dir": "artifacts/results/data/macos__server-initiated-flac__aiosendspin__to__sendspin-go",
"client_exit_code": 0,
"client_impl": "sendspin-go",
"reason": "FLAC header and chunk bytes match exactly",
"scenario_id": "server-initiated-flac",
"server_exit_code": 0,
"server_impl": "aiosendspin",
"status": "passed"
}Server summary (JSON)
RAW{
"audio": {
"bit_depth": 16,
"channels": 1,
"clip_seconds": 5.0,
"duration_seconds": 4.968,
"fixture": "/Users/runner/work/conformance/conformance/repos/sendspin-cli/tests/fixtures/almost_silent.flac",
"frame_alignment_samples": 576,
"frame_count": 39744,
"sample_rate": 8000,
"sent_audio_chunk_count": 69,
"sent_codec_header_sha256": "efdfadf8f1d1bb8520b015c54e57d2440cc1e99172ed5d99a92a7b77f0c68a62",
"sent_encoded_byte_count": 3886,
"sent_encoded_sha256": "a827ae929643694d40aad698c853eed5f5c47e7040c0ffd2ea952c7e3723724d",
"source_flac_sha256": "8fdda8244e318c63cd8b699fe461cd7cdddbb729327a0ba00d1bfdbe2192fe17",
"source_pcm_sha256": "ea4a8f1ced7d3ad85d46da1dea8cf98cd2cf75dbf305fb11cffea11b1e180952",
"trimmed_source_frames": 256
},
"client": {
"active_roles": [
"player@v1"
],
"client_id": "sendspin-go-client-id",
"name": "sendspin-go-client",
"supported_roles": [
"player@v1"
]
},
"discovery_method": "registry_fallback",
"implementation": "aiosendspin",
"initiator_role": "server",
"peer_hello": {
"payload": {
"client_id": "sendspin-go-client-id",
"device_info": {
"manufacturer": "Sendspin Conformance",
"product_name": "sendspin-go Conformance Client",
"software_version": "0.1.0"
},
"name": "sendspin-go-client",
"player@v1_support": {
"buffer_capacity": 2000000,
"supported_commands": [
"volume",
"mute"
],
"supported_formats": [
{
"bit_depth": 24,
"channels": 1,
"codec": "flac",
"sample_rate": 8000
},
{
"bit_depth": 16,
"channels": 1,
"codec": "flac",
"sample_rate": 8000
},
{
"bit_depth": 24,
"channels": 1,
"codec": "pcm",
"sample_rate": 8000
},
{
"bit_depth": 16,
"channels": 1,
"codec": "pcm",
"sample_rate": 8000
}
]
},
"supported_roles": [
"player@v1"
],
"trust_level": "none",
"unpaired_access": {
"enabled": false
},
"version": 1
},
"type": "client/hello"
},
"preferred_codec": "flac",
"role": "server",
"scenario_id": "server-initiated-flac",
"server_id": "va3GtO3V_cuMN7v-3526HVcaG2CnUyGkx47XVNMd8Xo",
"server_name": "aiosendspin server",
"status": "ok",
"stream": {
"bit_depth": 24,
"channels": 1,
"codec": "flac",
"codec_header": "ZkxhQ4AAACICQAJAAAAAAAbWAfQBcAAAAAAAAAAAAAAAAAAAAAAAAAAA",
"codec_header_sha256": "efdfadf8f1d1bb8520b015c54e57d2440cc1e99172ed5d99a92a7b77f0c68a62",
"sample_rate": 8000
}
}Server log
RAWINFO:aiosendspin.server.server:Starting Sendspin server on port 19010
INFO:aiosendspin.server.server:Sendspin server started successfully on 127.0.0.1:19010
WARNING:aiosendspin.server.server:No IP addresses available for mDNS advertising. Clients may not be able to discover this server. Consider specifying addresses manually via advertise_addresses.
WARNING:aiosendspin.server.connection.unknown-client:Accepting unencrypted legacy connection (transition mode)
INFO:aiosendspin.server.client.sendspin-go-client-id:non-compliant client: initial client/state omitted the required 'available' field
INFO:aiosendspin.server.client.sendspin-go-client-id:non-compliant client: initial client/state omitted required player timing fields
INFO:aiosendspin.server.client.sendspin-go-client-id:non-compliant client: initial client/state omitted muted despite declaring the mute command
INFO:aiosendspin.server.client.sendspin-go-client-id:non-compliant client: client/state used legacy player.state instead of top-level available
{
"audio": {
"bit_depth": 16,
"channels": 1,
"clip_seconds": 5.0,
"duration_seconds": 4.968,
"fixture": "/Users/runner/work/conformance/conformance/repos/sendspin-cli/tests/fixtures/almost_silent.flac",
"frame_alignment_samples": 576,
"frame_count": 39744,
"sample_rate": 8000,
"sent_audio_chunk_count": 69,
"sent_codec_header_sha256": "efdfadf8f1d1bb8520b015c54e57d2440cc1e99172ed5d99a92a7b77f0c68a62",
"sent_encoded_byte_count": 3886,
"sent_encoded_sha256": "a827ae929643694d40aad698c853eed5f5c47e7040c0ffd2ea952c7e3723724d",
"source_flac_sha256": "8fdda8244e318c63cd8b699fe461cd7cdddbb729327a0ba00d1bfdbe2192fe17",
"source_pcm_sha256": "ea4a8f1ced7d3ad85d46da1dea8cf98cd2cf75dbf305fb11cffea11b1e180952",
"trimmed_source_frames": 256
},
"client": {
"active_roles": [
"player@v1"
],
"client_id": "sendspin-go-client-id",
"name": "sendspin-go-client",
"supported_roles": [
"player@v1"
]
},
"discovery_method": "registry_fallback",
"implementation": "aiosendspin",
"initiator_role": "server",
"peer_hello": {
"payload": {
"client_id": "sendspin-go-client-id",
"device_info": {
"manufacturer": "Sendspin Conformance",
"product_name": "sendspin-go Conformance Client",
"software_version": "0.1.0"
},
"name": "sendspin-go-client",
"player@v1_support": {
"buffer_capacity": 2000000,
"supported_commands": [
"volume",
"mute"
],
"supported_formats": [
{
"bit_depth": 24,
"channels": 1,
"codec": "flac",
"sample_rate": 8000
},
{
"bit_depth": 16,
"channels": 1,
"codec": "flac",
"sample_rate": 8000
},
{
"bit_depth": 24,
"channels": 1,
"codec": "pcm",
"sample_rate": 8000
},
{
"bit_depth": 16,
"channels": 1,
"codec": "pcm",
"sample_rate": 8000
}
]
},
"supported_roles": [
"player@v1"
],
"trust_level": "none",
"unpaired_access": {
"enabled": false
},
"version": 1
},
"type": "client/hello"
},
"preferred_codec": "flac",
"role": "server",
"scenario_id": "server-initiated-flac",
"server_id": "va3GtO3V_cuMN7v-3526HVcaG2CnUyGkx47XVNMd8Xo",
"server_name": "aiosendspin server",
"status": "ok",
"stream": {
"bit_depth": 24,
"channels": 1,
"codec": "flac",
"codec_header": "ZkxhQ4AAACICQAJAAAAAAAbWAfQBcAAAAAAAAAAAAAAAAAAAAAAAAAAA",
"codec_header_sha256": "efdfadf8f1d1bb8520b015c54e57d2440cc1e99172ed5d99a92a7b77f0c68a62",
"sample_rate": 8000
}
}
Client summary (JSON)
RAW{
"audio": {
"audio_chunk_count": 69,
"received_encoded_sha256": "a827ae929643694d40aad698c853eed5f5c47e7040c0ffd2ea952c7e3723724d",
"received_pcm_sha256": null,
"received_sample_count": 0
},
"client_id": "sendspin-go-client-id",
"client_name": "sendspin-go-client",
"implementation": "sendspin-go",
"initiator_role": "server",
"peer_hello": {
"payload": {
"active_roles": [
"player@v1"
],
"connection_reason": "playback",
"name": "aiosendspin server",
"server_id": "va3GtO3V_cuMN7v-3526HVcaG2CnUyGkx47XVNMd8Xo",
"version": 1
},
"type": "server/hello"
},
"preferred_codec": "flac",
"role": "client",
"scenario_id": "server-initiated-flac",
"server": {
"active_roles": [
"player@v1"
],
"connection_reason": "playback",
"name": "aiosendspin server",
"server_id": "va3GtO3V_cuMN7v-3526HVcaG2CnUyGkx47XVNMd8Xo",
"version": 1
},
"status": "ok",
"stream": {
"bit_depth": 24,
"channels": 1,
"codec": "flac",
"codec_header": "ZkxhQ4AAACICQAJAAAAAAAbWAfQBcAAAAAAAAAAAAAAAAAAAAAAAAAAA",
"sample_rate": 8000
}
}Client log
RAW2026/07/21 05:30:41.436621 Handshake complete with server
2026/07/21 05:30:41.439177 Group update: id=606fa0fc-529b-4fa6-a742-4812b3df671a, state=stopped
2026/07/21 05:30:41.649630 Group update: id=606fa0fc-529b-4fa6-a742-4812b3df671a, state=playing
2026/07/21 05:30:47.375530 Group update: id=606fa0fc-529b-4fa6-a742-4812b3df671a, state=stopped
2026/07/21 05:30:47.880827 Read error: websocket: close 1000 (normal)
2026/07/21 05:30:47.881149 Connection closed
{
"audio": {
"audio_chunk_count": 69,
"received_encoded_sha256": "a827ae929643694d40aad698c853eed5f5c47e7040c0ffd2ea952c7e3723724d",
"received_pcm_sha256": null,
"received_sample_count": 0
},
"client_id": "sendspin-go-client-id",
"client_name": "sendspin-go-client",
"implementation": "sendspin-go",
"initiator_role": "server",
"peer_hello": {
"payload": {
"active_roles": [
"player@v1"
],
"connection_reason": "playback",
"name": "aiosendspin server",
"server_id": "va3GtO3V_cuMN7v-3526HVcaG2CnUyGkx47XVNMd8Xo",
"version": 1
},
"type": "server/hello"
},
"preferred_codec": "flac",
"role": "client",
"scenario_id": "server-initiated-flac",
"server": {
"active_roles": [
"player@v1"
],
"connection_reason": "playback",
"name": "aiosendspin server",
"server_id": "va3GtO3V_cuMN7v-3526HVcaG2CnUyGkx47XVNMd8Xo",
"version": 1
},
"status": "ok",
"stream": {
"bit_depth": 24,
"channels": 1,
"codec": "flac",
"codec_header": "ZkxhQ4AAACICQAJAAAAAAAbWAfQBcAAAAAAAAAAAAAAAAAAAAAAAAAAA",
"sample_rate": 8000
}
}
Server build log · python-adapters · built · 0.20s
RAWListing 'src'... Listing 'src/conformance'... Listing 'src/conformance/adapters'... Compiling 'src/conformance/adapters/__init__.py'... Compiling 'src/conformance/adapters/aiosendspin_client.py'... Compiling 'src/conformance/adapters/aiosendspin_server.py'... Compiling 'src/conformance/adapters/placeholder.py'... Compiling 'src/conformance/adapters/sendspin_jvm_client.py'... Compiling 'src/conformance/cli.py'... Compiling 'src/conformance/merge.py'... Compiling 'src/conformance/registry.py'... Listing 'src/sendspin_conformance.egg-info'... Listing 'scripts'... Compiling 'scripts/detect_regressions.py'... Compiling 'scripts/merge_results.py'... Compiling 'scripts/run_all.py'... Compiling 'scripts/setup_repositories.py'... Compiling 'scripts/setup_workspace.py'...
Client build log · sendspin-go-client · built · 2.17s
RAWNo build detail was recorded.