Cap’n Proto Schema¶

Author:

Rohit Goswami

Overview¶

The serve mode RPC protocol is defined in schema/bless_log.capnp. It uses the capability pattern: clients open a session and receive a LogSink capability scoped to that session.

Structs¶

LogLine¶

A single log line with timestamp, level, and message.

Field	Type	Description
timestamp	Float64	Unix epoch seconds (f64)
level	Level	Log level enum
message	Text	The log message

Level (enum)¶

Value	Name
0	trace
1	debug
2	info
3	warn
4	error

SessionMeta¶

Metadata sent when opening a session.

Field	Type	Description
label	Text	Run label
uuid	Text	Run UUID
command	Text	Command name
args	Text	Command arguments
hostname	Text	Client hostname
startTime	Float64	Unix epoch start time

SessionSummary¶

Returned by listSessions.

Field	Type	Description
uuid	Text	Run UUID
label	Text	Run label
command	Text	Command name
duration	Text	Human-readable duration
lineCount	UInt64	Total lines logged
exitCode	Int32	Command exit code

Interfaces¶

BlessServer¶

Method	Parameters	Returns
openSession	meta: SessionMeta	sink: LogSink
listSessions	limit: UInt32	sessions: List(SessionSummary)

LogSink¶

Method	Parameters	Returns
writeBatch	lines: List(LogLine)	void
close	exitCode: Int32, duration: Text	void

Data flow¶

Client connects to server via TCP
Client calls openSession with metadata
Server creates gzip file, returns LogSink capability
Client sends log lines in batches via writeBatch
Client calls close with exit code and duration
Server finalizes gzip file and writes to index