Principle:Cohere ai Cohere python Server Sent Events Decoding
| Field | Value |
|---|---|
| Source Repo | Cohere Python SDK |
| Source Doc | MDN SSE Specification |
| Domains | Streaming, HTTP, Event_Driven_Architecture |
| Last Updated | 2026-02-15 14:00 GMT |
Overview
A protocol-level mechanism for parsing Server-Sent Events from HTTP streaming responses into structured event objects.
Description
Server-Sent Events (SSE) is a W3C standard protocol for server-to-client streaming over HTTP. The SSE format uses a text/event-stream content type where events are separated by double newlines and consist of field:value lines (event, data, id, retry). The Cohere SDK implements an SSE decoder that processes raw HTTP response bytes into structured ServerSentEvent objects. The decoder handles charset detection, line-by-line parsing, multi-line data fields, and event boundary detection per the W3C specification.
Usage
This is an internal mechanism used transparently by V2Client.chat_stream(). Understanding SSE is relevant for debugging streaming issues, implementing custom streaming clients, or extending the SDK.
Theoretical Basis
SSE follows the event-stream interpretation algorithm defined in the HTML Living Standard. Events are delimited by blank lines. Each line is either a field (event:, data:, id:, retry:) or a comment (starting with :). The decoder maintains state between lines, accumulating data fields and emitting complete events when a blank line boundary is encountered.
The SSE protocol has the following key properties:
- Unidirectional: Data flows only from server to client
- Text-based: Events are encoded as UTF-8 text
- Self-delimiting: Blank lines separate events
- Typed: Each event has an event type, data payload, optional ID, and optional retry interval
- Stateful decoding: The decoder accumulates multi-line data fields and emits on blank line boundaries