The Wire
Drive the Messages API directly and account for every field in the request and the response.
$108
this phase
- Open1.1
Messages, Not Chat
Free previewOne stateless endpoint, the whole history resent every turn, and where the system prompt lives.
- 1.2
Streaming, Event by Event
message_start to message_stop, deltas accumulated by hand before you trust the SDK helper.
- 1.3
Every Stop Reason
end_turn, max_tokens, tool_use, pause_turn, refusal, and the branch most code forgets.
- 1.4
Thinking and Effort
Adaptive thinking, the effort ladder from low to max, and why budget_tokens now returns 400.
- 1.5
Counting Tokens Honestly
The count_tokens endpoint, why tiktoken undercounts Claude, and reading usage on every call.
- 1.6
Errors That Retry
429 and 529 back off, 400 never does, and retry-after beats your own exponential guess.