TOpenCode (OpenCode Zen)

Source: source/classes/topencode.prg

TOpenCode talks to the OpenCode Zen chat API (https://opencode.ai/zen/v1/chat/completions) with Authorization: Bearer public. No API key. Free models (hy3-free, mimo-v2.5-free, deepseek-v4-flash-free, nemotron-3-ultra-free, nemotron-3.5-lightning-free, laguna-s-2.1-free). Uses hb_curl. Async methods need the Harbour MT VM (build_new.bat <sample> hb32 mt).

Transport: hbcurl over a static libcurl (Schannel) — no libcurl.dll to ship. Curl sources and build scripts live in 3rdparty/ (outputs: lib/libcurl_static*.{lib,a} for bcc32/bcc64/msvc32/ msvc64/gcc).

Architecture

flowchart LR A[TOpenCode] --> B[hb_curl] B --> C["opencode.ai/zen/v1/chat/completions"] A -->|SendAsync| D[hb_threadStart] D --> E[oc_*.json]

Key DATA

DATA	Default	Description
`cModel`	`"hy3-free"`	Zen free model
`cUrl`	Zen chat completions	Endpoint
`nTemperature`	`0.7`	0.0–2.0
`aFallbackModels`	other free models	Used on rate limit
`lRunning`	`.F.`	Async in flight

Methods

Method	Description
`New( cModel )`	Own curl handle per instance (safe to run several in parallel).
`Send( cPrompt )`	Sync. Retries with `cFallbackModel()` on rate limit.
`SendWithSystem( cSys, cUser )`	Sync with a system prompt (agent role).
`SendAsync( cPrompt )`	Returns at once. Poll `IsRunning()`.
`SendWithSystemAsync( cSys, cUser )`	Async + system prompt.
`IsRunning()`	`.T.` until the worker writes the result file.
`GetValue()`	Assistant text from JSON; UTF-8 → ACP.
`Wait() / End()`	Join the thread; cleanup curl.
`SetModel() / SetTemperature()`	Change model / temperature.

Async writes oc_<ms>_<seq>.json via a .part file then rename, so three SendAsync() calls in the same tick do not collide and IsRunning() never reads a half-written body.

Example

#include "FiveWin.ch"

function Main()
   local o := TOpenCode():New( "mimo-v2.5-free" )
   o:Send( "Say hello in one sentence." )
   MsgInfo( o:GetValue() )
   o:End()
return nil

Samples

Sample	Description
`samples/ai/opencode1.prg`	Three agents, each with its own TOpenCode, SendAsync + timer. Build `hb32 mt`.
`samples/ai/opencode2.prg`	TWebView2 UI (WhatsApp layout): agents left, chat right, add/edit roles. Persists `opencode2.json`. Needs `opencode2.html` next to the exe. Build `hb32 mt`.

cd samples\ai
build_new.bat opencode1 hb32 mt
build_new.bat opencode2 hb32 mt
:: run from this folder (libcurl.dll)

Notes

No API key. OAuth / auth.json on TOpenCode is unused (Zen rejects sk- keys).
Async requires hbvmmt — pass mt to build_new.bat.
32-bit samples need the x86 libcurl.dll beside the exe (samples\ai).
Do not call the Zen API from inside TWebView2:bOnBind; queue the work and run it from a timer (see opencode2).