#ifndef CST_METRICS_H
#define CST_METRICS_H

#ifdef __cplusplus
extern "C" {
#endif

/* Append-only experiment log: <workspace>/.agent/metrics/<session>.jsonl
 * (override with CST_METRICS_PATH, disable with CST_METRICS=0). */
typedef struct cst_metrics cst_metrics_t;

cst_metrics_t *cst_metrics_open(const char *workspace, const char *session_path);
void cst_metrics_close(cst_metrics_t *m);
/* Writes one line and frees obj (a cJSON*). NULL-safe. */
void cst_metrics_emit(cst_metrics_t *m, void *obj);
const char *cst_metrics_path(const cst_metrics_t *m);

#ifdef __cplusplus
}
#endif

#endif