/**
 * 1M-context window size in tokens (documented single choice: 1,000,000).
 * EXPORTED because the adapter's late 1M rescue (`resolveContextWindowTokens`)
 * names it too — one number, one declaration, rather than a copy that can drift.
 */
export declare const ONE_MILLION_CONTEXT_TOKENS = 1000000;
/**
 * Safe-default (non-1M) context window size in tokens. Exported for the same
 * reason: `resolveContextWindow` compares the heuristic against it.
 */
export declare const DEFAULT_CONTEXT_WINDOW_TOKENS = 200000;
/**
 * Resolve the currently-active Claude Code model id from a runtime env map.
 * Returns the first non-empty `CLAUDE_CODE_MODEL_ENV_VARS` value (trimmed), or
 * `undefined` when none is present. Pure + exported for tests; the caller falls
 * back to the transcript `message.model` when this returns undefined.
 */
export declare function resolveClaudeModelFromEnv(env: NodeJS.ProcessEnv | undefined): string | undefined;
/**
 * Model-aware context-window size in tokens.
 *
 * Detection rule (documented):
 *   1. Empty / unknown model → DEFAULT_CONTEXT_WINDOW_TOKENS (200_000).
 *   2. Suffix heuristic — a model id containing `1m` (case-insensitive) is
 *      treated as 1M-context.
 *   3. Explicit allowlist — known 1M Claude model ids
 *      (ONE_MILLION_CONTEXT_MODELS).
 *   4. Everything else → 200_000 (the safe default).
 *
 * Callers MAY additionally infer ≥1M from the observed token count: if
 * `contextTokens > DEFAULT_CONTEXT_WINDOW_TOKENS`, the model cannot be a
 * 200K model and must be ≥1M (see `readClaudeTranscriptEstimate`).
 *
 * This is the HEURISTIC layer only. Explicit user overrides sit ABOVE it —
 * see `resolveContextWindow`, which is what the probe actually calls.
 */
export declare function modelContextWindowTokens(model: string): number;