@sema-agent/core/dist/brain/context-overflow.js

Stateless, task-oriented AI agent core

export const FLOOR_OUTPUT_TOKENS = 3000;
const CONTEXT_HEADROOM_TOKENS = 1000;
const CONTEXT_OVERFLOW_RE = /^input length and `max_tokens` exceed context limit: (\d+) \+ (\d+) > (\d+)(?!\w|[.,]\d|\s\d|[+\-*/])/;
const CONTEXT_OVERFLOW_PREFIX = "input length and `max_tokens` exceed context limit:";
function providerDiagnostic(body) {
    const trimmed = body.trim();
    if (!trimmed.startsWith("{"))
        return undefined;
    let parsed;
    try {
        parsed = JSON.parse(trimmed);
    }
    catch {
        return undefined;
    }
    if (typeof parsed !== "object" || parsed === null || Array.isArray(parsed))
        return undefined;
    const err = parsed.error;
    if (typeof err !== "object" || err === null || Array.isArray(err))
        return undefined;
    const message = err.message;
    return typeof message === "string" ? message : undefined;
}
function reportFrom(diagnostic) {
    const message = diagnostic.trimStart();
    const m = CONTEXT_OVERFLOW_RE.exec(message);
    if (m === null)
        return undefined;
    if (message.slice(m[0].length).includes(CONTEXT_OVERFLOW_PREFIX))
        return undefined;
    const [, rawInput, rawMax, rawLimit] = m;
    if (rawInput === undefined || rawMax === undefined || rawLimit === undefined)
        return undefined;
    const inputTokens = Number.parseInt(rawInput, 10);
    const maxTokens = Number.parseInt(rawMax, 10);
    const contextLimit = Number.parseInt(rawLimit, 10);
    if (!Number.isSafeInteger(inputTokens) || !Number.isSafeInteger(maxTokens) || !Number.isSafeInteger(contextLimit)) {
        return undefined;
    }
    if (inputTokens <= contextLimit - maxTokens)
        return undefined;
    return { inputTokens, maxTokens, contextLimit };
}
export function parseContextOverflow(status, body) {
    if (status !== 400)
        return undefined;
    const diagnostic = providerDiagnostic(body);
    return diagnostic === undefined ? undefined : reportFrom(diagnostic);
}
export function planOutputCapAdjustment(report, otherCapsInEffect = []) {
    const available = Math.max(0, report.contextLimit - report.inputTokens - CONTEXT_HEADROOM_TOKENS);
    if (available < FLOOR_OUTPUT_TOKENS)
        return { outcome: "below_floor", available };
    const current = Math.min(report.maxTokens, ...otherCapsInEffect.filter((c) => c !== undefined));
    if (available >= current)
        return { outcome: "no_progress", available, current };
    return { outcome: "adjust", maxOutputTokens: available, current };
}