earendil-works/pi · error · SessionError

invalid_payload

invalid_payload

Error message

Session id must be non-empty, contain only alphanumeric characters, '-', '_', and '.', and start and end with an alphanumeric character

What it means

Error "Session id must be non-empty, contain only alphanumeric characters, '-', '_', and '.', and start and end with an alphanumeric character" thrown in earendil-works/pi.

Source

Thrown at packages/agent/src/harness/session/jsonl/repo.ts:20

import { assertJsonSerializable, Session } from "../session.ts";
import { type ForkOptions, SessionError, type SessionRepo } from "../types.ts";
import { metadataFromHeader, parseHeader } from "./codec.ts";
import { fileResult } from "./errors.ts";
import { JsonlSessionStorage } from "./storage.ts";
import type {
	JsonlSessionCreateOptions,
	JsonlSessionListOptions,
	JsonlSessionMetadata,
	JsonlSessionRepoFileSystem,
	JsonlSessionRepoOptions,
	JsonlV4Header,
} from "./types.ts";

const SESSION_ID_PATTERN = /^[A-Za-z0-9](?:[A-Za-z0-9._-]*[A-Za-z0-9])?$/;

function validateSessionId(id: string): void {
	if (!SESSION_ID_PATTERN.test(id)) {
		throw new SessionError(
			"invalid_payload",
			"Session id must be non-empty, contain only alphanumeric characters, '-', '_', and '.', and start and end with an alphanumeric character",
		);
	}
}

function jsonlSessionDirectoryName(cwd: string): string {
	return `--${cwd.replace(/^[/\\]/, "").replace(/[/\\:]/g, "-")}--`;
}

async function jsonlSessionsRoot(options: JsonlSessionRepoOptions): Promise<string> {
	return fileResult(
		await options.fs.absolutePath(options.sessionsRoot),
		`Failed to resolve sessions root ${options.sessionsRoot}`,
	);
}

async function jsonlSessionDirectory(

View on GitHub (pinned to 4af9d21d3b)

Solutions

1. Use a session id that starts and ends with an alphanumeric character and contains only alphanumerics, dash, underscore, and dot.

When it happens

Trigger: Thrown at packages/agent/src/harness/session/jsonl/repo.ts:20 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of earendil-works/pi@4af9d21d3b (2026-08-24). Data as JSON: /api/errors/dda28c7c566d880e. Report an issue: GitHub.