langchain-ai/deepagents · error · RequestError

-32602

-32602

Error message

cwd: must match the working directory used to create the session

What it means

Every `[models].allowed` entry must be a non-empty string in `provider:model` form; `parse_model_allowlist` raises `ValueError` for non-string entries or blank strings. This keeps a silently-broken allowlist from degrading into an unintended deny-all.

Source

Thrown at libs/acp/deepagents_acp/server.py:415

        session_id: str,
        additional_directories: list[str] | None = None,  # noqa: ARG002  # capability is not advertised
        mcp_servers: list[McpServer] | None = None,
        **kwargs: Any,  # noqa: ARG002  # ACP protocol interface parameter
    ) -> LoadSessionResponse:
        """Restore and replay a persisted ACP session."""
        if not self._load_sessions:
            method = "session/load"
            raise RequestError.method_not_found(method)

        self._session_cwds[session_id] = cwd
        agent = self._checkpointed_agent(session_id)
        metadata = (await agent.aget_state(self._session_config(session_id))).metadata or {}
        if metadata.get(_ACP_SESSION_METADATA_KEY) is not True:
            self._forget_session(session_id)
            raise RequestError.resource_not_found(session_id)
        if metadata.get("cwd") != cwd:
            self._forget_session(session_id)
            raise RequestError.invalid_params(
                {"cwd": "must match the working directory used to create the session"}
            )

        self._session_mcp_servers[session_id] = list(mcp_servers or [])
        self._initialize_session_options(session_id)
        if self._restore_session_options(session_id, metadata):
            self._reset_agent(session_id)

        await self._replay_session(session_id, agent)
        return LoadSessionResponse(
            modes=self._session_mode_states.get(session_id),
            config_options=self._build_config_options(session_id) or None,
        )

    async def set_session_mode(
        self,
        mode_id: str,
        session_id: str,

View on GitHub (pinned to a1af029e6e)

Solutions

Remove empty or non-string entries from the array
Ensure every entry is a quoted `provider:model` or `provider:*` string
Regenerate or re-check the config after automated edits/templates

Example fix

# before
allowed = ["", "anthropic:claude-sonnet-4-5"]
# after
allowed = ["anthropic:claude-sonnet-4-5"]

Defensive patterns

Strategy: validation

Validate before calling

def clean_allowlist(entries: object) -> list[str]:
    if not isinstance(entries, list):
        raise TypeError("expected a list")
    cleaned = [e for e in entries if isinstance(e, str) and e.strip()]
    if len(cleaned) != len(entries):
        raise ValueError("allowlist contains empty or non-string entries")
    return cleaned

Type guard

def is_allowlist_value(value: object) -> bool:
    return isinstance(value, list) and all(
        isinstance(e, str) and e.strip() for e in value
    )

Try / catch

try:
    parsed = parse_model_allowlist(raw)
except ValueError as exc:
    logger.error("malformed [models].allowed: %s", exc)
    parsed = ()

Prevention

Filter empty strings out of generated config arrays
Keep every allowlist entry a quoted string — no bare numbers/booleans
Review templated config output for leftover empty placeholders

When it happens

Trigger: An entry like `allowed = ["", "anthropic:claude-sonnet-4-5"]`, `allowed = [42]`, `allowed = [true]`, or whitespace-only `" "` in the TOML array.

Common situations: Leftover empty string from templated config generation; wrong TOML type (integer/boolean) in the array; entries removed leaving an empty `""` behind.

Related errors

AI-assisted analysis of langchain-ai/deepagents@a1af029e6e (2026-08-29). Data as JSON: /api/errors/b66c69e8316662ba. Report an issue: GitHub.