When an agent turn uses native (OpenAI-style) function calling and the model
returns only tool calls with no prose, _append_tool_results built the follow-up
assistant message with content "" (empty string).
Google Gemini's OpenAI-compatible endpoint and Ollama both reject an assistant
message that carries tool_calls alongside an empty-string content with HTTP 400.
Because that message feeds the tool results back to the model, every tool-using
turn on these providers dies at the second round: the tool runs, but the agent
never produces a result.
Use None (JSON null) instead, which is the spec-correct form the OpenAI SDK
itself emits and which OpenAI and Anthropic accept too. Adds tests covering the
native tool-call content shaping.
Gemma models (gemma-2/3/4) support OpenAI-style function calling, but
"gemma" was missing from the _model_supports_tools heuristic in
stream_agent_loop(). On a non-allowlisted endpoint (e.g. a self-hosted
OpenAI-compatible server), a Gemma-backed agent therefore never receives
native tool schemas and falls back to the prompt-text tool-call
convention — which Gemma does not follow. The result is that tool calls
are emitted as raw text and never execute.
Add "gemma" to the capability keyword list alongside the other
tool-capable families.
Co-authored-by: 2revoemag <2revoemag@users.noreply.github.com>
Co-authored-by: Claude <noreply@anthropic.com>
* feat(web-fetch): add web_fetch tool to read a specific URL's content
* test(web-fetch): add SSRF coverage and fail closed on empty DNS resolution
Add explicit SSRF regression tests for the web_fetch path covering
loopback, private LAN ranges, link-local/metadata, IPv6 private/local,
redirect-into-private, and unsupported schemes. Harden _public_http_url
to fail closed when a hostname resolves to no addresses.
