The loop previously checked the token budget at the *bottom* of each
iteration, after the LLM call and tool work had already happened. By
the time the cap was caught the budget had been exceeded and the
overshoot was unbounded by the iteration's cost.
Move the check to the *top* of the loop so a new iteration is never
started past the budget. Document the policy explicitly: token_budget
is a soft cap on the tool-use loop only; the synthesis call is always
allowed to complete so callers get a structured ResearchResult rather
than a fallback stub. Capping synthesis is a separate, larger design
question (would require splitting the budget between loop and
synthesis up-front).
Verified: token_budget=5000, max_iterations=10 now stops after 2
iterations with budget_exhausted=True and a complete answer with
10 citations.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Both the MCP server and WebResearcher defaulted to
claude-sonnet-4-5-20250514, which 404s against the Anthropic API.
Update both defaults to claude-sonnet-4-6, which is current as of
2026-04.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
The synthesis step was passing max_tokens=4096 to Claude, which was
not enough for a full ResearchResult JSON over a real evidence set
(28 sources). The model's output got cut mid-string, json.loads
failed, and the agent fell back to a stub answer with zero citations.
The trace logger then truncated the raw_response to 1000 chars before
recording it, hiding the actual reason for the parse failure (the
truncated JSON suffix) and making the bug invisible from traces.
Fixes:
- Bump synthesis max_tokens to 16384
- Capture and log Claude's stop_reason on synthesis_error so future
truncation cases are diagnosable from the trace alone
- Log the parser exception text alongside the raw_response
- Stop slicing raw_response — record the full string
Verified end-to-end against the Utah crops question:
- Before: 0 citations, confidence 0.10, fallback stub
- After: 9 citations, confidence 0.88, real synthesized answer
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
New field on ResearchResult: open_questions — follow-up questions that
emerged from the research itself. Distinct from gaps (backward: what
failed) and discovery_events (sideways: what's lateral). Open questions
look forward: 'based on what I found, this needs deeper investigation.'
- OpenQuestion model: question, context, priority (high/medium/low),
source_locator
- Updated agent synthesis prompt to produce open_questions
- Updated agent result builder to parse open_questions from JSON
- 3 new tests for OpenQuestion model
- Updated existing tests for new field
77 tests passing.
Refs: archeious/marchwarden#1
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
WebResearcher — the core agentic research loop:
- Tool-use loop: Claude decides when to search (Tavily) and fetch (httpx)
- Budget enforcement: stops at max_iterations or token_budget
- Synthesis step: separate LLM call produces structured ResearchResult JSON
- Fallback: valid ResearchResult even when synthesis JSON is unparseable
- Full trace logging at every step (start, search, fetch, synthesis, complete)
- Populates all contract fields: raw_excerpt, categorized gaps,
discovery_events, confidence_factors, cost_metadata with model_id
9 tests: complete research loop, budget exhaustion, synthesis failure
fallback, trace file creation, fetch_url tool integration, search
result formatting.
Refs: archeious/marchwarden#1
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
