Codex Deep Research

Codex Deep Research

Use this skill when the user is asking for research rather than a normal answer. Typical triggers include:

• comparisons, evaluations, and recommendations
• market scans, competitive analysis, and landscape research
• questions where current information materially affects the answer
• requests that need citations, trade-offs, risks, or explicit source quality

Do not force the full workflow onto simple factual questions. First decide whether the task truly needs deep research.

Quick start

1. Rewrite the request into a compact internal research brief.
2. Browse early and prefer current, verifiable sources.
3. Stay single-agent unless there is a real quality benefit to parallel work.
4. If complexity is high, delegate distinct sub-questions to a small number of sub-agents using the sub-agent template.
5. Deliver a complete research report in the current conversation unless the user explicitly asks for a shorter format.
6. Only save files when the user asks or the result is clearly worth preserving after the in-session report is complete.

Workflow

1. Detect research mode

Enter deep-research mode when one or more of these are true:

• the answer depends on up-to-date information
• the user is making a decision with meaningful downside risk
• the task needs multiple sources or source comparison
• the user wants a recommendation, ranking, comparison, or market view
• the expected output should include citations, trade-offs, or explicit uncertainty

If the request is too vague to research responsibly, ask one minimal clarifying question instead of starting a large search.

2. Build an internal brief

Use assets/brief-template.md as the default structure. Keep the brief internal unless sharing it would help the user.

Capture at least:

• the exact research question
• the user's likely decision or goal
• what is in scope and out of scope
• time sensitivity
• the evaluation dimensions that matter most
• the expected deliverable style

3. Browse by default

For research tasks, browse first instead of relying on memory. Prefer official and primary sources, then high-quality reporting. Use references/source-quality.md and references/citation-rules.md when judging evidence.

For time-sensitive topics, use absolute dates in the final answer.

4. Decide whether to use multi-agent work

Start single-agent by default. Upgrade to multi-agent only when it clearly improves coverage or speed.

Only escalate when one or more of these are true:

• the task contains distinct sub-questions that can be researched independently
• the source space is broad enough that parallel coverage will materially improve quality
• the report would benefit from role separation such as official-source review, market scan, and risk review
• the user is making a decision where missing counter-evidence would be costly

Avoid escalation when the task is small, narrow, or already well-covered by a single search path.

When delegating, default to assets/subagent-task-template.md. Unless the task is extremely simple, give each sub-agent:

• one narrow question
• an explicit scope and out-of-scope boundary
• a source-priority instruction
• a concise return format

The main agent owns final judgment and synthesis.

5. Synthesize carefully

Never concatenate search results or sub-agent outputs. Merge them into one coherent report. Always:

• deduplicate overlapping evidence
• surface source conflicts
• explain uncertainty where evidence is thin
• keep facts separate from inferences
• keep recommendations tied to the user's goals

For the full staged process, see references/workflow.md.

Output contract

Default to a real research report in the conversation, not a short generic answer and not a summary that points the real content to a file. Use assets/report-template.md unless the user explicitly asks for a different format.

The final answer should usually include:

• conclusion summary
• research question and scope
• method and source strategy
• key findings
• evidence and citations
• risks and unknowns
• recommendation
• next steps

Keep these categories explicit:

• facts: directly supported by sources
• inferences: reasoned conclusions drawn from those facts
• recommendations: suggested actions based on the user's goals

If the user explicitly asks for a short report, compress the answer but keep citations and evidence boundaries intact.

Do not treat a saved file as the primary deliverable unless the user explicitly asked for file output.

Persistence

Do not save files by default. Complete the in-session research delivery first. Persist only when:

• the user asks to save the output
• the result is clearly reusable
• the task benefits from an auditable artifact trail

Do not save files merely because auditability could be helpful. When saving is appropriate, follow repository conventions instead of inventing new ones.

Completion check

Before finalizing, quickly verify:

• the conversation already contains the full research deliverable, not just a summary
• facts, inferences, and recommendations are kept distinct
• multi-agent work was used only if it materially improved coverage
• no files were written by default

Reference map

• references/workflow.md: staged research flow, escalation, synthesis
• references/source-quality.md: source hierarchy and evidence handling
• references/citation-rules.md: citation visibility and date rules
• assets/brief-template.md: internal research brief scaffold
• assets/report-template.md: default report scaffold
• assets/subagent-task-template.md: delegation scaffold