gsd-phase-researcher

gsd-phase-researcher is an agent for Claude Code, Codex from open-gsd/gsd-core. It costs 41 tokens per session (11,242 once invoked), scanned A, original, MIT.

A research agent for an implementation phase that investigates the technical area before planning begins. It records common approaches, risks, and confidence levels in a RESEARCH.md file for a later planner.

In plain words
What is it for?
Use it before planning a development phase to research the technology, identify pitfalls, and provide evidence for implementation decisions.
Why use it?
It reduces planning based on guesses by checking the relevant technology and documenting where claims came from. This is useful when a project phase involves unfamiliar tools or patterns.

Agent for Claude CodeCodex

Written for Claude Code and Codex: PostToolUse hook event, but also reads $CODEX_HOME. Also seen: reads .claude/ paths; mentions CLAUDE.md; positional $N argument.

Part of the gsd-core plugin — 72 skills, 64 agents, 7 hooks shipped together

Good fit Use it before planning a development phase to research the technology, identify pitfalls, and provide evidence for implementation decisions.

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Install with agentmods
npx agentmods add agents/open-gsd/gsd-core/gsd-phase-researcher
About the project

GSD Core is a framework that guides AI coding agents through a repeatable cycle of discussing decisions, planning, executing, verifying, and shipping software work. It is used with coding-agent runtimes to organize research and implementation in fresh-context subagents and reduce context degradation. The catalogue entries are its skills, agents, hooks, plugin, and instructions for those workflows.

open-gsd/gsd-core · 10,564 stars · on GitHub · opengsd.net

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/open-gsd/gsd-core

Made for: Claude Code, Codex.

Or install gsd-core, the plugin that ships this one along with the rest of its 72 skills, 64 agents, 7 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for gsd-phase-researcher

README.md
[![agentmods](https://agentmods.dev/badge/agents/open-gsd/gsd-core/gsd-phase-researcher/github.svg)](https://agentmods.dev/agents/open-gsd/gsd-core/gsd-phase-researcher)
Your own site
<a href="https://agentmods.dev/agents/open-gsd/gsd-core/gsd-phase-researcher"><img src="https://agentmods.dev/badge/agents/open-gsd/gsd-core/gsd-phase-researcher/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for gsd-phase-researcher

Your own site · 80×15
<a href="https://agentmods.dev/agents/open-gsd/gsd-core/gsd-phase-researcher"><img src="https://agentmods.dev/badge/agents/open-gsd/gsd-core/gsd-phase-researcher.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 41 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 11,242 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00041 $0.11242
Opus 5.5 $0.00016 $0.04497
Sonnet 5.5 $0.00008 $0.02248
Haiku 4.5 $0.00004 $0.01124

Measured 11d ago against content hash 92e78f3f91c0, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

gsd-phase-researcher scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -s http://localhost:27017 2>/dev/null
Origin

Copies of this mod

2 near-identical copies found in the catalogue:

agents/gsd-phase-researcher.md · 902 lines

How it starts

The opening of the file, as written. The whole thing — 902 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Spawned by /gsd:plan-phase (integrated) or /gsd:plan-phase --research-phase <N> (standalone).

@~/.claude/gsd-core/references/mandatory-initial-read.md

Core responsibilities:

  • Investigate the phase's technical domain
  • Identify standard stack, patterns, and pitfalls
  • Document findings with confidence levels (HIGH/MEDIUM/LOW)
  • Write RESEARCH.md with sections the planner expects
  • Return structured result to orchestrator

Claim provenance: Every factual claim in RESEARCH.md must be tagged with its source:

  • [VERIFIED: npm registry] — confirmed via tool (npm view, web search, codebase grep) AND discovered from an authoritative source (official docs, Context7)
  • [CITED: docs.example.com/page] — referenced from official documentation
  • [ASSUMED] — based on training knowledge, not verified in this session

Package name provenance rule: A package name discovered via WebSearch, training data, or any non-authoritative source must be tagged [ASSUMED] regardless of whether npm view confirms it exists on the registry. Registry existence alone does not confer [VERIFIED] status — a slopsquatted package also passes npm view. Only packages confirmed via official documentation or Context7 AND returning OK from gsd-tools query package-legitimacy check may be tagged [VERIFIED: npm registry].

In-repo value provenance rule: A claim about an in-repo discrete value — an enum, a schema or type union, an error code, a status constant, or a filesystem path — may be tagged [VERIFIED: …] only if you opened the source-of-truth file with Read this session. A codebase grep is not sufficient on its own: it confirms a string occurs, not that you read the definition. Cite the path and line range ([VERIFIED: src/types/order.ts:14-22]), and quote the values verbatim in RESEARCH.md beside the claim — paraphrase is forbidden. The quote is what makes the tag checkable — a citation with no quote beside it does not earn [VERIFIED], however precise the line range looks. Every value appearing in a code example or skeleton must also appear in that verbatim quote; a value that does not is [ASSUMED]. For a filesystem path, cite the line in the script that creates it, not the location you expect it to occupy. Training memory and a web search are not substitutes for reading the file — a discrete value that merely looks right fails at the executor's parse()/typecheck, the most expensive place to discover it.

Absent-evidence provenance rule: A compatibility claim resting on missing metadata — no python_requires, no engines field, no per-version classifier, no changelog entry, no matching row in a support matrix — does not earn [VERIFIED: …], however authoritative the source you consulted. Absence is silence about every value, not a constraint on one: a project declaring no supported versions says nothing about the version you want and nothing about the version you are standardizing on, so the same evidence "proves" both. The rule keys on the evidence, not the wording — "does not support 3.14" rephrased as "supports only up to 3.13" rests on the identical absence and earns the identical tag, and an absence is equally not evidence that the target is supported. A present constraint is the opposite case and is untouched: requires-python = ">=3.9,<3.12" is a declared exclusion and earns [VERIFIED: …], as does documentation stating the incompatibility affirmatively ([CITED: …]). What separates the two is whether the declaration bounds every value or only the ones it names: an explicit range or upper bound (requires-python, engines) speaks about all versions, so it is a present constraint, while an enumerated allow-list that stops short of your target (classifiers running :: 3.9 through :: 3.13 with no :: 3.14) speaks only about the versions it lists and stays silent on yours, so it is still a governed absence unless the project states the list is exhaustive. Reframing that silence as a positive finding — "the classifiers affirmatively declare support through 3.13" — is the same absence in different clothes and earns the same tag. The only route from an absence to [VERIFIED] is a positive falsification attempt: run it against the real target and paste the failing output — asserting that you ran it does not earn the tag, and a failure attributable to something else (a missing certificate, a wrong host) is not a falsification. A probe that succeeds refutes the claim: drop it rather than downgrade it. When the lookup itself failed, report no observation, never a declared absence. Everything short of this is [ASSUMED], which is always available — a probe you cannot run in this environment costs a confirmation checkpoint, not a blocked plan.

Read the full file on GitHub · 902 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 11d ago Changed 92e78f3f91c0
  2. 23d ago Changed · +8 lines c93e4d814d8a
  3. 24d ago Changed 57c07c786852
  4. 1mo ago First seen · 894 lines · 41 tokens per session scan A bab5c586927b

Subscribe to this mod's changes

gsd-phase-researcher is an agent published in the GitHub repository open-gsd/gsd-core (10,564 stars, last pushed today), licensed MIT. It adds 41 tokens to every session and 11,242 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.