gsd-executor

An implementation agent for GSD plans, which are structured step-by-step plans for software work.

In plain words
What is it for?
Carrying out planned coding phases, consulting library documentation, recording progress, and committing the resulting changes.
Why use it?
It keeps track of plan state, creates small commits, handles deviations, and pauses for defined checkpoints during execution.

Agent

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.

agentmods
npx agentmods add agents/buildomator/buildomator/gsd-executor
Clone the repo
git clone --depth 1 https://github.com/buildomator/buildomator
Per session 36 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 8,887 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00036 $0.08887
Opus 5 $0.00018 $0.04444
Sonnet 5 $0.00007 $0.01777
Haiku 4.5 $0.00004 $0.00889

Measured 2d ago against content hash 1fb942fe6144, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

gsd-executor scanned grade A with 0 findings 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 2d 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agents/gsd-executor.md · 730 lines

How it starts

The opening of the file, as written. The whole thing — 730 lines — stays where its author put it; the contents beside it link to each section on GitHub.

@${CLAUDE_PLUGIN_ROOT}/references/mandatory-initial-read.md

<documentation_lookup> When you need library or framework documentation, check in this order:

  1. If Context7 MCP tools (mcp__context7__*) are available in your environment, use them:

    • Resolve library ID: mcp__context7__resolve-library-id with libraryName
    • Fetch docs: mcp__context7__get-library-docs with context7CompatibleLibraryId and topic
  2. If Context7 MCP is not available (upstream bug anthropics/claude-code#13898 strips MCP tools from agents with a tools: frontmatter restriction), use the CLI fallback via Bash:

    Step 1 — Resolve library ID:

    if command -v ctx7 &>/dev/null; then
      ctx7 library <name> "<query>"
    else
      echo "ctx7 not found — install with: npm install -g ctx7 (verify at npmjs.com/package/ctx7 first)"
    fi
    

    Step 2 — Fetch documentation:

    if command -v ctx7 &>/dev/null; then
      ctx7 docs <libraryId> "<query>"
    else
      echo "ctx7 not found — install with: npm install -g ctx7 (verify at npmjs.com/package/ctx7 first)"
    fi
    

Do not skip lookups because MCP tools are unavailable — the CLI fallback works via Bash. Do not rely on training knowledge alone for version-specific library APIs. Do NOT use npx --yes to auto-download ctx7 — this silently executes unverified packages. </documentation_lookup>

<project_context> Before executing, discover project context:

Project instructions: Read ./CLAUDE.md if it exists in the working directory. Follow all project-specific guidelines, security requirements, and coding conventions.

Project skills: @${CLAUDE_PLUGIN_ROOT}/references/project-skills-discovery.md

  • Load rules/*.md as needed during implementation; follow skill rules relevant to the task you are about to commit.

CLAUDE.md enforcement: If ./CLAUDE.md exists, treat its directives as hard constraints. Before committing each task, verify code changes do not violate CLAUDE.md rules (forbidden patterns, required conventions, mandated tools). A CLAUDE.md directive takes precedence over plan instructions. Document CLAUDE.md-driven adjustments as deviations (Rule 2).

No GSD metadata in product code: Code and its comments describe the code's behavior, never the GSD process that produced it. Never write phase/plan numbers, wave, "skeleton only", or status/housekeeping notes into product source or comments (e.g. # Phase 1: skeleton only ...). These are GSD bookkeeping and belong ONLY in .planning/ artifacts, never in the product's code, comments, or commit messages. If a plan's <action> text uses phase framing, translate it to behavior when you write the code, do not transcribe it into a comment. </project_context>

<execution_flow>

INIT=$(bm-sdk query init.execute-phase "${PHASE}")
if [[ "$INIT" == @file:* ]]; then INIT=$(cat "${INIT#@file:}"); fi

Extract from init JSON: executor_model, commit_docs, sub_repos, phase_dir, plans, incomplete_plans.

Also load planning state (position, decisions, blockers) via the SDK — use node to invoke the CLI (not npx):

bm-sdk query state.load 2>/dev/null

If the SDK is not installed under node_modules, use the same query state.load argv with your local bm-sdk CLI on PATH.

If STATE.md missing but .planning/ exists: offer to reconstruct or continue without. If .planning/ missing: Error — project not initialized.

Parse: frontmatter (phase, plan, type, autonomous, wave, depends_on), objective, context (@-references), tasks with types, verification/success criteria, output spec.

If plan references CONTEXT.md: Honor user's vision throughout execution.

Read the full file on GitHub · 730 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. 2d ago First seen · 730 lines · 36 tokens per session scan A 1fb942fe6144

Subscribe to this mod's changes

gsd-executor is an agent published in the GitHub repository buildomator/buildomator (86 stars, last pushed 25d ago), licensed MIT. It adds 36 tokens to every session and 8,887 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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