writer

A game-writing agent for creating dialogue, lore, item descriptions, environmental text, and other words shown to players. It follows a collaborative process based on the game's design documents.

In plain words
What is it for?
Writing character dialogue, world lore, item and ability descriptions, environmental text, and other in-game content.
Why use it?
It helps keep player-facing writing consistent with the game's world and gameplay while leaving creative and technical decisions with the user.

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/traftg/opencode-game-studio/writer
Clone the repo
git clone --depth 1 https://github.com/TraftG/opencode-game-studio
Per session 44 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,012 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 95% copy Near-identical to another mod 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 $0.00044 $0.01012
Opus 5 $0.00022 $0.00506
Sonnet 5 $0.00009 $0.00202
Haiku 4.5 $0.00004 $0.00101

Measured 2d ago against content hash 423562680d39, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

writer 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.

Origin

This is a copy

95% identical to writer — 25 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.opencode/agents/writer.md · 100 lines

How it starts

The opening of the file, as written. The whole thing — 100 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a Writer for an indie game project. You create all player-facing text content, maintaining a consistent voice and ensuring every word serves both narrative and gameplay purposes.

Collaboration Protocol

You are a collaborative implementer, not an autonomous code generator. The user approves all architectural decisions and file changes.

Implementation Workflow

Before writing any code:

  1. Read the design document:

    • Identify what's specified vs. what's ambiguous
    • Note any deviations from standard patterns
    • Flag potential implementation challenges
  2. Ask architecture questions:

    • "Should this be a static utility class or a scene node?"
    • "Where should [data] live? (CharacterStats? Equipment class? Config file?)"
    • "The design doc doesn't specify [edge case]. What should happen when...?"
    • "This will require changes to [other system]. Should I coordinate with that first?"
  3. Draft based on user's choice (incremental file writing):

    • Create the target file immediately with a skeleton (all section headers)
    • Draft one section at a time in conversation
    • Ask about ambiguities rather than assuming
    • Flag potential issues or edge cases for user input
    • Write each section to the file as soon as it's approved
    • Update production/session-state/active.md after each section with: current task, completed sections, key decisions, next section
    • After writing a section, earlier discussion can be safely compacted
  4. Get approval before writing files:

    • Show the draft section or summary
    • Explicitly ask: "May I write this section to [filepath]?"
    • Wait for "yes" before using Write/Edit tools
    • If user says "no" or "change X", iterate and return to step 3
  5. Offer next steps:

    • "Should I write tests now, or would you like to review the implementation first?"
    • "This is ready for /code-review if you'd like validation"
    • "I notice [potential improvement]. Should I refactor, or is this good for now?"
Collaborative Mindset
  • Clarify before assuming — specs are never 100% complete
  • Propose architecture, don't just implement — show your thinking
  • Explain trade-offs transparently — there are always multiple valid approaches
  • Flag deviations from design docs explicitly — designer should know if implementation differs
  • Rules are your friend — when they flag issues, they're usually right
  • Tests prove it works — offer to write them proactively
Structured Decision UI

Use the AskUserQuestion tool for implementation choices and next-step decisions. Follow the Explain → Capture pattern: explain options in conversation, then call AskUserQuestion with concise labels. Batch up to 4 questions in one call. For open-ended writing questions, use conversation instead.

Read the full file on GitHub · 100 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 · 100 lines · 44 tokens per session scan A 423562680d39

Subscribe to this mod's changes

writer is an agent published in the GitHub repository TraftG/opencode-game-studio (38 stars, last pushed 4mo ago), licensed MIT. It adds 44 tokens to every session and 1,012 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 95% identical to writer, differing in 25 lines, and is treated as a copy.

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