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.
npx agentmods add instructions/tryghost/activitypub/agents-mdgit clone --depth 1 https://github.com/TryGhost/ActivityPubWhat 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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.01808 | $0.01808 |
| Opus 5 | $0.00904 | $0.00904 |
| Sonnet 5 | $0.00362 | $0.00362 |
| Haiku 4.5 | $0.00181 | $0.00181 |
Grade A, and why
ActivityPub AGENTS.md 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 yesterday.
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.
How it starts
The opening of the file, as written. The whole thing — 159 lines — stays where its author put it; the contents beside it link to each section on GitHub.
ActivityPub — agent guide
A multitenant ActivityPub server for Ghost, built with
Fedify, that publishes independent websites to the
Fediverse. See README.md for the human overview and /adr for the
Architecture Decision Records that own the rationale behind the patterns below.
Stack (versions in package.json / docker-compose.yml): Node + TypeScript,
Hono, Fedify, Awilix (DI), Zod, Knex + MySQL, Vitest (unit/integration),
Cucumber + Wiremock (e2e), Biome (lint/format), esbuild. Runs in Docker Compose
locally; Google Cloud Run in production.
Commands
Tests run inside a Docker container via pnpm, so extra flags passed to
pnpm do not reach the test runner — use the dedicated scripts below.
pnpm lint # Biome lint
pnpm fmt # Biome format
pnpm test:types # type check
pnpm test # everything (slow)
pnpm test:unit # unit only (fast)
pnpm test:integration # integration only (slow)
pnpm test:cucumber # e2e only (slow)
pnpm test:single 'path/to/test' # single unit/integration test (fast)
Run a single e2e test by tagging a Feature or Scenario with @only, then
pnpm test:cucumber @only.
pnpm dev # start app (also runs pending migrations)
pnpm logs # tail app logs (pnpm dev && pnpm logs to do both)
pnpm stop # stop app + service deps
pnpm wipe-db # wipe the database
pnpm fix # attempt to repair a broken local environment
Local services: nginx :80→:8080, MySQL :3307 (user ghost / pass
password / db activitypub), Pub/Sub emulator :8085, GCS emulator :4443.
Expose port 80 to the internet with tailscale funnel 80.
Migrations
pnpm migration 'name-of-migration' # create (no spaces in the name)
pnpm migrate # apply pending migrations
Migrations also run automatically on pnpm dev. Rollback is unsupported —
migrations are forward-only, so treat applied migrations as immutable.
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.
- yesterday First seen · 159 lines · 1,808 tokens per session scan A df8b9de5479a
ActivityPub AGENTS.md is an instructions file published in the GitHub repository TryGhost/ActivityPub (237 stars, last pushed 3d ago), licensed MIT. It adds 1,808 tokens to every session, about $0.0090 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.
Other instructions, from other repositories
mastodon-mcp AGENTS.md
AGENTS.md instructions for sandraschi/mastodon-mcp, covering mastodon-mcp — agent guide, standards, key files and quick ref.
mastodon-mcp CLAUDE.md
Claude Code instructions for sandraschi/mastodon-mcp, covering mastodon-mcp — claude / agent context, do, don't and commands.
contraponto AGENTS.md
AGENTS.md instructions for vepo/contraponto, covering agent instructions (contraponto), agents vs commands, rules — four pillars (always on), file-scoped rules (selected) and project agents.
contraponto CLAUDE.md
Claude Code instructions for vepo/contraponto, covering claude.md, start here, stack, commands and gotchas.
Ghost AGENTS.md
AGENTS.md instructions for TryGhost/Ghost, covering agents.md, required workflow, repository skills and task routing and important warnings.
Ghost CLAUDE.md
Claude Code instructions for TryGhost/Ghost, a project described as: Independent technology for modern publishing, memberships, subscriptions and newsletters.