How these plans were built
Every plan in the demo was built by a cold coding agent in a clean Docker container — handed nothing but the prompt below. No other instructions, no hand-holding, no editing of the agent's work — the transcripts are verbatim (the only touch is cosmetic: we standardized the project names). The agent read our public guide, cloned the product's open-source repo, and built & shared the plan entirely through the API.
The only setup was a scoped API key in an env var ($PB_API_KEY). The prompt tells the agent to use it and to stop rather than go hunting for credentials — the container has nothing else to find. That's the whole harness.
Full transcripts of all three runs are linked below — the actual step-by-step of each agent, single-agent, one clean run each. The prompt is the proof: drop it into a fresh container with a key and you'll get a comparable plan.
Ghost · github.com/TryGhost/Ghost
Your ProductBrain API key is in $PB_API_KEY and the base URL in $PB_API_URL.
Use them via those env vars; never print, echo, or hard-code the key. If
$PB_API_KEY is NOT set, STOP and tell me — do NOT search the filesystem, env
files, or credential stores for credentials.
1. Read the guide at https://productbrain.com/docs/llm-guide.md — it is the
full contract for reading and writing a ProductBrain plan.
2. Clone https://github.com/TryGhost/Ghost (a shallow clone is fine) and study
it enough to understand what the product does and what the team is actually
building and shipping.
3. Create a project named "Ghost" and build a ProductBrain plan for it through
the API. Build the plan the product genuinely warrants — don't hold back to
keep it small, and don't pad it to look thorough.
4. When the plan is in, mint a share link (POST /share) and give me the URL as
the deliverable.
Result: the Ghost plan. Full transcript →
Plausible · github.com/plausible/analytics
Your ProductBrain API key is in $PB_API_KEY and the base URL in $PB_API_URL.
Use them via those env vars; never print, echo, or hard-code the key. If
$PB_API_KEY is NOT set, STOP and tell me — do NOT search the filesystem, env
files, or credential stores for credentials.
1. Read the guide at https://productbrain.com/docs/llm-guide.md — it is the
full contract for reading and writing a ProductBrain plan.
2. Clone https://github.com/plausible/analytics (a shallow clone is fine) and
study it enough to understand what the product does and what the team is
actually building and shipping.
3. Create a project named "Plausible" and build a ProductBrain plan for it
through the API. Build the plan the product genuinely warrants — don't hold
back to keep it small, and don't pad it to look thorough.
4. When the plan is in, mint a share link (POST /share) and give me the URL as
the deliverable.
Result: the Plausible plan. Full transcript →
Immich · github.com/immich-app/immich
Your ProductBrain API key is in $PB_API_KEY and the base URL in $PB_API_URL.
Use them via those env vars; never print, echo, or hard-code the key. If
$PB_API_KEY is NOT set, STOP and tell me — do NOT search the filesystem, env
files, or credential stores for credentials.
1. Read the guide at https://productbrain.com/docs/llm-guide.md — it is the
full contract for reading and writing a ProductBrain plan.
2. Clone https://github.com/immich-app/immich (a shallow clone is fine) and
study it enough to understand what the product does and what the team is
actually building and shipping.
3. Create a project named "Immich" and build a ProductBrain plan for it through
the API. Build the plan the product genuinely warrants — don't hold back to
keep it small, and don't pad it to look thorough.
4. When the plan is in, mint a share link (POST /share) and give me the URL as
the deliverable.
Result: the Immich plan. Full transcript →