pip install ipython 'cooksafe>=0.2.0,<0.3.0'

import os
import re
import urllib.request
from pathlib import Path
from time import perf_counter

from cooksafe import JsonCache, make_playground_link
from IPython.display import Markdown, display
from typesafe_sdk import Choice, Noul, NoulCriteria, TypeSafeClient

TYPESAFE_MODEL = "jev-1.12"
PRICE = (0.042, 0.00)  # $ per 1M tokens (input, output); TypeSafe jev-1.12 as of 2026-09
client = TypeSafeClient(api_key=os.environ["TYPESAFE_API_KEY"], timeout=120.0)
json_cache = JsonCache(Path("json_cache.json"))

GIST = (
    "https://gist.githubusercontent.com/eugene-shvarts/6df7daf97233bf92bcdd6b386a0fa561"
    "/raw/5da03690611fb6ddcbaabdb91fb9f91d9751b113/build-memo.txt"
)


@json_cache
def fetch_document(url: str) -> str:
    request = urllib.request.Request(url, headers={"User-Agent": "typesafe-cookbook/1.0"})
    with urllib.request.urlopen(request) as response:
        return response.read().decode()


RAW = fetch_document(GIST)
print(RAW[:560])

Migration to the new build system

Hi everyone, quick heads up about the build system migration that is
happening next week. We have been running the new pipeline in shadow
mode for three weeks and the results look solid, so it is time to
make the switch for real.

What changes for you

The old make targets keep working until the end of the month. The new
entrypoint is a single command that wraps everything, including the
docs build that used to be separate.

bun run build

Generated artifacts no longer need to be committed. The new pipeline
uploads them

def to_lines(text: str) -> list[dict]:
    lines, gap = [], False
    for raw in text.split("\n"):
        stripped = re.sub(r"[\t ]+", " ", raw).strip()
        if not stripped:
            gap = bool(lines)  # a leading blank is not a break
            continue
        lines.append({"text": stripped, "gap": gap})
        gap = False
    return lines


def tag(items: list[dict], prefix: str) -> str:
    return "\n".join(
        f"{chr(10) if item['gap'] else ''}{prefix}{i:03d}| {item['text']}"
        for i, item in enumerate(items)
    )


def line_id(i: int) -> str:
    return f"L{i:03d}"


def block_id(i: int) -> str:
    return f"B{i:03d}"


LINES = to_lines(RAW)
print(f"{len(LINES)} non-blank lines. The model sees, e.g.:")
print("\n".join(tag(LINES, "L").splitlines()[19:24]))

28 non-blank lines. The model sees, e.g.:
L013| The cutover touches three teams, so check whether you are on this
L014| list before you plan anything for Monday:
L015| The platform team
L016| The web client team
L017| Whoever still owns the release tooling

def join_question(i: int) -> Noul:
    return Noul(
        instructions=f"Does line {line_id(i)} pick up mid-sentence, continuing a sentence left unfinished at the end of line {line_id(i - 1)}?",
        criteria=NoulCriteria(
            true="The line starts in the middle of a sentence that began on the previous line - the line break tore the sentence apart",
            false="The line begins a new sentence, item, heading, or thought of its own",
        ),
    )


@json_cache
def stitch(wording: str = "mid-sentence") -> dict:
    make = join_question if wording == "mid-sentence" else naive_join_question
    questions = {line_id(i): make(i) for i in range(1, len(LINES)) if not LINES[i]["gap"]}
    started = perf_counter()
    response = client.system_one(
        state=tag(LINES, "L"), questions=questions, model=TYPESAFE_MODEL
    )
    return {
        "joins": [
            response.answers[line_id(i)].noul if line_id(i) in response.answers else 0.0
            for i in range(len(LINES))
        ],
        "seconds": round(perf_counter() - started, 2),
        "usage": [response.usage.input_tokens, response.usage.output_tokens],
    }


result = stitch()
print(f"{sum(1 for l in LINES if not l['gap']) - 1} pair questions, one request, "
      f"{result['seconds']}s")

16 pair questions, one request, 0.32s

JOIN_AFTER_DANGLING, JOIN_AFTER_TERMINAL = 0.2, 0.5


def ends_terminal(text: str) -> bool:
    return re.search(r'[.!?:;…]["\')\]]*$', text) is not None


def merge(joins: list[float]) -> list[dict]:
    blocks = []
    for i, line in enumerate(LINES):
        bar = (
            JOIN_AFTER_TERMINAL
            if i and ends_terminal(LINES[i - 1]["text"])
            else JOIN_AFTER_DANGLING
        )
        if blocks and not line["gap"] and joins[i] >= bar:
            blocks[-1]["text"] += " " + line["text"]
            blocks[-1]["lines"].append(i)
        else:
            blocks.append({"text": line["text"], "lines": [i], "gap": line["gap"]})
    return blocks


blocks = merge(result["joins"])
healed = len(LINES) - len(blocks)
print(f"{len(LINES)} lines -> {len(blocks)} blocks ({healed} line breaks healed)")
for i, block in enumerate(blocks):
    n = len(block["lines"])
    print(f"{block_id(i)}  {n} line{'s' if n > 1 else ' '}  {block['text'][:62]}")

28 lines -> 17 blocks (11 line breaks healed)
B000  1 line   Migration to the new build system
B001  4 lines  Hi everyone, quick heads up about the build system migration t
B002  1 line   What changes for you
B003  3 lines  The old make targets keep working until the end of the month. 
B004  1 line   bun run build
B005  3 lines  Generated artifacts no longer need to be committed. The new pi
B006  2 lines  The cutover touches three teams, so check whether you are on t
B007  1 line   The platform team
B008  1 line   The web client team
B009  1 line   Whoever still owns the release tooling
B010  1 line   Things to do before Monday
B011  1 line   Update your local toolchain to version 2.4 or later
B012  1 line   Delete the old build cache directory
B013  1 line   Run the doctor script and fix anything it flags
B014  3 lines  If the doctor script reports a red result on the toolchain che
B015  2 lines  As Dana put it in the kickoff, "a migration nobody notices is 
B016  1 line   Thanks, and shout if anything looks off.

TYPE_CRITERIA = {
    "heading": "A short label or title that names the document or the section that follows it - not a full sentence of content",
    "paragraph": "Running prose: one or more complete sentences of explanatory or narrative text",
    "list_item": "One entry in a list of parallel items - an ingredient, a feature, a task, an attendee; reads as one of several sibling entries",
    "quote": "Words attributed to a person or source - quoted speech, a citation, an excerpt someone else wrote",
    "code": "Computer code, a shell command, terminal output, or a config snippet meant to be read verbatim",
    "callout": "A warning, tip, or important note that interrupts the flow to flag something the reader must not miss",
}
HLEVEL_CRITERIA = {
    "title": "The title of the whole document",
    "section": "A major section heading within the document",
    "subsection": "A minor heading nested under a section",
}
CALLOUT_CRITERIA = {
    "note": "Neutral extra information the reader should be aware of",
    "tip": "A helpful suggestion or shortcut that makes things easier",
    "warning": "A caution about something that can go wrong or cause harm",
}

HEADING_MAX_CHARS = 90  # longer blocks can't render as headings, so don't ask


def classify_questions(texts: list[str]) -> dict:
    questions = {}
    for i, text in enumerate(texts):
        bid = block_id(i)
        questions[f"type_{bid}"] = Choice(
            instructions=f"What kind of content is block {bid}?", criteria=TYPE_CRITERIA
        )
        if len(text) <= HEADING_MAX_CHARS:
            questions[f"hlevel_{bid}"] = Choice(
                instructions=f"As a heading, what level would block {bid} occupy in this document's structure?",
                criteria=HLEVEL_CRITERIA,
            )
        questions[f"step_{bid}"] = Noul(
            instructions=f"Is block {bid} an instruction in a sequence where the order of the items matters?",
            criteria=NoulCriteria(
                true="It is one step of a procedure - the items around it must happen in order",
                false="Order is irrelevant - it is a loose collection, or not a list item at all",
            ),
        )
        questions[f"callout_{bid}"] = Choice(
            instructions=f"What kind of aside is block {bid}?", criteria=CALLOUT_CRITERIA
        )
    return questions


@json_cache
def classify(texts: list[str], gaps: list[bool]) -> dict:
    tagged = tag([{"text": t, "gap": g} for t, g in zip(texts, gaps)], "B")
    questions = classify_questions(texts)
    started = perf_counter()
    response = client.system_one(state=tagged, questions=questions, model=TYPESAFE_MODEL)
    judgments = []
    for i in range(len(texts)):
        bid = block_id(i)
        type_answer = response.answers[f"type_{bid}"]
        hlevel = response.answers.get(f"hlevel_{bid}")
        judgments.append(
            {
                "type": type_answer.choice,
                "confidence": type_answer.confidence,
                "probabilities": type_answer.probabilities,
                "hlevel": hlevel.choice if hlevel else "section",
                "step": response.answers[f"step_{bid}"].noul,
                "callout": response.answers[f"callout_{bid}"].choice,
            }
        )
    return {
        "judgments": judgments,
        "n_questions": len(questions),
        "seconds": round(perf_counter() - started, 2),
        "usage": [response.usage.input_tokens, response.usage.output_tokens],
    }


classified = classify([b["text"] for b in blocks], [b["gap"] for b in blocks])
for block, judgment in zip(blocks, classified["judgments"]):
    block.update(judgment)
print(f"{classified['n_questions']} questions about {len(blocks)} blocks, one request, "
      f"{classified['seconds']}s\n")
print(f"{'block':<6}{'type':<11}{'conf':<6}{'companion used':<18}text")
for i, b in enumerate(blocks):
    companion = {
        "heading": f"level={b['hlevel']}",
        "list_item": f"step={b['step']:.2f}",
        "callout": f"kind={b['callout']}",
    }.get(b["type"], "-")
    print(f"{block_id(i):<6}{b['type']:<11}{b['confidence']:.2f}  {companion:<18}"
          f"{b['text'][:46]}")

62 questions about 17 blocks, one request, 0.51s

block type       conf  companion used    text
B000  heading    0.99  level=title       Migration to the new build system
B001  paragraph  0.98  -                 Hi everyone, quick heads up about the build sy
B002  heading    0.75  level=section     What changes for you
B003  paragraph  0.89  -                 The old make targets keep working until the en
B004  code       1.00  -                 bun run build
B005  paragraph  0.90  -                 Generated artifacts no longer need to be commi
B006  paragraph  0.43  -                 The cutover touches three teams, so check whet
B007  list_item  0.99  step=0.15         The platform team
B008  list_item  1.00  step=0.16         The web client team
B009  list_item  0.99  step=0.12         Whoever still owns the release tooling
B010  heading    0.96  level=section     Things to do before Monday
B011  list_item  0.98  step=0.86         Update your local toolchain to version 2.4 or 
B012  list_item  0.99  step=0.87         Delete the old build cache directory
B013  list_item  0.92  step=0.90         Run the doctor script and fix anything it flag
B014  callout    0.65  kind=warning      If the doctor script reports a red result on t
B015  quote      0.99  -                 As Dana put it in the kickoff, "a migration no
B016  paragraph  0.92  -                 Thanks, and shout if anything looks off.

STEP_THRESHOLD = 0.5
HEADING_MARK = {"title": "#", "section": "##", "subsection": "###"}
CALLOUT_MARK = {"note": "NOTE", "tip": "TIP", "warning": "WARNING"}


def to_markdown(blocks: list[dict]) -> str:
    groups = []
    for b in blocks:
        if b["type"] in ("list_item", "code") and groups and groups[-1][0] == b["type"]:
            groups[-1][1].append(b)
        else:
            groups.append((b["type"], [b]))
    parts = []
    for kind, items in groups:
        if kind == "list_item":
            ordered = sum(b["step"] for b in items) / len(items) >= STEP_THRESHOLD
            parts.append("\n".join(
                f"{n + 1}. {b['text']}" if ordered else f"- {b['text']}"
                for n, b in enumerate(items)
            ))
        elif kind == "code":
            parts.append("```\n" + "\n".join(b["text"] for b in items) + "\n```")
        elif kind == "heading":
            parts.append(f"{HEADING_MARK[items[0]['hlevel']]} {items[0]['text']}")
        elif kind == "quote":
            parts.append(f"> {items[0]['text']}")
        elif kind == "callout":
            parts.append(f"> [!{CALLOUT_MARK[items[0]['callout']]}]\n> {items[0]['text']}")
        else:
            parts.append(items[0]["text"])
    return "\n\n".join(parts) + "\n"


markdown = to_markdown(blocks)
print(markdown)

# Migration to the new build system

Hi everyone, quick heads up about the build system migration that is happening next week. We have been running the new pipeline in shadow mode for three weeks and the results look solid, so it is time to make the switch for real.

## What changes for you

The old make targets keep working until the end of the month. The new entrypoint is a single command that wraps everything, including the docs build that used to be separate.

```
bun run build
```

Generated artifacts no longer need to be committed. The new pipeline uploads them to the registry automatically, and checking them in just creates merge conflicts.

The cutover touches three teams, so check whether you are on this list before you plan anything for Monday:

- The platform team
- The web client team
- Whoever still owns the release tooling

## Things to do before Monday

1. Update your local toolchain to version 2.4 or later
2. Delete the old build cache directory
3. Run the doctor script and fix anything it flags

> [!WARNING]
> If the doctor script reports a red result on the toolchain check, do not proceed with the migration. Ping the infra channel first and we will sort it out together.

> As Dana put it in the kickoff, "a migration nobody notices is the only kind worth shipping."

Thanks, and shout if anything looks off.

playground_link = make_playground_link(
    tag(blocks, "B"),
    classify_questions([b["text"] for b in blocks]),
    models=[TYPESAFE_MODEL],
)
display(Markdown(f"🔗 [Open the stitched memo + questions in the TypeSafe playground]({playground_link})"))

tokens = [result["usage"], classified["usage"]]
total_in, total_out = sum(t[0] for t in tokens), sum(t[1] for t in tokens)
cost = total_in / 1e6 * PRICE[0] + total_out / 1e6 * PRICE[1]
n_joins = sum(1 for l in LINES if not l["gap"]) - 1
print(f"pass 1  {n_joins} questions  {result['seconds']}s")
print(f"pass 2  {classified['n_questions']} questions  {classified['seconds']}s")
print(f"total   {total_in + total_out:,} tokens  "
      f"{result['seconds'] + classified['seconds']:.1f}s  ${cost:.4f}")

pass 1  16 questions  0.32s
pass 2  62 questions  0.51s
total   10,211 tokens  0.8s  $0.0003

print("join  line")
for i, line in enumerate(LINES[:18]):
    join = "    " if i == 0 or line["gap"] else f"{result['joins'][i]:.2f}"
    print(f"{join}  {line_id(i)}| {line['text'][:66]}")

join  line
      L000| Migration to the new build system
      L001| Hi everyone, quick heads up about the build system migration that 
0.77  L002| happening next week. We have been running the new pipeline in shad
0.62  L003| mode for three weeks and the results look solid, so it is time to
0.39  L004| make the switch for real.
      L005| What changes for you
      L006| The old make targets keep working until the end of the month. The 
0.42  L007| entrypoint is a single command that wraps everything, including th
0.59  L008| docs build that used to be separate.
      L009| bun run build
      L010| Generated artifacts no longer need to be committed. The new pipeli
0.48  L011| uploads them to the registry automatically, and checking them in
0.40  L012| just creates merge conflicts.
      L013| The cutover touches three teams, so check whether you are on this
0.50  L014| list before you plan anything for Monday:
0.22  L015| The platform team
0.11  L016| The web client team
0.12  L017| Whoever still owns the release tooling

def naive_join_question(i: int) -> Noul:
    return Noul(
        instructions=f"Are lines {line_id(i - 1)} and {line_id(i)} part of the same paragraph?",
        criteria=NoulCriteria(
            true="The two lines belong to the same paragraph of running text",
            false="The two lines belong to different paragraphs or different pieces of content",
        ),
    )


naive = stitch("same-paragraph")
print(f"{'':14}{'mid-sentence':>13}{'same paragraph':>16}")
for i in (15, 16, 17, 20, 21):
    print(f"{line_id(i)}{'':2}{LINES[i]['text'][:36]:<38}"
          f"{result['joins'][i]:>7.2f}{naive['joins'][i]:>13.2f}")
print(f"\nblocks after merge: {len(blocks)} (mid-sentence) vs "
      f"{len(merge(naive['joins']))} (same paragraph)")

               mid-sentence  same paragraph
L015  The platform team                        0.22         0.77
L016  The web client team                      0.11         0.81
L017  Whoever still owns the release tooli     0.12         0.78
L020  Delete the old build cache directory     0.08         0.88
L021  Run the doctor script and fix anythi     0.05         0.91

blocks after merge: 17 (mid-sentence) vs 12 (same paragraph)

uncertain = min(blocks, key=lambda b: b["confidence"])
print(f'"{uncertain["text"]}"')
print(f"confidence {uncertain['confidence']:.2f}: ", end="")
print(", ".join(f"{k} {v:.2f}" for k, v in
                sorted(uncertain["probabilities"].items(), key=lambda kv: -kv[1])[:3]))

"The cutover touches three teams, so check whether you are on this list before you plan anything for Monday:"
confidence 0.43: paragraph 0.53, list_item 0.24, callout 0.19