Breaking change: defineDoc and defineDocFamily now require an explicit checkpointWhen predicate; no default is supplied. Set policies on built-in documents, examples, tests, and triage state, and document the required API.
- pi-ai: AI_TELEMETRY_SCHEMA; pi.ai.request and pi.ai.poll spans around Models requests via a lazyStream observer
(no provider changes), first_chunk and block events (never per delta), usage/cost end attributes, provider_error
status with a bounded message, aborted stays ok; duration, first-chunk, token and cost metrics; option renamed
telemetryContext -> telemetry (a parent span)
- pi-telemetry: TelemetryContext carries readonly metrics and propagation capabilities on every span
- chord/context: Context.telemetry is always a TelemetrySpan (NOOP default); withTelemetry takes spans
- durable: DURABLE_TELEMETRY_SCHEMA; pi.durable.submit (inputs start their own trace linked to the caller) and
pi.durable.phase spans for every task phase; stored carriers on submissions and tasks (TaskOptions.trace, links);
entry, submission, checkpoint, replay and report events after commit; resumed tasks stay in their trace; phase
duration, active task and report metrics; failed phases carry fixed categories with bounded messages
onReport info is tagged by type (session_failed, task_faulted, task_parked,
migration_failed, task_outdated, task_error, extension_error, host_error,
listener_error). Task reports carry a ReportTask; restart-limit and outdated
definition reasons are typed fields instead of error.cause strings; host_error
names the failing HarnessOptions callback.
- Close reads the records it writes back on the line, after admitted commits, so a queued abort mark survives.
- A task's report names the extension that installed the definition it ran, captured at reservation.
- Terminal and completing records drop the restart count; retryTask() ignores them.
- wake() counts a reconcile pass only when it has work, so a run's end sends no extra active wake.
- A failed agent resolution no longer breaks the tool result path that names a tool's extension.
- Spec §10.1 list, changelog sections, test cleanup of killed storages.
- A close writes the tasks it stopped back as pending, so only a crash counts a restart.
- An abort mark starts the count over; an abort handler cut off restartLimit times ends the task faulted.
- Only a changed state resets the count; raised and lowered limits reach the scheduler and the graph.
- wake() stays active while a reconcile pass is scheduled or underway; failed migrations recompute it.
- Reports name the extension whose code failed (hooks, wrappers, sections, tools, a task's installer),
runtime.report() takes a source, and the parked report carries blocked: restart_limit.
- The task graph keeps only what blocked reasons read, and shows abandoned tasks waiting for a definition.
- Open counts restarts per task; at settings.restartLimit (default 5) a task is parked as blocked
(restart_limit) until Harness.retryTask().
- onReport(error, info) with ReportInfo: session, task (faulted), extension, listener, host, timer, wake.
Task faults are reported.
- settings.afterFailedRun: keep, continue, or withdraw the inputs queued behind a failed run.
- TaskGraphNode.blocked follows registry changes and failed migrations.
- README: fallback alarm before Harness.open in the Durable Object example.
The README example and the test worker arm the recovery alarm before resume() in the constructor and in
alarm(). Timers should not fire early, and callers recheck; nativeTimer no longer needs a non-null assertion.
Due sleeps are picked up at every scheduling pass, so a pass that drops the timer cannot strand them.
Code mode drops a global's result after the script finished instead of reading an ended invocation's clock.
A foreground timer the host declines falls back to setTimeout; the default timer never fires early; Progress
rechecks its clock; an undelivered onWake is offered again. Spec, README, and tests follow.
Runs the storage conformance suite, the schema migration, an alarm-woken sleep across an eviction, and a
turn recovered through the recovery alarm in workerd via @cloudflare/vitest-plugin (npm run test:workers).
fix(durable): decline background timers in Cloudflare Workers. With nodejs_compat, timers have an unref(),
so the idle-memory timers were armed and a pending one kept a Durable Object from hibernating or being evicted.
Tasks end a phase asleep with runtime.sleepUntil() or { status: "sleeping", until, checkpoint }:
no invocation is held, the deadline survives restarts, and the task resumes at its checkpoint once due.
Generation retry/poll and compaction retry sleep this way. Harness.wake() and HarnessOptions.onWake let
a host such as a Durable Object wake the process itself. HarnessOptions.setTimer arms every Harness
timer, and chord Progress paces on an injectable clock. SQLite migrates to schema version 2 to admit
the sleeping status.
Like env, models and settings may be a function returning the current value.
Generation, compaction, hooks and tools read it at each use (api.models at each
access), so a host can replace its model configuration without reopening the
Harness. A plain object still works.
OutputBuffer, Progress, boundOutput, sanitizeOutput, characterEnd and the
output types move from Durable's internal harness/output.ts to the new
Chord subpath, with OutputSkip (the shape of Durable's ShellOutputSkip) and
utf8ByteLength. Durable imports them from Chord; its truncate.ts re-exports
Chord's utf8ByteLength instead of keeping a second copy.
Context derivation moved a system message to the front only when user messages
alone preceded it. After a compaction that keeps an assistant message, the
baseline written for the next run followed the kept history and the new input,
so Anthropic and OpenAI Codex requests had no initial prompt or tool set.
Derivation now identifies the harness baseline: the first pi.system entry after
the head marker, or of the transcript when no earlier entry carries a system
message, even one omitted later. Its message leads even past assistant
messages. Only the first system message ever moves, so replay is unchanged;
other system messages after an assistant message stay in place.
closes#10904
toBase64 grew each 8 KiB chunk a character at a time; V8 kept every
concatenation node until the final join, about 138 MB of heap for a
3 MiB image, beyond a Durable Object's 128 MB limit.
closes#10923
An environment may list the files, directories and symbolic links below a
directory: relative / paths, depth first in name order, without .git and
what git ignores in work trees, bounded with a truncated flag. Callers fall
back to their own walk when it is missing or fails with not_supported.
The env conformance suite checks it with the new listFiles option.
A wait is rejected when it closes a cycle in the wait-for graph: waits of
tasks that are not abort-marked, and holds of live ordinary owned work. The
rejection names the cycle. Replaces the owner-chain rule, so a background task
may wait on its conversation's owner. Approach and tests from #10533 by
@odysseus0.
fixes#10411
- ToolRegistration.deferred: not offered to the model until modelTools names it
- modelTools gains { remove?, add? }; control.addTools writes names to add, so
loaded tools follow the others in load order and a load only appends
- Agent.deferred lists deferred tools not loaded yet
- @earendil-works/pi-durable/tool-search: the coding agent's tool_search (BM25)
- the codemode section leaves deferred tools out
joinAdjacentText checked endsWith on the growing joined string, which
makes V8 flatten the concatenation on every item. Collect each text run
in an array, check the separator against the last non-empty part, and
join once. Same fix in the durable code mode copy.
closes#10678
pi-codemode no longer exports MCP_TYPESCRIPT_PREAMBLE or mcpStructuredContentSchema(); output schemas render as their own types, as in the coding agent.
- structuredOutput is always the tool's own value; a schema tool's error text
without one becomes a tool_error diagnostic on nested results
- code mode: a schema tool's error result with its value resolves (bash nonzero
exit), schema-less tools resolve with their text, as in the coding agent
- codemode prompt section with tool declarations by namespace within an inline
budget; searchTools/describeTool/describeNamespace from the start data
- result layout of the coding agent: header, text markers, console block,
truncation within max_output_tokens and the tool's output limits, spill and
image files in a recorded output directory (a rerun overwrites them)
- models.*: catalog globals; classify/generateImages as hidden internal tools
(nested calls with usage), at most four at once
- Lark grammar of the script source as constrainedSampling
A host that closes its CodemodeSandbox before the Harness, as on a graceful
shutdown, made the running code mode call store "Script error (aborted):
Sandbox closed" as its result, so the script never resumed. A run the sandbox
aborts without the call asking for it now stores nothing and ends with the
call's invocation; the next process replays the script.
details.calls (CodemodeToolDetails): each tool call the script made, in call
order, with status ok/error/cancelled, duration, and cut arguments and error;
calls still running or not yet launched when the script ended are cancelled.
Written once with the result: live progress is pi.live.nestedTools.
bench:codemode compares a code mode script with a plain tool making the same
nested calls: 1,000 parallel calls 0.82 vs 0.78 ms/call, sequential 1.52 vs
1.10 ms/call (two more commits per call: the journal entry and the count).
A codemode tool whose scripts call the conversation's tools as nested calls and
survive a restart. The script runs deterministically (pi-codemode start()); each
result is journaled before it is delivered. A rerun starts the script again from
the stored start data, delivers the journaled results in order (nested calls
reattach by key c<id>), checks every recorded call count, holds calls the
journal lacks until replay ends and checks them against earlier attempts' keys,
then continues live. A call launches only once the count of the drain that made
it is committed, so a rerun can prove which calls are new. Divergence, a changed
module version or sandbox fingerprint, and a passed deadline end the call with a
stored error; a decided outcome is returned without a VM. store()/load() keep
values per conversation, rewindable and forked as of the fork's entry.
pi-codemode: CodemodeRun.finished, set when the outcome is decided.
Programs calling a tool with structuredOutputSchema got isError and no text when
its error result omitted structuredOutput; they now get its bounded output,
collapsed like a schema-less tool's, so a code mode script sees the error text.
A thrown error's message stays in its tool_error diagnostic.
A generation waiting on a blocking threshold compaction sent its request
whatever the outcome. When summarization failed, the context was still above
the blocking threshold: a session at 996K of a 1M window got an empty length
answer on every turn and nothing showed the error. The generation now fails
with model_error (Compaction failed: <error>) when its compaction failed,
faulted, was orphaned, or was aborted directly; a compaction that found
nothing to compact or was declined still lets the request go ahead.
pi.live.compactionFailure keeps the newest failure (task, reason, error)
until a compaction produces a summary. The agent events' snapshot carries it,
and compaction_end carries error for a failed compaction.
Replayed thinking is often not part of the live context (for example,
radius drops it, and Anthropic drops blocks that do not match their
request), but serializeConversation included all of it. A Pi Mobile
session at ~996K of 1M context tokens produced 1.38M-token summarization
requests that failed on every attempt. Providers only return summaries of
the reasoning anyway; visible text, tool calls, and tool results record
what happened.
- Input submissions take entry: { kind, data } (InputEntry): placed as that
kind with that data and the content as user message, instead of pi.user.
Kinds must be non-empty strings outside pi.*. Queued inputs carry it in
their pi.inbox item.
- Writes with only kind and data (no model, head, edits) are appended and
settled done at once, busy or not; only a queued reset holds them back.
- Experimental hosts render such inputs as user messages and title by them.
closes#10407
createNodePhotonImages() now runs Photon in a worker thread, so preparing a large photo (a second or two) no longer blocks the event loop: in the test a 6-megapixel image blocked the loop over 200 ms inline and under 100 ms with the worker. The worker keeps the process alive only while it prepares an image, exits after 30 s without images to free Photon's WebAssembly memory, and a worker that cannot start falls back to the calling thread. Options: { worker: false, idleMs }.
The Session kept every document it loaded or created in memory for the life of the process: every conversation and
session document ever touched, built-in and third-party. Now a cached document that no watch or document state
observes leaves the cache once it was not read or written for `documentRetentionMs` (HarnessSettings and
createSession options; default ten minutes, 0 drops it right after use, Infinity keeps documents; anything that is not
a number of milliseconds means the default), and loads from Storage again on its next access. An observer pins the
incarnation it observes and releases it when that incarnation retires.
Eviction runs on the mutation line, after every commit outcome (published, no-write, rejected, failed settlement) and
from one unreferenced timer for the next expiry, so a transaction never loses a tracker it holds. Where timers cannot
be unreferenced only commits evict. Cache bookkeeping is contained: a throwing clock or setting never changes an
operation's outcome. A hot document moves in the eviction order at most once per granule (a tenth of the retention,
up to 1 s), keeping the fan-out bench at HEAD's speed.
`npm test` runs the durable suite a second time with every unattached document evicted right after use.
5,000 conversations kept 26,000 documents and about 3.8 KB each; with a 50 ms retention, after waiting, none
(bench:document-cache).
The scheduler kept every conversation edge it saw and, for conversation owners, chain loads, and owners of known
tasks, the ended tasks above them, for the life of the process. Now an owner edge or an ended task's ownership is kept
only while something is listed below it in #below: only the chains above live work are known, whole. Unneeded nodes
are queued and swept at the end of each publication, or by a sweep job on the Session line after operations that
publish nothing (rejected commits, reads), never during an operation, so a commit that creates work below a chain its
own callback loaded keeps it. Later work in an old conversation loads its chain from storage again.
Removes #conversationOwners, #pinned, #knownChildren, and #forget. A queued input triggers the withdrawal scan only
while some task has cancellation intent, and chains are loaded only for queued inputs.
10,000 ended subagent cycles under a live parent: 10,000 settled tasks and 10,001 edges before, 0 and 1 now
(bench:scheduler-memory); a later message into an old subagent conversation reads 7 records instead of 5.
Session, Harness, and runtime reads such as snapshot(), documentState(), watchDoc(), and getTask() may queue on the mutation line a commit callback holds; on a cache miss they never resolve. Documented on Session.commit, TaskRuntime.commit, and in the spec's pitfalls.
NestedCallsDoc (one index per caller, a key per nested call, copied on every admission) and NestedResultDoc are
replaced by NestedCallDoc (`pi.tool.nested-call`): a task-scoped family of the caller keyed by the call's key,
holding { taskId, result? }. Admission creates the member; the nested call's terminal commit adds its result;
executeTool() reads it by key. No commit rewrites another call's document.
TaskRuntime.ownedTasks(context) returns copies of the live tasks a task owns directly, whichever invocation
created them, from the scheduler's index. A tool call settling aborts the live nested calls among them, which
the removed index used to list. A task memo marks a tool that made a nested call in any attempt, so settling a
leaf still skips scanning pi.live.
8000 parallel nested calls: 9.2 s -> 2.7 s, linear (bench:scheduler-fanout).
Every reconcile pass walked up from every live task to the root to find cancelling owners, and owned live work,
idle scopes, chain loads, reservation, finalization, and failFast checks each scanned all live tasks. A chain of n
held tasks cost about n^3 steps: 500 took 12 s, 20,000 never finished.
The ownership semantics are unchanged; in-memory indexes, rebuilt at open, hold each pass's candidates:
- #below: the ownership tree downward around live work; owned live work, idle scopes, and conversation aborts walk
down from one node. Ended tasks stay while walks pass through them (conversation owners, chain loads, owners of
known tasks), so loaded chains stay loaded.
- #intent: cascades walk down from tasks with cancellation intent, not entering another such task, so the nearest
cancelling owner still decides the reason; upward checks return at once when it is empty.
- #unloaded: only tasks whose chain is not loaded are loaded, and count as inside every scope until then.
- #finalizeChecks: finalize is a worklist in rounds from the nearest live holder of ended work.
- #runnable and #waiters: reservation and failFast candidates.
No walk recurses.
Chain of 500 held tasks: 12.3 s -> 50 ms; 20,000: 1.5 s. 8000 parallel nested calls: 18.8 s -> 9.2 s
(bench:scheduler-fanout); the rest is document copying of the nested-call index.
read returns an image file as one image block (programs get an ImageContent) plus an info diagnostic,
instead of an unsupported_image error. Limits are the conversation model's inputLimits.images.resize,
by default 2000x2000 pixels and 4.5 MB of base64.
- Without a processor: PNG, JPEG, GIF, and WebP within the limits pass through undecoded; the byte limit
is checked before reading the file, dimensions from the header. Larger images and BMP are error results.
- With createCodingTools({ images }): the processor orients by EXIF, converts BMP to PNG, and shrinks to
fit. ImageProcessor.prepare is async.
- @earendil-works/pi-durable/images: createPhotonImages(wasm) on @silvia-odwyer/photon 0.3.3 (web build);
/images/node and /images/cloudflare load the wasm. The root and ./tools entries never reach it (enforced
in check-entry-graphs).
- An image must be read whole: one that changes while read is read again, unlike a growing text file.
- A model without image input gets a diagnostic that it sees a placeholder.
Nested tool calls: ToolExecutionApi.executeTool() runs another tool as its own pi.tool task owned by the caller,
keyed for replay-safe reattachment. Results for programs live in the caller's NestedResultDoc until it settles;
pi.live.nestedTools shows each call with the arguments it runs with and a summary. TaskOptions.abandonOnRestart
aborts work its creator awaited only in memory before it runs again after a restart.
Structured output: structuredOutputSchema and structuredOutput, validated; a tool without a schema gives programs its
bounded output (one text as a string, one image as itself, else the list). ToolExecutionResult.content is now output.
callers and modelTools decide who may call a tool.
Storage errors: any error a Storage method throws fails the Session, which closes itself; later calls and waits reject
with SessionFailed, watches end with session_failed, and Session.closed settles. Nothing retries in the Harness.
StorageRejected is removed; StorageRequestError marks invalid reads that fail only their call. Listener and onReport
errors are contained and reported.
Also updates scripts/issues/triage.ts and the vacation experiment for the content -> output rename.
The idle check reads settings.contextRetentionMs from commit listeners,
reconciliation, and the expiry timer. A throwing settings getter escaped as an
unhandled rejection; it is now reported and the kept contexts are dropped.
runtime.context() keeps each conversation's last read range and derived
view. A later read by any of the conversation's tasks with the same head
marker scans and derives only the entries committed since, so a
generation no longer rereads and re-derives the whole transcript for
each model request. Busy conversations keep the range; idle ones for
settings.contextRetentionMs (default ten minutes), checked on task
changes and by one unreferenced timer where the runtime supports it.
Kept entries are frozen; each read returns its own view arrays.
Add openDurableObjectSqliteStorage(ctx.storage) in
@earendil-works/pi-durable/storage/sqlite/cloudflare: SQLite storage on
a SQLite-backed Cloudflare Durable Object, without per-row copies.
A run's input is committed before the system prompt is rendered, so requests
started with the user message. Anthropic then sent the tool list at the top of
every request and each tool change invalidated the whole prompt cache. Context
derivation now moves a system message preceded only by user messages to the
front. A live e2e test gates the cache reuse across a tool change.
closes#10542
pi-ai's AssistantMessageEventStream sets AssistantMessage.durationMs with a
monotonic clock for every API implementation. The agent loop and the durable
tool task set ToolResultMessage.durationMs around execute(). Durable task
records carry startedAt/endedAt stamped by the Session. The coding agent's bash
renderer shows Took from the recorded duration, also after a reload.
closes#10549
