agentfootprint
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The explainable agent framework — backtrack a wrong answer to the exact context that caused it (evidence, not guesses). Built on footprintjs.
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TypeScript
/**
* conversation — the refusals that guard a runner's per-instance state.
*
* Pattern: teaching refusal at a boundary (the shape `runInput` uses for a
* caller's message, applied to a caller's TIMING).
* Role: core/ layer. An `Agent` keeps the last run's executor, run context,
* answer and pause on ITSELF — that is what makes `checkpoint()`,
* `getLastSnapshot()` and `followUp()` possible at all. Those fields
* have exactly one owner at a time, and until 9.2.0 nothing said so.
* Emits: N/A — these fire before a run starts.
*
* ## Why these are refusals and not warnings
*
* Both shapes below used to SUCCEED, which is the entire problem. Two `run()`
* calls overlapping on one Agent both resolved with plausible answers, and the
* per-instance state afterwards belonged to whichever finished last: the
* conversation `checkpoint()` handed back was the other run's, the snapshot
* `getLastSnapshot()` served was the other run's, and every event carried the
* other run's meta. That is not concurrency, it is corruption — and nothing in
* the recording said so, because each run's own trace looked perfect.
*
* A message sent while a person still owes the agent an answer used to start a
* fresh run and silently abandon the pending question. A consent gate that can
* be walked around by sending another message is not a consent gate.
*
* Neither refusal is new policy. `standingAgent` has refused both since it
* existed (it serializes runs globally and calls that "a correctness
* requirement rather than a tuning choice", and answers a message that arrives
* mid-question with `AwaitingDecisionError`), and `recordedChat.send` refuses
* an overlapping turn in the same words. 9.2.0 moves the guarantee from the
* compositions down to the primitive, so it holds however you drive it.
*
* The names are deliberately NOT the hosting ones. `hosting/errors.ts` already
* owns `ConcurrentRunError` and `AwaitingDecisionError`, both of which carry a
* `sessionId` and speak about a session; core has no sessions, and two classes
* sharing one name across two doors is the duplicate-type hazard this codebase
* has fixed before.
*/
/**
* Thrown when `run()` / `resume()` is called on a runner that is already
* running.
*
* One instance answers one turn at a time. To run two turns at once, build two
* agents — a chart is built once per instance and instances are cheap — or put
* the turns behind `standingAgent({ onConcurrentInvoke: 'enqueue' })`, which
* queues them.
*
* @example
* ```ts
* // Refused: both would write the same instance's last-run state.
* await Promise.all([agent.run({ message: 'a' }), agent.run({ message: 'b' })]);
*
* // Fine: two instances, two sets of state.
* await Promise.all([agentA.run({ message: 'a' }), agentB.run({ message: 'b' })]);
* ```
*/
export declare class RunInFlightError extends Error {
readonly code: "ERR_RUN_IN_FLIGHT";
/** The runner that is busy, by its configured id. */
readonly agentId: string;
/** The run already in flight, so a log line can be joined to its trace. */
readonly activeRunId: string;
constructor(door: string, agentId: string, activeRunId: string);
}
/**
* Thrown when a new message is sent to an agent whose last run PAUSED to ask a
* person something, and that question has not been answered.
*
* The pause is not a failure and not a stale flag — it is unfinished work with
* a person on the other end. Answer it with `resume(checkpoint, decision)`, or
* say plainly that it is being dropped with `abandonPause()`; both are visible
* in the record, and silently starting a fresh run was not.
*/
export declare class PendingQuestionError extends Error {
readonly code: "ERR_PENDING_QUESTION";
/** The tool that asked, when the pause named one. */
readonly toolName?: string;
/** The id of the tool call that asked, for joining back to the trace. */
readonly toolCallId?: string;
constructor(door: string, pending: {
toolName?: string;
toolCallId?: string;
question?: string;
});
}
/**
* Thrown by `resume(checkpoint, input, options)` when the run would carry two
* identities — refused before anything runs:
* - `options.identity` names an identity other than the one the run's memory
* namespace and credentials are restored with (`scope.runIdentity`, whatever
* its source) — including an OWNERLESS pause (the per-run default or the
* session rung) resumed by a named person;
* - the checkpoint's own fields disagree (a session-rung marker on an
* identity that carries a person).
*
* The ownerless case is the fail-closed reading of an open owner question; a
* later release may relax it behind an explicit opt-in, never by default.
*
* One run never carries two identities. The resumed run keeps the paused run's
* memory namespace and credential identity (`scope.runIdentity`, restored from
* the checkpoint — a resume never re-seeds), so honouring a different caller
* would give the run one person's memory and vault and another person's
* `ctx.identity`, `EventMeta.principal` and stored ownership. Ownership is
* derived from the run and never moved; the same law, and the same `code`, as
* the hosting door's `SessionOwnershipConflictError`.
*
* Neither identity is named in the message: an error is read by whoever
* provoked it. Nothing has run and no state has moved when it is thrown.
*/
export declare class ResumeIdentityConflictError extends Error {
readonly code: "ERR_SESSION_OWNERSHIP_CONFLICT";
constructor();
}
/** Why a resume could not carry its paused run's redaction — see `ResumeRedactionError`. */
export type ResumeRedactionReason = 'unreadable' | 'missing' | 'unknown-pattern';
/**
* Thrown by `resume(checkpoint, input, options)` when the paused run's
* redaction cannot be carried into the resumed leg — refused before anything
* runs, so a leg its policy could not keep covered never starts:
* - `'unreadable'` — the checkpoint's `runRedaction` (the policy the paused
* run was covered by, as plain data) is not one this library wrote;
* - `'missing'` — the checkpoint says its run kept values out of its records
* (footprintjs's `redactionMarks`: the names it masked) but carries no
* policy. Every leg of a covered run writes its policy into its checkpoint,
* so this one was altered; a `redact` passed to the resume cannot stand in
* for the policy the run was covered by, so it is refused all the same;
* - `'unknown-pattern'` — the carried policy names a pattern this side does
* not hold. A pattern is never compiled from a checkpoint (one built to hang
* the matcher could come back from storage someone else controls): a
* carried pattern is a reference to one the agent declares, the library's
* vocabulary holds, or the resume names — pass the run's `redact` to
* `resume(checkpoint, input, { redact })` when the run was handed one.
*
* Every way, the resumed leg would write what the paused leg kept out into
* every record of its own. No policy, pattern, name or value appears in the
* message.
*/
export declare class ResumeRedactionError extends Error {
readonly code: "ERR_RESUME_REDACTION";
readonly reason: ResumeRedactionReason;
constructor(reason: ResumeRedactionReason);
}
/**
* Why `followUp()` found no conversation to continue.
*
* - `'never-run'` — no run on this agent got past input admission yet
* (before the first run, or when the first turn was refused).
* - `'last-run-unfinished'` — the last run ended without an answer (it threw);
* its conversation rides `RunCheckpointError.checkpoint`.
* - `'last-input-refused'` — input middleware refused the last run's message.
* A refusal raises `MessageDeniedError`, which carries no checkpoint: the
* refused attempt admitted no conversation, so the one to continue is the
* checkpoint taken after an earlier ACCEPTED run.
*/
export type NoConversationReason = 'never-run' | 'last-run-unfinished' | 'last-input-refused';
/**
* Thrown by `followUp()` when there is no conversation to follow up on.
*
* `followUp()` continues THIS agent's own last completed run. Before the first
* one there is nothing to continue, and a "follow-up" that quietly became a
* first turn would be the very confusion the door exists to remove.
* `reason` says which of those it was, so a caller can branch on it.
*/
export declare class NoConversationError extends Error {
readonly code: "ERR_NO_CONVERSATION";
readonly reason: NoConversationReason;
constructor(door: string, reason: NoConversationReason);
}