Run the observer daemon

The observer reads encounter-family records from the firehose, folds them through an ObservationMethod, and publishes a dev.idiolect.observation record on each flush. Observations are the durable summary; encounters are the event log.

The crate is idiolect-observer. Its daemon binary lives behind the daemon feature.

What it produces

A dev.idiolect.observation record carries:

the observer's DID,
a structured method descriptor (name, version, optional parameters and code reference),
a scope describing which records the aggregation covers,
the method's output payload (shape is method-defined),
a signature.

The record kind is shared with deliberation tallies via the deliberationOutcome lexicon, but that is a separate record-kind, not an observation flavour.

Why the observer publishes records, not just metrics

Observations are content-addressed and signed, like any other ATProto record. A consumer reading an observation can:

verify the signer DID,
ask the indexer for the underlying encounters and re-fold them independently,
treat the observation as a soft assertion of fact, not a single source of truth.

A central metrics endpoint cannot do that. The same record shape also lets multiple observers run in parallel and disagree.

Run the daemon

cargo install --path crates/idiolect-observer --features daemon

The shipped binary's exact CLI surface is documented by its --help. It wires:

A firehose stream (tapped, via the indexer's firehose-tapped feature, transitively pulled in by daemon).
A SQLite cursor store.
An ObserverHandler<M, P> connecting an ObservationMethod to an ObservationPublisher.
A flush schedule that triggers observation publication.

Bundled methods

The spec at observer-spec/methods.json declares eight bundled methods. Each lives in crates/idiolect-observer/src/methods/.

Method	Folds
`correction-rate`	Per-lens correction counts grouped by reason.
`encounter-throughput`	Encounter traffic by kind and downstream result.
`verification-coverage`	Per-lens verification counts by kind, result, and distinct verifiers.
`lens-adoption`	Per-lens encounter count and distinct invokers.
`action-distribution`	Encounter counts grouped by `use.action`, optionally rolled up through a vocab.
`purpose-distribution`	Encounter counts grouped by `use.purpose`.
`basis-distribution`	Record counts grouped by `basis` variant, bucketed by record kind.
`attribution-chains`	`dev.idiolect.belief` counts by holder and subject.

Methods come in two forms (declared in the spec): record-form methods consume &IndexerEvent<IdiolectFamily> directly; instance-form methods consume a panproto WInstance and wrap into the record form via InstanceMethodAdapter.

default_methods() returns boxed instances of every record-form method; instance-form methods need a caller-supplied schema resolver and are constructed individually.

Add a method

Edit observer-spec/methods.json, add the method's entry, run cargo run -p idiolect-codegen. The generated descriptor table picks up the new method. Implement ObservationMethod (or InstanceMethod) in crates/idiolect-observer/src/methods/<module>.rs and add it to the default_methods() constructor.

Operational notes

Observers should run with their own DID, distinct from the DIDs whose encounters they observe.
Multiple observers publishing observations of the same scope is expected and useful; consumers can require quorum among $k$ of $n$ trusted observers before treating an observation as authoritative.

Note on `deliberation-tally`

The shipped deliberation-tally method emits its per-statement per-stance vote counts inside an observation.output blob, not as a typed dev.idiolect.deliberationOutcome record. The data shape is the same; the surface differs. A variant that publishes the typed outcome record directly is a small refactor on top of the existing DeliberationTallyMethod.