Summarise every token with view --summary

[bajtos]

Written by Claude.

Reading the audience out of a pasted proof takes one ucantool view -i per entry today:

for i in 0 1 2 3 4; do
  ucantool view -i "$i" -j proof.txt | jq -r '.[1]["ucan/dlg@1.0.0-rc.1"].aud'
done

There is no way to learn the entry count except walking -i until it errors, every entry costs a process, and the jq path carries the spec version. A script comparing audiences against a configured DID breaks silently when UCAN moves past 1.0.0-rc.1, because jq -r on a missing key prints null, which a naive comparison reads as "audience does not match".

--summary decodes every token in the input and reports its fields:

$ ucantool view --summary proof.txt
+---+-----------------------+---------------------------+--------------------------+
| # |        COMMAND        |         AUDIENCE          |          ISSUER          |
+---+-----------------------+---------------------------+--------------------------+
| 0 | /s3/request/authorize | did:web:ingot.dev.example | did:web:hilt.dev.example |
+---+-----------------------+---------------------------+--------------------------+

$ ucantool view --summary -j proof.txt | jq -r '.[].aud'
did:web:ingot.dev.example

The JSON keys (index, tag, cmd, iss, aud, sub, exp) are fixed by this tool rather than borrowed from the encoded tag, so .[].aud keeps resolving across UCAN versions. The tag is reported as a value for callers that care. An entry that decodes as no known token kind reports its index and an error, leaving the other entries readable. A single delegation summarises the same way as a container.

-j without --summary is untouched: it still emits DAG-JSON of the container with entries as opaque bytes.

One behaviour change worth review

The container branch now reads its entries straight out of the input. It used to decode the container and re-encode it as raw to get the entry list, and that roundtrip sorts the entries bytewise and silently drops the ones decodeTokens cannot read, so indices and entry count could disagree with the file. The plain view table on a container therefore now shows the file's real entries in file order, and for a container whose entries were not already sorted, the displayed root CID changes. Containers this tool produces are already sorted, so nothing moves on the happy path.

Stripping the transport encoding (codec byte, base64, gzip) locally duplicates about twenty lines that container.Decode keeps unexported. We can remove that duplication after fil-forge/ucantone#55 is landed.

Tests

cmd/view_test.go drives rootCmd the way cmd/delegate_test.go does, building fixtures with ucantool delegate rather than committing any. It pins that every entry of a three-command container appears with its audience, that the JSON keys carry no spec version, that a bare delegation summarises, that an undecodable entry reports its index without hiding the others, and that -i <n> and --summary agree on the audience of entry n. Both paths go through one decodeToken helper, so they cannot drift on what counts as a delegation.