Files

T

retoor cc1c130b51 CAP protocol both directions: agent speak plus orchestrator drivers (1.39.0)

- Agent side: --cap-manifest plus --cap-speak stream-json binding with
  transcript-diff frames, diff/transcript artifacts, session config
- Orchestrator: PTY driver (settle heuristics on PtyProc/TuiVtScreen),
  stream-json, ACP-stdio (permission/elicit/fs/terminal serving) and
  A2A drivers (dual draft/current spelling, SSE mapping)
- Sessions, fleets: worktrees, master plans, mediated routing,
  budget refusal, audit log, research auto-answerer, --cap CLI
- cap.md contract with drift tests; research/cap-protocol archive
- Suites 1119 + 16 green

2026-10-18 13:17:35 +02:00

2.1 KiB

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A2A a2a.proto (wire shapes)

Metadata

Field	Value
Institute	Molodetz Institute — Research & Retrieval Division
Subject	cap-protocol
Document type	Source Dossier
Tier	1
Source title	A2A specification/a2a.proto
Source URL	https://github.com/a2aproject/A2A/blob/main/specification/a2a.proto
Source type	schema
Source date (published)	Unknown, not stated (living file)
Date researched	2026-10-18
Researched by	tai (agent), model: Muse Spark, on behalf of retoor
Research method	direct raw-file fetch, read selectively (TaskState, TaskStatus, Part, TaskStatusUpdateEvent, AgentExtension)
Confidence	High
Status	Active

Summary

The machine-readable A2A schema behind the template-generated spec tables: 9-state TaskState enum, TaskStatus (state + message + timestamp), Part oneof (text/raw/url/data + metadata + filename + media_type), status/artifact update events, AgentExtension (uri/description/required/params).

Key findings

TASK_STATE_INPUT_REQUIRED = 6 exists, validating CAP's C.4 mapping row; JSON form is lowercase (working, input-required, ...).
Parts are a oneof: exactly one of text/raw/url/data, with media_type on all variants; CAP's TextPart/DataPart map to the text/data arms.
TaskStatusUpdateEvent carries task_id + context_id + full TaskStatus; artifact updates are separate events, matching CAP's split mapping.
context_id is REQUIRED on updates: multi-turn correlation key tai's driver must persist per session.

Pros / strengths

Unambiguous field shapes with presence/required annotations; no prose interpretation needed.
Confirms CAP's event mapping (C.4) is implementable against real A2A frames.

Cons / limitations / caveats

Read selectively (5 messages of ~40); security/push/video-part messages not reviewed.
Proto is the schema, not the JSON mapping; JSON enum casing confirmed only via the reference driver's test fixtures.

Relevance to tai

Schema source for tai's A2A driver frame parsing and expose-server synthesis.

Changelog

Date	Change
2026-10-18	Initial dossier created.

2.1 KiB Raw Blame History