A2A authenticates every inbound request via bearer token in do_POST
(401 before dispatch). Without overriding authorization_is_upstream=True,
the gateway's per-platform user allow-list ({PLATFORM}_ALLOWED_USERS)
rejects A2A peers because their identity is a token-derived name or
pod IP, not a platform account in any configured allow-list. Messages
never reach the agent and callers get empty replies.
This is authorization delegated to the bearer-token transport, not a
fail-open: every request is 401'd if the credential is wrong.
Reported by kuangmi-bit (PR #41711 comment, Jun 27).
Attribution: gfdsa's a2a-hermes repro fixture (LOCAL PATCH triad-hermoperator).
The other two patches from gfdsa's fixture were already in our branch:
- k8s Agent Card URL derivation (_request_public_url, commit ea59b85c2)
- send() gating on metadata['notify'] (reply-capture fix, commit ea59b85c2)
All 168 tests pass (151 unit + 17 integration).
Two bugs reported by gfdsa (PR #41711 comment, Jul 12) that break the
official a2a-sdk 1.1.0 Python client:
1. Task objects serialized non-spec createdAt/lastModified fields.
The A2A v1.0 Task proto (lf.a2a.v1.Task) only has id, contextId,
status, artifacts, history, metadata. Strict ProtoJSON parsers
reject unknown fields with ParseError. Removed both fields from
build_task(); created_at param kept for call-site compatibility.
2. SSE streaming frames were not JSON-RPC wrapped. A2A v1.0 §9.4
requires data: {"jsonrpc":"2.0","id":...,"result":{StreamResponse}}.
sse_data() now accepts req_id and wraps in JSON-RPC envelope.
sse_done() changed from 'data: {}' to SSE comment ': done' so
SDK doesn't try to parse an empty JSON-RPC response.
All call sites in adapter.py (_emit_terminal, _rpc_message_stream,
_rpc_tasks_subscribe) updated to thread req_id through.
Tests updated: 153 pass (151 unit + 17 integration, including 2 new
tests for JSON-RPC envelope wrapping and fallback behavior).
Refs: gfdsa/a2a-hermes reproduction repo
## File/data Parts (v1.0 unified Part)
- file_part(url=, raw=, filename=, media_type=) builds v1.0 file Parts
- data_part(data, media_type=) builds v1.0 data Parts
- message_with_parts(role, parts, context_id=) builds Messages with mixed Part types
- extract_text now renders file/data Parts into the text stream:
- File with URL: '[file: name] https://url (mediaType)'
- File with raw: '[file: name] N bytes base64-encoded (mediaType)'
- Data: '[data (mediaType)]\n{json}'
- v0.3 file (file.fileWithUri) and data (kind=data) still accepted
- Outbound replies stay text-only (agent produces text)
## Push notification config full CRUD
- get_push_config(task_id, config_id) — retrieve by task, optionally by configId
- list_push_configs(task_id) — list all configs for a task (max 1 per task)
- delete_push_config(task_id, config_id) — remove a config
- New JSON-RPC methods: tasks/pushNotificationConfig/get, /list, /delete
- New adapter handlers: _rpc_push_config_get, _list, _delete
- All return spec-shaped PushNotificationConfig with configId + createdAt
## Tests
- 6 new unit tests for Part builders + extract_text with file/data
- 13 new unit tests for push config get/list/delete (happy + error paths)
- 2 new integration tests over real HTTP:
- test_mixed_parts_delivered_to_agent: file URL + data JSON reach agent
- test_push_config_crud_over_http: full create→get→list→delete cycle
- Old test_extract_text_skips_non_text_parts replaced (now renders, not skips)
Total: 151 tests (134 unit + 17 integration), 0 failed.
DESIGN.md updated: file/data Parts and push config CRUD removed from
out-of-scope list.
Consolidates 5 follow-up PRs onto the a2a-work branch:
1. Reply-capture fix (#56437): adapter.send() now only resolves the
blocked RPC Future when metadata['notify'] is True (the gateway's
final-reply marker). Interim sends no longer short-circuit the
response. Also accepts **kwargs in connect() for reconnect compat.
2. Slash command passthrough (#53743): wrap_inbound() passes /-prefixed
text through unwrapped so the gateway command processor sees it.
Fixes /sethome deadlock during A2A onboarding. Documented security
trade-off (bearer auth at network layer compensates).
3. Routable URL in Agent Card (#53736): _build_card() now derives URL
from A2A_PUBLIC_URL env > X-Forwarded-Host/Host header > bind host.
Fixes k8s bug where Agent Card advertised 0.0.0.0.
4. contextId multi-turn memory (#53756): _handle_inbound_task() now
checks top-level params.contextId first (A2A spec), falls back to
params.message.contextId (legacy). Outbound a2a_call also sends
contextId at both top-level and inside message.
5. Type checker fixes (#53759): TypedDict for _SCHEMAS, _FunctionSchema,
_ToolSchema. Removes str() band-aid casts.
All 45 tests pass including new tests for each fix.
Zero core files modified — only plugins/platforms/a2a/ and tests/.
Credits: @davidrobertson (#56437), @knoal (#53736, #53743, #53756,
#53759), @kuangmi-bit (slash command bug report), @gfdsa (k8s URL bug
report), @shivasymbl (#45996 userContext OBO).
Single platform-adapter plugin under plugins/platforms/a2a/ — zero core
edits — that supersedes the entire A2A PR/issue cluster. Built on the
ctx.register_platform + ctx.register_tool surface the codebase now exposes.
Outbound (a2a toolset): a2a_discover / a2a_call / a2a_list let the agent
call any A2A-compliant peer over JSON-RPC message/send. Inbound (platform
adapter): a stdlib http.server serves an Agent Card at
/.well-known/agent.json and routes incoming tasks into the agent's LIVE
gateway session (the #11025 insight) — same agent, full memory — returning
the reply over A2A.
Security on by default: no bearer token => 127.0.0.1-only bind; constant-
time bearer auth; inbound prompt-injection filtering + untrusted-peer
framing; outbound credential redaction; append-only audit log; per-context
conversation persistence outside the compaction pipeline.
Stdlib only (no a2a-sdk). 37 tests incl. a live HTTP round-trip
(card + message/send + reply) and a bearer-auth 401 path.