## Summary
Fixes#2794. Related: #2692.
`resolve_model_switch_method()` reads the `configId` key from each
`session/new` `configOptions` entry and skips entries that lack it.
`claude-agent-acp` (v0.61.0) keys its entries with `id`, so every
model-category entry was skipped, the desired model never matched, and
Claude Code sessions fell back to the CLI default from the user's
`~/.claude/settings.json`. The only trace was a `pool::model` WARN that
never reaches the per-agent log files.
This is the ACP-side half of the symptom reported in #2692. The open
desktop-side PRs (#2695, #2701, #2696) inject `ANTHROPIC_MODEL` at
spawn, which masks the problem for spawn-time selection but leaves the
config-option switch path broken.
## Changes
- `resolve_model_switch_method()` accepts either `configId` or `id` when
extracting the config id. The set request is unchanged: the ACP SDK
schema takes `configId` as the request param and the adapter resolves it
against its `id`-keyed entries, so only the read side needed fixing.
- Regression test with an `id`-keyed `configOptions` payload mirroring
the real adapter response (including `models: null`, so the unstable
fallback path cannot rescue the match).
- Doc comment on `extract_model_config_options()` notes the key drift.
## Testing
`cargo test -p buzz-acp --lib`: 599 passed, 0 failed. The new test fails
on main and passes with this change.
Verified against the real adapter: a stdio JSON-RPC probe of the bundled
`claude-agent-acp` 0.61.0 confirms `session/new` returns `id`-keyed
config options with `opus[1m]` present as a value, and the SDK's
`SetSessionConfigOptionRequest` schema accepts `{sessionId, configId,
value}` as sent by `session_set_config_option()`.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Signed-off-by: chillerno1 <gh.chiller@pm.me>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
ACP harnesses that name a session from the first text they receive all
land in the same place: every managed Buzz agent opens with the
identical `[Base] You are operating inside the Buzz platform…` framing,
so the harness session list shows a wall of indistinguishable rows.
Because sessions are keyed per channel, one agent active in several
channels produces several of them.
This sends the name out of band instead. `session/new` carries
`_meta.sessionTitle` with `Agent · #channel`, composed from the agent's
`display_name` (or its unique `name` handle) and the channel it is
serving. The prompt is untouched — no tokens spent, no perturbation of
the prompt contract, and nothing new for the desktop observer's section
parsing to handle.
The mechanism is harness-agnostic: Buzz sends the field on every ACP
`session/new` regardless of which harness is behind it, and adapters
that don't read it ignore it per spec.
## Inert until a consuming adapter ships
ACP adapters ignore `_meta` members they do not recognize, so against an
adapter with no reader a Buzz session gets no title and nothing else
changes. Three adapter halves consume it — Codex, Goose, and Claude Code
(linked below); this half and each reader are only useful together, and
each reader lands independently.
No version floor is added. `codex_adapter_is_outdated_with_path` already
gates codex-acp on major version `>= 1`
(`desktop/src-tauri/src/managed_agents/discovery.rs:1276-1284`) and this
feature needs nothing above that — an older adapter is not broken by the
extra member, it simply ignores it.
## What changes
**`crates/buzz-acp`** owns sanitization and composition.
`sanitize_session_title` collapses whitespace, drops control characters,
and caps at `SESSION_TITLE_MAX_CHARS` (80) by character, not byte, so a
multi-byte character cannot be split. `compose_session_title` truncates
only the channel part against that cap, so the agent name always
survives; when the agent name alone fills the cap the channel is dropped
rather than the name. `session_new_full` sets `_meta.sessionTitle` when
a title exists and omits `_meta` entirely when it does not, since an
adapter may distinguish an absent member from a null one.
**`desktop/src-tauri`** only resolves and exports.
`resolve_session_title` picks `display_name` or falls back to `name`,
and `spawn_agent_child` writes it to `BUZZ_ACP_SESSION_TITLE` — or
removes the variable when neither candidate yields anything printable.
DMs, unresolved channels, and heartbeat sessions get the bare agent name
with no channel suffix.
## Four properties that are easy to remove by accident
**Control characters are stripped at the desktop boundary, not in the
harness.** An interior NUL cannot cross the environment boundary at all
— `Command::env` fails the entire spawn rather than passing it through.
Deferring the strip to `buzz-acp` would let a corrupted display name
turn display chrome into a spawn failure. A display name that is *only*
control characters falls back to `name`.
**The title is hashed into `spawn_config_hash`.** Without it, renaming
an agent left the running process with a stale title and no restart
badge. The hash runs the same `resolve_session_title` the spawn writes,
and skips it when a user env override shadows `BUZZ_ACP_SESSION_TITLE` —
spawn writes the title *before* the layered user env, so the override is
what actually runs, and it already reaches the hash through
`descriptor.env`. Hashing the record-derived value under an override
would badge a rename that changes nothing.
**One channel resolve serves both consumers.**
`resolve_new_session_channel_context` returns `(is_dm, title_channel)`
from a single metadata lookup, feeding both the canvas block's DM check
and the title. `ChannelInfoResolver` caches only `Some`, so two
independent calls against an unresolvable channel pay the full
`fetch_channel_info` retry sequence twice — two timeouts plus a retry
delay each — directly in front of `session/new`, precisely when the
relay is already degraded.
**The `"unknown"` channel name is treated as absent.**
`fetch_channel_info` substitutes the literal `"unknown"` for a metadata
event with no `name` tag. Composing that sentinel would title every
unnamed channel `Agent · #unknown`, reintroducing the exact collision
the suffix exists to remove while naming a channel something it isn't.
The startup cache already refuses `channel_type == "unknown"` for the
same reason.
Closes#2334
Related — the adapter halves that consume `_meta.sessionTitle`:
-
[codex-acp#338](https://github.com/agentclientprotocol/codex-acp/pull/338)
— Codex
-
[aaif-goose/goose#10712](https://github.com/aaif-goose/goose/pull/10712)
— Goose
-
[claude-agent-acp#920](https://github.com/agentclientprotocol/claude-agent-acp/pull/920)
— Claude Code
---------
Signed-off-by: Will Pfleger <pfleger.will@gmail.com>
Agent commits were authored by a raw 63-character npub, which makes `git
log`, `git blame`, and GitHub's author column effectively unreadable.
This uses the agent's display name for `user.name` instead, while
leaving the pubkey where it does real work.
## What changes
`build_git_env` in `crates/buzz-dev-mcp/src/shim.rs` now reads
`BUZZ_ACP_DISPLAY_NAME`, sanitizes it, and uses the result as
`user.name`. When the variable is absent or unusable it falls back to
`info.npub` — byte-identical to today's behavior.
`user.email`, `user.signingkey`, and the whole credential/signing block
are untouched. The pubkey is what NIP-98 auth, NIP-GS signing, and
contributor matching key on, and it stays in the email verbatim.
`crates/buzz-acp/src/lib.rs` forwards the variable into the dev-mcp
server's declared env, mirroring the existing `BUZZ_AUTH_TAG` block. It
reads `std::env::var` directly rather than going through `Config`, so
the variable is picked up whenever the process has it.
`crates/buzz-agent/src/mcp.rs` adds one `PASSTHROUGH_ENV` entry so ACP
clients that spawn `buzz-agent` without declaring the variable on the
wire still propagate it.
## Why a dedicated variable
`BUZZ_ACP_DISPLAY_NAME` is its own contract rather than a reuse of the
ACP session title. Commits outlive sessions: a session title is
per-session UI chrome and may be composed downstream into `Agent ·
#channel`, and if that composed form ever reached the env var, git
attribution would change silently with no test able to catch it. Git
identity gets a variable whose contract is "bare agent display name,
never channel-qualified."
Nothing writes it yet — a one-line Desktop write lands as a follow-up.
Until then `std::env::var` returns `Err`, the npub fallback fires, and
behavior is byte-for-byte current `main`.
## Sanitizing
Strip control characters, Unicode format characters, and angle brackets;
collapse whitespace runs, trim, cap at 80 characters (by `chars()`, so a
multi-byte name is never split mid-UTF-8).
Angle brackets go because git drops them silently rather than erroring:
`Duncan <evil@x.com>` renders as `Duncan evil@x.com <hex@relay>`. It
forges nothing, but it reads as though it might.
The empty result also has to cover more than literal emptiness. git's
`ident.c` treats a set of characters as "crud" — stripped from both
ends, and fatal when a name is *nothing but* those characters:
```
$ git -c user.name=';;' commit -m t
fatal: name consists only of disallowed characters: ;;
```
Verified against git 2.54.0 by committing with each ASCII byte 32..=126
as the entire `user.name`: exactly space, `"`, `'`, `,`, `:`, `;`, `<`,
`>`, `\` abort, plus all control characters (the predicate is `c <=
32`). `.` is not crud in this version, despite older lore. Names that
merely *contain* crud are fine — `O'Brien` and `Smith, Jr.` both commit
cleanly — so the check is "at least one non-crud character survives,"
not "no crud present." Without it, a display name of `;;` or `""` would
abort every commit that agent makes.
## Unicode format characters
`char::is_control` covers only category `Cc`. Category `Cf` — zero-width
spaces and joiners, bidi embedding and override marks, invisible math
operators, tag characters — is neither control, nor whitespace, nor git
crud, so those characters survived every one of the checks above. A
display name of nothing but U+200B ZERO WIDTH SPACE therefore satisfied
"at least one non-crud character survives" and git accepted the commit
with a visually blank author:
```
# pre-fix, BUZZ_ACP_DISPLAY_NAME set to two U+200B
$ git log -1 --format='%an' | xxd -p
e2808be2808b0a
```
Embedded marks were the other half: a trailing U+202E RIGHT-TO-LEFT
OVERRIDE reorders everything after it, so a stored author line renders
as something other than what it stores — the same confusion class the
angle-bracket filtering exists to prevent.
`is_unicode_format` rejects the whole `Cf` category rather than the
known-bad marks, because the boundary that matters is "invisible or
reorders text", not "the codepoint someone thought of". The 21 ranges
come from the UCD's `DerivedGeneralCategory.txt` (17.0.0), cross-checked
against Python's `unicodedata` (16.0.0); both yield exactly the same
set. They are inlined as a `matches!` rather than pulling in a
Unicode-tables crate for one predicate, and a test asserts both
endpoints of every range plus the codepoints immediately outside them —
including U+2065, which sits inside the U+2060 block but is unassigned
rather than `Cf`.
Filtering happens inside the existing per-word filter, so a format-only
name collapses to empty and falls out through the same `None` → npub
path as a crud-only name. No new fallback logic. And because filtering
precedes truncation, invisible padding cannot eat the 80-character
budget.
## NUL is handled one layer up
An interior NUL is a sibling constraint that cannot be fixed here: it
makes `Command::env` fail the entire spawn before this code runs, so it
has to die at the writer. #3028 establishes that pattern for the session
title in `resolve_session_title` via `filter(|c| !c.is_control())`, and
the Desktop follow-up that writes `BUZZ_ACP_DISPLAY_NAME` inherits it.
The shim sanitizer is a second line of defense for values that arrive
from somewhere other than Desktop.
## Verified end to end
Driving the real `buzz-dev-mcp` binary over stdio MCP and committing
inside its shimmed environment:
```
# BUZZ_ACP_DISPLAY_NAME="Duncan Idaho"
Duncan Idaho <dcfd242e...0f95@buzz.block.builderlab.xyz>
verify_exit=0
# BUZZ_ACP_DISPLAY_NAME unset
npub1mn7jgtj4w2pd0g0zeuhxsa6jy6p0rewxz4kujt98my82ahfmp72sxjexk7 <dcfd242e...0f95@buzz.block.builderlab.xyz>
verify_exit=0
# BUZZ_ACP_DISPLAY_NAME=";;" (crud-only; would otherwise be fatal)
npub1mn7jgtj4w2pd0g0zeuhxsa6jy6p0rewxz4kujt98my82ahfmp72sxjexk7 <dcfd242e...0f95@buzz.block.builderlab.xyz>
verify_exit=0
# BUZZ_ACP_DISPLAY_NAME=U+200B U+200B (format-only; would otherwise be blank)
npub1mn7jgtj4w2pd0g0zeuhxsa6jy6p0rewxz4kujt98my82ahfmp72sxjexk7 <dcfd242e...0f95@buzz.block.builderlab.xyz>
verify_exit=0
# BUZZ_ACP_DISPLAY_NAME="Duncan" + U+202E (bidi override stripped)
Duncan <dcfd242e...0f95@buzz.block.builderlab.xyz>
verify_exit=0
# BUZZ_ACP_DISPLAY_NAME="Dun" + U+200B + "can" (zero-width removed, word not split)
Duncan <dcfd242e...0f95@buzz.block.builderlab.xyz>
verify_exit=0
```
Signature verification passes in every case — the signing identity is
unchanged.
`Related: #3028` — it establishes the Desktop-side env plumbing this
builds beside; the one-line Desktop follow-up that writes
`BUZZ_ACP_DISPLAY_NAME` alongside the session title ships after it
merges. Not a dependency: with the variable absent, `std::env::var`
returns `Err` and the npub fallback keeps current behavior exactly.
---------
Signed-off-by: Will Pfleger <pfleger.will@gmail.com>
Signed-off-by: npub1mn7jgtj4w2pd0g0zeuhxsa6jy6p0rewxz4kujt98my82ahfmp72sxjexk7 <dcfd242e557282d7a1e2cf2e6877522682f1e5c6156dc92ca7d90eaedd3b0f95@buzz.block.builderlab.xyz>
Co-authored-by: npub1mn7jgtj4w2pd0g0zeuhxsa6jy6p0rewxz4kujt98my82ahfmp72sxjexk7 <dcfd242e557282d7a1e2cf2e6877522682f1e5c6156dc92ca7d90eaedd3b0f95@buzz.block.builderlab.xyz>
## Problem
Auth-class errors (expired OAuth token, HTTP 401) are non-retryable: the
token won't self-repair between attempts. Today, `PromptOutcome::Error`
for an application-class error falls into the generic `queue.requeue()`
path, burning up to 10 retry slots over a long backoff window before
dead-lettering. Will's canary run observed the 401 message being retried
repeatedly.
## Solution
Add `is_auth_error()` that classifies `AcpError::AgentError` messages
matching two narrow patterns observed in the field:
- `"Re-authenticate"` — emitted by the Claude CLI for expired OAuth
tokens
- `"API Error: 401"` — present in Claude/Codex HTTP-401 responses
Conservative matching is intentional: a false positive (misclassifying a
transient error as non-retryable) silently drops a user message, which
is worse than a false negative (extra retries on an auth error).
In `handle_prompt_result`, a new branch intercepts the failing batch
before `queue.requeue()` for auth-class errors and dead-letters
immediately, posting a user-visible notice to re-authenticate the CLI
(e.g. `claude /login` or `codex login`).
The transport/application split in `PromptOutcome::Error` is untouched —
this only changes batch fate after an application-class auth error.
## Tests
6 new tests in `error_outcome_emission_tests`:
1. `is_auth_error` matches `Re-authenticate` message
2. `is_auth_error` matches `API Error: 401` message
3. `is_auth_error` rejects other `AgentError` messages (usage credits,
etc.)
4. `is_auth_error` rejects transport errors (I/O, WriteTimeout)
5. Auth error dead-letters immediately — 0 pending channels after
`handle_prompt_result`
6. Non-auth application error still requeued — 1 pending channel after
`handle_prompt_result`
Full `cargo test -p buzz-acp`: 598/598 passing.
Signed-off-by: Will Pfleger <pfleger.will@gmail.com>
Co-authored-by: npub1mn7jgtj4w2pd0g0zeuhxsa6jy6p0rewxz4kujt98my82ahfmp72sxjexk7 <dcfd242e557282d7a1e2cf2e6877522682f1e5c6156dc92ca7d90eaedd3b0f95@buzz.block.builderlab.xyz>
