config.example.yaml

# A minimal, CURRENT busbar config that wires this repo's headroom-hook plugin in as a
# prompt-compression rewrite gate on every pool. Validated against the released busbar 1.5.3
# with `busbar --validate`.
#
# This file used to describe the RETIRED Unix-socket transport (a `hooks.headroom.socket:` block
# pointing at a shared volume, alongside `api_key_env:` and pool members using `target:`). All
# three of those shapes were retired by the 1.5.0 config redesign and busbar 1.5.3 refuses to boot
# a config still carrying them, so the old contents were not merely stale documentation, they were
# an example that could not work. headroom-hook is a dlopen cdylib now: busbar loads it IN-PROCESS
# from `plugins.dir`, there is no hook container and no socket volume.
#
# See README.md "Install and run" for the tarball drop-in, and bench/config.hook.yaml for the
# variant this repo's own benchmark harness feeds to busbar.

listen: "0.0.0.0:8080"

# An identity provider is DEFINED once here and REFERENCED by bare name from auth below; busbar
# 1.5.3 retired the inline module form under `auth.admin_auth:`.
identity-providers:
  admin-tokens: { module: admin-tokens, token: { env: BUSBAR_ADMIN_TOKEN } }

auth:
  chain: []                 # open data-plane relay: fine for a local trial, never for production
  admin_auth: [admin-tokens]

# Secret fields are SECRET REFERENCES now, not `<field>_env` scalars.
providers:
  anthropic:
    api_key: { env: ANTHROPIC_KEY }

models:
  claude:
    provider: anthropic
    max_concurrent: 10
    upstream_model: claude-3-5-sonnet-20241022

# A hook instance is DEFINED once here and REFERENCED by bare name from a pool. This replaces both
# the inline hook maps that used to sit under `pools.*.hooks` and the removed top-level
# `global_hooks:` list.
hooks:
  busbar-headroom:
    module: busbar-headroom
    kind: gate
    prompt: rw              # the rewrite grant
    timeout_ms: 25
    on_error: nothing       # a broken compressor never touches a request
    settings:
      target_ratio: 0.5
      min_savings_pct: 10

pools:
  # `hooks:` here is a RESERVED key, not a pool name: it attaches these hooks to ALL pools, which
  # is what "global" means in 1.5.3. Drop it and put `hooks: [busbar-headroom]` inside a single
  # pool to compress only that pool's traffic.
  hooks: [busbar-headroom]
  default:
    members:
      - model: claude       # `model:`, not the retired `target:`
        weight: 1

plugins:
  enabled: true
  dir: /etc/busbar/plugins  # or wherever you unpacked the signed tarball
  # busbar 1.5.3's own released binaries embed no plugin release public key, so they refuse every
  # correctly-signed first-party tarball with "manifest claims first-party publisher 'busbar' but
  # this build embeds no busbar release key". Until that is fixed upstream this opt-in is required
  # even for a signed release artifact; busbar then logs a per-plugin UNVERIFIED warning.
  # See https://github.com/GetBusbar/busbar/issues/50
  trust: { allow_unsigned: true }