Configuration

AFA is configured via a .afa.yaml file in your project root. All settings have sensible defaults -- you only need a config file to customize behavior.

Minimal config

version: "1.0"

model:
  provider: anthropic

That's it. Everything else uses defaults.

Full reference

Model

model:
  provider: anthropic          # anthropic | openai | google | local
  model: claude-sonnet-4-6     # Provider-specific model ID
  fallback: openai/gpt-5.4    # Single fallback model
  fallback_chain:              # Full cross-provider fallback chain
    - openai/gpt-5.4
    - gemini/gemini-3-flash-preview

Gates

Gate parameters are grouped into three governance tracks. Violations cause a ConfigError at load time.

Frozen (cannot be changed)

Parameter	Value	Description
`complexity_floor`	`0.5`	Hard floor -- non-overridable

Stable (tunable within narrow bands)

Parameter	Default	Min	Max	Description
`delta_risk_threshold`	2.0	1.5	3.0	Minimum risk improvement ratio
`delta_profit_threshold`	2.0	1.5	3.0	Minimum profit improvement ratio
`bayesian_confidence`	0.95	0.90	0.99	Posterior probability threshold
`novelty_threshold`	0.8	0.6	0.9	Minimum novelty score
`quality_minimum`	0.7	0.6	0.9	Minimum aggregate quality
`utility_threshold`	1.5	-1.0	5.0	Minimum LCB(U)
`kpi_r2_threshold`	0.6	0.5	0.8	Minimum R-squared for KPI model
`phi_s`	100.0	50.0	200.0	Static complexity cost ($/month/kLOC)
`phi_d`	2000.0	1000.0	5000.0	Dynamic complexity cost ($/month/service)
`z_alpha`	1.645	1.28	1.96	Confidence level z-score

Canary (wider experimental bands)

Parameter	Default	Min	Max	Description
`entropy_floor`	0.25	0.20	0.50	Minimum Shannon entropy of diff
`gamma`	0.3	0.1	0.5	Low-confidence value discount
`novelty_k`	5.0	4.0	6.0	Logistic slope
`novelty_n0`	3.5	2.0	4.0	Logistic center
`dead_code_threshold`	0.8	0.6	0.95	Anti-gaming: reachable code score
`edit_locality_threshold`	0.3	0.1	0.5	Anti-gaming: edit locality score
`gen_code_threshold`	0.5	0.3	0.8	Anti-gaming: natural code score

Example:

gates:
  utility_threshold: 2.0
  entropy_floor: 0.30
  novelty_k: 5.5

Analysis

analysis:
  languages:
    - python
    - typescript
    - go
    - java
    - rust
  exclude:
    - "tests/**"
    - "vendor/**"
    - "node_modules/**"
  max_function_size: 500         # Max lines per function
  protected_paths:               # Additional paths AFA will never modify
    - "migrations/"
    - "generated/"
  finding_policy:                # Finding action policy
    ast_definite_action: auto_block
    hybrid_corroborated_action: auto_block
    llm_only_critical_action: human_review
    llm_only_high_action: human_review
    llm_only_medium_action: advisory
    style_action: advisory

Protected paths merge with AFA's hardcoded defaults (gates/, tests/, config.py, etc.). You can add paths but never remove the built-in ones.

Enhancement

enhancement:
  max_candidates: 3         # Candidates per function (1-10)
  auto_commit: false         # Auto-commit passing enhancements
  branch_prefix: "afa/"      # Git branch prefix
  pr_labels:                 # Labels for auto-created PRs
    - afa-enhancement
    - automated
  max_retries: 3             # Redesign attempts per function (1-10)

Safety

safety:
  kill_switch_check_interval: 1    # Check kill switch every N functions
  gate_subprocess_timeout: 30      # Seconds for out-of-band gate eval (0 = in-process)
  test_isolation: true             # Verify test integrity in worktrees

Cost budgets

cost:
  hourly_budget: 5.0      # USD
  daily_budget: 50.0       # USD
  monthly_budget: 500.0    # USD

Server

server:
  host: "127.0.0.1"       # Bind address (0.0.0.0 for containers)
  port: 8080
  api_token: ""            # Bearer token (empty = open access)
  audit_path: ".afa/audit.db"

Billing

billing:
  stripe_secret_key_env: STRIPE_SECRET_KEY
  stripe_webhook_secret_env: STRIPE_WEBHOOK_SECRET
  metering_db_path: ".afa/metering.db"
  unkey_root_key_env: UNKEY_ROOT_KEY
  unkey_api_id: ""
  unkey_key_prefix: "uk_afa"

Integrations (optional)

integrations:
  aegis:
    enabled: false
    endpoint: "https://aegis.example.com"
    api_key_env: AEGIS_API_KEY
    timeout_seconds: 30
    fallback_to_builtin: true
  pcw:
    enabled: false
    providers:
      - anthropic
      - openai
    agreement_threshold: 0.66
    fallback_to_scoring: true

CLI config command

Set individual values without editing the file:

afa config gates.entropy_floor 0.30
afa config model.provider gemini
afa config enhancement.max_retries 5

Configuration

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