token-budget

name	token-budget
description	Token budget tracking and enforcement for Gastown convoy-level execution. Hard limits with pre-execution checking, per-convoy and per-agent tracking, structured stop reasons.
format	"2025-10-02T00:00:00.000Z"
version	1.0.0
status	ACTIVE
updated	"2026-04-04T00:00:00.000Z"
triggers	["sizing or enforcing a token budget for a convoy or multi-agent batch","pre-execution budget check before dispatching agents","need a structured stop reason when a budget limit is reached"]

Token Budget Enforcement

Pre-execution budget gating for multi-agent convoy execution. Prevents token overspend by checking budgets BEFORE API calls, not after. Identified by the 12 Primitives analysis (Primitive 5) as the #1 actionable improvement.

Activation

This skill activates when:

• A convoy execution starts (mayor creates a convoy)
• Agents are spawned within a convoy
• Any agent is about to make an API call during convoy execution
• Budget reporting is requested during or after execution

Architecture

Budget Hierarchy

Convoy Budget (hard limit, default 500K tokens)
  |
  +-- Agent A budget (hard limit, default 100K tokens)
  +-- Agent B budget (hard limit, default 100K tokens)
  +-- Agent C budget (hard limit, default 100K tokens)

The convoy budget is the aggregate ceiling. Individual agent budgets prevent any single polecat from consuming a disproportionate share.

Check-Before-Execute Pattern

Every API call in a convoy MUST follow this sequence:

1. Estimate the projected token cost for the call
2. Check checkBudget(budget, agentId, projectedCost) — returns BudgetCheckResult
3. If allowed: false — stop immediately, do NOT make the API call
4. If reason: 'warning_threshold' — proceed but log the warning
5. If reason: 'ok' — proceed normally
6. After execution — recordUsage(budget, agentId, actualInput, actualOutput)
7. Persist — saveBudget(budget, budgetDir) to survive crashes

Structured Stop Reasons

Reason	Meaning	Action
ok	Under budget, no concerns	Proceed
warning_threshold	Past warning % but under hard limit	Proceed, log warning
convoy_budget_exceeded	Convoy would exceed hard limit	STOP, do not call API
agent_budget_exceeded	Agent would exceed its limit	STOP, do not call API

Core API

Types

interface TokenBudget {
  convoyId: string;
  maxTokensPerConvoy: number;      // Hard limit for entire convoy
  maxTokensPerAgent: number;       // Hard limit per polecat
  warningThresholdPercent: number;  // Warn at this % (e.g., 80)
  currentUsage: BudgetUsage;
  createdAt: string;               // ISO 8601
  updatedAt: string;               // ISO 8601
}

interface BudgetCheckResult {
  allowed: boolean;
  reason: 'ok' | 'warning_threshold' | 'convoy_budget_exceeded' | 'agent_budget_exceeded';
  remainingTokens: number;
  usagePercent: number;
}

Functions

Function	Signature	Description
createBudget	(convoyId, config?) => TokenBudget	Initialize a budget for a convoy
checkBudget	(budget, agentId, projectedCost) => BudgetCheckResult	Pre-execution gate check
recordUsage	(budget, agentId, input, output) => void	Track actual usage after execution
getBudgetReport	(budget) => BudgetReport	Summary for logging/display
saveBudget	(budget, budgetDir) => Promise<void>	Persist to .chipset/state/budgets/
loadBudget	(convoyId, budgetDir) => Promise<TokenBudget | null>	Load from disk
deleteBudget	(convoyId, budgetDir) => Promise<void>	Remove budget file
listBudgets	(budgetDir) => Promise<string[]>	List all persisted convoy budget IDs

Default Values

Parameter	Default	Recalibration note
maxTokensPerConvoy	500,000 tokens	Was set conservatively pre-INLINE-SERIAL pattern. v1.49.621 actuals: ~50-300K per convoy under inline-serial Opus/Sonnet authoring (~10-15% of this default). Default retained for safety margin; missions may explicitly cap lower based on convoy shape.
maxTokensPerAgent	100,000 tokens	Pre-recursive-spawn-block default; with INLINE SERIAL the agent IS the convoy, so per-agent ≈ per-convoy.
warningThresholdPercent	80%	Unchanged.

v1.49.621 retrospective lesson 3 — projection recalibration: Wave 1+2+3+4 fleet token spend came in at ~26% of projected ceiling under INLINE SERIAL authoring. Future missions should project Opus convoys at ~75-300K and Sonnet convoys at ~30-150K based on output volume × ~1.5K tokens/100-line-of-output heuristic. Reserve 3-5× headroom over the projection for safety; do not 10× as this skill historically did.

State Persistence

Path: .chipset/state/budgets/{convoyId}.json

Follows the same durability contract as beads-state:

• Atomic writes (write temp -> fsync -> rename)
• JSON with sorted keys for git-friendly diffs
• Filesystem-only, no database dependencies
• Crash-recoverable (partial writes leave only temp files)

Integration Points

Mayor Coordinator

When the mayor creates a convoy, it should also create a token budget:

const convoy = await stateManager.createConvoy('Sprint 1', beadIds);
const budget = createBudget(convoy.id, {
  maxTokensPerConvoy: 500_000,
  maxTokensPerAgent: 100_000,
});
await saveBudget(budget, '.chipset/state/budgets');

Polecat Worker

Before each API call in GUPP autonomous mode:

const budget = await loadBudget(convoyId, '.chipset/state/budgets');
const check = checkBudget(budget!, agentId, estimatedTokens);
if (!check.allowed) {
  // Structured stop — include reason in termination message
  return { stopped: true, reason: check.reason, remaining: check.remainingTokens };
}
// ... make API call ...
recordUsage(budget!, agentId, actualInput, actualOutput);
await saveBudget(budget!, '.chipset/state/budgets');

Witness Observer

The witness can periodically check budget health:

const budget = await loadBudget(convoyId, '.chipset/state/budgets');
const report = getBudgetReport(budget!);
if (report.warningActive) {
  // Alert: convoy approaching budget limit
}

Module Location

• Implementation: src/chipset/gastown/token-budget.ts
• Tests: src/chipset/gastown/token-budget.test.ts
• Barrel export: src/chipset/gastown/index.ts