Spend ledger with reservations: one budget for a tree of agents

$0.005 USDC per call · Agent infrastructure · POST /api/v1/spend-ledger · Id spend-ledger

A budget shared by a task tree, in integer minor units. reserve() atomically holds an amount if the remaining budget covers it (expired holds are freed automatically); commit() records what was actually spent, up to the hold; release() frees a hold. These are real reservations, not a snapshot: two workers cannot both reserve the last dollar. It records spending; it does not move money.

What you get

Keeps a swarm of paying sub-agents inside one budget for $0.005 per reservation.

Call it

Send the JSON body below to https://agents.writerslogic.com/api/v1/spend-ledger. An unpaid request answers 402 with the price and how to pay; a request that fails with a 5xx status is not charged.

curl -i -X POST https://agents.writerslogic.com/api/v1/spend-ledger \
  -H 'content-type: application/json' \
  -d '{"op":"reserve","ledger":"task:research-42","reservationId":"subagent-3-call-1","amountMinor":250,"requestId":"sa3-r1"}'

Input

Field	Type	Required	Description
`op`	string; one of "open", "reserve", "commit", "release", "status"	yes
`ledger`	string	yes	Ledger name, e.g. task:research-42.
`currency`	string	no	open: currency or token code, e.g. USD or USDC.
`budgetMinor`	integer; 0..1000000000000000	no	open: total budget in minor units.
`reservationId`	string	no
`amountMinor`	integer; 0..1000000000000000	no	reserve: amount to hold. commit: amount actually spent (at most the hold).
`ttlSeconds`	integer; 1..86400	no	reserve: hold lifetime; default 600.
`tenantId`	string	no	Required for API-key callers (namespaced as key:<tenantId>; keep it unguessable). Ignored when a wallet paid: the payer address is the tenant.
`requestId`	string	no	Caller-chosen id for this mutation. A retry with the same id and same input returns the stored response (24 h) instead of applying twice; the same id with different input is rejected. Send one on every mutation you may retry: without it a retry is applied again (fleet-memory record appends a duplicate; a repeated spend-ledger commit or release answers NO_HOLD because the first call already took effect).

Example request body

{
  "op": "reserve",
  "ledger": "task:research-42",
  "reservationId": "subagent-3-call-1",
  "amountMinor": 250,
  "requestId": "sa3-r1"
}

Result

The response is { "data": ..., "_provenance": ... }. data carries these fields; _provenance is a signed W3C Verifiable Credential with a C2PA-style manifest, checked free at POST /api/v1/verify-provenance.

Field	Type	Required	Description
`status`	string; one of "pass", "fail", "unknown", "unsupported"	no	pass: every rule held. fail: a rule was violated (see witnesses). unknown: the input lacks the evidence to decide. unsupported: outside what this engine covers. Missing evidence is never a pass.
`op`	string	no
`currency`	one of	no
`budgetMinor`	one of	no
`committedMinor`	one of	no
`reservedMinor`	one of	no	Sum of live holds.
`availableMinor`	one of	no
`reservation`	one of	no
`witnesses`	array<object>	no
`versions`	object	no	Every semantic dependency of this answer (engine, tables and their as-of dates, tokenizer, calendar, rounding profile).
`limits`	array<string>	no
`deterministic`	boolean	no	Always true: pure code, no model.

Pay and connect

Available through: x402 (USDC on Base), MCP. MCP clients reach it through the agent-coordination-kit package.

Machine-readable

This agent as JSON (schemas, example, OpenAPI operation)
Free signed sample response
OpenAPI 3.1 · Catalog · Index of every agent