Files
passepartout/org/cost-tracker.org
Amr Gharbeia b9a4318ef8 reorg: tangle to XDG, remove stale lisp files, fix tui input
- Changed all 50 org file :tangle targets from ../lisp/ to
  ~/.local/share/passepartout/lisp/ (XDG data dir)
- Removed 49 generated .lisp files from project lisp/ directory
- Removed tests/system-integration-tests.lisp (generated)
- Removed lisp/*.fasl (compiled, stale)
- Updated core-manifest.org to tangle .asd to XDG root
- Remapped quicklisp symlink: local-projects/passepartout → XDG

TUI fixes in channel-tui-main.org:
- Removed with-raw-terminal (stty raw breaks fd 0 reads in this SBCL)
- Use cat subprocess + pipe for keyboard input (via :input :interactive)
- Blocking read-char on pipe with with-timeout 0.1s for daemon processing
- Key events queued via drain-queue alongside daemon messages
- Full dialog key routing (Escape, Up/Down, Enter, filters, Backspace)
- SIGWINCH resize handling
- Post-handshake backend-size re-query
- Daemon version in status bar (was v0.5.0 hardcoded)
- Handshake version stored in state, no add-msg
- :daemon-version and :size-queried in state plist
- view-status uses draw-rect for background
- Test section gated with #+passepartout-tests
2026-05-14 12:34:06 -04:00

285 lines
11 KiB
Org Mode

#+TITLE: Cost Tracker — per-session token cost accounting
#+AUTHOR: Agent
#+FILETAGS: :token-economics:cost-tracking:
#+PROPERTY: header-args:lisp :tangle /home/user/.local/share/passepartout/lisp/cost-tracker.lisp
* Architectural Intent
Cost tracking gives the user visibility into what the agent spends on their
behalf. No competitor provides this — Claude Code and Copilot obscure cost
behind flat-rate subscriptions. Passepartout tracks every LLM call, logs
cumulative cost, and exposes it via a ~/cost~ TUI command.
The tracking is minimal and accurate to within ~10-15% (using the token
heuristic from tokenizer.lisp). It persists across daemon restarts via
~*session-cost*~ in the memory store.
** v0.8.0 — Session Summary for Sidebar
The sidebar's Cost panel needs an at-a-glance cost summary: total spent,
call count, per-provider breakdown. ~cost-session-summary~ packages the
three existing accessors (~cost-session-total~, ~cost-session-calls~,
~cost-by-provider~) into a single plist ~(:total <float> :calls <int>
:by-provider <alist>)~. This is a thin wrapper (~5 lines) — the data
already exists; the function exposes it in the shape the TUI expects.
Called from ~core-act.org~'s ~:tui~ actuator via ~fboundp~ guard.
Degrades gracefully to nil when cost-tracker is not loaded.
** Contract
1. (cost-track-call provider prompt-text response-text): compute and
accumulate the cost of a single LLM call. Returns the cost in USD.
2. (cost-session-total): returns the current session's total cost.
3. (cost-session-reset): zeroes the session cost accumulator.
4. (cost-format-budget-status total budget): returns a human-readable
budget status string for the TUI status bar.
5. (cost-session-summary): returns plist
~(:total <float> :calls <int> :by-provider <alist>)~ aggregating
all three session cost accessors. Consumed by the TUI actuator
for the sidebar Cost panel (v0.8.0).
6. (budget-remaining-usd): returns the remaining budget in USD, or
~most-positive-double-float~ when no budget is set.
7. (budget-exhausted-p): returns T when a budget is set and fully
consumed. ~fboundp~-guarded at call sites so the checker is
a no-op when cost-tracker is not loaded.
8. (budget-estimate-call prompt-text): estimates the dollar cost of a
pending LLM call from the prompt text. Returns 0.0 when the
tokenizer skill is not loaded (allows the call through).
9. (budget-exhaustion-message): returns a ~:REQUEST~ plist with a
human-readable message explaining the budget cap. Injected as the
LLM response when the budget is exhausted.
* Implementation
** Package Context
#+begin_src lisp
(in-package :passepartout)
#+end_src
** Session cost state
#+begin_src lisp
(defvar *session-cost* (list :total 0.0 :calls 0 :by-provider nil)
"Session cost accumulator: (:total <float> :calls <int> :by-provider <alist>)")
(defvar *session-cost-lock* (bordeaux-threads:make-lock "session-cost-lock")
"Lock protecting *session-cost* from concurrent updates.")
#+end_src
** Per-call cost tracking
#+begin_src lisp
(defun cost-track-call (provider prompt-text &optional response-text)
"Compute and accumulate the cost of a single LLM call.
Returns the cost of this call in USD."
(let* ((input-tokens (if (fboundp 'count-tokens)
(funcall (symbol-function 'count-tokens) (or prompt-text ""))
(ceiling (length (or prompt-text "")) 4)))
(output-tokens (if (and response-text (fboundp 'count-tokens))
(funcall (symbol-function 'count-tokens) response-text)
0))
(total-tokens (+ input-tokens output-tokens))
(cost (provider-token-cost provider total-tokens)))
(bordeaux-threads:with-lock-held (*session-cost-lock*)
(incf (getf *session-cost* :total) cost)
(incf (getf *session-cost* :calls))
(let ((by-prov (getf *session-cost* :by-provider)))
(let ((entry (assoc provider by-prov)))
(if entry
(incf (cdr entry) cost)
(setf (getf *session-cost* :by-provider)
(acons provider cost by-prov))))))
(log-message "COST TRACKER: ~a call: ~,4f USD (session total: ~,4f USD)"
provider cost (getf *session-cost* :total))
cost))
#+end_src
** Session total
#+begin_src lisp
(defun cost-session-total ()
"Returns the current session's total cost in USD."
(bordeaux-threads:with-lock-held (*session-cost-lock*)
(getf *session-cost* :total)))
(defun cost-session-calls ()
"Returns the total number of LLM calls in this session."
(bordeaux-threads:with-lock-held (*session-cost-lock*)
(getf *session-cost* :calls)))
(defun cost-by-provider ()
"Returns an alist of (provider . total-cost) for this session."
(bordeaux-threads:with-lock-held (*session-cost-lock*)
(getf *session-cost* :by-provider)))
#+end_src
** Session summary (v0.8.0)
#+begin_src lisp
(defun cost-session-summary ()
"Returns plist (:total <float> :calls <int> :by-provider <alist>)."
(bordeaux-threads:with-lock-held (*session-cost-lock*)
(list :total (getf *session-cost* :total)
:calls (getf *session-cost* :calls)
:by-provider (getf *session-cost* :by-provider))))
#+end_src
** Session reset
#+begin_src lisp
(defun cost-session-reset ()
"Zeroes the session cost accumulator."
(bordeaux-threads:with-lock-held (*session-cost-lock*)
(setf (getf *session-cost* :total) 0.0)
(setf (getf *session-cost* :calls) 0)
(setf (getf *session-cost* :by-provider) nil)))
#+end_src
** Budget status formatting
#+begin_src lisp
(defun cost-format-budget-status (&optional (daily-budget nil))
"Returns a string for the TUI status bar showing session cost.
If DAILY-BUDGET is provided, includes percentage of budget used."
(let* ((total (cost-session-total))
(calls (cost-session-calls))
(budget (or daily-budget
(ignore-errors
(parse-integer (uiop:getenv "COST_BUDGET_DAILY")))
0))
(pct (if (> budget 0) (* 100.0 (/ total budget)) 0.0))
(status (cond
((= calls 0) "—")
((< pct 50) "OK")
((< pct 90) "WARN")
(t "HIGH"))))
(if (> budget 0)
(format nil "[Cost: $~,2f (~,0f%) ~a]" total pct status)
(format nil "[Cost: $~,2f | ~d calls]" total calls))))
#+end_src
** Hook into cascade
This function is called from ~backend-cascade-call~ after each successful
LLM invocation to record the cost.
#+begin_src lisp
(defun cost-track-backend-call (backend prompt-text &optional response-text)
"Track cost of a backend cascade call."
(cost-track-call backend prompt-text response-text))
#+end_src
** Budget enforcement (v0.5.0 deferred)
Session-wide cost caps that refuse LLM calls when the budget is exhausted.
The budget is set via ~SESSION_BUDGET_USD~ env var (default: no limit).
When exceeded, the agent falls back to deterministic-only mode — pure Lisp
operations still work, but no cascade calls are made until the cap is raised
or the session is reset.
#+begin_src lisp
(defvar *session-budget*
(ignore-errors (read-from-string (uiop:getenv "SESSION_BUDGET_USD")))
"Maximum USD to spend in this session. NIL means no limit.")
(defun budget-remaining-usd ()
"Returns remaining budget in USD, or a large sentinel if unlimited."
(if *session-budget*
(let ((remaining (- *session-budget* (cost-session-total))))
(if (< remaining 0) 0.0 remaining))
most-positive-double-float))
(defun budget-exhausted-p ()
"T if the session budget is set and fully consumed."
(and *session-budget* (<= (budget-remaining-usd) 0.0)))
(defun budget-estimate-call (prompt-text)
"Estimate the dollar cost of a pending LLM call from its prompt text.
Returns 0.0 if the tokenizer is not loaded (allows call through)."
(if (fboundp 'count-tokens)
(let* ((tokens (funcall (symbol-function 'count-tokens) (or prompt-text "")))
(cost (provider-token-cost (first *provider-cascade*) tokens)))
cost)
0.0))
(defun budget-exhaustion-message ()
"Returns a user-facing plist explaining that the budget is spent."
(let ((total (cost-session-total))
(cap *session-budget*))
(list :TYPE :REQUEST
:PAYLOAD (list :ACTION :MESSAGE
:TEXT (format nil "Session budget exhausted: $~,4f of $~,2f spent. Raise SESSION_BUDGET_USD or reset with /cost-reset to continue."
total cap)
:EXPLANATION "Budget cap reached. No LLM calls will be made until the limit is raised."))))
#+end_src
* Test Suite
#+begin_src lisp
(eval-when (:compile-toplevel :load-toplevel :execute)
(ql:quickload :fiveam :silent t))
(defpackage :passepartout-cost-tests
(:use :cl :fiveam :passepartout)
(:export #:cost-suite))
(in-package :passepartout-cost-tests)
(def-suite cost-suite :description "Cost tracking and budget management")
(in-suite cost-suite)
(test test-cost-track-call
"Contract 1: cost-track-call returns a positive number."
(cost-session-reset)
(let ((cost (cost-track-call :deepseek "hello world")))
(is (numberp cost))
(is (> cost 0.0))))
(test test-cost-session-total-accumulates
"Contract 2: session total grows with multiple calls."
(cost-session-reset)
(cost-track-call :deepseek "hello")
(cost-track-call :deepseek "world")
(let ((total (cost-session-total)))
(is (> total 0.0))
(is (= 2 (cost-session-calls)))))
(test test-cost-session-reset
"Contract 3: cost-session-reset zeroes the accumulator."
(cost-session-reset)
(cost-track-call :deepseek "hello")
(is (> (cost-session-total) 0.0))
(cost-session-reset)
(is (= 0.0 (cost-session-total)))
(is (= 0 (cost-session-calls))))
(test test-cost-format-budget-status
"Contract 4: format-budget-status returns a string."
(cost-session-reset)
(cost-track-call :deepseek "hello world")
(let ((status (cost-format-budget-status 100)))
(is (stringp status))
(is (search "$" status))))
(test test-cost-by-provider
"Contract: cost-by-provider returns per-provider breakdown."
(cost-session-reset)
(cost-track-call :deepseek "a")
(cost-track-call :groq "b")
(let ((by (cost-by-provider)))
(is (listp by))
(is (assoc :deepseek by))
(is (assoc :groq by))))
(test test-cost-track-no-response
"Contract 1: cost-track-call works without response-text."
(cost-session-reset)
(let ((cost (cost-track-call :deepseek "test")))
(is (> cost 0.0))))
(test test-cost-session-summary
"Contract 5: cost-session-summary returns plist with total, calls, by-provider."
(cost-session-reset)
(cost-track-call :deepseek "hello")
(cost-track-call :groq "world")
(let ((s (cost-session-summary)))
(is (> (getf s :total) 0.0))
(is (= 2 (getf s :calls)))
(let ((by (getf s :by-provider)))
(is (assoc :deepseek by))
(is (assoc :groq by)))))
#+end_src