fix: cost tracker $0.00 bug — add token estimation fallback for DeepSeek (v4.4.3)

DeepSeek models on OpenRouter omit the usage object, causing all token counts and costs to log as zero. Added character-based estimation fallback (~3.75 chars/token), token_source column to distinguish measured vs estimated data, and admin UI indicators (amber warnings, ~ prefix on estimates). Updated DeepSeek/Qwen pricing table. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-04-14 08:32:30 +07:00
parent 52a83439b1
commit 5d5019bda3
6 changed files with 138 additions and 12 deletions
--- a/ARCHITECTURE.md
+++ b/ARCHITECTURE.md
@@ -321,6 +321,27 @@ Migration for existing peptides via admin "Migrate Existing Peptides to Categori
 | `psa_directory_card_extras` | Filter | Allows adding HTML to directory cards (e.g., observation count badge). |
 | `psa_rest_compound_data` | Filter | Allows enriching REST compound data before response. Receives `$data`, `$post_id`. |

+### API Logs Table (`wp_psa_api_logs`)
+
+Custom table created via `dbDelta` on plugin activation. Tracks every OpenRouter API call for cost monitoring and budget enforcement.
+
+| Column | Type | Description |
+|--------|------|-------------|
+| `id` | BIGINT AUTO_INCREMENT | Primary key |
+| `created_at` | DATETIME | Timestamp of API call |
+| `provider` | VARCHAR(50) | API provider (default: `openrouter`) |
+| `model` | VARCHAR(100) | Model identifier (e.g., `deepseek/deepseek-v3.2`) |
+| `prompt_tokens` | INT | Tokens in prompt (measured or estimated) |
+| `completion_tokens` | INT | Tokens in completion (measured or estimated) |
+| `total_tokens` | INT | Sum of prompt + completion tokens |
+| `estimated_cost_usd` | DECIMAL(10,6) | Estimated cost in USD |
+| `request_type` | VARCHAR(20) | `validation` or `generation` |
+| `peptide_name` | VARCHAR(200) | Peptide being processed |
+| `success` | TINYINT(1) | Whether the API call succeeded |
+| `token_source` | VARCHAR(20) | `api` (measured from response), `estimated` (character-based fallback), or `none` (v4.4.3) |
+
+**Why `token_source`:** Some OpenRouter models (notably DeepSeek) omit the `usage` object from API responses. When this happens, `PSA_OpenRouter` estimates tokens from character length (~3.75 chars/token). The `token_source` column lets the admin UI clearly distinguish measured vs. estimated data.
+
 ### Options (Plugin Settings)

 Stored in `wp_options` table:
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,22 @@ All notable changes to the Peptide Search AI plugin will be documented in this f
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

+## [4.4.3] - 2026-04-14
+
+### Fixed
+- **Cost tracker $0.00 bug**: DeepSeek models on OpenRouter omit the `usage` object from API responses, causing all token counts and costs to log as zero. Added character-based token estimation fallback (~3.75 chars/token for scientific English) so spend is always tracked.
+
+### Added
+- `token_source` column in `psa_api_logs` table distinguishing measured (`api`) vs. estimated (`estimated`) token counts. Migrated via `dbDelta` on plugin activation.
+- DeepSeek and Qwen model pricing in `PSA_Cost_Tracker::estimate_cost()`: `deepseek/deepseek-v3.2`, `deepseek/deepseek-chat`, `deepseek/deepseek-r1`, `qwen/qwen3.6-plus:free`.
+- `PSA_Cost_Tracker::get_monthly_estimated_count()` method for querying how many API calls used estimates in a given month.
+- Admin UI indicators for estimated data: amber warning icon on monthly summary ("includes estimates"), `~` prefix on estimated token/cost values in the log table, and tooltips explaining the estimation method.
+- Diagnostic logging of raw `usage` field from OpenRouter for models that report zero tokens (temporary — remove after confirming).
+
+### Changed
+- `PSA_OpenRouter::send_request_once()` now passes `token_source` to cost tracker alongside token counts.
+- Version bump to 4.4.3.
+
 ## [4.3.0] - Unreleased

 ### Added
--- a/includes/class-psa-admin.php
+++ b/includes/class-psa-admin.php
@@ -482,6 +482,7 @@ class PSA_Admin {
 	private static function render_usage_summary(): void {
 		$current_spend  = PSA_Cost_Tracker::get_monthly_spend();
 		$current_tokens = PSA_Cost_Tracker::get_monthly_tokens();
+		$estimated_count = PSA_Cost_Tracker::get_monthly_estimated_count();
 		$budget         = floatval( self::get_setting( 'monthly_budget', PSA_Config::DEFAULT_MONTHLY_BUDGET ) );
 		$budget_remaining = ( 0.0 === $budget ) ? __( 'Unlimited', 'peptide-search-ai' ) : '$' . number_format( max( 0, $budget - $current_spend ), 2 );
 		$recent_logs    = PSA_Cost_Tracker::get_recent_logs( 20 );
@@ -490,7 +491,11 @@ class PSA_Admin {
 		<div style="background:#f5f5f5;padding:15px;border-radius:4px;margin-bottom:20px;">
 			<h3><?php esc_html_e( 'This Month', 'peptide-search-ai' ); ?></h3>
 			<p>
-				<strong><?php esc_html_e( 'Spend:', 'peptide-search-ai' ); ?></strong> $<?php echo esc_html( number_format( $current_spend, 2 ) ); ?><br />
+				<strong><?php esc_html_e( 'Spend:', 'peptide-search-ai' ); ?></strong> $<?php echo esc_html( number_format( $current_spend, 2 ) ); ?>
+				<?php if ( $estimated_count > 0 ) : ?>
+					<span style="color:#b45309;font-size:12px;" title="<?php echo esc_attr( $estimated_count ); ?> API calls used character-based token estimates because the model did not report usage data">&#9888; includes estimates</span>
+				<?php endif; ?>
+				<br />
 				<strong><?php esc_html_e( 'Tokens:', 'peptide-search-ai' ); ?></strong> <?php echo esc_html( number_format( $current_tokens ) ); ?><br />
 				<strong><?php esc_html_e( 'Budget Remaining:', 'peptide-search-ai' ); ?></strong> <?php echo esc_html( $budget_remaining ); ?>
 			</p>
@@ -512,11 +517,24 @@ class PSA_Admin {
 				</thead>
 				<tbody>
 					<?php foreach ( $recent_logs as $log ) : ?>
-						<tr>
+						<?php $is_estimated = ( isset( $log->token_source ) && 'estimated' === $log->token_source ); ?>
+						<tr<?php echo $is_estimated ? ' style="color:#92400e;"' : ''; ?>>
 							<td><?php echo esc_html( $log->created_at ); ?></td>
 							<td><code><?php echo esc_html( $log->model ); ?></code></td>
-							<td><?php echo esc_html( number_format( $log->total_tokens ) ); ?></td>
-							<td>$<?php echo esc_html( number_format( $log->estimated_cost_usd, 4 ) ); ?></td>
+							<td>
+								<?php if ( $is_estimated ) : ?>
+									<span title="Estimated from character length — model did not report token usage">~<?php echo esc_html( number_format( $log->total_tokens ) ); ?></span>
+								<?php else : ?>
+									<?php echo esc_html( number_format( $log->total_tokens ) ); ?>
+								<?php endif; ?>
+							</td>
+							<td>
+								<?php if ( $is_estimated ) : ?>
+									<span title="Cost estimated from approximate token count">~$<?php echo esc_html( number_format( $log->estimated_cost_usd, 4 ) ); ?></span>
+								<?php else : ?>
+									$<?php echo esc_html( number_format( $log->estimated_cost_usd, 4 ) ); ?>
+								<?php endif; ?>
+							</td>
 							<td><?php echo esc_html( $log->request_type ); ?></td>
 							<td><?php echo esc_html( $log->peptide_name ); ?></td>
 							<td><?php echo ( 1 === (int) $log->success ) ? '&#10003;' : '&#10007;'; ?></td>
--- a/includes/class-psa-cost-tracker.php
+++ b/includes/class-psa-cost-tracker.php
@@ -39,6 +39,7 @@ class PSA_Cost_Tracker {
 			request_type VARCHAR(20) NOT NULL,
 			peptide_name VARCHAR(200) DEFAULT '',
 			success TINYINT(1) NOT NULL DEFAULT 1,
+			token_source VARCHAR(20) NOT NULL DEFAULT 'api',
 			INDEX idx_created_at (created_at),
 			INDEX idx_request_type (request_type)
 		) $charset_collate;";
@@ -66,6 +67,7 @@ class PSA_Cost_Tracker {
 	 *     @type string   $peptide_name         Name of peptide being processed
 	 *     @type bool     $success              Whether API call succeeded
 	 *     @type float    $estimated_cost_usd   Cost (or 0 to auto-calculate)
+	 *     @type string   $token_source         'api' (from usage response), 'estimated' (character-based), or 'none'
 	 * }
 	 * @return int|false Insert ID or false on error.
 	 */
@@ -84,13 +86,14 @@ class PSA_Cost_Tracker {
 		$peptide_name  = $data['peptide_name'] ?? '';
 		$success       = ! empty( $data['success'] ) ? 1 : 0;
 		$estimated_cost = floatval( $data['estimated_cost_usd'] ?? 0 );
+		$token_source   = $data['token_source'] ?? 'api';

 		// Auto-sum tokens if not provided.
 		if ( 0 === $total_tokens && ( $prompt_tokens > 0 || $completion_tokens > 0 ) ) {
 			$total_tokens = $prompt_tokens + $completion_tokens;
 		}

-		// Auto-calculate cost if not provided.
+		// Auto-calculate cost if not provided and we have token data.
 		if ( 0 === $estimated_cost && $prompt_tokens > 0 ) {
 			$estimated_cost = self::estimate_cost( $model, $prompt_tokens, $completion_tokens );
 		}
@@ -105,9 +108,10 @@ class PSA_Cost_Tracker {
 			'request_type'       => sanitize_text_field( $request_type ),
 			'peptide_name'       => sanitize_text_field( $peptide_name ),
 			'success'            => $success,
+			'token_source'       => sanitize_text_field( $token_source ),
 		);

-		$insert_format = array( '%s', '%s', '%d', '%d', '%d', '%f', '%s', '%s', '%d' );
+		$insert_format = array( '%s', '%s', '%d', '%d', '%d', '%f', '%s', '%s', '%d', '%s' );

 		// phpcs:ignore WordPress.DB.DirectDatabaseQuery
 		$result = $wpdb->insert( $table_name, $insert_data, $insert_format );
@@ -198,6 +202,45 @@ class PSA_Cost_Tracker {
 		return (int) $result;
 	}

+	/**
+	 * Count how many API calls this month used character-based token estimates.
+	 *
+	 * Why: Lets the admin UI flag when reported costs include approximations
+	 * so operators can distinguish measured spend from estimated spend.
+	 *
+	 * @param int|null $year  Year (defaults to current year).
+	 * @param int|null $month Month (defaults to current month).
+	 * @return int Number of estimated rows this month.
+	 */
+	public static function get_monthly_estimated_count( ?int $year = null, ?int $month = null ): int {
+		global $wpdb;
+
+		if ( null === $year ) {
+			$year = (int) gmdate( 'Y' );
+		}
+		if ( null === $month ) {
+			$month = (int) gmdate( 'm' );
+		}
+
+		$table_name = $wpdb->prefix . 'psa_api_logs';
+		$month      = max( 1, min( 12, (int) $month ) );
+
+		$start_date = gmdate( 'Y-m-01', mktime( 0, 0, 0, $month, 1, $year ) );
+		$end_date   = gmdate( 'Y-m-t', mktime( 0, 0, 0, $month, 1, $year ) ) . ' 23:59:59';
+
+		// phpcs:ignore WordPress.DB.DirectDatabaseQuery
+		$result = $wpdb->get_var(
+			$wpdb->prepare(
+				'SELECT COUNT(*) FROM ' . $table_name . ' WHERE created_at >= %s AND created_at <= %s AND token_source = %s', // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- table name is safe, built from $wpdb->prefix.
+				$start_date,
+				$end_date,
+				'estimated'
+			)
+		);
+
+		return (int) $result;
+	}
+
 	/**
 	 * Check if current month's budget has been exceeded.
 	 * Budget of 0 means unlimited.
@@ -251,9 +294,16 @@ class PSA_Cost_Tracker {
 	 */
 	public static function estimate_cost( string $model, int $prompt_tokens, int $completion_tokens ): float {
 		// Known model pricing per 1 million tokens (input, output).
+		// Why: OpenRouter pricing varies by model; we maintain known rates here and
+		// fall back to a conservative default for unlisted models so cost tracking
+		// always produces a usable upper-bound estimate.
 		$pricing = array(
-			'google/gemini-2.5-flash'      => array( 0.15, 0.60 ),
-			'google/gemini-2.0-flash-001'  => array( 0.10, 0.40 ),
+			'google/gemini-2.5-flash'         => array( 0.15, 0.60 ),
+			'google/gemini-2.0-flash-001'     => array( 0.10, 0.40 ),
+			'deepseek/deepseek-v3.2'          => array( 0.27, 1.10 ),
+			'deepseek/deepseek-chat'          => array( 0.27, 1.10 ),
+			'deepseek/deepseek-r1'            => array( 0.55, 2.19 ),
+			'qwen/qwen3.6-plus:free'          => array( 0.00, 0.00 ),
 		);

 		$model = sanitize_text_field( $model );
--- a/includes/class-psa-openrouter.php
+++ b/includes/class-psa-openrouter.php
@@ -147,8 +147,28 @@ class PSA_OpenRouter {
 		}

 		// Log API call with token usage.
-		$prompt_tokens = (int) ( $body['usage']['prompt_tokens'] ?? 0 );
+		$response_text   = $body['choices'][0]['message']['content'];
+		$prompt_tokens   = (int) ( $body['usage']['prompt_tokens'] ?? 0 );
 		$completion_tokens = (int) ( $body['usage']['completion_tokens'] ?? 0 );
+		$token_source    = 'api';
+
+		// Diagnostic: log the raw usage structure once per model so we can verify
+		// whether the provider returns token counts. Remove after confirming.
+		if ( 0 === $prompt_tokens ) {
+			$usage_raw = isset( $body['usage'] ) ? wp_json_encode( $body['usage'] ) : 'missing';
+			error_log( 'PSA: OpenRouter usage field for model ' . $model . ': ' . substr( $usage_raw, 0, 300 ) );
+		}
+
+		// Fallback: estimate tokens from character length when the API reports zero.
+		// Why: Some OpenRouter models (e.g. deepseek) omit the usage object entirely.
+		// Approximation: ~3.75 characters per token for English scientific text.
+		if ( 0 === $prompt_tokens && 0 === $completion_tokens ) {
+			$prompt_tokens     = (int) ceil( strlen( $prompt ) / 3.75 );
+			$completion_tokens = (int) ceil( strlen( $response_text ) / 3.75 );
+			$token_source      = 'estimated';
+
+			error_log( 'PSA: Token usage estimated from character length for ' . $peptide_name . ': prompt=' . $prompt_tokens . ', completion=' . $completion_tokens );
+		}

 		PSA_Cost_Tracker::log_api_call(
 			array(
@@ -159,10 +179,11 @@ class PSA_OpenRouter {
 				'request_type'        => $request_type,
 				'peptide_name'        => $peptide_name,
 				'success'             => true,
+				'token_source'        => $token_source,
 			)
 		);

-		return $body['choices'][0]['message']['content'];
+		return $response_text;
 	}

 	/**
--- a/peptide-search-ai.php
+++ b/peptide-search-ai.php
@@ -3,7 +3,7 @@
 * Plugin Name: Peptide Search AI
 * Plugin URI:  https://example.com/peptide-search-ai
 * Description: Searchable peptide database with AI-powered auto-population and browsable directory.
- * Version:     4.4.2
+ * Version:     4.4.3
 * Author:      Terence
 * License:     GPL v2 or later
 * Text Domain: peptide-search-ai
@@ -15,7 +15,7 @@ if ( ! defined( 'ABSPATH' ) ) {
 	exit;
 }

-define( 'PSA_VERSION', '4.4.2' );
+define( 'PSA_VERSION', '4.4.3' );
 define( 'PSA_PLUGIN_DIR', plugin_dir_path( __FILE__ ) );
 define( 'PSA_PLUGIN_URL', plugin_dir_url( __FILE__ ) );
 define( 'PSA_PLUGIN_FILE', __FILE__ );