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    Reference

    API Changelog

    A running log of changes to the AlterLab API. New endpoints, breaking changes, improvements, and fixes.

    Versioning Policy

    AlterLab uses URL path versioning (/api/v1/). Breaking changes get a 90-day deprecation window. See the API Versioning Policy for details.

    Latest Changes

    v6.0.6Faster AI Integrations and Scrape Reliability
    October 22, 2026
    New

    Guided Interactive First Scrape

    The onboarding experience now guides you directly into a pre-configured sample request within the playground. You can execute a reliable initial scrape immediately upon signup without manual configura...

    Improved

    Faster Timeouts for Unreachable Requests

    Requests hitting irrecoverable block pages now terminate immediately without stalling through retry cascades. This reduces response latency and frees up request throughput when target sites are blocke...

    Improved

    Smarter Regional Route Selection

    The request engine now remembers failure outcomes across geographic locations to bypass blocked paths automatically. This improves success rates for location-sensitive target sites while optimizing ov...

    Improved

    Transparent Signup Credit Display

    Signup grants and balance indicators now clearly display a $1 free credit alongside per-tier pricing details. This ensures predictable usage tracking across different scraping parameters and target co...

    Fixed

    Reliable Zero-Result SERP Processing

    Fixed an issue where search engine API calls returned gateway timeout errors on pages with no organic search results. Search requests now complete successfully and return valid structured payloads reg...

    Fixed

    OAuth Authorization Redirect Handling

    Resolved a security policy conflict that blocked redirects during the OAuth consent step. External client applications can now authenticate and complete authorization flows without interruption.

    Security

    Accurate Remote Proxy IP Attribution

    Requests routed through remote tool proxies now correctly forward the original end-user IP address. This ensures IP allowlists and geographic access policies are enforced accurately across proxy conne...

    Improved

    General bug fixes and improvements

    Plus 14 internal improvements for better reliability and performance.

    v6.0.5Performance Improvements
    October 21, 2026
    Improved

    fix(AI engine): give learning-gate consumer fixture the state reads

    The test fixture builds via and now sets the attributes provides, which 's deferral path reads.

    Improved

    fix(api): schedule auto-pause counts platform queue-full and stale-claim failures — capacity inciden

    | File | Change | Requirements |.

    Improved

    perf(dashboard): detailed-logs crawl grouping via partial index and keyset pagination

    The page query in mode does not bound its work by the page size:.

    Improved

    fix(backup): logical-generation selectors fail closed on an in-progress generation instead of skippi

    Both workflow selectors (introduced in c203331a45, "make logical publication atomic") copied the writer's strict whole-namespace inventory validation instead of the reader semantics of th.

    Improved

    fix(monitoring): publish recovery outcomes for billing/payment error-trigger checks

    These checks predate the fail-closed recovery contract (/).

    Improved

    feat(monitoring): stable check keys and fail-closed recovery closer for log-monitor eMemos, plus sta

    log-monitor has no stable logical identity per issue class.

    Improved

    fix(stealth): worker image installs floating latest Chrome (155) while identity constants claim Chro

    The Chrome binary install was written as a floating (introduced in b509d0ae8c, moved in c4a422b001/c320b45fc7 for root/su reasons) while the identity was later frozen at a HTTP client-verified major (...

    Improved

    fix(monitoring): stop labelling warning-threshold counts Critical in error-trigger eMemos and list u

    Severity is a one-way ratchet: the filename and Severity line record the peak, never the current observation, and an age/cycle timer converts mere persistence into Critical.

    Improved

    decide: re-measure Cloudflare T4 after and set telemetry-gated policy for cloudflare_js and cloudfla

    This is policy, not a code defect.

    Improved

    feat(monitoring): alert on Cloudflare Workers daily request quota before Error 1027

    The Workers request quota was never instrumented.

    Improved

    General bug fixes and improvements

    Plus 10 internal improvements for better reliability and performance.

    v6.0.4Smarter Failover, Auto-Pause, and Improved Reliability
    October 20, 2026
    New

    Auto-pause for failing schedules

    Scheduled jobs now track consecutive failures and automatically pause when targets remain broken. You will receive instant notifications so you can investigate before wasting API credits.

    New

    Automatic fallback on request challenges

    You can now enable opt-in fallbacks for high-tier extraction requests. If a request encounters a challenge or timeout, the system automatically attempts secondary extraction modes.

    Improved

    Adaptive per-domain request pacing

    Request pacing now dynamically adjusts based on real-time target domain responsiveness. This improves overall extraction throughput while minimizing blocks and strain on target servers.

    Improved

    Automatic back-off for URL failures

    Consecutive failures on specific URLs now trigger automatic back-off delays. This halts repetitive retries against unreachable endpoints and conserves your API credit quota.

    Improved

    Bounded concurrency for sticky sessions

    Sticky session connections now enforce concurrency limits across requests. This guarantees consistent session reuse and improves extraction success rates during multi-step web flows.

    Fixed

    Accurate billing for challenge responses

    Resolved an issue where responses returning challenge pages were marked as successful extractions. Requests blocked by target site challenges are no longer charged full credits.

    Fixed

    Correct batch job refund calculation

    Fixed a ledger calculation discrepancy for batch extractions. Failed individual jobs inside a batch now correctly receive credit refunds against the initial batch debit.

    Fixed

    Real-time credit balance cache updates

    Fixed cache ordering gaps during credit balance updates. Account balances and API entitlement limits now update immediately in real time following any transaction.

    Fixed

    Search endpoint request stability

    Fixed network egress timeouts occurring on search extraction calls. Search requests now experience consistent response times and higher overall completion rates.

    Improved

    General bug fixes and improvements

    Plus 58 internal improvements for better reliability and performance.

    v6.0.3Faster Browser Scraping and Page Accuracy
    October 18, 2026
    New

    Subresource Caching for Faster Rendering

    Browser-rendered requests now cache static assets like scripts and stylesheets. This significantly reduces response latency and accelerates page rendering.

    Improved

    Accurate Minimal Page Delivery

    Single-page app shells, directory listings, and minimal landing pages are now recognized and delivered accurately. Content is returned immediately without being misclassified as blocked or triggering ...

    Improved

    Faster Processing for Sparse Content

    Eliminated redundant retry loops when requests encounter pages with naturally minimal markup. Scrapes now complete much faster when pages contain limited body text or basic layouts.

    Fixed

    Reduced False Detection Blocks

    Resolved an issue where lightweight tracking scripts injected by target site security systems were falsely flagged as challenges. Scraped pages now return their complete response body without false bl...

    Fixed

    Enhanced Browser Session Reliability

    Fixed an operational issue where browser rendering processes could fail on worker nodes without active virtual displays. Display environments are now verified prior to execution to guarantee seamless ...

    Improved

    General bug fixes and improvements

    Plus 1 internal improvement for better reliability and performance.

    v6.0.2Accurate Format-Specific Scrape Responses
    October 17, 2026
    Fixed

    Format-aware repeat detection caching

    Scraping requests for identical URLs using different output formats now correctly bypass cached data generated in other formats. This ensures you receive properly formatted scraped content every time ...

    Improved

    General bug fixes and improvements

    Plus 3 internal improvements for better reliability and performance.

    v6.0.1Enhanced Request Diagnostics and API Stability
    October 16, 2026
    New

    Job Request Option Snapshots

    Scraper jobs now store a snapshot of submitted options like JavaScript rendering, timeouts, and cost caps. This allows you to easily audit and reproduce request behavior from your dashboard.

    Improved

    Fast Failures on Unreachable Target Sites

    When target servers are unreachable, requests now fail fast instead of running extended retries. This reduces response times by up to 80 seconds on offline targets and avoids extra charges.

    Improved

    Accurate Target Health Monitoring

    Domain health tracking now ignores user-level rate limits and skipped retry steps. This prevents false domain pauses and keeps your extraction pipelines running smoothly.

    Fixed

    Modern Web App Content Validation

    Pages containing large inline hydration state are no longer incorrectly flagged as empty shells. This ensures complete content extraction on modern web applications.

    Fixed

    Precise Target Error Classification

    Target site server errors and 5xx status codes are now accurately classified as origin errors rather than security blocks. This improves status reporting clarity and retry routing.

    Fixed

    Reliable Target Connection Timeouts

    Connection timeouts during target site checks are now handled more accurately. Inconclusive proxy connections are distinguished from down targets for predictable request resolution.

    Fixed

    Automatic Recharge Status Resolution

    Fixed an issue where automatic balance top-ups could stay stuck pending after payment gateway errors. Failed recharges now resolve cleanly so you can retry or update billing details.

    Security

    API Key Authentication Stability

    High server load no longer triggers false unauthorized errors or IP security flags on valid API keys. When authentication capacity is briefly saturated, the API now returns 503 with error auth_unavail...

    Breaking

    render_js Requires a Tier 4 Cap

    Requests that set advanced.render_js to true with cost_controls.max_tier below "4" are now rejected with 422 at submission, before any charge, on /api/v1/scrape, /api/v1/batch items and /api/v1/crawl....

    Improved

    General bug fixes and improvements

    Plus 11 internal improvements for better reliability and performance.

    v6.0.0Smarter Rate Limits and Detailed Analytics
    October 15, 2026
    New

    Account-wide rate limits

    Rate limits are now evaluated across your entire account rather than per individual API key. This ensures consistent capacity management when distributing API keys across multiple services.

    New

    Extraction cost analytics API

    A new API endpoint provides detailed metrics on verified data extraction costs and coverage rates across your requests. Use these insights to optimize request parameters and monitor cost efficiency in...

    Improved

    Resource bounds for PDF parsing

    PDF parsing and text extraction now include safety limits on document size and stream decompression. This prevents timeout errors when processing complex or highly compressed PDF documents.

    Improved

    Improved challenge page detection

    Diagnostic responses now accurately identify verification challenges appearing on 4xx HTTP status pages. Scrapes on affected sites now properly report verification requirements rather than generic ori...

    Improved

    Enhanced anti-detection compatibility

    Updated request execution profiles to better match standard browser behavior on protected target websites. This improves success rates on domains enforcing strict security checks.

    Fixed

    Batch billing reconciliation fixes

    Fixed edge cases where add-on features like proxy routing and structured extraction were miscalculated during batch job execution. Billing reconciliations now accurately reflect actual job usage.

    Fixed

    Dashboard deposit UI fixes

    Resolved issues in the web dashboard where payment authorization errors were collapsed into generic messages. You can now view structured error feedback and manage quick deposits seamlessly.

    Fixed

    Authenticated request limit fix

    Fixed an issue where valid API key requests within your plan allowance were occasionally throttled by secondary rate limiters. Keyed requests now reliably receive their full plan throughput.

    Fixed

    Preserved batch error details

    Error classification categories and failure diagnostics are now permanently retained for failed or cancelled batch jobs. This enables easier troubleshooting through the dashboard and API.

    Fixed

    Dashboard support connection stability

    Fixed an issue where live support sessions in the dashboard could enter an unrecoverable state after transient disconnects. The widget now automatically reconnects and resumes your chat session.

    Security

    Web session security hardening

    Hardened dashboard authentication proxies and session binding validations across administrative routes. This provides stronger access controls and protects user sessions against unauthorized proxying.

    Improved

    General bug fixes and improvements

    Plus 47 internal improvements for better reliability and performance.

    Fixed

    Reliable SDK Batch Scraping

    Resolved an issue where batch scraping calls in the Python and Node SDKs returned request formatting errors. Batch jobs now serialize correctly and execute without failure.

    Fixed

    Uninterrupted Authenticated API Traffic

    Fixed an issue that caused valid API requests using API keys to trigger unexpected rate limits. Authenticated traffic now bypasses global rate-limiting checks seamlessly.

    v5.3.1Faster Target Validation and Clearer Errors
    October 14, 2026
    New

    Zero-cost short-circuiting for constraint limits

    When request parameters set execution limits below what a target domain requires, requests now short-circuit immediately. These requests return instant diagnostic feedback without incurring billing ch...

    Improved

    Faster validation for unreachable target servers

    Lightweight pre-checks now verify target web server availability before full execution. Requests targeting unreachable origins fail significantly faster, avoiding unnecessary waiting times.

    Fixed

    Accurate messaging for target DNS errors

    Transient domain resolution failures on target URLs are no longer misclassified as security blocks. You now receive explicit error feedback whenever a target hostname fails to resolve.

    Fixed

    Clearer diagnostic error and suggestion messages

    Error messages and troubleshooting tips returned during access blocks have been updated for clarity. Diagnostic responses now offer actionable guidance instead of suggesting sites are unscrapable.

    Fixed

    Restored page context in script evaluation

    Custom JavaScript evaluation actions now execute in the main page window context as expected. Evaluated scripts maintain full access to DOM elements, window properties, and global objects.

    Fixed

    Safe payment deposits during network dropouts

    Quick-deposit account funding calls now include idempotency keys and enhanced retry safety. Network connection dropouts during deposit processing no longer report false failure statuses.

    Fixed

    Historical analytics for organization accounts

    Organization usage dashboards and breakdown charts now correctly include historical usage recorded before team setup. Account administrators can view complete usage trends across all billing periods.

    Fixed

    Accurate organization refund attribution

    Automatic refunds for add-on services now strictly attribute credits to the organization funding principal. Credits are reliably returned to the primary team wallet in multi-user accounts.

    Improved

    General bug fixes and improvements

    Plus 23 internal improvements for better reliability and performance.

    v5.3.0Performance Improvements
    October 13, 2026
    Improved

    fix(ci): track restore-drill verifier pin a115befe in its contract test

    (, merged via ) moved the immutable storage verifier pin in from to (object-data-policy V4).

    Fixed

    prune-storage orders generations by caller-chosen filename stamp (review finding — )

    in ranked storage generations by the client-chosen filename stamp, so a holder of the key could commit far-future generations and make delete every real generation in a lane (review finding from .

    Improved

    fix(stealth): make advanced browser device classes coherent across identity, client hints and TLS

    ## Audit findings (why current behavior existed).

    Improved

    fix(worker): native Firefox identity on the T4 Firefox engine

    ## Audit (why it was this way).

    New

    fail-closed target egress helper, origin-egress metric, AST CI guard

    Adds (, ): SSRF and request-time DNS validation, system proxy only (no proxy means refusal, never a direct origin-IP fetch), one pinned UA/header set per call, manual redirect loop re-validating every...

    Fixed

    remove origin-IP content-type HEAD and smart-render probe, delete dead egress code

    Stops the live origin-IP leak: the API sent unproxied requests to customer targets on extensionless scrape submissions ( HEAD) and a self-identifying GET for.

    Improved

    fix(monitoring): alert on per-job thin-content false successes, not T4 selector misses

    divided (per T4 browser *attempt*, includes retries and later-failed jobs, "miss" = generic article selectors absent in ~2s) by (per job, all tiers).

    New

    give T1 a bounded grace after an early T2 win in the tier race

    In the T1/T2 tier race, T1 gets a 1 s head start before T2 (HTTP client) also starts.

    Fixed

    tier-learning attribution, evidence wiring, BYOP rotation counter (, )

    Accounting, wiring and telemetry only — no escalation or tier-selection change.

    Fixed

    T3 pool lease setup and tier rejection log context (, )

    Members: , .

    Improved

    fix(monitoring): ensure jq on cloud provider from root cron setup; detect blind probe venv

    - (run as root on every deploy by ) now ensures via apt-get.

    New

    route the storage_shared backup lane to Netcup (netcup:storage policy scheme, sender + verifier)

    Owner decision : publish the protected user-uploads lane to the Netcup relay namespace instead of .

    New

    storage namespace + backup-storage-relay account in the Netcup backup relay

    Owner decision moves the protected user-uploads backup lane off Cloudflare onto Netcup.

    Fixed

    owner-lease fenced profile claim republish

    The stale-claim reaper republished a processing profile claim once its heartbeat score was older than 120s, with no proof the original handler had stopped.

    New

    LLM inbound filter for support@ routing ticket / crm / ignore

    Every email to support@ currently becomes a ticket (34 of 98 email tickets on 2026-10-10 were noise, 6 were CRM/sales).

    Improved

    General bug fixes and improvements

    Plus 9 internal improvements for better reliability and performance.

    v5.2.0Enhanced Scraper Reliability and Diagnostic Transparency
    October 12, 2026
    New

    Isolated Custom Browser Sessions

    Custom browser scraping requests now enforce state isolation between concurrent calls. Cookies and local storage are kept isolated per request, preventing cross-session data leaks.

    New

    Expanded Request Diagnostic Traces

    Diagnostic endpoints now include full trace histories and metadata for automated retries. You can inspect exact request details to simplify debugging failed attempts.

    Improved

    Updated Modern Browser Signatures

    Automated request headers now match current modern browser release versions and header standards. This resolves unexpected challenge blocks on target websites with strict browser checks.

    Improved

    Higher Challenge Resolution Reliability

    Request routing and retry mechanisms have been refined for protected target websites. Requests now achieve significantly higher success rates and reduced challenge failure rates.

    Fixed

    Billing Usage Chart Availability

    Fixed a server error that occurred when fetching usage charts without explicit parameters. Billing usage endpoints now reliably return historical consumption data.

    Fixed

    Consistent Error Response Headers

    Cached error responses for missing or deleted pages now properly retain execution headers. Duplicate job tracking identifiers have also been removed from cached error responses.

    Fixed

    Scraping Profile Update Integrity

    Resolved an issue where delayed requests could overwrite actively rebuilding scraping profiles. Profile configurations now accurately reflect only the latest requested build state.

    Fixed

    Support Email Thread Matching

    Inbound support replies now accurately match existing ticket threads across merged conversations. This prevents duplicate tickets when responding from different email clients.

    Security

    Accurate Client IP Evaluation

    Authentication rate-limiting guards now correctly identify real client IP addresses through proxy paths. This ensures fair rate limit enforcement and improved security.

    Improved

    General bug fixes and improvements

    Plus 12 internal improvements for better reliability and performance.

    Improved

    General improvements

    This release includes general improvements and maintenance updates.

    How to Stay Updated

    1

    Check this page for a summary of all API changes with each release.

    2

    Visit the full changelog for a detailed, filterable timeline of all product updates including frontend and infrastructure changes.

    3

    Watch for deprecation headers in API responses. Deprecated endpoints return a Sunset header with the removal date.

    Change Types

    TypeDescriptionAction Required?
    NewNew endpoints, parameters, response fields, or SDK methodsNo
    ImprovedPerformance improvements, better error messages, enhanced behaviorNo
    FixedBug fixes, corrected behavior, resolved edge casesNo
    SecuritySecurity patches and vulnerability fixesReview recommended
    BreakingRemoved fields, changed types, removed endpoints (announced 90+ days in advance)Yes - update your code

    Full Changelog

    For a complete, filterable timeline of all AlterLab updates including frontend changes, infrastructure improvements, and more, visit the full changelog.

    View Full Changelog→
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    Last updated: June 2026

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