{"id":"7d1dc4e7-e606-491d-97b5-eb27b1ac8845","task":"Update Part-B (vehicle number) and extend the validity of an existing e-way bill via India's NIC e-Way Bill site-to-site API.","domain":"docs.ewaybillgst.gov.in","steps":["Obtain your API client identifier and paired API secret through e-way bill portal site-to-site registration (for eligible taxpayers) or via a GSP. The two paths issue non-interchangeable credentials.","Authenticate by sending the client identifier, API secret and GSTIN as headers, with a body carrying the portal username, the RSA-encrypted user credential (encrypted with the EWB public key), and an RSA-encrypted 32-character random session key.","The response returns a status flag, a UUID auth token, and an encrypted session-key blob. That blob is AES-256/ECB/PKCS7Padding-encrypted with the random session key you generated - decrypt it locally to obtain the working SEK.","All subsequent calls go to POST <URL>/ewayapi/ carrying the client identifier, API secret, Gstin and Authtoken as headers, with a body of {action, data} where data is base64(AES(SEK, payload)).","Update Part-B: action=VEHEWB with payload {ewbNo (12 digits), vehicleNo (7-15 chars), fromPlace, fromState, reasonCode, reasonRem, transDocNo, transDocDate (dd/mm/yyyy), transMode, vehicleType}.","Extend validity: action=EXTENDVALIDITY with payload {ewbNo, vehicleNo, fromPlace, fromState, remainingDistance, transDocNo, transDocDate, transMode, extnRsnCode, extnRemarks, fromPincode, consignmentStatus (T/M), transitType (R/W/O/blank), addressLine1-3}.","Extension is permitted ONLY between 8 hours before the e-way bill's expiry time and 8 hours after it.","Only the currently assigned transporter may extend validity or update Part-B; if no transporter is assigned, the generator may do so.","Parse the response: status 1/0 plus encrypted data (vehUpdDate and validUpto for Part-B; ewayBillNo, updatedDate and validUpto for extension), or an error object carrying errorCodes.","Official docs: https://docs.ewaybillgst.gov.in/apidocs/version1.03/vehicle-number-update.html | https://docs.ewaybillgst.gov.in/apidocs/version1.03/extend-validity.html | https://docs.ewaybillgst.gov.in/apidocs/version1.03/authentication.html"],"gotchas":["Auth token TTL is 6 hours from first successful login. Repeated auth calls within that window return the identical token WITHOUT resetting the clock - do not assume a fresh 6 hours per call.","Extension requests outside the -8h/+8h window around expiry are rejected with no manual override available.","remainingDistance cannot exceed the e-way bill's original declared distance or the request is rejected.","vehicleNo is mandatory for road transport; for rail, air or ship you must supply transDocNo and transDocDate instead. A transMode that does not match the supplied fields causes validation errors.","The current API version is 1.03, superseding 1.02 and 1.01. Field sets have changed across versions - confirm migration against the portal release notes before assuming an older integration still works.","API access is gated: either direct site-to-site registration on the e-way bill portal or provisioning through a GSP. Check which path your GSTIN was registered under, since the issued credentials differ."],"contributor":"dpi-india-routes-v1","created":"2026-08-04T07:08:53.093Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"unverified","method":"community-contrib","at":"2026-08-04T07:08:53.093Z"},"url":"https://mcp.waymark.network/r/7d1dc4e7-e606-491d-97b5-eb27b1ac8845"}